US2301798A - Thread-trimming mechanism for buttonhole sewing machines - Google Patents

Description

Nav. 10, 1942. E. P. SPAINE #2,301,798

THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 21, 1940 1l Shet `s-Sheet 1 grwMwo/o award @,jain@ wm am E. P. SPAINE Nov. 10, 1942.

THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 2l, 1940 11 Sheets-Sheet 2 (giward ,Dm/free NV-A10, l942- E. P. sPAlNE 2,301,798.

THREAD-THINKING IIECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 2l, 1940 11 Sheets-Sheet 3 Nov. l0, 1942. E, P. sPAlNE 2,301,798

'. -THREAD-TRIMING MECHANISM FOR BU'IITONHOLE SEWING MACHINES Original Filed Sept. 21, 1340 i 11 Sheets-Sheet 4 Nov. 10, 1942. E. P. sPAlNE 2,301,798

THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 2 1, 1940 ll Sheets-Sheet 5 @ward /gaz'fzei 95 LQM @www Nov. 10, 1942.

E. P sPAlNE THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 2l, 1940 1l Sheets-Sheet 6 Se im ward g3,

Noi. l0, 1942. E. P. sPAlNE i l 2,301,798

THREAD-TRIMMING MECHANISM FOR BUTTONHGLE. SEWING MACHINES Original Filed Sept. 21, 1940 ll Sheets-Sheet 7 l ik MM @D @am @M Q 7M Citta/meg.

NOV- 10, 1942. E. P. sPAlNE 2,301,798

THREAD-THINKING MECHANISM FOR BUTTONHOLE SEWING MACHINES original Filed sept. 21, 1940 11 sheets-sheet 8 E. P. SPAINE Nov. l0, 1942.

THREAD-TRIMMING MECrIANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 21, 1940 l1 Sheets-Sheet 9 THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 2l, 1940 l1 SheetsUSheet 10 11H1 f 56k 3mm t @amphi 'QJ/@2204x5529 Nov. l0, 1942. E. P. sPAlNE THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original Filed Sept. 2l, 1940 1l Sheets-Sheet l1 nl M EMM w m Mm 9&0. 3 y L. w, w 1 w. Zw. Fw/d m MVP c Patented Nov. l0, 1942 THREAD-TRIIWMIN G MECHANISM FOR BUTTONHOLE SEWING MACHINES Edward P. Spaine,

Bridgeport, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Original application Sep tember 21, 1940, Serial Divided and this application June 12, 1941, Serial N0. 397,682

(Cl. 11B- 252) 7 Claims.

This invention relates to buttonhole sewing machines of the adjustable automatic type which cut and sew buttonholes of variable length within the range of the machine. Such a machine is disclosed in my copending application, Serial No. 357,698, nled September 2l, 1940, of which this application is a division.

The present invention has for an object to provide improved needle-thread trimming mechanism particularly adapted for an adjustable automatic buttonhole sewing machine of the above described type, which thread-trimming mechanism will cut and hold the needle-thread between sewing periods, releasing the needle thread and at the begining of a sewing operation and so controlling the needle-thread that the beginning end thereof will be drawn down flush withi the work.

Another object of the invention is to provide the thread-trimmer with improved actuating mechanism to avoid clashing with the needle `or parts of the work-clamp.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying-drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In order to understand the construction and mode ot operation of the present invention it is necessary to describe the details of construction and mode of operation of the automatic buttonhole sewing machine in which it is embodied, as

set forth in my said copending application.

Oi the accompanying drawings, Fig. 1 is a right side elevation of a buttonhole sewing machine embodying the invention. Fig. 2 is a detail view of the thread-cutter actuating cam mounted on the one-revolution cross rotary shaft located. in the machine-bed. Fig. 3 is a left side elevation of the machine. Fig. 4 is a front end elevation -oi the machine with the lower plates of the workclamp in transverse section. Fig. 5 is a rear end elevation of the machine. Fig. 6 is a diagrammatic representation of a square-bar buttonhole produced by th'e machine. Fig. 7 is a bottom plan view of the machine. Fig. 8 is a horizontal section through the bracket-arm standard of the machine at the level of the buttonhole cutter shaft and with the separable sections of the workclamp removed from the machine-bed. Fig. 9 is mechanism shown Fig, 8, at the period of the buttonhole producing cycle when the stop-motion latch is tripped to stop the stitch-forming mechanism at the close of the return side-stitching i operation on a -buttonho1e.

Fig. 10 shows the stop-motion latch holding the shiftable stop-motion lever in running position. Fig. 11 is a top plan view of the longitudinal feed-cam and connections actuated thereby, including the longitudinal feed uncoupling device an'd the auxiliary mechanism for returning the work-clamp to initialposition after a buttonhole has been stitched. Fig, l2 is a disassembled perspective view of the longitudinal feed disabling connection or coupling.` Fig. 13 is a section substantially on the line l3l3, Fig. 1l. Fig. 14 is a section substantially on the line i4-l4, Fig. 11. Fig. 15 is an inside face view of the auxiliary work-clamp return cam and follower connections which are shown in top plan in Fig. il. Fig. 16 is an outer face view of the ad- Justable pattern-wheel which is mounted at the left side of the machine-bed, externally of" the latter. Fig. 17 is a sectional view substantially on the line l1-l|, Fig. 7. Iliig 18 is a sectional view of the pattern-wheel on the line |8-l8, Fig.-

16. Fig. 19 is a sectional view of the patternwheel on the line I9-|9, Fig. 16.

Fig. 20 is a sectional view of the pattern-wheel on the line 2li-20, Fig. 16. Fig. 21is a perspective view of the removable and replaceable barstitch-controlling section of the lateral feed-cam in the pattern-wheel. Fig.,22 is a plan view of the back-feed and locking means for the longitudinal slide-frame of the work-clamp, taken just ,before the vback-feed is accomplished. Fig. 23 is a similar view taken just after the back-feed is accomplished. Fig, 24 is a perspective view of the pattern-wheel, complete. Fig. 24l is a fragmentary elevational view of the pattern-wheel showing the bar-stitch start-and-stop control segments for the stitch-forming mechanism. Fig. 25 is a disassembled perspective view of the pattern-wheel. Fig. 26 is a development of the lateral feed-camsgroove in the pattern-wheel. Fig.

