US1579200A - Thread-cutter for sewing machines - Google Patents
Thread-cutter for sewing machines Download PDFInfo
- Publication number
- US1579200A US1579200A US523056A US52305621A US1579200A US 1579200 A US1579200 A US 1579200A US 523056 A US523056 A US 523056A US 52305621 A US52305621 A US 52305621A US 1579200 A US1579200 A US 1579200A
- Authority
- US
- United States
- Prior art keywords
- thread
- work
- needle
- cutter
- stitch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- D—TEXTILES; PAPER
- D05—SEWING; EMBROIDERING; TUFTING
- D05B—SEWING
- D05B65/00—Devices for severing the needle or lower thread
-
- D—TEXTILES; PAPER
- D05—SEWING; EMBROIDERING; TUFTING
- D05B—SEWING
- D05B3/00—Sewing apparatus or machines with mechanism for lateral movement of the needle or the work or both for making ornamental pattern seams, for sewing buttonholes, for reinforcing openings, or for fastening articles, e.g. buttons, by sewing
- D05B3/06—Sewing apparatus or machines with mechanism for lateral movement of the needle or the work or both for making ornamental pattern seams, for sewing buttonholes, for reinforcing openings, or for fastening articles, e.g. buttons, by sewing for sewing buttonholes
-
- D—TEXTILES; PAPER
- D05—SEWING; EMBROIDERING; TUFTING
- D05B—SEWING
- D05B73/00—Casings
- D05B73/04—Lower casings
- D05B73/12—Slides; Needle plates
-
- D—TEXTILES; PAPER
- D05—SEWING; EMBROIDERING; TUFTING
- D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
- D05D2303/00—Applied objects or articles
- D05D2303/08—Cordage
Definitions
- This invention relates to sewing machines and particularly to buttonhole sewing machines having stitch-forming devicesl includingneedle and loop-taker mechanlsms disposed mainly at opposite ⁇ sides of the Work; the 'loop-taker mechanism operating to detain a loop of needle-thread when the stitch-forming devices come to rest.
- Machines of this character have heretofore been provided with thread and staycord severing devices operating automatically at the end of the sewing operation with the object of relievin the operator of the necessity for cutting time various threads by hand,and thereby shortening the time required by the operator to'remove the stitched work from the machine and insert work lto be stitched.
- the present invention has for a primary object to particularly of the buttonhole type referred provide a sewing machine, more to, withthread-cutting mechanism of such a. i character ythat it will operate ⁇ to ⁇ trim the pearance' rand will not need to be subes-,
- Another object of the invention is to pro- .vide means for taking care of the short ends of thread constitu-ting the severed needlen loops, so that they will not clog the stitchforming mechanism or be sewed in.
- a further object of the invention is to provide, in combination with the threadeutting mechanism contemplated, means for ho ⁇ iing the beginning end of the needlethread, such means preferably operating in such a manner that the beginning end ofthe ncedlethread will be substantially concealed in the work.
- the invention has for an object to provide means for insuring that the beginning end of the stay-cord will be substantially even with the initial stitches so as to avoid the necessity of trimming the beginning end of the st Iay-cord.
- the above and other objects, as will hereinafter appeal', are attained by mounting a. thread-severing device below the xlevel of the work-holder, and preferably independently of the turret, with its blade or blades transverse to the plane of the work and so positioned as to engage and cut. the threads, including the stay-cord, close to the last stitch, before the clamping feet are raised to release the work.
- the thread-severing implement is in the form of a scissors device, one of the blades of which is bluntly pointed and adapted to graze the under surface of the work exposed by an aperture.
- the other blade is preferably mounted on the same side of the first-mentioned blade as the last stitch in the work, in order that the threads may be out very close to the end of the seam or buttohole.
- the severed loop of needlethread retained by the loop-taker mechanism is removed from the field of action of the stitch-forming mechanism preferably by means of a movable thread-engaging device made up in the form of a gripper' and mounted alongside the thread-severing device so as to seize the severed needle-loop and carry it away from the stitch-forming mechanism when the thread-severing device is retracted.
- the thread-severing device and gripper are preferably operated simultaneously with the buttonhole-cutter by means of an operative connection receiving motion from the latter.
- Means are preferably provided above the work fornipping the needle-thread end leading from the needle, so that; the initial stitches may be formed without nnthreading the needle.
- a pull-otf may, in some cases, be provided to afford enough slack at the beginning of the sewing operation to permit the needle to descend to the limit ot' its stroke without unduly straining the needles thread or pulling the thread out ⁇ of the nipper.
- the beginning end of the needlethread is pleferably released by the nipper in time to take advantage of the thread absorbing action of the stitch-forming mechanism to draw down the beginning end of the needlethread substantially flush with the work and thereby render such end practically invisible.
- auxiliary threadcutter may also be associated above thev work with the. nippel' in case it is desired to reduce the length ot' needle-thread end held by the nipper and thus reduce the length of thread end to be absorbed or drawn back into the work by the stitch-forming mechanism. It is to be understood, however, that while the use of such auxiliary thread-cutter above the work is ⁇ deemed preferable in the present embodiment, of the invention, it is not in all eases essential to the productioinot' satis factory work.
- a cord-nipper being preferably provided to arrest the feed of the cord ⁇ while the work and initial stitches are slid toward the end of the cord, the cord being released when its end is even with the initial stitches.
- An under thread pull-ofi ⁇ is also preferably provided for the purpose of atl'ording enough slack looper-thread so that the initial Stitches may be formed without nnthreading the looper.
- Fig. 1 is a right side elevation, partly in section, of a buttonhole sewing machine embodying the invention; the parts being in their respective positions occupied during the buttonhole cuttingIr and thread-cutting operations.
- Fig. 2 is a left side elevation of the machine at the end of the buttonhole-producing cycle, the work-holder being open.
- Fig. 3 is a detail view of the guide-bracket for the needle-thread nipper releasing rod shown in Fig. 2.
- Fig. 4 is a detail seetional view of the needle-thread check shown in Fig. 2.
- Fig. 5 is a side elevation of certain parts of the needle-thread nipper thread mechanism shown in F ig. 2.
- Fig. G is a front elevation of the machine with the work-supporting plates in section.
- Fig. 7 is a fragmentary top plan view of the mechanism below the work-holder.
- Fig. 8 is a detail of the stay-cord nipper.
- Fig. 9 is a plan view of the work-supporting plate sections adjacent the sewing point.
- Fig. 1() is a bottom view of the neeiiethroat or button and the thread-cutting scissors and nassociated devices, the scissorsV having advanced nearly to cutting position.
- Fi 11 is a left side elevation ot' the needle-t read ⁇ mechanism and associated parts at the point of the cycle when the initial stitches are being formed; the dotted lines showing the movement of certain parts to o'pen the nipper and release the beginning end of the needlethread
- Fig. 12 is a similar view of the parts at the end of the cycle when the buttonhole is being cut and just after the thread-nipper has been tripped.
- Fig. ⁇ 13 is a fragmentary plan view of the workholder including the upper clamping feet and associated parts at the end of the sewing operation but prior to the advance of the buttonhole-cutter.
- F ig.' 14 is a. sectional view on the line 14, 14, Fig. 13; the thread-nipper having been-tripped.
- Fig. is a perspective view of the scissors device, thread-gripper, and associated parts, at the end of the sewing operation and prior to the advance of such parts.
- Fig. 16 is a similarview with the parts in advanced or cuttingr and gripping position.
- Fig. 17 1s a simllar view showing the scissors and gripper beingretracted to remove the severed needle-loop from the vicinity of the stitch-forming mechanism.
- Fig. 18 is a perspective view of the rear side of .the' scissors device.
- is a bottom erspective, view of the needle-throat or utton.
- Fig. is a front elevation of the scissors device and associated parts, showing the connection with the lower buttonhole-cutter lever for .tripping the latch which holds the needleloo gripper open.
- Fig. 21 is an enlarged eevation of the scissor-blades showing one of-them grazing the under surface of the work and entering between such surface and the threads to be cut.
- Fig. 22 is a side elevation of the stay-cord nlpper and looper-thread pull-off levers and their operating cam.
- Fig. 23 is a side elevation of the stay-cord nlpper and looper-thread pull-off levers and their operating cam.
- Fig. 24 is a rear elevation of the actuating mechanism for the needle-thread nipper.
- Fig. 25 is a plan view of' the ⁇ timing cam member of such mechanism.
- Fig. 26 is a perspective view of such timing cam and its follower in. the respective positions which they occupy before the machine is started, as in Fig. 24.
- Fig. 27 is a similar view showing the cam-follower pin about to be elevated to open the needle-thread nipper.
- Fig. 2S is a similar view showing the cam-follower pin fully elevated and latched in ejected position.
- Fig. 29 is a rear elevation'of the same parts, the cam-follower'pin having re turned to its lower level.
- Figs. 30 and 3l are sectional views illustrating the operation of covering the bcginning'eud of the stay-cord.
- Figs. 32 and 33 are front and reverse views, respectively, of the finished buttonhole as produced by the machine;
- the invention is embodied in a sewing niachine of the buttonhole type constructed substantially in accordance with the disclosure of my United States Patent No. 15,324 reissued April 4, 1922.
- a machine of this type as shown"pa ⁇ rticularly in Fig. 1, comprises a frame including a hollow boit-like bed 1 from one end of which rises the standard 2 carrying the bracket-arm 3 which terminates in the needle-bar carrying head 4.
- the stitch-forming inechanism is constructed substantially in ⁇ accordance with the disclosure of my Patent No. 1,372,-
- the turret 6 also carries the needle-throat or button 11 which is formed with the usual needle-aperture 12 and guide-way for the staycord c.
- the needlethread is shaded and the looper-thread is shown clear, or without shadingVin the various figures.
- the stitch-forming mechanism isl operatedv from the sewing shaft 12Y at the rear end of which-is the usual belt-pulley 13 and stop-motion device which is constructed substantially in accordance with the disclosure of my said-.reissued Patent No. 15,324, and includes the tilting stop-motion lever 14 which is pivoted at l5 and carries the stopping tooth 16 adapted for cooperation in a manner well known with the stopping cam 17.
- the usual feed-wheel 18 which is driven during the sewing by a suitable one-way gear-driven connection with the uprighfshaft 19 driven by the bevel-gear connection 20, 21 with the sewing shaft 12, as shown in my said reissued atent.
- the feed-wheel is connected to be riven at a higher speed both prior and subsequent to sewing by the usual automatically operated clutch' (not shown) intermediate the constantly running shaft 22 and the rapid feed-'shaft 23 which'latter is permanently geared at 23 to the feed-wheel 18.
- the work-holder which lhas the usual operative connections with ⁇ - the feed-wheel, comprises the lower work-supporting plates 24 and the upper pivotally mounted clamping feet 25' sustained by the respective clamping levers 26, Fig. 2, pivotcd at 27.
- the clamp isclosedin the usual manner either by rearward pressure against the fingerpiece 28 or downward pressure on the arm 29 fixed to the clamp-closing rock-shaft ⁇ 30.
- the clamp is usually closed autmnatically at the beginning of the sewing operation by the action of the usual three-armed rock-lever 31, 32, 3Q havingr a roll 33 at the t'orward end of the armV 31 adapted to depress the arm 25); the free end of the arm 2 carrying la slide-bolt adapted for temporary engagement with the cam-groove 35 in the inner tare of the continuously rotating pulley 3G which is loose on the buttonhole cutter shatt 3i', all as more fully explained in my said reissued Patent No. 15,324.
- the pulley 3G Upon arrival o' the work-holder at cutting position the pulley 3G is connected t'or a single rotation to the cutter-shaft 37 carrying the usual cutter advancing and retracting: cani 39 -and the cutter closing cams 40, 4.1 which the latter operate to rock their respective upper and lower cutter-levers 42, 43 upon their common fulcrum f1.4 sustained by the usual travelling fulerum-block 15, Fig. 7, mounted in the slide-ways 16 in the bed 1.
- the fulcriun-block 45 has rigid with it a rearwardly extending arm 47, Fig. 1.
- a cam 50, Fig. 2 on the cutter-sliaft rocks a bellcrank-lever 51 connected to the push-rod 52 which engages the then upright arm 53 on the claznp-closini,r rock-shaft 30 and pushes such arm forwardly to the position shown in Fig. 2, thereby etl'ertinfl the raising of the clamping lect and the release of the work.
