US3176640A - Cutting device for sewing machines - Google Patents

Description

April 6, 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet 1 INVENT OR Ner'ino Mar'fcgnio BY WAG/U ATTORNEY April 6, 1965 N. MARFORIO CUTTING DEVICE FOR SEWING MACHINES 13 Sheets$heet 2 Filed March 15, 1963 ma i INVENTOR Neryarforio M/ ATTORNEY Bi f April 6, 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet 3 INVENT OR Nerino Marforio,

BY M) ATTORNEY Apnl 6, 1965 N. MARFORIO CUTTING DEVICE FOR SEWING MACHINES 13 Sheets-Sheet 4 Filed March 15, 1963 INVENTOR Nerino harforio,

ATTORNEY 1 April 6, 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1965 13 Sheets-Sheet 5 Fig. 5

:1 LL H a 1 ////A V //5 INVENT OR ATTORNEY April 6, 1965 N. MARFORlb 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15. 1963 13 Sheets-Sheet 6 Fig. 6

INVENTOR Ner'ino Marforio ATTORNEY April 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet '7 "1 X/ Y 8 XII F 112 1d Fig 166 60 XIIL...

Fig.9 62a 68 62 INVENTOR N erino Mar'forio ATTORNEY April 6, 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES filed March 15, 1965 13 Sheets-Sheet 8 10a 26b H g f H 1055 INVENTOR Ner no Marfor 0, BY M ATTORNEY April 19651 M'ARFOREO CUTTING? DEVICE; FOR SEWING: MAGH'INES 151 Sheets-Sheet: 9

Filled March 15, I963? INVENTOR rlno Marijdrio, BY W ATTORNEY April 1965 N. MARFORIO 3,17 40 CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet 10 INVENTOR ATTORNEY April 1965 N. MARF'ORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet 11 INVENTOR erino Marforio BY I ATTORNEY April 6, 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet 12 INVENTOR Nerino Marforio,

ATTORNEY April 6, 1965 N. MARFORIO 3,176,640

CUTTING DEVICE FOR SEWING MACHINES Filed March 15, 1963 13 Sheets-Sheet 13 INVENT OR 7 r'no I"? "for 0, BY MM/ ATTORNEY United States Patent 3,175,649 CUTTING DEVICE FOR SEWWG MACHINES Nerino Marforio, Milan, Italy, assignor to S. p. A. Virginie Rirnoidi e3: (1., Milan, Italy Filed Mar. 15, 1%3, Ser. No. 265,538 4 (Ziahns. (6!. 112-123) This invention relates to a one-needle sewing machine, wherein the movements of the needle and other members cooperating in forming the stitches and cutting the material being sewn, are derived from one main shaft extending throughout the length of the machine frame beneath the working table aligned with the needle plate.

One-needle sewing machines of this class for effecting one-needle twoor three-thread seams, as well as twoneedle machines for forming so-called safety seams from four or five threads are known.

The device for cutting the edges of the material being sewn, comprising a pair of cooperating cutters, is arranged in such machines ahead of the needle or needles and is therefore displaced with respect to the latter in the direction of feed of the material being sewn.

This imposes a limit with respect to the possibility of effecting seams along very narrow-curved paths as required in carrying out work of various kinds on articles of wear, such as in sewing shirt cuffs, ladies dresses and the like.

It is moreover known that, in order to carry out work of the kind mentioned above, double-chain stitch seams are required, for which purpose arm machines capable of forming a double-chain stitch seam are employed. Arm machines do not attain high speeds comparable with those obtainable on one-needle machines, as required in series manufacture of articles of wear.

This invention provides a one-needle sewing machine capable of effecting seams along very narrow-curved paths and of sewing garments or the like requiring doublechain stitch seams.

A further object of this invention is to provide a sewing machine of the type referred to, wherein the device feeding the work being sewn in highly reliable in feeding the material being sewn.

A further object of this invention is to provide a sewing machine of the type referred to above, which can be easily converted to a machine capable of edecting one-needle or safety seams.

According to this invention the above objects are fulfilled by a one-needle machine adapted to effect doublechain stitch seams, wherein the device for cutting the material being sewn is arranged past the needle and is thereby offset from the latter in the direction of feed of the material being sewn.

Further characteristic features and advantages of this invention will be clearly understood from the'appended description referring by way of a non-limiting example to an embodiment shown on the accompanying drawings, wherein:

FIGURE 1 is a front part sectional elevational view of the improved machine,

FIGURE 2 is a plan view in which the presser foot, needle bar and top cutter supporting mechanism have been omitted,

FIGURE 3 is a longitudinal sectional View,

FIGURE 4 is a part sectional end view,

FIGURE 5 is an end view opposite to FIGURE 4,

FIGURES 6, 7 and 8 are sectional views on lines VI VI, VII-VII and VIIIVIII of FIGURE 3,

FIG. 6a shows a detailed sectional view of the connection between arm 35 and sleeve 40,