27 is a. central longitudinal section of the develop..

ment shown in Flg.26. Fig. 28 is an enlarged view of the needle-thread-cutting mechanism shown in Fig. 4. Fig, V29 is a transverse sectional view of the thread-cutting and thread-nipping blades of the thread-cutting mechanism.

Fig. 30 is an elevation of the thread-cutting mechanism, the reverse of that shown in full lines in Fig. l28. Fig. 31 is a top face view of a plan view oi' the stop-motion latch-tripping 55 the thread-wiwi' blade'hOldeI' Complete F18 32 is a similar view of the thread-cutter bladeholder, with the cover-plate removed. Fig. 33 is a view of the cover-plate for the parts shown in Fig. 31. Fig. 34 is a section on the line .3d-34, Fig. 31. Fig. 35 is a sectional view on the line -35-35, Fig. 34. Fig. 36 is a perspective view of the thread-cutter supporting bracketshown in Fig. 30, and Fig. 37 is a disassembled perspective view of the thread-cutter swing-controlling cam and associated parts, shown in Fig. 30.

The machine is constructed with a frame including the hollow box-like bed I from one end of which rises the standard 2 of the overhanging bracket-arm 3 terminating in the head 4.

The stitch forming mechanism is constructed substantially in accordance with the disclosure of U. S. Patent No.` 1,372,473, dated March 22, 1921, and comprises the usual upper endwise reciprocatory and laterally vibratory needle 5 and under thread-looping devices including the threaded looper 6 and loop-retainer 1, which upper and under stitch-forming devices are mounted to turn about a vertical axis, as in placing the stitches radially about the eyelet-end of a buttonhole. The well known mechanism for turning the stitch-forming devices about a vertical axis is constructed substantially in accordance with the disclosure of U. S. Patent No. 1,162,207, dated November 30, 1915; No. 1,534,017, dated April 2l, 1925 and said reissued Patent No. 15,324. The mechanism includes the intercannected upper and lower sector gears 8 and 9 and the stitch-rotating cam-groove Il), Fig. 7, which is cut in the under face of the main feedwheel II mounted as usual in the bed I.

The stitch-forming devices are driven as usual from the main sewing shaft I2 which `receives power from the continuously running belt pulley I3 through a known form of clutch I4 controlled by the usual stop-motion lever l5 which is tiltable with its supporting rock-shaft I6 from full line or stop sewing position, Fig. 3, to dotted line 'or running position, to start the sewing operation. The stop-motion lever I5 is biased to stop sewing position by the spring I1 and, when permitted, will automatically resume its stop sewing position.

When the stitch-forming mechanism is being driven, the main feed-wheel II receives a slow step-by-step motion through the gears I3, Fig. 7, from the pin-and-star wheel device i9 which is driven by the main sewing shaft l2 in the usual manner through the bevel gears 20 and vertical shaft 2I from which the upper or needleoperating shaft 22 is driven. The main feedwheel II is permanently connected by the large bevel gears 23 to the cross rotary shaft 2li in the bed I which cross rotary shaft carries the adjustable pattern-wheel Zito be more particularly described.

The work-clamp is o f the travelling type and is constructed substantially in accordance with said reissued Patent No. 15,324. It comprises the lower clamp-plates 26 and the upper clampfeet 21 which are depressed into clamping engagernent with the work by the connected rockshaft sections28, 29, Fig. 4, the former of which is connected to an arm 30, Fig. 1,- adapted to be depressed by the usual clamp-closing lever 3i actuated at the beginning of a buttonhole-making cycle by a cam-groove 32, Fig. 5, in a continuously running belt-pulley 33 loose on the buttonhole cutter shaft 34. A slide-pin 35, carried bythe rearwardly extending arm 36 of the clamp-closing lever 3l is permitted to enter the feed-cam groove 39 in the main feed-wheel II operating on the follower lever 40 fulcrumed at 4I on the bed I and connected at its free end through a disconnectible coupling device c, Fig. 12, to the longitudinal slide-frame 38.

The disconnectible coupling device c, whereby the longitudinal feed of the machine may be disabled, comprises the block 42, Fig. 12, having at one end an ear 43 by which it is pivotally connected at 44 to the free end of the lever 40. Drilled in and longitudinally of the block 42 is a hole 45' which slidably receives the pin 45 having at one end a head 46 which is pivoted at 41 to the block 48 screwed to the under side of a member of the longitudinal slide-frame 38 of the work-clamp.V Journaled on the block 42 is a spring-biased rock-shaft 49 having rigidly mounted thereon a safety latch-arm 50 received in a safety recess 5I in the side of the pin 45. The rock-shaft 49 also rigidly carries a latcharm 52 which engages behind the lug 53 on the side of the head 46 of the pin 45 when the safety latch 50 enters the notch 5I. At this time the head 46 of the pin 45 is in engagement with the proximate end of the block 42 and is locked there by the latch 52. The safety notch 5I and arm 56 prevent interference between the latch 5' and lug 53 until the lug 53 reaches a position where the latch 52 is free to drop in behind it, Fig. 11. Fast to therock-shaft 49 is the upstanding operating arm 54 which extends across the outer edge of the lever arm 55, Fig. 3, fast on the vertical rock-shaft 56 journaled in brackets 51 at the left hand side of the bed I. The rock-shaft 56 also has fast thereto the rearwardly extending stopmotion-latch-tripping arm 58 and the forwardly extendingY arm 5,9 which is acted upon by the cam-rise 60 on the pattern-wheel 25.