- the needle-throat or button of a machine of the type under consideration supports the portion of the work immediately adjacent the sewing point and is adapted to guide a stay-cord to the stitch-forming mechanism so that the stitches will be formed over the stay-cord and bind the later in position aroun'l the buttonhole.
- the stitch-formin; lr mechanism of a machine ot thi ⁇ type under consideration is stopped, a loop of needle thread is retained by the loop-taker mechanism. Consequently, when -the work is shifted rearwardly from sewing to cutting position, there are it'our thread lengths lead ing: from the needle-hole in the button tothc last stitch. One of these threads is the stay-cord. Another is the under or looper-thread; The remaining two are the limbs of the detained needle-loop.
- these threads arefA not only severed to permit ready removal of the work and facilitate restarting of the machine, but they are severed very close to the last stitch before the work-holder is opened, whereby certainty and uniformity of operation is attained and the work aceeptably finished before it leaves the machine; subsequent retrimming operations being unnecessary.
- the thread-cutting mechanism comprises a thread-severing implement preferably in the form of a scissors device, Figs. 17 and 18, and including the ledger-blade 51 and cutter-blade'52 pivotal-ly mounted on the screwpin 53 threaded into the thread-cutter carrier 54.
- a spring-washer 55 beneath the head of the screw 53 maintains the scissorblades in operative Contact with one another.
- the ledger-blade 51 is pointed at its Aupper end and at its lower end is slotted at 51" to admit the screw 55 threaded into the carrier 54.
- the screw 55 and slot 51 permit adjustment of the blade 51 about the pivot 53 to raise or lower the path of movement of its pointed extremity so that the latter ⁇ will properly graze the under surface of the work without digging into the latter.
- the scissors-carrier 54 is preferabl formed with a foot 56 having a rib-andy;
- the tension 57 of the scissors-support 58 which is preferably in the form of a lever pivoted on the horizontal screw-pin 59, Fig. 6, sustained by the turret casing or curb 60.
- the axis of the pivotscrew 59 is directly below and substantially ⁇ in intersecting relation with a line normal to the work at the sewing point.
- ReceivedI within the second-men; tLoned aperture is the pin extension 6 of a horizontal arm 69 of a bellcrank-lever,
- the scissors carrier lever 5R is rocked about its fulcrum 59 to advance the scissors from their retracted or inactive position, Fig. l5, to cutting position, Figs. 16 and 20, during which-movement the point of the ledger-blade passes between the under surface of the work and the threads leading from the last stitch to the needle-throat, as shown in Figs. lO, 14 and 21.
- the work-supporting plates 24, Fig. 9, are
- Needle Zoop-refrnom'ng means.
- the means for removing the severed nedle-thread loop from the vicinity of the stitchfforming implements preferabl comprises a gripper having the relative y separable jaws 78, 79.
- the jaw 78 is formed as -an extension of the plate 80 which is ⁇ se cured to the front side of the scissors-carrier 54.
- the plate 80 is formed with the ears 81 between which ispivoted at 82 the A jaw-lever 8. at the free end of which is the jaw 79. l
- the jaw-lever 83 is backed by a which and is alsol formed with an angular extension arm 86 ⁇ fand hold the which is adapted when the jaws -78, 79
- the latchiarm s6 is fixed to one en of the fulcrum-pin 87 which is journaled inthe carrier 54 and carries at its other end an arm 88 having a bent extremity 89 ads-pted to be lifted to release the gripper jawlever 83 by the upward movement of the lateral pin 90, Fig. 16 and 20, xed to the lower cutter-lever 43.
- the gripper-jaw lever 83 is also formed with a bent arm 91 which is adapted, when the scissors carrier is retracted, to strike gripper-jaws to release the severed needle-loop.
- the spring 93 surrounding thepin 87 serves to re-set the latch 86 in the position shown in Fig, 15 to hold the gripper-jaws open during their next advance to loop-seizing position. lVhen the gripper-jaws are advanced to loop-seizing position and the latch 86 is tripped by. the upward movement of the lower buttonhole cutter lever, the jaws 78, 79, seize the severed needle-thread loop n, as shown in Fig.'16. The severed needle-loop is removed from the vicinity of the stitch-forming invstrumentalities during the subsequent retraction of the gripper, as shown in Fig. 17.
- the latter may e provided at its under side intermediate the cord-guiding apertures 94 with a check in the form of a hght spring 95, Fig. 19.
- the stay-cord is led from the supply through the tube 96, Fig. 22, and check 97; thence between the nipper-jaw 98 and the adjacent vertical wall of the bed 1; thence through the guides 99, 99 and 99, Fig. T, to the button 11.
- the nipper-jaw 98, Fig. 8 is in the form of a plate which is supported by the two screws 98', loosely received in the apertured end of the nipper--lever 100. At its center the plate 98 is backed by the adjustable screw 101 to vary the grip of the plate 98 upon the cord.
- the lever 100
- the lever 100 carries a camroll 103 which is actuated by the outer face cam 104 on the disk 105 lixed to the rapid fe'd shaft 23.
- rl ⁇ he spring 10G, Fig. T tends to rock the lever 100 to release the cord.
- the cam 101 is timed to cause the plate 98 to grip the cord as soon as the machine is started and hold the cord during the formation of the initial stitches, Figs. 30 and 31, so that the initial stitches will be slid along by the initial feed of the work to a position even with the end of the cord, Fig. lil, hereupon the cord is released and allowed to feed with the buttonhole.
- a looper-tliread pullo1i is preferably provided for the purpose of affording slack looper-thread at the completion of the stitching, so that the loopcr-thread will not be under strain when it is severed and so that the end of the looper-thread will not he pulled back through the button 11 at the eginning of the next sewing operation.
- Pivoted on the screw 10T, Fig. 0, is the pulloli' lever 108 at the lower end of which is the hook 109 which engages the looper-thread between the tension device 110 and the stationary thread-guide 111.
- the lever 108 is connected at its upper end to a link-bar 112 which passes freely through an aperture in the side wall of the bed 1 and at its outer grooved end is embraced by the forward forked extremity 1123, Fig 22, of the lever 114 fulcrnmed on the screw 102 and at .its rearward end, Fig. 7, carrying a roll 115 adapted to be actuated by the cam 110 on the inner face of the cam-disk 105.
- the cam 116 is timed to give the pull-oil' lever one complete oscillation from full to dotted line position and return, Fig. 0,y when the sewing operation has been completed and at about the time the rapid feed is thrown into action to shift the work to ci tting position.
- a spring 117 on the bar 11 between the collar 118 and the bed 1 operates to restore the pull-oil' lever 108 to its full line position.
- an upper thread-controlling element is preferably provided to act upon the needle-thread length between the needle-eye and the work.
- Such eement is preferably in the form of a thread-nipper operating at the endof the sewing operation to catch the needle-thread before it is severed below the work and hold such thread during the formation of the initial stitches; means being preferably provided to cause the nipper to release the end of the needle-thread in time for such thread to be drawn down to an inconspicuous or substantially invisible position by the pull or thread-absorbing action of the stitchforming instrumentaiities.
- An auxiliary thread-cutter may, if desired, be associated above the work with the needle-thread nipper to somewhat reduce the length of needlethread end to be absorbed or drawn back into the work during the formation of the initial stitches.
- an upper thread-nipper having an auxiliary thread-cutter associated therewith.
- These elements are in the form of the usual compound blade 119, Figs. 13 and 14, which is mounted on the pivot-pin 120 journaled in the left-hand worlcelamping foot 25 and operates between the upper and lower resilient arms 121, 122, in the usual manner as disclosed, for example, in my Patent No. 1,369,371, of February 22, 1921.
- the compound bladc 119 has a hook-shaped extremity which swings across the lead of the needle-thread at the end of the sewing operation, catching such thread and nipping it between the resilient arms 121, 122.
- the blade 119 has a sharpened lower corner 123 and the lower resilient arm 122 is sharpened or fitted with a ledger-blade 124, the needle-thread will be severed as well as nipped above the Work, as illustrated in Fig. 14.
- the mechanism for operating the nipperblade 119 is similar in its principle of operation to that disclosed in my said Patent No. 1,369,371.
- the pivotpin 120 carries the usual crank-arm 125 to which is pivotally connected at 126 the forward end of the link 127 pivotally connected at its rearward end at 128 to the lower end of the lever-plate 129.
- the lever-plate 129 is pivoted at 130 to a bracket-plate 131 secured by screws 132, Fig. 12, to the inner face of the usual fulcrum block in which the upper work-clamping arm 26 is pivoted.
- a coil spring 133 connected at its opposite ends, respectively, to the bracket-plate 131 and lever-plate 129 serves to draw the link 127 rearwardly and shift the blade 119 to nipping position, Figs. 12v and 14.
- a stop 134 mounted on the bracket-plate 131 limits the motion of the lever-plate 129 under the influence of the spring 133.
- the lever-plate 129 is formed vwith a laterally extending arm 135 which is positioned in the path of downward movement of the horizontally and forwardly extended lower end 136 of-the vertical nipper opening rod 137.
- the lever-plate 129 is also formed with a forwardly extended tooth 138 under which snaps the lateral tooth 139 of the latch-plate 140 pivoted at 141 to the bracket-plate 131.
- a spring 142 connected at its opposite ends, respectively, to the latchplate 140 and bracketplate 131 yieldingly holds the plate 140 in labelling or dotted line position, Fig. 11.
- the lateh-plate 140 is fitted at its lower end with an adjusting screw 143, Fig.
- the release of the needle-thread end at theproper time is secured by connecting the rod 137 with a timing cam 145 which is mounted on the ⁇ vertical shaft 146 journaled in the .bracket-arm 3 in alinement with the shaft 19 and driven by a two-to-one speed reducing ,bevel-gear connection 147 with the needle-bar operating shaft 148, which is driven in the usual manner by the one-totwo speed multiplyingr bevel-gear connection 149 to the ⁇ shaft 19.
- the rod 137 l is pivotally connected at ils upper end at l5() to the forward end of the lever 151 and is guided in its movement by being passed through an aperture in a guide-bracket 152, Figs.
- the lever 151 is pivoted at 155 tothe bracket arm 3 and at its rearward end is pivotally connected at 156 to the lower end of the link 157, Fig. 24, which ⁇ is apertured at its upper end to fit the reduced end 158, Fig. 25, of the boss 159 formed at the lower end of the slide-plate 160 having its opposite edges longitudinally grooved at 161 to slidably lit the opposed vertical ribs 162 afforded by cutting away the wall of the housing 163 which incloses the timing cam 145.
- the boss 159 on the slide-plate 160 is aperturcd to receive the slide-pin 165 which is adapted, when released, to be projected to ward the timing cam 145 by the leaf-spring 166 mounted on the link 157.
- the slide-pin is formed with'a circumferential groove 167 which is adapted to be entered by the lower end-portion of a latch-lever 16S pivotally mounted at 168 Von the slide-plate 160. Ihe la-teh 16S acts during the major portion of the sewing operation to hold the Islide-pin 165 in ejected position and ont of engagement with the active portions of the timing cani 145, as shown in Fig.V 29.
- the sewing is completed, however, andthe stopmotion lever 14 springs ⁇ to stopping position, Figs. 1 and 2.
- the characteristic upand-down motion of the stopping tooth 16 operates in a well known manner, as explained in my said reissued Patent No. 15,324 to rock the lever 169 and cause the pin 170 to engage under the latch 171 and lift the tension release bar 172.
- the har 172 is formed at its upper end with a wedge 173, Fig. 24, which cooperates with the tension release i n 174 to Vseparate the disks of the tension device 175.
- the har 172 carries a lateral pin 176 which lifts the tail 177 of the latch-lever 16S against the pressure of the spring 178 and releases thoslide-pin 165, whereupon the latter is projected into engagement with the then siationary cam 145 by the spring 166, as shown in Figs. 24, 25 and 26.
- the tension release bar lifting pin 170, Fig. 2 is carried inwardly beyond the latch 171 and the tension-release. pin 172 drops into the positionshown in Fig. 5, thus restoring the tension on the needlethread.
- the cam 145 is provided with a lower circular ledge 179 and a cam-rise 1S() leading to the ledge 130 which in the initial movement of the stitch-forming mechanism passes under the inner end of the slide-pin 165 and lifts the latter enough to depress the extension 136 ot the rod 137 substantially into engagement with the extension 135 of the lever-plate 129.