The stop-motion lever I5 is, at times, latched in running position by the spring-biased latch lever 6I which is fast on the vertical rock-shaft 52 journaled at the rear end of the bed I. The lever 6I has a notch aording a locking shoulder 53 engaged by the angle-piece 64 on the arm 65 depending from and fast on the rock-shaft i6 which carries the stop-motion lever I5. The rock-shaft 62 also carries the lever-arm 66 having a roller 61 in position to be engaged by the stop-motion latch-tripping arm 58, as shown in Figs. 9 and 10.

Means are provided to lock the longitudinal slide-frame of the work-clamp against movement on the bed I whenever the longitudinalfeed coupling c is disconnected. To accomplish this, there is securd to the longitudinal slideframe 38, Fig. 9, a rearwardly extending bar 68, I

- hole.

ly, thus imparting a small reverse movement or second or return side stitching operation of the buttonhole, before the barring operation.

The lateral feed motions of the work-clamp which are compounded with the longitudinal feed-motions of the work-clamp to sew around a buttonhole are, in the present machine derived from the lateral feed-cam groove 13 in the pattern-wheel 25. The cam-groove 13 is entered by the lower end of the slide-bolt 14 which is carried by the lateral feed-lever 15 fulcrumed at 18 on the bed I and carrying at its forward end a block 11 which is received in the longitudinal slideway 18 in the block 19 screwed to the crossslide plate 31. The slide-bolt 14 is carried in the cylindrical boss 80 at the rear end of the lever 15 and has a finger-piece or pin 8l projecting laterally from it through an inverted L-shaped slot 82, Fig. 16, in the boss 80. When this pin 8| is turned into the vertical leg of the inverted L-shaped slot, it is depressed by the leaf-spring 83 to the lower end of such slot, In this position the slide-bolt 14 is free to ride the bottom of the lateral feedcam groove 13 and to follow and be controlled by said cam groove even in the regions 84 where the cheeks of said groove are cut away to a certain radial extent or level. When the slide-bolt is raised to its higher level and the finger-piece 8| thereof turned into the horizontal portion of the inverted L-shaped slot 82, Fig. 16, the slide-bolt still runs in the cam groove 13 and is controlled thereby in all regions thereof except the region 84 where the cheeks or side walls of the cam groove 13 are cut away. It is in this region that the cam groove 13 controls the lateral feed of the work-clamp in sewing around the eyelet end of the buttonhole. When it is desired to produce a straight buttonhole, that is, a buttonhole having no eyelet end, the slide-bolt is raised to its higher position, Fig. 16, so that it is not under the control of the cam-groove 13 when encountered by the cut away side-portions 84 at the eye-forming portion thereof. At this period of the cycle the travelling key 85 on the bracket 86 fastened to the longitudinal slide frame 38 enters a diametrical slot 81 in the upper end of the slide bolt 14 and locks the work-clamps against lateral displacement when out of control of the lateral feed-cam groove 13. When in its lower position lthe slide bolt 14 is not encountered by the locking key 85. Thus, by setting the slide bolt 14 in either of two positions, the machine may be made to produce either an eyelet-end or a noneyelet-end buttonhole, at the will of the operator.

The longitudinal feed-cam groove 38 is designed to impart to the work-clamp a certain fixed overall longitudinal motion. At the start of a buttonhole-producing cycle the work-clamp occupies a position at one extreme end of its range of longitudinal traveling movement, known as buttonhole-cutting position.` When the machine is started, the connected feed and pattem-vcheels H, 25, are at rst driven by a rapid-feed driving mechanism to carry the work-clamp quickly from starting position to the point of its longitudinal motion where the stitching is to begin. When this point is reached the stitch-forming mechanism is started and the rapid-feed drive is thrown out. The stitching then progresses down the first sidev of the buttonhole, around the eyelet-end and back along the return side of the buttonhole to a point adjacent the rst stitch, at which point the .stitch-forming mechanism is stopped. In machines of the prior` art adapted to sew unbarred buttonholes of variable length it is customary at this point to throw in the rapid feed driving mechanism to effect a quick return of the workclamp to its initial position (buttonhole cutting position). In other machines of the prior art adapted to sew taper-barred buttonholes of variable length such, for example, as the machine of U. S. Patent No..2,190,614; February 13, 1940, the lateral feed-cam includes two barring camsections which are peripherally adjustable to vary the timing of their operation in the longitudinal travel of the work-clamp,

The present machine works on a different principle. Here, the lateral feed-cam has only one barring cam-section 88, Figs. 18, 21, 26 and l2'?. This barring cam-section is fixed in its timon the pattern-wheel as to encounter the follower slide-bolt 14 as soon as practicable after completion of the return side stitching operation of the longest buttonhole within the range of the machine. For shorter barred buttonholes, instead of providing for a change of timing of the barring cam-section 83 by adjusting it peripherally of the pattern-wheel, it is, in the present machine, retained in a fixed position on the pattern-wheel and, when the return side stitches of the buttonhole are completed, the sewingmechanism is stopped, the work-clamp is disconnected from the longitudinal feed-cam and locked against longitudinal shift. The rapid-feed is thrown into drive the feed-cam system idly around to bar-stitch sewing position, whereupon the sewing mechanism is again started and stopped to sew the bar. After this, the rapid feed-drive is again thrown in to operate an auxiliary mechanism toreturn the work-clamp to its initial or buttonhole cutting position where it is reconnected to the longitudinal feed-cam in readiness for the next buttonhole-producingcycle.

In the work of the present machine, the bar is what is known as a square-bar. That is, it is sewn square across the end of the buttonhole. Tp accomplish this, itis preferable that the sewing mechanism be turned about its vertical axis, say between the time of completion of the last side stitch and the rst bar stitch. 'I'here is thus an intimate timed relationship between the barring cam-section 88 on the pattern-wheel and the eccentric stitch-rotating portion I0' of the stitch-rotating cam-groove lil in the main feed-wheel I l. This relationship is not disturbed by any adjustment of the present machine. The timing is made right for the longest buttonhole within the range of the machine and, for shorter buttonholes, the cam-system is rapidly and idly turned variable angular distances, depending upon the length of the buttonhole, from the variable 'position wher'e the sewing mechanism is stopped at the completion of the return sidestitching operation, to an invariable barring` position.

The pattern-wheel with which the present machine is equipped comprises a main supporting disk 89 having avlarge cylindrical extension 90 constituting a bearing or arbor for a pair of internally toothed rings 9|, 92. These rings are held on the arbor 90 by the face-plate 93. Journaled in the coaxial holes in the disk 99 and faceplate 93 is` the shaft l94 to which is fixed the 94 is fitted with the knurled head 90 by which it may be turned to adjust the rings 9|, 92 simultaneously and to equal extents in opposite directions upon and relative to the disk 89. The rings may be clamped in adjusted position by the clamp-nut 99 and pressure head |00, Fig. 19, carried by the small plate IOI under the nut 99 which is threaded upon the bolt |02 passing through the disk 09.

The inner ring 92 carries the start-sewing cam rise segment |03 the outer edge of which engages the follower nose |04 of the lever |05, connected by the link |06 to the lever arm 55 of the stop-motion device to shift the stop-motion lever I5 to its dotted line or running position Fig. 3; the cam-segment |03 having a total height suiilcient to shift the lever-arm 55 far enough for the shoulder 53 of the latch-lever 5I to engage the angle piece 94 and latch the stopnotion lever I5 in running position. As shown, the cam-segment |03 has a rather abrupt nose which initially engages the follower |04 and has a rise suilicient to shift the levers 55 and I5 far enough to start the sewing mechanism but not far enough to allow the latch 5| to drop into retaining position relative to the lever 95. The abrupt nose of the cam-segment |03 is followed by a more gradual rise terminating ai; the crest |03' which is high enough to permit engagement of the shoulder 53 of latch 6I with the anglepiece 54 on lever 65. This provides an easy metion of the parts to sewing position and relieves the parts 'of undue strain. The outer ring 9i, Fig. 25, carries the stop-sewing cam 80 which trips the latch 9| at the end ofthe return side stitching operation. The cam has an arcuate tail portion |01 which holds the follower-lever 59 and longitudinal slide-frame locking tooth 1| in the locking position, Fig. 9, until after the bar Ais] sewn. Each oi the elements |03 and 60 is peripherally adjustable upon its respective ring carrier 92 and 9|, as shown in Fig. 25.

There is screwed to the face-plate 99 a segmental plate |00 which is thick enough to meet the operative edge of the tail-piece |07 of the longitudinal slide-frame locking carri and hold the lock on, after the tail-piece |01 rides beyond the follower-lever 59. The segmental plate has an end shoulder |09 which finally releases the follower-lever 59 to unlock the longitudinall slideframe and release the latch-lever 54 of the coupling device c, between the longitudinal slideframe andthe longitudinal feed-cam lever 40.

This occurs in the inal rapid-feed of the camsystem after the bar-sewing operation is conipleted.

The present machine may be adjusted to sew buttonholes with or without an eye and to sew around or to suspend sewing at the eye end. To

sew a buttonhole without an' eye and with sewing suspended, means are provided to stop and start the sewing operation at the eye end of the buttonhole. To this end the locking bar 58 extending rearwardly from the longitudinal slide-frame '3s is steed at its free end with a cross slide pm I0 'which may be manually shifted from inoperative position shown in full lines in Figs. 5, 8 and 9 to dotted line position, Fig. 8, where its enlarged head-end H0 is effective to engage the reduced upper end 61" of the roll 51 and trip the latch-lever 6| to release the stop-motion lever I5 and stop the stitch-forming mechanism, when the longitudinal slide-frame nears the end of its initial travelling movement. The cross slide pin ||0 is mounted in a block H0, Figs. 3 and 8, which is mounted for adjustment on and lengthwise of the longitudinal slide-frame extension bar 6l, by the usual screw ||0b and slot ||0 expedient. Thus, the point at the end of the buttonhole where the ilrst side stitching operation may be stopped, is variable by adjustment of the slide-pin ||0 lengthwise of its carrier bar 50.

To start the sewing mechanism for the sewing of the return side of the buttonhole there is adjustably mounted on theI pattern-wheel disk 09 a start-sewing cam-segment ||I which is in the same plane as the cam-segment |03 previously described and, like the latter, has an abrupt nose followed by a gradual rise sufilcient to shift the stop-motion lever to a position where it will be retained in runningposition by the latchlever 6|, after the segment rides beyond the follower-nose |04'.