- the rise 130 initially lifts the slide-plate 160 sufficiently to take up the lost-motion in the train of connections with the latch-plate 129.
- the ledge 186 is a camrise 181, Fig. 2T ⁇ leading to a second ledge 182 which lifts the plate 160 sulliciently to rock the level 129 and set the needle-thread nipper in open position.
- the rise 181 is preferably timed to e'ect the release of the needle-thread end at about the time the needle-bar completes the 11p-stroke following the lirst descent. of the needle through the work. Further movement ofthe cani 145 carries the cam incline 18?
- the needle-thread passes trom the supply through the guide-tube 191 and light threadcheck 185; thence between the tension-disks 175 and through the guide-aperture 166, Fig. 25, in the wall of the ram housing' 162'). rlfhe needle-thread next passes through the eye 1ST at the end of the check-spring IHS; thence through the ⁇ :guides 189 ⁇ 19t), and under the pull-ott bar 191, Fig. 2. which at its lower end is connected to the clamp-closing lever 31 and operates prior to sewing, as indicated in Fig. 2, to pull enough needlethread through the then open tension 175 to permit.
- the needle toI reach the bottom of its stroke, in its initial descent, without unduly strainingr the needle-thread. From the pullotl' 191 the needle-thread passes through the guide 192 and under the guide-bar 193: thence into the hollow needle-bar 194 and to the needle 5.
- the thread-cheek 185 preferably comprises a cylindrical body 195, Fig. i, apertured to receive the spring 196 and movable disk 197.
- the upper disk 19S is carried at the upper end of the pin 19t) tixed in the support 195 by the set-screw 200.
- the pin 199 is apertured at 201 to guide the needle-thread between the disks.
- the purpose of the thread-cheek 185 is to apply a licht resistance to the needle-thread so that diningV the action ot the pull-ott1 191 and when the main tension 175 is opened, overrnnning of the needle-thread will be prevented.
- the threearmed lever 31, 22, 32 is rocked to close the work-clamp and operate the needle-thread pull-ott' 191.
- the arm 32 of the three-armed lever operates as usual to spread the work-clamp and trip the rapid feed into action to quickly shiit the work-holder forwardly from cuttinr position, Figs. 12 and 13, to sewing position, Fig. 11.
- the cam 101 closes the staycord nipper 9S and as the Work slides ⁇ forwardly over the button 11, the end of the -stay-cord c it bent sidewise or rearwardly during the insertion of the work, is brushed ⁇ back into line with the buttonholc, as shown in Fig. 30. so that it will be embraced by the initial stitches.
- the stopinotion lever 14 When the sewing is completed, the stopinotion lever 14 is tripped and arrests the action of the stitch-forming mechanism, at the same time releasing the tension 1T5 and plunger-pin 165, as previously described.
- the rapid feed is again thrown into action and quickly carries the clamped and stitched work to cutting position, thereby drawingV out the loo1u-1-thre:nl ⁇ stay-cord c, and both limbs of the detained needle-loop u from the aperture in the button 11, as shown in Fig. 15, and positioningr these threads horizontally across the path of advance of the scissors device 51 ⁇ 52.
- the cutter-shaft 3T Upon the arrival of the work at cutting position, the cutter-shaft 3T is coupled as usual to the pulley 36 for a single rotation and operates to advance the buttonhole cutter levers 42 and 43 to cutting position and to close them upon the work.
- the advance movement of the buttonhole cutter levers also etects the advance of the scissors de- Vice and needle-loop gripper to their operative position, Fig. 16.
- the screw 143 is preferably so adjusted as to effect the tripping of the needle-loop nipper before the scissors device severs the lower threads.
- the stop 92 is struck by the arm 91 of the nipper-jaw 79 and the latter is opened, thus releasing the severed needle-loop 71 just prior to the final stoppage of the machine.
- the buttonholes b, Figs. 32 and 33 when removed from the machine, are entirelyv finished; the cord c and sewing threads being neatly trimmed at the point d close to the end of the buttonhole. Moreover, this result is attained With certainty since the work is held in position by the work-clamp until the threads are actually cut.
- a sewing machine including stitchforming mechanism, 'an apertured worksupport, a thread-cutter including a pointed blade disposed transverse to the work-support, and means for projecting the point of said blade into said aperture but not appreciably above the upper surface of the work-support so as to graze the under surface of the work 2.
- a sewing machine including stitch- 'forming mechanism, an apertured work-support, a scissors thread-cutter having its blades disposed below the work-support and in planes transverse to the work-support and means for projecting said thread-cutter into saidaperturc but not appreciably above the upper surface of said work-support.
- a thread-cutter including a blade disposed transverse to the surface of the work and having a pointed extremity, and means for moving said thread-cutter transversely of the lead of the thread and in a -path such that the extremity of said blade will graze the surface of the work and enter between such surface andthe thread to be cut.
- a thread-cutter including a blade having a pointed extremity, said thread-cutter being pivotaly mounted so as to direct the movement of the pointed extremity of said blade in a curved path grazing the surface of the work crosswise of the lead of the thread in a plane transverse to the surface of the work, whereby such bladel will enter between the surface of the .work and the thread to be cut preparatory to the cutting action.
- a sewing machine having, in combination, stitch-forming mechanism including a needle, a needle-throat, a work-clamp, automatic clamp-opening means, a thread-cutting element below the work-clamp, and
- a thread-cutter including a blade disposed below the workclamp 1n a plane transwbflerse to the work and having a pointed extremity, and means for moving said thread-cutter transversely of the lead of the thread while the work-clamp is closed, to cause the extremity of said blade to enter between the surface of the work and the thread and sever the thread.
- a sewing machine having, in combination, stitch-forming mechanism including needle and loo -taking devices, means including a yneed e-throat for sustaining the work against the thrust of the needle, a thread-cutter mounted below the work to operate in a plane transverse to the plane of the work, and means for moving said thread-cutter to cause the latter to graze the under surface of the work and sever the thread drawn out from the n,needle-throat 8.
- a sewing machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental looptaking means, a work-support, a threadcutter including a blade having a cutting edge and a pointedextremity, said threadcutter being mounted to move in a curved path transverse to the plane of the work so that the pointed extremity of said blade will graze the surface of the work transversely of the lead of the thread and separate from such surface the thread tol be cut, and means for moving the thread-cutter in the prescribed path.
- a sewmg machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental loop-taking means, a work-support, a thread-cutter mounted below the work-support and including a blade having a cutting edge and a pointed extrelmty, said thread-cutter being mounted to move in a path such that the pointed extremity of said blade will graze the under surface of the work and separate from such surface the thread to be cut, and means for moving the thread-cutter in the prescribed path.
- a sewing machine having, in combination, stitch-forming ymechanlsm including a reciprocating needle and complemental loop-taking means, a work-su port, a thread-cutter pivotally mounted be ow the work-sup ort to operate in a plane trans ⁇ verse to t e lane of the work, said threadcutter include in a blade having a cutting edge and a polnted extremity, the curved pathl of movement of which azes the under surface of the workV at t e highest point of such path, and means for operating said thread-cutter.
- a sewing machine including a reciprccating needle and complemental looptaking means, a work-support, a thread-cutter in the form of atravelling scissors device and includingfa blade having a cutting edge and a ointed extremity, said scissors device bem disposed edgewise relative to the work an being mcnnted to move in a path such that the pointed extremity of said ⁇ blade Will graze the surface of thework and enter between such surface and the thread to be out, and ⁇ means for moving the threadcutter in the prescribed path.
- a sewing machine having stitch-form- ⁇ ing mechanism, a needle-throat, a work-holder having a lower work-supporting surface and formed with a thread-cutter clearance aperture exposing the under surface of the work, and a thread-cutter mounted below the work-holder and ada ted tn engage the under surface ofthe woiili exposed by said aperture and sever the thread drawn out from the needle-throat.
- stitch-forming mechanism including a reciprocatin needle and a needle throat member, a wor r-clamp having lower work-supporting and upper clamping means, the work-supporting means being formed with an elongated clearance slot for the needlethroat member, said work-supporting means being also formed with a thread-cutter clearance slot intersecting said needle-throat clearance slot between the ends of the latter, and a thread-cutter movably mounted below the work-clamp to operate on the under side of the work through said thread-cutter clearance slot.
- a sowing machine having stitch-forming mechanism including a reci rocating needle, work-supporting means aving a needle-hole and a thread-cutter clearance aperture spaced from the needle-hole and over which the thread tobe cut is positioned by shifting the work subsequent to sewing, a thread-cutter mounted below the work-support and comprising a cutting blade disposed in a plane transverse to 'the plane of the work, and means for moving said blade to cause its point to graze the under surface of the work exposed by said clearance aperture and am between such surface and the thread leadmg from the needle-hole to the last stitch.
- a buttonhole sewingl machine comprising, stitch-forming mechanism including a reciprocating needle and complemental looptaking means, a work-clamp, means for relav tively moving the stitch-forming mechanism and work-clamp to Sew around a buttonhole, a scissors thread-cutter mounted below the work-clamp with its blades in planes transverse to the plane of the work, and the direction of length of the buttonhole, and means for operating said thread-cutter.
- a sewing machine having stitch-forming mechanism including a reciprocating needle, a needle-throat a work-clamp including upper and lower clamping means, means for relatively moving the stitch-forming mechanism and work-clamp to sew a group of stitches and to relatively separate the latter ,iand the stitch-forming mechanism subsequent to sewing to draw out a length of thread from the needle-throat, and threadcutting means disposed below the lane of the work and ada ted to sever sai thread length close to the ast stitch while the workclamp remains closed and in control of the work.
- a sewing machine having a frame, stitch-forming mechanism inclu ing a reci rocating needle, a needle-throat, a wor clamp including upper and lower clamping means, means for relatively moving the stitch-forming mechanism and work-clamp to sew a group of stitches and to relatively separate the latter and the stitch-forming mechanism subsequent to sewing to draw out a llength of thread from the needle-throat, said lower clamping means being apertured to expose a portion of the under surface of the work and said length of thread, and thread-cutting means mounted on the machinelframe independently of the work-holder and adapted to sever said exposed thread len h close to the last stitch.
- a buttonhole sewing machine having, in combination, stitch-forming devices including a needle, loop-taker mechanism, a needle-throat, and a turret carrying the looptaker mechanism and needle-throat, a workholder means for relatively moving the stitch-forming mechanism and work-holder subsequent to the sewing operation to space the stitched buttonhole from the needlethroat and position the sewing threads leading from the last stitch to the needle-throat horizontally against the under surface of the work, a scissors thread-cutter disposed at the same side of the work as the turret and including blades disposed transverse to the plane of the work, one of theblades of said scissors being 'pointed and adapted' to enter between the sewing thread and the work at a point close to the last stitch, and means for projecting said scissors to cutting position and for closing them upon the sewing thread.
- stitch-forming mechanism including a needle, a needlethroat, a work-holder including clamping feet occupying a position laterally spaced from the needle-throat after the sewing has been completed, and a thread-cutter including a cutting blade disposed in a plane transversely ot' the plane of the work, said blade being pointed and adapted to enter between the under surface of the work and the thread leading from the needle-throat tothe last stitch.
- stitch-forming mechanism including a needle, a-needlethroat, a work-holder including clamping feet occupying a position laterally spaced from the needle-throat after the sewing has been completed, and a scissors thread-'cutter including blades disposed in planes transversely to the plane of the Work, one-of said blades being pointed and adapted to enter between the under surface of the work and the thread leading from the needle-throat to the last stitch, and the otheriof said blades being disposed at the same side of the first mentioned blade as the last stitch.
- a sewing machine having, in combination, stitch-forming mechanism including a needle, a turret, and loop-taking means mounted on the turret, a 'work-holder including lower work-supporting plates and upper clamping feet, a buttonhole cutter, means for effecting a relative shift between the stitch-forming mechanism and workholder subsequent to the sewing operation to afford clearance for the operation of the buttonhole-cutter, and a thread-cutter mounted at the same side of the work as the turret and including a thread engagingV blade operating in a plane transverse to the plane of the work-supporting plates and between the sewing point and the cutting position of the buttonhole-cutter.
- a buttonhole sewing machine having a frame comprising a bed and bracket-arm, stitch-forming mechanism, a work-holder, means for relatively moving the stitch-forming mechanism and work-holder to sew around a buttonholc and to relatively separate the buttonhole and stitch-forming mechanism lengthwise of the machine-bed subsequent to sewing, thereby drawing out a length of vthread from the needle-throat, and a thread-cutter including a blade pivoted on an axis extending lengthwise of the machine-bed, said blade being adapted to sever said length of thread.