There is screwed to the thick segmental plate |08 a thinner segmental plate ||2 which has a cam-incline ltimed to engage and operate .the lower horizontal leg ||4 of the needle-thread tension-release lever l| I5 ata time in the cycle immediately after completion of the bar sewing operation and 'substantially simultaneous with the unlocking of the longitudinal slide-frame. The needle-thread tension-release mechanism between'the levergI I5 and the tension device Iii is of usual construction and is disclosed in U. S. Patent No. 2,165,016, July 4, 1939. When the machine is at rest, Fig. 3, the needle-thread tension device ||Q0 "is held released. It is restored during the initial rapid feed of the work-clamp from buttonhole cutting position to the position where sewing begins; when the machine is set to produce the longest buttonhole Iwithin its range.

To start and stop the stitch-forming mechanism for the sewing of the bar there is secured directly to the pattern-wheel body-disk the segmental plates II'I, IIB, the former presenting the start-bar-sewing cam-rise II9 and the latter the stop-bar-sewingf drop-oi! shoulder |20 which plates ride under and are engaged bythe follower nose |04 oi the stop-motion control lever |05. The outer radially coincident edges of the segmental plates |I1 are not high enough-to displacethe stop-motion lever 65 far enough for engagement of the latch II with the angle-plate El, consequently the follower-nose |04 rides the coincident circular edges of the segmental plates ||`I, iI throughout the bar-sewing period and the sewing stops when the nose |04 drops o1! of' the shoulder |20. The plates'I II, III are secured to the body disk 09 by the screw |2I which passes through arcuate slots in the plates Ill, ||3 permitting independent timing adjustments thereof. The purpose for these adjustments is to compensate for either an increase or decrease of the width of bight of the sewing, or width of buttonhole cutting space between the side stitches of the buttonhole, which changes would call for an increase or decrease in the length of the stitched bar. Also, theseadjustments permit the bar to be shifted to the right or left of the buttonhole.

'stitched and barred, the longitudinal slidevcutting position. To this end there is provided an' auxiliary clamp-shifting mechanism, as follows:

Cut in the inner face oi' the bevel gear 23 on the cross rotary shaft 24 of the cam system of the machine is the cam-slot |22, Fig. 15, entered. by the follower roll |23 on the vertical lever-|24 fulcrumed at |25 on the frame-bracket |24. 'I'he lever |24 is connected by the link |21 to the horizontal lever |25, Fig. 11, fulcrumed on the bearing stud |25 which supports the main feed-wheel Il and carrying at its' free end a roller stud |30-in position to engage and operatethe floating intermediate lever |3| fulcrumed at |32 on the bed i. The lever |3| floats between the roller stud |30 and the head 45 of the coupling rod 45 which pivotally carries the block 41 screwed to the 1ongitudinal slide-frame 35. The function of the floating lever |3| is to transmit the rather sharply curved or arcuate motion of the roller-stud |30 on the lever |28 to the rectilinearly movable head 45 of the coupling rod 45 in pushing the longitudinal slide-frame back to initial position. The portion of the cam-slot |22 from a to b, Fig.A 15, acts to restore the longitudinal slide-frame to initial position, while the portion from d to e is shaped to withdraw the lever |25 from the oating lever 3| fast enough to avoid blockingthe After the buttonhole has been completely.

advance of the longitudinal slide-frame under the influence of thelongitudinal feed-cam 39 early in a buttonhole-producing'cycle. `When the lever 59 is released by the patternwheel shoulder |59 to unlock the longitudinal slide-frame and release the latch-lever 54 'from its dotted line position, Fig. 14, the rock-shaft 49 and safety latch-arm 59 immediately move under the influence of their biasing spring until the nose of the lever 5l engages the cylindrical wall of the coupling rod 45 on lwhich it rides until the rod and longitudinal slide-frame 35 are restored to initial position, whereupon the nose 50' drops into the'safety-noich 5|, as shown in Fig. 14, and the latch-arm 52 engages behind the latter to the block 42. 'I'his re-connects the longitudinal slide-frame 35 to the longitudinal feedcam 39. When the machine is at rest, Fig. i1, the lever |29 and follower-roll |30, with the floating intermediate lever |3| are at one extreme posltion and serve to lock the longitudinal slideframe against movement from initial position until the machine is started, whereupon the follower-roll |30 is withdrawn as above explained.

'I'he rapid feed mechanism is called upon to operate at least three times in the buttonholeproducing cycle of the presentmachine; first, to

'lug 53 on the slide-pin head 45 and locks the rapidly shift the work-clamp from buttonhole- ..79

over to y release the l toothed lever |54 cutting position to a is to begin; second, toidly turn the feed-cam system to barring position at the close of the return side stitching operation; and third, to restore the work-clamp to buttonhole-cutting posi-I tion after the bar is sewn. It may be called upon to operate to rapid feed at the eye end of a noneyed buttonhole, 1n case the machine is set to stop the sewing near the end of the first sidestitching operation by setting the slide-pin `I i0 in its dotted line position, Fig. 8. A

'I'he rapid-feed drive of the connected feedcam and pattern-wheel 25, is accomplished by the constantly running rapid-feed drive-shaft operating levers,.the clutch is engaged and the shaft -24 is coupled to its drive-shaft |33 or. in other words, the rapid-feed is thrown in. This rapid-feed mechanism is, so far, constructed substantially in accordance with the disclosure of said U. S. Reissue Patent 15,324. The clutch-operator is constituted by a crossslide rod |4I carrying an arm |42 having at its free end a fork |43 which engages the grooved hub of the cone |40. The cross-slide rod |4| is biased by the coil-spring |44 in a direction to throw out the rapid-feed. 'I'he rod I4| is shoved endwise against the pressure of the spring |44, to throw in the rapid-feed. by the continuouslyreciprocating push-bar 45 which is pivoted at |45, Fig. 5, to the arm |41 of a bell-crank |45 actuated by the crank |49 the rapid-feed drive-shaft |33. The push-bar |45 is held by the latch |50 in .a depressed position, Figs. 1 and 17, where it may reciprocate idly. When the latch |50 is swung push-bar |45, the latter is drawn upwardly by its spring |5|, effecting engagement oi the stud-pin |52 on the cross-slide shaft i4| by the shoulder |53 on the push-bar |45 whichthereupon shoves the cross-slideshaft `|4| to its extreme rapid-feed throw-in position in which it is retained by engagement of the shoulder |54 on the latch-lever |55 by the lower edge of the plate |55 on the hub of the forked arm |42.