- a sewing machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental looptaking means mounted at opposite sides of the plane of the work.
- a thread-cutter carrying lever pivotcd at the loop-taker side of the work on' an axis transverse to and in substantially intersecting relation with a line normal to the plane of the work at the sewing point, and a thread-cutter including a pointed blade mounted on said hner and adapted .
- a sewing machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental looptaking means mounted at opposite sides of the plane of the work, a thread-cutter carrying lever pivoted at the loop-taker side of the work on an axis transverse to and in substantially intersecting relation with a line normal to the plane of the work at the sewing point, and a thread-cutter including a scissors device mounted on said lever, one
- a buttonhole sewing machine having, in combination, stitch-forming devices including needle and loop-taker mechanisms having a predetermined period of action, said loop-taker mechanism operating to retain a loop of needle-thread at the under side of the Work when the stitch-forming devices come to rest, a thread-cutter mounted below the work for travellingmovcment toward and' away from the stitch-forming mechanism and adapted to sever both limbs of suchretaining loop, and means including a thread-engaging device movable with such thread-cutter toward and away from the stitch-forming mechanism for seizing such loop vand removing it from the field of action of the stitch-forming mechanism.
- a buttonhole sewing machine having, in combination, stitch-forming devices including needle and loop-taker mechanisms havlng a predetermined period of action
- said loop-takery ⁇ mechanism operating to retain a loop of needle-thread at the under side of the work when the stitch-forming devices ycome to rest, means for severing both limbs of such retained loop, and a threadgripper having relatively separable jaws Vadapted to seize such loop and remove it from the field of action ofthe stitch-forming mechanism.
- a buttonhole sewing machine having, in combination, stitch-forming devices 'including needle and loop-taker mechanisms having a predetermined period of action, said loop-taker mechanism operating to retain a loo of needle-thread when the stitchforming evicescome to rest, a thread-cutter below the work for severing both limbs of such retained loop, and a thread-gripper, carried by said thread-cutter and o eratlng to seize such loop and remove it rom the field of action of the stitch-forming mechanism.
- a buttonhole sewing machine having, in combination, stitch-forming devices including needle and loo -taker mechanisms having a predetermine period of action, said loop-taker mechanism operating to retain a loop of needle-thread when the stitchforming devices come to rest, means for severing both limbs of' such retained loop, a thread-gripper having separable jaws adapt ed to seize such loop and remove it from the field of action of the stitch-forming mechanism, a buttonhole-cutter, and connections between said buttonhole-cutter and the gripper for actuating the latter.
- Arbuttornhole sewing machine having, in combination, stitch-formin devices, including needle and loop-taker mechanisms, a stop-motion, said loop-taker mechanism operating to retainaV loop of needle-thread when thexstitch-forming mechanism Acomes 'to rest, means for severing both limbs of the retained needle-loop, a gripper including a spring-pressed jaw for seizing said loo for removal from the field of action o lthe stitch-forming mechanism, a latch for hold- .ing said jaw open, and. means for tripping said latch when the ing position. d
- a buttonhole sewing machine having, in combination,,stitch-forming devices, including needle and loop-taker mechanisms, a ⁇ stop-motion, said loop-taker mechanism operating to retain a loop of needle-thread when the stitch-forming mechanism comes to rest, a buttonhol'e-cutter, means for severing both limbs of the retained needle-loop, a grlpper including a spring-pressed jaw for seizing said loop for removal from the field of action of the stitch-forming mechanism,
- gripper is in loop-seiz- -a latchVA for holding ⁇ said jaw. open, and Vmeans on the buttonhole-cutter for tripping Said latch.y
- a buttonhole sewing machine having, in combination, stitch-forming devices, including needle andloop-talrer mechanisms ⁇ a stop-motion, said loop-taker mechanism operating to retain a loop of needle-thread when the stitch-forming mechanism comes toy rest, means for severing both limbs of the Vretained needle-loop, a gripper for seizing 32.
- a buttonhole sewing machine having, y
- a work-holder, stitch-form ing devices including upper thread mechanism, under thread mechanism, and a turret on which the under thread mechanism is mounted, a needle-throat mounted on said turret and adapted to guide a stay-cord to the stitch-formm mechanism, means adapted at the en ⁇ d o the sewing operation to sever the cord between the needle-throat and the Work, and meansfor arresting the feed of the cord during the formation of the initial stitches of the buttonhole, said. means being timed to release the cord when the end thereof is substantially even with the initial stitches.
- a buttonhole sewing machine having, in combination, stitch-forming mechanism, a work-holder, a feed-wheel, a stay cord guide adjacent the lstitch-formingl mech ⁇ anism, means for arresting the feed of the cord duringthe formation of the initial stitches, and means for severing Ythe cord between said guide and the work subsequent to sewing.
- A' buttonhole sewing machine having, in comibination, stitch-forming mechanism, a work-holder, a feed-wheel and connections with the stitch-forming mechanism through which the feed-wheel is driven during the sewing to space the stitches around the buttonhole, a stay cord guide adjacent the stitch-forming mechanism, means for severing the stay cord between'said guide and the work subsequent to sewing, and 4a stay7 cord nipper connected to the feed-wheel for arresting the feed of the cord during the formation of the initial stitches.
- a buttonhole sewing machine having, in combination, a Work-holder, stitch-forming mechanism. including upper thread mechanism, under thread mechanism, and i a turret on which the under thread mechanism is mounted, a needle-throat mounted on said turret and formed with a sta cord delivery aperture, means acting at t e end,
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Sewing Machines And Sewing (AREA)
Description
April s ,1926. 1,579,200
E. B. ALLEN THREAD CUTTER FOR SEWING MACHINES Filed Deo. 17, 1921 K 8 sheets-Sheet 2 INVENTOR WITNESSES:
if VMI/WM, 'A l 2 #ma WK ATTORNEY April 6 1926. y
, E. B. ALLEN THREAD CUTTER FOR SEWING MACHINES Filed De@` 17. 1921 s sheets-sheet 2 INVENTOR Y @mL/im BY//p v ATTORNEY lllllllllll-IIIIJII WITNESSES: i
E. B. ALLEN April 6 1926.
THREAD CUTTER FOR SEWTNG MACHTNES Filed une@ 1?. 1921 8 Sheets-Sheet 5 p, INVENTOR WITNESSESZ 2e/Law ATTORNEY April"6 1926 E. B. ALLEN THREAD CUTTER FOR SEWTNG MACHYNES Filed DSC, 17. 1921 8 ShenfS-Sheet M n R m m m V W A m f Y/ B 1%; mwmfvw NN www.: rr..
WITNESSES:
April 6 1926.
E. B. ALLEN THREAD CUTTER FOR SEWING MACHINES Filed Dec. 17, 1921 8 Sheets-Sheet y5 INVENTOR ATTORNEY April 6 1926.
E. B. ALLEN THREAD'CUTTER FOR SEWING MACHINES Filed Deo, 17. 1921 8 Sheets-Sheet 6 INVENTOR {eM/5. M
ATTORNEY wlTNsssEs r//M, L? c April 6 1926.
E. B. ALLEN THREAD CUTTER FOR SEWING MACHTNES Filed Dec. 17. 1921 8 Sheets-Sheet 7 |NVENTOR BY? N WITNESSES:
April 6 1926.
E. B. ALLEN THREAD CUTTER FOR SEWING MACHINES 8 Sheeis-Sheet 8 Filed DSC. 1'7. 1921 hwN WTNESSES:
'ITORNEY Patented Apr. e, 1926.
l UNIT-ED vSTATES PATENT OFFICE.
EDWARD B. ALLEN, OF NEWTOWN, CQNNECTICUT, ASSIGNOR TO THE SINGER KANU- FACTUBING COMPANY, 0F `ELIZABETH', NEW JERSEY, A CORPORATION OF NEW Application med December To all whom it 'may concern.'
Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at 'Newtowm in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Thread Cutters for Sewing Machines, `of which the following is a specification, reference being had therein to the accompanying drawin This inventionrelates to sewing machines and particularly to buttonhole sewing machines having stitch-forming devicesl includingneedle and loop-taker mechanlsms disposed mainly at opposite `sides of the Work; the 'loop-taker mechanism operating to detain a loop of needle-thread when the stitch-forming devices come to rest. Ono
' type of such machines also commonly embodies a rotary turret which carries the loop-taker ore under thread mechanism and also carries the needle-throat or work-supporting but-ton through which the needle reciprocates; the button being commonly apertured to guide a stay-cord to the stitch` forming mechanism in such wise that the stitches will be formed over the cord and bind the cord in its place around the buttonhole. Machines of this character have heretofore been provided with thread and staycord severing devices operating automatically at the end of the sewing operation with the object of relievin the operator of the necessity for cutting time various threads by hand,and thereby shortening the time required by the operator to'remove the stitched work from the machine and insert work lto be stitched. i
While prior thread-cutting devices may have operated satisfactorily 1n freeing the work from the sewing threads and thereby enabling the operator to shift or remove the Work from the machine Without delay, they have not operated to trim the threads, including the cord, with certainty and in such a marmer that the buttonholes, as removed from the machine, were finished buttonholes that is, acceptable to the trade Without being retrimmed by hand. While attemptshave been made to'provide buttonhole 1nachines with thread-cutting devices for trimming the `threads close enough to the buttonhole .to avoid. the necessity of v a hand re-' i THREAD-corran Fon SEWING MACHINES.
11, i921. semi Np. 523,05.
trimming operation, such attempts have` not been successful in meeting the demands of the trade, since the mechanisms heretofore produced have either failed to cut the thread clean and with certainty or have failed to cut the thread close enough to the buttonhole to produce an acceptable tinished'buttonhol i For example, it has heretofore been proposed to mount a scissors device with its lades in parallelism with the work-supporting plates of the Work-holder and between such plates and the Work. In order to operate such a scissors device it is therefore necessary that the work-clamping feet be first raised to release the Work prior to the projection of the scissors device to cutting position, The necessity for releasing the work before the threads are cut is disadvantageous in that the Work is not held under control at the time the threads are cut and uniformly satisfactory results are impossible of attainment. An accidental disarrangement of the released work will have .a tendency to affect. the length of the trimmed threadsor mayeven carry the threads beyond the range of action of the trimmer. There is Valso danger that the stitching will be'cut and the Work damaged. Still, further, in prior machines having devices which operate to cut both limbs of the needle-loop detained by the loop-taker mechanism, ditliculty is encountered for the reason that the short end of thread constituting the severed needle-loop is not taken care of and is frequently caught up bv Ithe stitch-forming devices and sewed inf thus marring the product. An accumulation of such short ends`on the turret may also interfere with `the proper action of the under thread mechanism.
The present invention has for a primary object to particularly of the buttonhole type referred provide a sewing machine, more to, withthread-cutting mechanism of such a. i character ythat it will operate `to` trim the pearance' rand will not need to be subes-,
quently retrimmed by hand.V
Another object of the invention is to pro- .vide means for taking care of the short ends of thread constitu-ting the severed needlen loops, so that they will not clog the stitchforming mechanism or be sewed in.
A further object of the invention is to provide, in combination with the threadeutting mechanism contemplated, means for ho`iing the beginning end of the needlethread, such means preferably operating in such a manner that the beginning end ofthe ncedlethread will be substantially concealed in the work.
Still further, the invention has for an object to provide means for insuring that the beginning end of the stay-cord will be substantially even with the initial stitches so as to avoid the necessity of trimming the beginning end of the st Iay-cord.
In accordance with the present improvement, as embodied in a. buttonhole sewing machine, the above and other objects, as will hereinafter appeal', are attained by mounting a. thread-severing device below the xlevel of the work-holder, and preferably independently of the turret, with its blade or blades transverse to the plane of the work and so positioned as to engage and cut. the threads, including the stay-cord, close to the last stitch, before the clamping feet are raised to release the work. Preferably, the thread-severing implement is in the form of a scissors device, one of the blades of which is bluntly pointed and adapted to graze the under surface of the work exposed by an aperture. in the Work-support and enter between such surface and the horizontally disposed threads leading from the aperture in the needle-throat or work-supl porting button to the last stitch. The other blade is preferably mounted on the same side of the first-mentioned blade as the last stitch in the work, in order that the threads may be out very close to the end of the seam or buttohole.
The severed loop of needlethread retained by the loop-taker mechanism is removed from the field of action of the stitch-forming mechanism preferably by means of a movable thread-engaging device made up in the form of a gripper' and mounted alongside the thread-severing device so as to seize the severed needle-loop and carry it away from the stitch-forming mechanism when the thread-severing device is retracted. The thread-severing device and gripper are preferably operated simultaneously with the buttonhole-cutter by means of an operative connection receiving motion from the latter. Means are preferably provided above the work fornipping the needle-thread end leading from the needle, so that; the initial stitches may be formed without nnthreading the needle. A pull-otf may, in some cases, be provided to afford enough slack at the beginning of the sewing operation to permit the needle to descend to the limit ot' its stroke without unduly straining the needles thread or pulling the thread out` of the nipper. The beginning end of the needlethread is pleferably released by the nipper in time to take advantage of the thread absorbing action of the stitch-forming mechanism to draw down the beginning end of the needlethread substantially flush with the work and thereby render such end practically invisible.
`An auxiliary threadcutter may also be associated above thev work with the. nippel' in case it is desired to reduce the length ot' needle-thread end held by the nipper and thus reduce the length of thread end to be absorbed or drawn back into the work by the stitch-forming mechanism. It is to be understood, however, that while the use of such auxiliary thread-cutter above the work is` deemed preferable in the present embodiment, of the invention, it is not in all eases essential to the productioinot' satis factory work.
inasmuch as it has been found impracticable to form the initial stitches tlnsb with the end of a short length of stayrord projecting' from the button, it is preferred to sever the cord at a sufficient distance from the button to afford a eordend long enough to be enclosed with certainty and bound down by the initial stitches, a cord-nipper being preferably provided to arrest the feed of the cord `while the work and initial stitches are slid toward the end of the cord, the cord being released when its end is even with the initial stitches.
An under thread pull-ofi` is also preferably provided for the purpose of atl'ording enough slack looper-thread so that the initial Stitches may be formed without nnthreading the looper.
In the accompanying drawings, Fig. 1 is a right side elevation, partly in section, of a buttonhole sewing machine embodying the invention; the parts being in their respective positions occupied during the buttonhole cuttingIr and thread-cutting operations. Fig. 2 is a left side elevation of the machine at the end of the buttonhole-producing cycle, the work-holder being open. Fig. 3 is a detail view of the guide-bracket for the needle-thread nipper releasing rod shown in Fig. 2. Fig. 4 is a detail seetional view of the needle-thread check shown in Fig. 2. Fig. 5 is a side elevation of certain parts of the needle-thread nipper thread mechanism shown in F ig. 2. the
parts being in the respective positions which they occupy while the machine is sewing. Fig. G is a front elevation of the machine with the work-supporting plates in section. Fig. 7 is a fragmentary top plan view of the mechanism below the work-holder. Fig. 8 is a detail of the stay-cord nipper. Fig. 9 is a plan view of the work-supporting plate sections adjacent the sewing point. Fig. 1() is a bottom view of the neeiiethroat or button and the thread-cutting scissors and nassociated devices, the scissorsV having advanced nearly to cutting position. Fi 11 is a left side elevation ot' the needle-t read `mechanism and associated parts at the point of the cycle when the initial stitches are being formed; the dotted lines showing the movement of certain parts to o'pen the nipper and release the beginning end of the needlethread, Fig. 12 is a similar view of the parts at the end of the cycle when the buttonhole is being cut and just after the thread-nipper has been tripped. Fig. `13 is a fragmentary plan view of the workholder including the upper clamping feet and associated parts at the end of the sewing operation but prior to the advance of the buttonhole-cutter. F ig.' 14 is a. sectional view on the line 14, 14, Fig. 13; the thread-nipper having been-tripped. Fig. is a perspective view of the scissors device, thread-gripper, and associated parts, at the end of the sewing operation and prior to the advance of such parts. Fig. 16 is a similarview with the parts in advanced or cuttingr and gripping position. Fig. 17 1s a simllar view showing the scissors and gripper beingretracted to remove the severed needle-loop from the vicinity of the stitch-forming mechanism. Fig. 18is a perspective view of the rear side of .the' scissors device.
Fig. 19| is a bottom erspective, view of the needle-throat or utton. Fig. is a front elevation of the scissors device and associated parts, showing the connection with the lower buttonhole-cutter lever for .tripping the latch which holds the needleloo gripper open. Fig. 21 is an enlarged eevation of the scissor-blades showing one of-them grazing the under surface of the work and entering between such surface and the threads to be cut. Fig. 22 is a side elevation of the stay-cord nlpper and looper-thread pull-off levers and their operating cam. Fig. 23
.is a development of such cam. vFig 24 is a rear elevation of the actuating mechanism for the needle-thread nipper. Fig. 25 is a plan view of' the` timing cam member of such mechanism. Fig. 26 is a perspective view of such timing cam and its follower in. the respective positions which they occupy before the machine is started, as in Fig. 24. Fig. 27 is a similar view showing the cam-follower pin about to be elevated to open the needle-thread nipper. Fig. 2S is a similar view showing the cam-follower pin fully elevated and latched in ejected position. Fig. 29 is a rear elevation'of the same parts, the cam-follower'pin having re turned to its lower level. Figs. 30 and 3l are sectional views illustrating the operation of covering the bcginning'eud of the stay-cord. Figs. 32 and 33 are front and reverse views, respectively, of the finished buttonhole as produced by the machine;
For the purpose of thepresent disclosure the invention is embodied in a sewing niachine of the buttonhole type constructed substantially in accordance with the disclosure of my United States Patent No. 15,324 reissued April 4, 1922. A machine of this type, as shown"pa`rticularly in Fig. 1, comprises a frame including a hollow boit-like bed 1 from one end of which rises the standard 2 carrying the bracket-arm 3 which terminates in the needle-bar carrying head 4. The stitch-forming inechanism is constructed substantially in `accordance with the disclosure of my Patent No. 1,372,-
-473 of March 22, 1921, and comprises the laterally vibrating needle 5 and the usual loop-taker `or under thread mechanism lnounted on the rotary turret 6 and including the threaded looper 7 lion-threaded looper 8 and their respective loop-detainers 9 and 10. The turret 6 also carries the needle-throat or button 11 which is formed with the usual needle-aperture 12 and guide-way for the staycord c. The needlethreadis shaded and the looper-thread is shown clear, or without shadingVin the various figures.
The stitch-forming mechanism isl operatedv from the sewing shaft 12Y at the rear end of which-is the usual belt-pulley 13 and stop-motion device which is constructed substantially in accordance with the disclosure of my said-.reissued Patent No. 15,324, and includes the tilting stop-motion lever 14 which is pivoted at l5 and carries the stopping tooth 16 adapted for cooperation in a manner well known with the stopping cam 17.
Within the bed 1 is mounted the usual feed-wheel 18 which is driven during the sewing by a suitable one-way gear-driven connection with the uprighfshaft 19 driven by the bevel-gear connection 20, 21 with the sewing shaft 12, as shown in my said reissued atent. The feed-wheel is connected to be riven at a higher speed both prior and subsequent to sewing by the usual automatically operated clutch' (not shown) intermediate the constantly running shaft 22 and the rapid feed-'shaft 23 which'latter is permanently geared at 23 to the feed-wheel 18.
The work-holder which lhas the usual operative connections with`- the feed-wheel, comprises the lower work-supporting plates 24 and the upper pivotally mounted clamping feet 25' sustained by the respective clamping levers 26, Fig. 2, pivotcd at 27. The clamp isclosedin the usual manner either by rearward pressure against the fingerpiece 28 or downward pressure on the arm 29 fixed to the clamp-closing rock-shaft` 30. The clamp is usually closed autmnatically at the beginning of the sewing operation by the action of the usual three-armed rock- lever 31, 32, 3Q havingr a roll 33 at the t'orward end of the armV 31 adapted to depress the arm 25); the free end of the arm 2 carrying la slide-bolt adapted for temporary engagement with the cam-groove 35 in the inner tare of the continuously rotating pulley 3G which is loose on the buttonhole cutter shatt 3i', all as more fully explained in my said reissued Patent No. 15,324. i
It is understood by those skilled in the art that; when a machine ot' this type is not in operation, the pulleys 12' and 31' are runningl freely on their respective Y.shafts l2 and 3T: the pulley l being geared at 3S, Fig.- 1, to the shaft 22 so as to drive the latter ronstantly. lhen the machine is started, the bolt or slide-piu 34 is released and allowed to enter the ram-groove 35 in the pulley 36, whereupon thil three-armed rock-lever receives one complete oscillation, serving in its initial morement to close the rlampsaud in its return movement to spread the latter. 'lhe rock-lever also operatesduring;V its return movement through connections (not shown) with the arm 32 to eti'eet the roupling ot the feed-wheel 13 and rapid toedshat't .23 to the rapid drive shaft 2; whereupon the work-holder is rapidly shifted torwardlyy from cutting position to sewinglr position. W'hen the \\jorklmlder reaches sewing position the rapid drive-shaft 22 is unclutched from the rapid 'feed-shaft 23 and feed-wheel 19, and the stitch-forming;r mechanism is started` whereupon the feed-wheel and rapid feed-shaft 23 are more slowly driven `through the usual ,a'ear connections with the sewing,r shaft. and the work is moved in the usual path to space the stitches around the buttonhole. lVhen the sewixugY is completed the stop-motion lerer 1i is tripped to stop the sewing shat't 12 and the rapid feed-shaft 23 and feed-wheel 1S are again connected to the rapid drive-shaft E22 which operates to rapidly shift the workholder rearwardly from sewing to cutting position.
Upon arrival o' the work-holder at cutting position the pulley 3G is connected t'or a single rotation to the cutter-shaft 37 carrying the usual cutter advancing and retracting: cani 39 -and the cutter closing cams 40, 4.1 which the latter operate to rock their respective upper and lower cutter-levers 42, 43 upon their common fulcrum f1.4 sustained by the usual travelling fulerum-block 15, Fig. 7, mounted in the slide-ways 16 in the bed 1. The fulcriun-block 45 has rigid with it a rearwardly extending arm 47, Fig. 1. which is connected by the usual link 48 and cam-follower 49 to the cam 39, it being understood that the fulerum-block 45 is first advanced to carry the cutter-levers bodily forward to cutting position, whereupon the cams 40 and '11 close the cutter-levers upon the work, indicated in dotted lines in Fig. 1.
After the buttonhole has been cut and duringir the reti-acting movement of the buttonhole cutter levers,.a cam 50, Fig. 2, on the cutter-sliaft rocks a bellcrank-lever 51 connected to the push-rod 52 which engages the then upright arm 53 on the claznp-closini,r rock-shaft 30 and pushes such arm forwardly to the position shown in Fig. 2, thereby etl'ertinfl the raising of the clamping lect and the release of the work.
lt is well known that the needle-throat or button of a machine of the type under consideration supports the portion of the work immediately adjacent the sewing point and is adapted to guide a stay-cord to the stitch-forming mechanism so that the stitches will be formed over the stay-cord and bind the later in position aroun'l the buttonhole. Also, it is known that when the stitch-formin; lr mechanism of a machine ot thi` type under consideration is stopped, a loop of needle thread is retained by the loop-taker mechanism. Consequently, when -the work is shifted rearwardly from sewing to cutting position, there are it'our thread lengths lead ing: from the needle-hole in the button tothc last stitch. One of these threads is the stay-cord. Another is the under or looper-thread; The remaining two are the limbs of the detained needle-loop.
Thread-cutter.
In accordance with the present improvement these threads arefA not only severed to permit ready removal of the work and facilitate restarting of the machine, but they are severed very close to the last stitch before the work-holder is opened, whereby certainty and uniformity of operation is attained and the work aceeptably finished before it leaves the machine; subsequent retrimming operations being unnecessary.