The latch |50 is engaged by a lever-arm |51 on Ithe rock-shaft |55 which is journaled in thebed i and has rigidly connected to it two arms |59, |50 by means of which it may be operated to throw in the rapid-feed. The first mentioned arm |59 carries a spring-pressed tripping tooth ISI which is engaged and depressed bythe pin |52 on the downwardly extending arm |53 of the three-armed clamp-closing lever 3|, 35, |53,

which at the beginning of. a buttonhole-prov ducing cycle receives an impulse from a clampclosing cam-groove in the inner face of the continuously running belt-pulley33 loose on the buttonhole-cutter shaft 34,l previously referred to. The seoondmentioned arm |50 of the rock-shaft |58 is actuated to throw in the rapid-feed by the which engages the arm |50 whenever-` the stop-motion lever l5 acts to stop the sewing operation. The actuating mechanism for the toothed lever is the same as that disclosed position where the sewing lateral extension The throw-out of the rapid feed is accomplished by tripping the latch-lever |55 to release the spring-biased clutch-operator slide-rod |4|. The latch-lever |55, Figs. 5 and 11, has an extension 6 2,301,798 -m' u.' s. Patent No. 1,504,306, of august 12, 1924.

|65 which enters the forked end |69 of a lever |61 fulcrumed at |69 on the inner wall of the. bed I. 'I'he lever |61 has a free end portion |69 which is in position to be engaged by the -rapidfeed throw-out tooth |10 fixed on the inner face o1' the pattern-wheel 29. The tooth |10 is the tooth which throws out the final rapid-feed ac- .,tign after the work-clamp has been restored to 'f tuttocuore-cutting position at the close or a butltombale-producing cycle. `All of the rapid-feed'- actions in the present machine which precede this iinal rapid-feed action are terminated by the shift of the stop-motion control link |09 through the usual mechanism disclosed in U. S. Patent No.

2,190,614, February 13, 1940. s'uen mechanism includes the upstanding link-actuated lever |'1|, Fig. 1'7, fulcrumed on the screw |69 and having a thrust-bar |19 which is fulcrumed at |14 be- Vtween the spaced ears rigid with the lever |61. 'Further details of this known mechanism are fully disclosed in said U. S. Patent No. 2,190,- 614 and need not be more particularly described herein. It will sufce to explain that every time thelink |06 is shifted endwise to start the sewing mechanism, the immediately preceding rapid-feed action is automatically thrown-out by action of the lever |1| on the lever |61 through the thrustbar |13. This automatically takes care of (1) the `discontinuance of the initial rapid feed of the work-clamp from starting position to the position where the sewing is to'begin; (2) the |12 which bears upon the.

which is rigidly mounted a uuu exea blade in. having a shear cutting edge |99. Fulcrumed on the pin |90 is the movable blade 9| having aV shear cuttingedge |92 complemental to the fixed shear cutting edge |89. The body-member |91 has a slideway |99 cut longitudinally thereof and in this slideway is located the slide-bar |94 having in one 'edge a semi-circular recess |99 for' the circular end |96 of the movable blade |9|. A

biasing spring |91 connects a pin |99 on the slidebar |94 to a xed pin |99 on the body-plate |91.

This spring urges the movable cutter to close to full line position, Figs. 29 and 31. A cover-plate 200, having a hook 20| at its lower end, is screwed to the body-plate |91 to hold the slide-bar and movable cutter-blade in their respective ways in the body plate |81. From the foregoing it willv be apparent that a push at the end of 'the bar |94 remote from the shear cutters will open the latter and when such a push is relieved the cutters will close and'sever the thread, at the same time y nipping the needle end of the thread between the movable blade 9| and the cover-plate 299.

The body-plate |01 and parts carried thereby is screwed to the -head 202 of a tubular shaft 299 which is ,'iournaledv in a bearing support at one discontinuance of the-rapid feed at the eye-end of the buttonhole when the machine is set to sewv a non-eyed buttonhole and the sewing is stopped and started at such end to avoid overcrowding of the stitches; and (3) the discontinuance of the rapid-feed action between the return side stitching operation and the bar stitching operation. The final rapid-feed action is, as before .explained, terminated by action of the tooth |10 on the lever |61.

The lmachine has a conventional under thread tension-device |16, Fig. 4, and spring-biased tension-release lever |11 fulcrumed at |19'on the bed-frame and carrying two spaced pins |19 'ibetween which extends the arm |90 of a rock-shaft I9| extending with and lengthwise oi' thebed and through the rear end wall oi' the latter where it carries the arm |92 that is acted upon by the inclined face |93 of a block |04 carried at Ithe lower end of the stop-motionoperating lever 65. The mechanism functions to release the under thread tension when the stop-motion devicefunctions to stop the stitch-forming mechanism. The

. mechanism is fully disclosed in U'. S. Patent No.