The thread-cutting mechanism comprises a thread-severing implement preferably in the form of a scissors device, Figs. 17 and 18, and including the ledger-blade 51 and cutter-blade'52 pivotal-ly mounted on the screwpin 53 threaded into the thread-cutter carrier 54. A spring-washer 55 beneath the head of the screw 53 maintains the scissorblades in operative Contact with one another. The ledger-blade 51 is pointed at its Aupper end and at its lower end is slotted at 51" to admit the screw 55 threaded into the carrier 54. The screw 55 and slot 51 permit adjustment of the blade 51 about the pivot 53 to raise or lower the path of movement of its pointed extremity so that the latter` will properly graze the under surface of the work without digging into the latter. It
` may be here explained that the point of the ledger-blade is not sharpened like a needlepoint but is somewhat dulled or rounded so that it will not catch the fibers of the work. The scissors-carrier 54 is preferabl formed with a foot 56 having a rib-andy;
groove connection 56 with the rearward eX-,
tension 57 of the scissors-support 58 which is preferably in the form of a lever pivoted on the horizontal screw-pin 59, Fig. 6, sustained by the turret casing or curb 60. The yscrew 61, Fig. 7, which secures the scissorscarrier Vto the lever 58, passes throueh a slot 62 in the foot 56 and permits adjustment of the scissors-carrier lengthwise of the buttonhole or, in other words, lengthwise of the direction of movement of the workholder from sewing to cutting position; this adjustment determining the distance from the end of the buttonhole at which the` threads are out.' The axis of the pivotscrew 59 is directly below and substantially` in intersecting relation with a line normal to the work at the sewing point. When the lever 58 is rocked, the point of the ledgerblade is caused to graze the undersurfaceV of Athe-.work which is substantially tangent to the path of movement of such point.
Mounted on the lever 58 by means of the rib-and-groove connection 63, Fig. 7, and
the screw-and-slot expedient 64, Fig. 6, for
adjustment, is a block 65 carrying the pin extension 66 which enters an aperture in the connection block 67 having a second aperture at right angles to and innon-intersecting relation `with the first-mentioned aperture. ReceivedI within the second-men; tLoned aperture is the pin extension 6 of a horizontal arm 69 of a bellcrank-lever,
pivoted at 70 to the bracket '71 mounted on the turret casing 60. The upright arm 72 of the bellcrauk-lcvcr is connected by means of the bent link 73 to the.cutterlever fulcrum-pin 44. Thus, when the cutter-levers are advanced at the close of the buttonholeproducing cycle, preparatory to cutting the buttonhole, the scissors carrier lever 5R is rocked about its fulcrum 59 to advance the scissors from their retracted or inactive position, Fig. l5, to cutting position, Figs. 16 and 20, during which-movement the point of the ledger-blade passes between the under surface of the work and the threads leading from the last stitch to the needle-throat, as shown in Figs. lO, 14 and 21.
The work-supporting plates 24, Fig. 9, are
formed with the usual clearance slot 24 Vslot 24a ythe stop 92 and open the 'xed thereto a lateral pin 74 which enters a cam-groove 75 in a static-nary cam-block 76 fixed to the bed l. This cam groove 75 is concentric with the pivot-screw 59 throughout themajor portion of its length to hold the scissors open, but at its upper end 77 is extended inwardly ltoward the axis of the.
`detained needle-loop, the looper-thread and the stay-cord which lie lengthwise of the and across the slot 24". Needle Zoop-refrnom'ng means.
The means for removing the severed nedle-thread loop from the vicinity of the stitchfforming implements preferabl comprises a gripper having the relative y separable jaws 78, 79. The jaw 78 is formed as -an extension of the plate 80 which is `se cured to the front side of the scissors-carrier 54. Y The plate 80 is formed with the ears 81 between which ispivoted at 82 the A jaw-lever 8. at the free end of which is the jaw 79. l
The jaw-lever 83 is backed by a which and is alsol formed with an angular extension arm 86`fand hold the which is adapted when the jaws -78, 79
The gripper-jaw lever 83 is also formed with a bent arm 91 which is adapted, when the scissors carrier is retracted, to strike gripper-jaws to release the severed needle-loop. The spring 93 surrounding thepin 87 serves to re-set the latch 86 in the position shown in Fig, 15 to hold the gripper-jaws open during their next advance to loop-seizing position. lVhen the gripper-jaws are advanced to loop-seizing position and the latch 86 is tripped by. the upward movement of the lower buttonhole cutter lever, the jaws 78, 79, seize the severed needle-thread loop n, as shown in Fig.'16. The severed needle-loop is removed from the vicinity of the stitch-forming invstrumentalities during the subsequent retraction of the gripper, as shown in Fig. 17.
ing of the stay-cordc from its fruideway in the button 11, the latter may e provided at its under side intermediate the cord-guiding apertures 94 with a check in the form of a hght spring 95, Fig. 19.
The stay-cord is led from the supply through the tube 96, Fig. 22, and check 97; thence between the nipper-jaw 98 and the adjacent vertical wall of the bed 1; thence through the guides 99, 99 and 99, Fig. T, to the button 11. The nipper-jaw 98, Fig. 8, is in the form of a plate which is supported by the two screws 98', loosely received in the apertured end of the nipper--lever 100. At its center the plate 98 is backed by the adjustable screw 101 to vary the grip of the plate 98 upon the cord. The lever 100,
ig. 22, is fulcrumed upon lthe screw1 102 which enters the bracket 102 on the bed 1. At its rear end the lever 100 carries a camroll 103 which is actuated by the outer face cam 104 on the disk 105 lixed to the rapid fe'd shaft 23. rl`he spring 10G, Fig. T, tends to rock the lever 100 to release the cord, The cam 101 is timed to cause the plate 98 to grip the cord as soon as the machine is started and hold the cord during the formation of the initial stitches, Figs. 30 and 31, so that the initial stitches will be slid along by the initial feed of the work to a position even with the end of the cord, Fig. lil, hereupon the cord is released and allowed to feed with the buttonhole.
Zooper thread puZZ-of.
A looper-tliread pullo1i is preferably provided for the purpose of affording slack looper-thread at the completion of the stitching, so that the loopcr-thread will not be under strain when it is severed and so that the end of the looper-thread will not he pulled back through the button 11 at the eginning of the next sewing operation. Pivoted on the screw 10T, Fig. 0, is the pulloli' lever 108 at the lower end of which is the hook 109 which engages the looper-thread between the tension device 110 and the stationary thread-guide 111. The lever 108 is connected at its upper end to a link-bar 112 which passes freely through an aperture in the side wall of the bed 1 and at its outer grooved end is embraced by the forward forked extremity 1123, Fig 22, of the lever 114 fulcrnmed on the screw 102 and at .its rearward end, Fig. 7, carrying a roll 115 adapted to be actuated by the cam 110 on the inner face of the cam-disk 105. The cam 116 is timed to give the pull-oil' lever one complete oscillation from full to dotted line position and return, Fig. 0,y when the sewing operation has been completed and at about the time the rapid feed is thrown into action to shift the work to ci tting position. A spring 117 on the bar 11 between the collar 118 and the bed 1 operates to restore the pull-oil' lever 108 to its full line position.
N @edle-thread nipper.
To avoid a ossible accidental unthreading of the needle and to facilitate the starting of the sewing operation, an upper thread-controlling element is preferably provided to act upon the needle-thread length between the needle-eye and the work. Such eement is preferably in the form of a thread-nipper operating at the endof the sewing operation to catch the needle-thread before it is severed below the work and hold such thread during the formation of the initial stitches; means being preferably provided to cause the nipper to release the end of the needle-thread in time for such thread to be drawn down to an inconspicuous or substantially invisible position by the pull or thread-absorbing action of the stitchforming instrumentaiities. An auxiliary thread-cutter may, if desired, be associated above the work with the needle-thread nipper to somewhat reduce the length of needlethread end to be absorbed or drawn back into the work during the formation of the initial stitches.
In the accompanying drawings there is disclosed an upper thread-nipper having an auxiliary thread-cutter associated therewith. These elements are in the form of the usual compound blade 119, Figs. 13 and 14, which is mounted on the pivot-pin 120 journaled in the left-hand worlcelamping foot 25 and operates between the upper and lower resilient arms 121, 122, in the usual manner as disclosed, for example, in my Patent No. 1,369,371, of February 22, 1921. The compound bladc 119 has a hook-shaped extremity which swings across the lead of the needle-thread at the end of the sewing operation, catching such thread and nipping it between the resilient arms 121, 122. If, as in the particular construction disclosed, the blade 119 has a sharpened lower corner 123 and the lower resilient arm 122 is sharpened or fitted with a ledger-blade 124, the needle-thread will be severed as well as nipped above the Work, as illustrated in Fig. 14.
The mechanism for operating the nipperblade 119 is similar in its principle of operation to that disclosed in my said Patent No. 1,369,371. In the present instance the pivotpin 120 carries the usual crank-arm 125 to which is pivotally connected at 126 the forward end of the link 127 pivotally connected at its rearward end at 128 to the lower end of the lever-plate 129. The lever-plate 129 is pivoted at 130 to a bracket-plate 131 secured by screws 132, Fig. 12, to the inner face of the usual fulcrum block in which the upper work-clamping arm 26 is pivoted.
A coil spring 133 connected at its opposite ends, respectively, to the bracket-plate 131 and lever-plate 129 serves to draw the link 127 rearwardly and shift the blade 119 to nipping position, Figs. 12v and 14. A stop 134 mounted on the bracket-plate 131 limits the motion of the lever-plate 129 under the influence of the spring 133.
AThe lever-plate 129 is formed vwith a laterally extending arm 135 which is positioned in the path of downward movement of the horizontally and forwardly extended lower end 136 of-the vertical nipper opening rod 137. The lever-plate 129 is also formed with a forwardly extended tooth 138 under which snaps the lateral tooth 139 of the latch-plate 140 pivoted at 141 to the bracket-plate 131. A spring 142. connected at its opposite ends, respectively, to the latchplate 140 and bracketplate 131 yieldingly holds the plate 140 in labelling or dotted line position, Fig. 11. The lateh-plate 140 is fitted at its lower end with an adjusting screw 143, Fig. 13, the free end of which is directed toward the fulcruin-pin 44 of the huttonhole cutter-levers and is in position to be struck and displaced forwardly to release the lever-plate 129 by the vertical wall portion 144, Fig. 13, of theuppeecutterlever 42, when the buttonhole cutter levers are advanced to cutting position at the end of the sewing operation.
The release of the needle-thread end at theproper time is secured by connecting the rod 137 with a timing cam 145 which is mounted on the `vertical shaft 146 journaled in the .bracket-arm 3 in alinement with the shaft 19 and driven by a two-to-one speed reducing ,bevel-gear connection 147 with the needle-bar operating shaft 148, which is driven in the usual manner by the one-totwo speed multiplyingr bevel-gear connection 149 to the `shaft 19. The rod 137 lis pivotally connected at ils upper end at l5() to the forward end of the lever 151 and is guided in its movement by being passed through an aperture in a guide-bracket 152, Figs. 2 and 3, fixed to the fulcrum-pin 153 of the usual bellcrank gearsegment 154 which is commonly used in machines of the present type to turn the needlebar mechanism in synchronism with the turret in sewing around the eye of the buttonhole.
The lever 151 is pivoted at 155 tothe bracket arm 3 and at its rearward end is pivotally connected at 156 to the lower end of the link 157, Fig. 24, which `is apertured at its upper end to fit the reduced end 158, Fig. 25, of the boss 159 formed at the lower end of the slide-plate 160 having its opposite edges longitudinally grooved at 161 to slidably lit the opposed vertical ribs 162 afforded by cutting away the wall of the housing 163 which incloses the timing cam 145.
Itwill be clear that an up-and-down motion of the slide-plate 160 along its Ways 162 Will rockthe lever 151 and set the needlethread nipper in open position; the latch `plate 140 operating to hold the nippel` open. A spring 164, Fig. 2, connected at its opposite ends, respeetivcly,'to the lever 151 and standard i2 restores the rod 137 to its elevated position and the slide-plate 160 to its lowermost position. 1
The boss 159 on the slide-plate 160 is aperturcd to receive the slide-pin 165 which is adapted, when released, to be projected to ward the timing cam 145 by the leaf-spring 166 mounted on the link 157. The slide-pin is formed with'a circumferential groove 167 which is adapted to be entered by the lower end-portion of a latch-lever 16S pivotally mounted at 168 Von the slide-plate 160. Ihe la-teh 16S acts during the major portion of the sewing operation to hold the Islide-pin 165 in ejected position and ont of engagement with the active portions of the timing cani 145, as shown in Fig.V 29. lVhen the sewing is completed, however, andthe stopmotion lever 14 springs` to stopping position, Figs. 1 and 2. the characteristic upand-down motion of the stopping tooth 16 operates in a well known manner, as explained in my said reissued Patent No. 15,324 to rock the lever 169 and cause the pin 170 to engage under the latch 171 and lift the tension release bar 172. In the present instance the har 172 is formed at its upper end with a wedge 173, Fig. 24, which cooperates with the tension release i n 174 to Vseparate the disks of the tension device 175.