2,210,638; granted August 5, 1940.

The machine has the conventional buttonholecuttingmechanism including the enacting upper and lower cutter levers |95, |96, Fig. l, which are driven in the usual manner by the one-rotation buttonhole-cutter shaft 34. While the present. machine is designed to cut the buttonhole after sewing, itis entirelyimmaterial to the inven- -tion whether the buttonhole is out before or after sewing. l

The machine is provided with the following means to cut and hold the neev:llethread. The thread-cutting and -nipping implement nconiprises a thick plate-like body-member |91 on ment to the thread-cutter implement on the axis of its tubular fulcrum shaft 209 .relative to its carrier-lever 204, when such carrier-lever is operated to advance the thread-cutter implement from retracted position (dotted lines Fig. 29) to threadcutting position/ (full lines Fig. 28).

Journaled in the tubular fulcrum shaft 299 is a rock-shaft 2|9 having at one end a' tappet arm'2l4 the toe end 2|5 of which is so positioned 'as to engage and push upon the end of the slide- Y bar |94 to open the thread-cutter blade |9|. The

rock-shaft zn has .nxedwits opposite emi a' crank-arm 2|6 carrying at its free end the pivoted and spring-biased toe-piece 2|1 which, in the cutter-advancing movement of the carrier-lever 204 engages the cam-piece 2|9 of the arm 2|9 fixed to the bracket 201. This engagement of the toe-piece 2|1 with the, cam-piece 219 rocks the shaft 2|3 in the vtubular shaft 209 and causes the tappet toe'2l6 to push in the ,slide-bar |94 and open the cutter-blade |9|. As soon as the toevpiece 2|1 passes beyond .the cam-piece 2|9'the slide-bar |94 is released and drawn by its spring |91 to close the blades |9|, |99, 209 upon the needle-thread, as shown in Fig. 28. In the return movement of the carrier-lever 294, the toppiece 2|1 wipes idly past the cam-piece 2|9, being free to swing on its pivot-screw 2|9in this direction. 'I'hestop-screw 220, which is engaged by the tail 22| ofthe toe-piece 2|1, prevents swinging of the toe-piece 2|1 inthe reverse direction when the thread-cutter is advanced to full line position, Fig. 28.- V

When the thread-cutter is retracted after -cutting and nipping theend of needlethread leading to the needle 5, the heel 222 of the tappetarm 2M is brought intoengagement with the stationary abutment' 229 vertically adiustably mounted on the bracket-arm head 4 of the machine freme. The initial engagement ofthe heel l lower the release of the portion 239,

ary thread-guides 245.

'instrumentalitiea The usual gimp or cord G to engage and operate the lever ascuas 222 with the abutment 222 is a mere contact, not sufficient to cause the tappet-arm 2|4 to open the thread-nipper blade ISI. A slight further retraction of the carrier-lever 204, before the initial stitch oi the next buttonhoie is made,

I by the unam to the crooked lever 22s which 1s screwed to a lower lever-arm 235 fulcrumed at 23|' within thev standard 2 and having at its end a roller 2li tracking the cam 232 onthe cross rotary shaft 24. The spring 223, Fig. l, applied'to the lever 22l'retalns the follower-roll 2li against the cam 232. Thevcam 232 has a let oil' notch 234 which releases thelever 229 and v'allows' the thread-cutter to'advance and cut and seize the needle-thread during the final rapidfeed movement of the cross rotary shaft 24. The cam 222 also has a slight rise at 235 to eifect before the needle starts down on its nrst stitch. This release rise terminates at lthe point 235, Fig. 2.

To pull suiilcient slack needle-thread from the supply for the beginning of the sewing operation,

, there is secured to the clamp-closing lever il,

Fig. l', a pull-off rod 231 which rises through the guide 235 and has at its upper end a horizontal Fig. 3, working between two station- At the time the clampclosing lever 3i operates, the needle-thread tension is held open by the lever H5 and tail of the tension-release segment H2 on the patternwheel 25. 'Ihe pull-ol! is adjusted to measure enough needle-thread from the supply so that the beginning end of needle-thread will be drawn down flush with the work by the stitch-forming is supplied to the needle-throat member 2li through a gimp pulloil' and slack-giving device including the gimpiension device 242 which is carried by the lever 242, Fig. 1. actuated by the cross-rotary shaft 24, substantially in accordance with the disclosure of U. S. Patent No. 2,210,638, granted August 6, 1940.

Operation The operation is briefly as follows: At the stnrt of the operation the tripping of the clamp-closing mechanism causes the actuation of the threearmed clamp-closing lever li, 55, ill which closes the work-clamp and actuates the needle-thread pull-01225. The thread trimmer is in retracted position and is closed. The recovery motion of the clamp-closing'lever causes the stud-pin |82 |59 to trip the rapid-,feed into action to shift the work-clamp from initial position to the position where sewing is to begin. In that shift of the work-clamp the thread-trimmer is further retracted to cause the stationary abutment 223 to release the needlethread end. The pattern-wheel cam-rise Il! starts the sewing mechanism; the stop-motion lever being latched in running position. The

vsewing startsat the point s, Fig. 6, and continues tozand around the eyelet-end t to the point u which ls a little short of the starting point s measured lengthwise of the buttonhoie. When -tm end point u is reached the stitch-forming mechanism is stopped and the longitudinal slidei stop-motion causes the pawl A the bar-sewing beginning end of needle-thread initial position, the closed thread-cutter is rethread end.

thread. 'I'he tension vi'ra'me of the work-clamp is uncoupled from the longitudinal feedcam.and given va slight reverse feed movement by the inclined face 12 of vthe locking pin 1i which locks the longitudinal slideframe in barring position. The action of the i64, Fig. 1, to trip the rapid feed into operation to feed the cam system idly around to a constant barring position Just previous to which the stitch-forming mechanism is preferably turned around its vertical axis-to bar-stitching position.

I'he cam rise H8 on the pattern-'wheel starts operation which proceeds from the point v, Fig. 6. square across the end of the buttonhoie to the point w. It will be noted that the bar overlaps the end stitches at both sides cut after the bar is completed' and before the work-clamp is shifted out of barring position.

When the machine ls at rest, the thread-cutter is in its retracted position closed upon the end of needle-thread running to the needle. When the machine is started, the pull-off is operated by the clamp-closing lever to pull a constant amount of thread from the supply so that the initial thread end will be drawn down flush with the work in the formation of the rst stitch. During the initial rapid feed movement of the cross-rotary shaft 24, before the sewing starts, the thread-cutter is further retracted 'by the rise 235 on cam 222 sumciently to release the needle- This occurs before the work-clamp is moved away from initial position. The machine now sews and bars the buttonhoie. Early in the iinal rapid feed, after barring, the threadcutter is advanced and closed upon the needleis released by the cam inoline III on pattern-Wheel segmental plate i i2. During reverse rotation of stitch-forming mechanism and return movement of work-clamp to tracted to initial position and it pullsV a constant length of thread downwardly through eye of needle for any length buttonhoie the machine may be set to produce, to begin the next sewing operation and secure uniformity in the iinal hidden disposition of the beginning end of needlethread flush with the work.

The present thread-trimmer is mounted to` operate in a fixed path with respect to the sewing needle while the work-clamp is locked in barring position regardless of the length of the buttonhole within the range of the machine.

The compound motion of the thread-trimmer, shown by the upwardly convex curved dot-anddash line in Fig. 28, carries the trimmer over the top of the clamp-foot 21 and thence downwardly to clear the needle-point bya sufficient margin.

Having thus set forth the nature of the invention, what I claim herein is:

l.' A buttonhoie sewing machine having stitchforming mechanism including an upper endwise reciprocatory needle, a work-holder, feeding mechanism to relatively move the stitch-forming mechanism and work-holder into and out of sewing relation* and to sew about a buttonhoie, a stop-motion device for the stitch-forming mechanism adjustable to vary the times o! starting and stopping of the stitch-forming mechanism.

whereby buttonholes of various lengths may be sewn, a thread-trimmer Amounted at the needle side of the work independently of the workholder, and means to actuate said thread-trimmer at the close of a sewing period and before the 'stitch-forming mechanism and work-holder arel relatively shifted out of sewing relation.

2. In a buttonhole sewing machine, the combination with stitch-forming mechanism including an upper thread-carrying needle and complemental under thread mechanism, work-holding means, feeding mechanism including feed-- cams and connections for relatively moving the stitch-forming mechanism and work-holding means to sew about a buttonhole, a rapid feed drive including a cro rotary shaft journaled in the machine bed and connected to said feed-cams for driving the latter between sewing periods, a

needle-thread trimmer mounted above the workholding means, anda cam on said cross rotary shaft and connections for operating said needlethread trimmer.

3. In a sewing machine, a

crumed on said bracket-arm, a thread-cutter comprising a complete-,scissors device mounted for pivotal movement on and relative to said lever. a cam for controlling said pivotal movement, and means to actuate said lever to advance frame including a bed and an overhanging bracket-arm, a lever fulsaid thread-cutter from a retracted position to a thread-severing position.

4. In a sewing machine, a frame including-a bed and an overhanging bracket-arm, a lever fulcrumed on said bracket-arm,I a thread-,cutter comprising a complete scissors device mounted for pivotal movement on and relative to said lever, a cam for controlling said pivotal move- A ment, and means to actuate said lever to advance said thread-cutter from a retracted position to a thread-severing position, and means to open and close said scissors device in the advancing movement of the latter.

5. A buttonhole sewing machine having stitchi forming mechanism including a"reciprocatory eye-'pointed needle and complemental under thread mechanism, a stop-motion device for the 1 stitch-forming mechanism, a tension device for the needle-thread, an automatic tension releaser,A

a needle thread cutter and nipper mountedv at the needle side of the work for bodily movement.

from retracted position to thread-cutting and -nippingl position and return, anl automatic needle-thread pull-off device operative on the needle-thread before it is released by said nipper,`

and means to effect the release of the needlethread by said nipper before'the needle descends i on the first stroke of a sewing period.

6. In a sewing machine, a thread-carrying needle, a needle thread-cutter and -nipper, a carl rier therefor, means to actuate said carrier to advance said thread-cutter and -nipper from a retracted position to needlethread-cutting and nipping position and return, means to impart a further retractive movement to saidthread-v cutter and -nipper, and an abutment engaged by said thread-cutter and -nipper in'its further retractive movement andoperative to open said nipper and release the needle-thread end.

7. A buttonhole sewing machine having stitchforming mechanism including an upper endwise reciprocatory needle, a work-holder, feeding mechanism to relatively move the stitch-forming mechanism and work-holder 'into and out of sewing relation and to sew about a buttonhole, a stop-motion device 'for the stitch-forming mechanism adjustable to vary the times of starting and stopping of the stitch-forming mechamsm, whereby buttonholes ofV various lengths may be sewn. a combined thread-trimmer and thread-end-holder mounted at the needle side of the work independentlyof the work-holder, means to advance said thread-trimmer' and thread-end-holder and to close the same on the 4thread leading from the needle-eye to the last for buttonholes of any length the machine may be set to produce.

EDWARD P. SPAINE.

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