The har 172 carries a lateral pin 176 which lifts the tail 177 of the latch-lever 16S against the pressure of the spring 178 and releases thoslide-pin 165, whereupon the latter is projected into engagement with the then siationary cam 145 by the spring 166, as shown in Figs. 24, 25 and 26.
lVhen the stitch-forming mechanism is Iagain started, the tension release bar lifting pin 170, Fig. 2, is carried inwardly beyond the latch 171 and the tension-release. pin 172 drops into the positionshown in Fig. 5, thus restoring the tension on the needlethread. The cam 145 is provided with a lower circular ledge 179 and a cam-rise 1S() leading to the ledge 130 which in the initial movement of the stitch-forming mechanism passes under the inner end of the slide-pin 165 and lifts the latter enough to depress the extension 136 ot the rod 137 substantially into engagement with the extension 135 of the lever-plate 129. In other words, the rise 130 initially lifts the slide-plate 160 sufficiently to take up the lost-motion in the train of connections with the latch-plate 129. At the end ot the ledge 186 is a camrise 181, Fig. 2T` leading to a second ledge 182 which lifts the plate 160 sulliciently to rock the level 129 and set the needle-thread nipper in open position. The rise 181 is preferably timed to e'ect the release of the needle-thread end at about the time the needle-bar completes the 11p-stroke following the lirst descent. of the needle through the work. Further movement ofthe cani 145 carries the cam incline 18? into engagement with the inner end ot the pin 165 whereupon such pin is ejected and hitched by the lever 168, as shown in. Fig. 2h. The ledge 182 subsequently rides from under the pin 165 and permits the latter to drop to its initial position upon the lower-most ledge 179 Where it rides idly duringV the balance of the sewing operation. as shown in Fig. 29.
The needle-thread passes trom the supply through the guide-tube 191 and light threadcheck 185; thence between the tension-disks 175 and through the guide-aperture 166, Fig. 25, in the wall of the ram housing' 162'). rlfhe needle-thread next passes through the eye 1ST at the end of the check-spring IHS; thence through the `:guides 189` 19t), and under the pull-ott bar 191, Fig. 2. which at its lower end is connected to the clamp-closing lever 31 and operates prior to sewing, as indicated in Fig. 2, to pull enough needlethread through the then open tension 175 to permit. the needle toI reach the bottom of its stroke, in its initial descent, without unduly strainingr the needle-thread. From the pullotl' 191 the needle-thread passes through the guide 192 and under the guide-bar 193: thence into the hollow needle-bar 194 and to the needle 5.
The thread-cheek 185 preferably comprises a cylindrical body 195, Fig. i, apertured to receive the spring 196 and movable disk 197. The upper disk 19S is carried at the upper end of the pin 19t) tixed in the support 195 by the set-screw 200. The pin 199 is apertured at 201 to guide the needle-thread between the disks. The purpose of the thread-cheek 185 is to apply a licht resistance to the needle-thread so that diningV the action ot the pull-ott1 191 and when the main tension 175 is opened, overrnnning of the needle-thread will be prevented.
Oper/H5071.
.Vhcn the machine is ready to start, Fig. 2, the work-clamping feet are in raised position; the main tension 175 is open and the plunger-pin 165 is in engagement with the cani 145. as shown in Figs. 2l and 25. The end ofthe needle-thread is held by the nippcr 119, 121. The looper-thread and cord are sticking up through the aperture in the button 11 and the louper-thread is in a slackcondition clue to the operation of the looperthread pull-ott at the close of the previous cycle o1 operations. The stay-cord nipper is open.
Then the machine is started, the threearmed lever 31, 22, 32 is rocked to close the work-clamp and operate the needle-thread pull-ott' 191. In its return movement, the arm 32 of the three-armed lever operates as usual to spread the work-clamp and trip the rapid feed into action to quickly shiit the work-holder forwardly from cuttinr position, Figs. 12 and 13, to sewing position, Fig. 11. At the beginning of the rapid feed motion, the cam 101 closes the staycord nipper 9S and as the Work slides` forwardly over the button 11, the end of the -stay-cord c it bent sidewise or rearwardly during the insertion of the work, is brushed `back into line with the buttonholc, as shown in Fig. 30. so that it will be embraced by the initial stitches.
1V hen the work reaches sewing position the rapid feed mechanism is thrown out ot' action and the stop-motion lever 14 is tilted to start the stitch-forming mechanism. At about the end of the up-stroke ot the needle i'ollowilngr its initial descent, the cam 145 operates to release the end of needle-thread held by the nipper 119, 121, whereupon such end is absorbed or drawn back into the work by the action of the stitch-forming' instrunlentalities in substantially the manner disL closed in my said Patent No. 1.236951'4'1. then the work has been fed sulliciently to slide the initial stitches even with the end ot the stay-cord, Fig. 31, the cam 101 passes heyond the follower 163 and releases the staycord so that the latter will toed with the buttonhole. The beginning end of the seam thus presents a finished appearance and the sewing proceeds in the usual nianuer around the buttonhole.
When the sewing is completed, the stopinotion lever 14 is tripped and arrests the action of the stitch-forming mechanism, at the same time releasing the tension 1T5 and plunger-pin 165, as previously described. The rapid feed is again thrown into action and quickly carries the clamped and stitched work to cutting position, thereby drawingV out the loo1u-1-thre:nl` stay-cord c, and both limbs of the detained needle-loop u from the aperture in the button 11, as shown in Fig. 15, and positioningr these threads horizontally across the path of advance of the scissors device 51` 52.
Upon the arrival of the work at cutting position, the cutter-shaft 3T is coupled as usual to the pulley 36 for a single rotation and operates to advance the buttonhole cutter levers 42 and 43 to cutting position and to close them upon the work. The advance movement of the buttonhole cutter levers also etects the advance of the scissors de- Vice and needle-loop gripper to their operative position, Fig. 16.
The screw 143 is preferably so adjusted as to effect the tripping of the needle-loop nipper before the scissors device severs the lower threads.
When, as in .the present instance, the needle-thread is cut above the Work, the wedging 4action of the point of the ledgerblade 51 of the scissors device, in passing between the threads and the under surface of the work, exerts a pull on the threads and draws down the needle-thread end before the lower threads are severed. lVhen the cutter-levers 42, 43 recede, the scissors device is retracted and the needle-loop nipper recedes, Fig. 17, carrying with it the detained needle-loop 71 both limbs of which were severed by the action of the scissors, as'shown in Fig. 16. As the scissors-carrier nears its retracted position, the stop 92 is struck by the arm 91 of the nipper-jaw 79 and the latter is opened, thus releasing the severed needle-loop 71 just prior to the final stoppage of the machine. Thus the buttonholes b, Figs. 32 and 33, when removed from the machine, are entirelyv finished; the cord c and sewing threads being neatly trimmed at the point d close to the end of the buttonhole. Moreover, this result is attained With certainty since the work is held in position by the work-clamp until the threads are actually cut.
lVhile the invention is disclosed as embodied in a buttonhole sewing machine, its field of usefulness in its broader aspects, embracessewing machines generally, `as will be obvious to those skilled in the art without further discussion.
Having thus set forththe nature of the invention, what I claim herein is- 1. A sewing machine including stitchforming mechanism, 'an apertured worksupport, a thread-cutter including a pointed blade disposed transverse to the work-support, and means for projecting the point of said blade into said aperture but not appreciably above the upper surface of the work-support so as to graze the under surface of the work 2. A sewing machine including stitch- 'forming mechanism, an apertured work-support, a scissors thread-cutter having its blades disposed below the work-support and in planes transverse to the work-support and means for projecting said thread-cutter into saidaperturc but not appreciably above the upper surface of said work-support.
3. ln a sewing machine in which that portion of the thread to be cut lies substantially parallel to and in contact with the surface of the work, a thread-cutter including a blade disposed transverse to the surface of the work and having a pointed extremity, and means for moving said thread-cutter transversely of the lead of the thread and in a -path such that the extremity of said blade will graze the surface of the work and enter between such surface andthe thread to be cut.
4. In a sewing machine, in which that portion of the thread to be cut lies substantially parallel to and in contact with the surface of theV work, a thread-cutter including a blade having a pointed extremity, said thread-cutter being pivotaly mounted so as to direct the movement of the pointed extremity of said blade in a curved path grazing the surface of the work crosswise of the lead of the thread in a plane transverse to the surface of the work, whereby such bladel will enter between the surface of the .work and the thread to be cut preparatory to the cutting action. y
5. A sewing machine having, in combination, stitch-forming mechanism including a needle, a needle-throat, a work-clamp, automatic clamp-opening means, a thread-cutting element below the work-clamp, and
automatic means for moving said element before the work-clamp is opened to engage and sever the thread or threads at a point inteimediate theneedle-throat and Ithe last stitc i.
` 46. In a sewing machine in which the work is held in a work-clamp and that portion of the thread to be cut lies substantially parallel to and in contact with the Vun` der surface of the work, a thread-cutter including a blade disposed below the workclamp 1n a plane transwbflerse to the work and having a pointed extremity, and means for moving said thread-cutter transversely of the lead of the thread while the work-clamp is closed, to cause the extremity of said blade to enter between the surface of the work and the thread and sever the thread.
7. A sewing machine having, in combination, stitch-forming mechanism including needle and loo -taking devices, means including a yneed e-throat for sustaining the work against the thrust of the needle, a thread-cutter mounted below the work to operate in a plane transverse to the plane of the work, and means for moving said thread-cutter to cause the latter to graze the under surface of the work and sever the thread drawn out from the n,needle-throat 8. A sewing machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental looptaking means, a work-support, a threadcutter including a blade having a cutting edge and a pointedextremity, said threadcutter being mounted to move in a curved path transverse to the plane of the work so that the pointed extremity of said blade will graze the surface of the work transversely of the lead of the thread and separate from such surface the thread tol be cut, and means for moving the thread-cutter in the prescribed path.
9. A sewmg machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental loop-taking means, a work-support, a thread-cutter mounted below the work-support and including a blade having a cutting edge and a pointed extrelmty, said thread-cutter being mounted to move in a path such that the pointed extremity of said blade will graze the under surface of the work and separate from such surface the thread to be cut, and means for moving the thread-cutter in the prescribed path.
10. A sewing machine having, in combination, stitch-forming ymechanlsm including a reciprocating needle and complemental loop-taking means, a work-su port, a thread-cutter pivotally mounted be ow the work-sup ort to operate in a plane trans` verse to t e lane of the work, said threadcutter inclu in a blade having a cutting edge and a polnted extremity, the curved pathl of movement of which azes the under surface of the workV at t e highest point of such path, and means for operating said thread-cutter.
11. A sewing machine including a reciprccating needle and complemental looptaking means, a work-support, a thread-cutter in the form of atravelling scissors device and includingfa blade having a cutting edge and a ointed extremity, said scissors device bem disposed edgewise relative to the work an being mcnnted to move in a path such that the pointed extremity of said` blade Will graze the surface of thework and enter between such surface and the thread to be out, and `means for moving the threadcutter in the prescribed path.
12. A sewing machine having stitch-form-` ing mechanism, a needle-throat, a work-holder having a lower work-supporting surface and formed with a thread-cutter clearance aperture exposing the under surface of the work, and a thread-cutter mounted below the work-holder and ada ted tn engage the under surface ofthe woiili exposed by said aperture and sever the thread drawn out from the needle-throat.
13. In a buttonhole sewing machine, stitch-forming mechanism including a reciprocatin needle and a needle throat member, a wor r-clamp having lower work-supporting and upper clamping means, the work-supporting means being formed with an elongated clearance slot for the needlethroat member, said work-supporting means being also formed with a thread-cutter clearance slot intersecting said needle-throat clearance slot between the ends of the latter, and a thread-cutter movably mounted below the work-clamp to operate on the under side of the work through said thread-cutter clearance slot. n
14. A sowing machine having stitch-forming mechanism including a reci rocating needle, work-supporting means aving a needle-hole and a thread-cutter clearance aperture spaced from the needle-hole and over which the thread tobe cut is positioned by shifting the work subsequent to sewing, a thread-cutter mounted below the work-support and comprising a cutting blade disposed in a plane transverse to 'the plane of the work, and means for moving said blade to cause its point to graze the under surface of the work exposed by said clearance aperture and am between such surface and the thread leadmg from the needle-hole to the last stitch.
15. A buttonhole sewingl machine comprising, stitch-forming mechanism including a reciprocating needle and complemental looptaking means, a work-clamp, means for relav tively moving the stitch-forming mechanism and work-clamp to Sew around a buttonhole, a scissors thread-cutter mounted below the work-clamp with its blades in planes transverse to the plane of the work, and the direction of length of the buttonhole, and means for operating said thread-cutter.
16. A sewing machine having stitch-forming mechanism including a reciprocating needle, a needle-throat a work-clamp including upper and lower clamping means, means for relatively moving the stitch-forming mechanism and work-clamp to sew a group of stitches and to relatively separate the latter ,iand the stitch-forming mechanism subsequent to sewing to draw out a length of thread from the needle-throat, and threadcutting means disposed below the lane of the work and ada ted to sever sai thread length close to the ast stitch while the workclamp remains closed and in control of the work.
17. A sewing machinehavin a frame, stitch-forming mechanism inclu ing a reci rocating needle, a needle-throat, a wor clamp including upper and lower clamping means, means for relatively moving the stitch-forming mechanism and work-clamp to sew a group of stitches and to relatively separate the latter and the stitch-forming mechanism subsequent to sewing to draw out a llength of thread from the needle-throat, said lower clamping means being apertured to expose a portion of the under surface of the work and said length of thread, and thread-cutting means mounted on the machinelframe independently of the work-holder and adapted to sever said exposed thread len h close to the last stitch.
18. A buttonhole sewing machine having, in combination, stitch-forming devices including a needle, loop-taker mechanism, a needle-throat, and a turret carrying the looptaker mechanism and needle-throat, a workholder means for relatively moving the stitch-forming mechanism and work-holder subsequent to the sewing operation to space the stitched buttonhole from the needlethroat and position the sewing threads leading from the last stitch to the needle-throat horizontally against the under surface of the work, a scissors thread-cutter disposed at the same side of the work as the turret and including blades disposed transverse to the plane of the work, one of theblades of said scissors being 'pointed and adapted' to enter between the sewing thread and the work at a point close to the last stitch, and means for projecting said scissors to cutting position and for closing them upon the sewing thread.
19. In a sewing machine, stitch-forming mechanism including a needle, a needlethroat, a work-holder including clamping feet occupying a position laterally spaced from the needle-throat after the sewing has been completed, and a thread-cutter including a cutting blade disposed in a plane transversely ot' the plane of the work, said blade being pointed and adapted to enter between the under surface of the work and the thread leading from the needle-throat tothe last stitch.
20. In a sewing machine, stitch-forming mechanism including a needle, a-needlethroat, a work-holder including clamping feet occupying a position laterally spaced from the needle-throat after the sewing has been completed, and a scissors thread-'cutter including blades disposed in planes transversely to the plane of the Work, one-of said blades being pointed and adapted to enter between the under surface of the work and the thread leading from the needle-throat to the last stitch, and the otheriof said blades being disposed at the same side of the first mentioned blade as the last stitch.
21. A sewing machine having, in combination, stitch-forming mechanism including a needle, a turret, and loop-taking means mounted on the turret, a 'work-holder including lower work-supporting plates and upper clamping feet, a buttonhole cutter, means for effecting a relative shift between the stitch-forming mechanism and workholder subsequent to the sewing operation to afford clearance for the operation of the buttonhole-cutter, and a thread-cutter mounted at the same side of the work as the turret and including a thread engagingV blade operating in a plane transverse to the plane of the work-supporting plates and between the sewing point and the cutting position of the buttonhole-cutter.
22. A buttonhole sewing machine having a frame comprising a bed and bracket-arm, stitch-forming mechanism, a work-holder, means for relatively moving the stitch-forming mechanism and work-holder to sew around a buttonholc and to relatively separate the buttonhole and stitch-forming mechanism lengthwise of the machine-bed subsequent to sewing, thereby drawing out a length of vthread from the needle-throat, and a thread-cutter including a blade pivoted on an axis extending lengthwise of the machine-bed, said blade being adapted to sever said length of thread.
23. A sewing machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental looptaking means mounted at opposite sides of the plane of the work. a thread-cutter carrying lever pivotcd at the loop-taker side of the work on' an axis transverse to and in substantially intersecting relation with a line normal to the plane of the work at the sewing point, and a thread-cutter including a pointed blade mounted on said hner and adapted .when said lever is swung on its pivot to enter between the under surface of the work and the thread leading from the last stitch to the sewing point, for severing such thread.
24. A sewing machine having, in combination, stitch-forming mechanism including a reciprocating needle and complemental looptaking means mounted at opposite sides of the plane of the work, a thread-cutter carrying lever pivoted at the loop-taker side of the work on an axis transverse to and in substantially intersecting relation with a line normal to the plane of the work at the sewing point, and a thread-cutter including a scissors device mounted on said lever, one
ofthe blades of said scissors device being adapted when said lever is swung on its pivot to enter between the under surface of the work andthe thread leading from the last stitch to the sewing point, and means for closing said scissors device to sever the thread. i
25. A buttonhole sewing machine having, in combination, stitch-forming devices including needle and loop-taker mechanisms having a predetermined period of action, said loop-taker mechanism operating to retain a loop of needle-thread at the under side of the Work when the stitch-forming devices come to rest, a thread-cutter mounted below the work for travellingmovcment toward and' away from the stitch-forming mechanism and adapted to sever both limbs of suchretaining loop, and means including a thread-engaging device movable with such thread-cutter toward and away from the stitch-forming mechanism for seizing such loop vand removing it from the field of action of the stitch-forming mechanism.
26. A buttonhole sewing machine having, in combination, stitch-forming devices including needle and loop-taker mechanisms havlng a predetermined period of action,
said loop-takery` mechanism operating to retain a loop of needle-thread at the under side of the work when the stitch-forming devices ycome to rest, means for severing both limbs of such retained loop, and a threadgripper having relatively separable jaws Vadapted to seize such loop and remove it from the field of action ofthe stitch-forming mechanism.
c 27. A buttonhole sewing machine having, in combination, stitch-forming devices 'including needle and loop-taker mechanisms having a predetermined period of action, said loop-taker mechanism operating to retain a loo of needle-thread when the stitchforming evicescome to rest, a thread-cutter below the work for severing both limbs of such retained loop, and a thread-gripper, carried by said thread-cutter and o eratlng to seize such loop and remove it rom the field of action of the stitch-forming mechanism.
28. A buttonhole sewing machine having, in combination, stitch-forming devices including needle and loo -taker mechanisms having a predetermine period of action, said loop-taker mechanism operating to retain a loop of needle-thread when the stitchforming devices come to rest, means for severing both limbs of' such retained loop, a thread-gripper having separable jaws adapt ed to seize such loop and remove it from the field of action of the stitch-forming mechanism, a buttonhole-cutter, and connections between said buttonhole-cutter and the gripper for actuating the latter.
29. Arbuttornhole sewing machine having, in combination, stitch-formin devices, including needle and loop-taker mechanisms, a stop-motion, said loop-taker mechanism operating to retainaV loop of needle-thread when thexstitch-forming mechanism Acomes 'to rest, means for severing both limbs of the retained needle-loop, a gripper including a spring-pressed jaw for seizing said loo for removal from the field of action o lthe stitch-forming mechanism, a latch for hold- .ing said jaw open, and. means for tripping said latch when the ing position. d
,i 30. A buttonhole sewing machine having, in combination,,stitch-forming devices, including needle and loop-taker mechanisms, a` stop-motion, said loop-taker mechanism operating to retain a loop of needle-thread when the stitch-forming mechanism comes to rest, a buttonhol'e-cutter, means for severing both limbs of the retained needle-loop, a grlpper including a spring-pressed jaw for seizing said loop for removal from the field of action of the stitch-forming mechanism,
gripper is in loop-seiz- -a latchVA for holding `said jaw. open, and Vmeans on the buttonhole-cutter for tripping Said latch.y
31. A buttonhole sewing machine having, in combination, stitch-forming devices, including needle andloop-talrer mechanisms` a stop-motion, said loop-taker mechanism operating to retain a loop of needle-thread when the stitch-forming mechanism comes toy rest, means for severing both limbs of the Vretained needle-loop, a gripper for seizing 32. A buttonhole sewing machine having, y
in combination, a work-holder, stitch-form ing devices including upper thread mechanism, under thread mechanism, and a turret on which the under thread mechanism is mounted, a needle-throat mounted on said turret and adapted to guide a stay-cord to the stitch-formm mechanism, means adapted at the en`d o the sewing operation to sever the cord between the needle-throat and the Work, and meansfor arresting the feed of the cord during the formation of the initial stitches of the buttonhole, said. means being timed to release the cord when the end thereof is substantially even with the initial stitches.
33. A buttonhole sewing machine having, in combination, stitch-forming mechanism, a work-holder, a feed-wheel, a stay cord guide adjacent the lstitch-formingl mech` anism, means for arresting the feed of the cord duringthe formation of the initial stitches, and means for severing Ythe cord between said guide and the work subsequent to sewing. j
34. A' buttonhole sewing machine having, in comibination, stitch-forming mechanism, a work-holder, a feed-wheel and connections with the stitch-forming mechanism through which the feed-wheel is driven during the sewing to space the stitches around the buttonhole, a stay cord guide adjacent the stitch-forming mechanism, means for severing the stay cord between'said guide and the work subsequent to sewing, and 4a stay7 cord nipper connected to the feed-wheel for arresting the feed of the cord during the formation of the initial stitches.
35. A buttonhole sewing machine having, in combination, a Work-holder, stitch-forming mechanism. including upper thread mechanism, under thread mechanism, and i a turret on which the under thread mechanism is mounted, a needle-throat mounted on said turret and formed with a sta cord delivery aperture, means acting at t e end,
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US523056A US1579200A (en) | 1921-12-17 | 1921-12-17 | Thread-cutter for sewing machines |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US523056A US1579200A (en) | 1921-12-17 | 1921-12-17 | Thread-cutter for sewing machines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US1579200A true US1579200A (en) | 1926-04-06 |
Family
ID=24083489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US523056A Expired - Lifetime US1579200A (en) | 1921-12-17 | 1921-12-17 | Thread-cutter for sewing machines |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US1579200A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4784072A (en) * | 1986-04-23 | 1988-11-15 | Dorina Nahmaschinen Gmbh | Sewing machine handle operated threading device |
-
1921
- 1921-12-17 US US523056A patent/US1579200A/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4784072A (en) * | 1986-04-23 | 1988-11-15 | Dorina Nahmaschinen Gmbh | Sewing machine handle operated threading device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2298246A (en) | Machine for attaching articles | |
| US1579200A (en) | Thread-cutter for sewing machines | |
| US1988460A (en) | Buttonhole sewing machine | |
| US1816308A (en) | Thread-cutting mechanism for sewing machines | |
| US1999145A (en) | Article-attaching machine | |
| US1841102A (en) | Thread-cutting mechanism for sewing machines | |
| US2335827A (en) | Article attaching machine | |
| US1711483A (en) | Thread-controlling mechanism for buttonhole-sewing machines | |
| US1369371A (en) | Thread cutting and nipping mechanism for sewing-machines | |
| US1820569A (en) | Thread trimmer for sewing machines | |
| US2499335A (en) | Thread-trimming and pull-off mechanism for sewing machines | |
| US1255970A (en) | Sewing-machine. | |
| US1373227A (en) | Button-sewing machine | |
| US2161140A (en) | Sewing machine | |
| US1401973A (en) | Thread cutter for sewing machines | |
| US1352514A (en) | Sewing-machine | |
| US1234258A (en) | Thread cutting and holding device for sewing-machines. | |
| US798130A (en) | Thread cutting and holding device for sewing-machines. | |
| US2210638A (en) | Thread and cord trimmer for buttonhole sewing machines | |
| US2070029A (en) | Thread-cutter for sewing machines | |
| US1346814A (en) | Thread-severing mechanism for sewing-machines | |
| US1743356A (en) | Thread trimmer for sewing machines | |
| US1600206A (en) | Buttonhole-sewing machine | |
| US1938128A (en) | Thread-cutting mechanism for sewing machines | |
| US1406742A (en) | Sewing machine |