FIGURES 9 and 10 are sectional views on lines IX- IX and X-X of FIGURE 1,

FIGURES 11 and 12 are sectional'views on lines X XI and XIIXII of FIGURE 8, 7

FIGURE 13 is a side elevational view of'constructional details of the machine frame,

FIGURE 14 is a sectional view online XIV-XIV of FIG. 13,

FIGURE 15 is a diagrammatical side elevational view of the machine, showing details of the device for cutting the fabric being sewn and driving means therefor,

FIGURES 16, 17 and 18 are sectional 'views on lines XVIXVI, XVII-XVII and XVIIIXVIII of FIG- URE 15. I

FIGURES l9 and 20 are a front and a longitudinal sectional view, respectively, of the assembly on the machine frame of the lower cutter and supporting means therefor,

FIGURES 21, 22 and 23 are a side elevational, plan and front view, respectively, of the lower cutter and support therefor,

FIGURES 24 and 25 are a side elevational and front view, respectively, of the top cutter and supporting and' driving means therefor,

FIGURE 26 is a diagrammatical perspective view of the machine showing the path of the needle and looper threads,

FIGURE/27 is a perspective view of the region on the machine comprising the needle plate, fabric cutting device and discharge channel for cuttings, 7

FIGURE 28 is a perspective View of the channel for discharging cuttings or waste.

FIGURES 29, 30, 31 and 32 are perspective views showing diagrammatically on an enlarged scale the formation of the double-chain stitch effected by the machine.

Similar parts are denoted throughout the figures by the same reference numerals.

The machine shown on the drawings comprises a frame 1 resting on a case 2 acting as a reservoir for collecting lubricating oil and incorporating the circulating pump for lubricating oil, filter therefor and shaft (not shown) having keyed thereto a pulley 3 for driving the pump.

The frame 1 includes a higher middle portion, the inside 4 of which opens towards the case 2 and upwardly and is closed at the top by a cover plate 5 of transparent material. The latter is protected but for a small projection 5a of dome shape by a metal cover plate 6 externally provided with adjustable thread tension devices 7.

The middle portion of the frame ends in a vertical wall In (FIGURE 3) and is formed with a lower front extension covered from above by a plate 8 acting as a working table over which the work being sewn travels, and which is defined at the front by a vertical wall 111 parallel with the wall la.

A cover plate 9 is secured by means of screws to the overhanging portion of the wall 1a on the middle portion of the frame overlying the working table 8. This cover plate covers the mechanisms supported by the wall is, which shall be described hereafter and externally carries the lever 19 supporting the presser foot 11 which cooperates in feeding the work being sewn and in positioning the latter during formation of the stitches.

An intermediate region of the lever 18 is biassed by a rod 12 which is constantly urged downwardly by a spring 13, so that the lever it together with the presser foot 11 are constantly pressed in the direction of the needle plate 14, FIGURE 2, which is fiush with the working table 8.

The lever it (FIGURE 4) ends oppositely the presser foot ill with a fork 15. The latter is hinged through the interposition of a pin 16 to a bored lug 16 fixedly secured to the front face of a pivot 18, FIGURE 2, ex-

tending parallel with the working table 8 and journalled in the wall 1a of the middle frame portion. The pivot 18 extends beyond the opposite side of the wall in and carries at its protruding end a lever 19, FIGURE 5. An arm 29, FIGURE 4, is secured to the same end of the pivot 18 as the lug 16 and is accommodated by a recess 10:: in the face of the lever It turned towards the wall In. The rod 12 carries in proximity to its lower end a roller 12a acting on a shoulder 10b on-the lever Ill. Above the roller 12a the rod 12 is formed with a tooth 12b which is normally engaged from its underside by a collar 21 on a pivot 22 extending parallel with the rod 12 in a seat in the wall In, the pivot 12 being urged downwardly by a spring 23. The stop end of the pivot 22 is hinged between the arms of a fork 24 ending by a small lever 24a. The fork is cam-shaped so that, by pressing on the lever 24a and rotating it in the direction of the arrow 25, FIG. 4 the pivot is lifted. Lifting of the pivot 22 causes the collar 21 to engage with the tooth 12b on the pin 12 which is likewise lifted against the action of the spring 13. Since on lifting of the pivot 12 the roller 12a stops acting on the shoulder 10b on the lever 10, the latter can now swing laterally around the pin 16, and of course rotate about the axis of the pivot 18, and disengage from the arm 20. Normally, in order to lift the presser foot 11 from the needle plate 14, a lever 19 is lowered, which rotates the pin 18 in anticlockwise direction and rotates in the same sense the arm which lifts the lever 10 against the action of thespring 13. These processes occur without acting upon the pin16 acting as a hinge pin for the lever 19.

The main shaft 26, FIGURE 3, of the machine is journalled in the rear portion of the frame, which is likewise somewhat lower, by bearings 27 and in the forward wall 1b by a bearing 28. The shaft is moreover supported by an intermediate bushing 29 secured to the frame and carries at its rear end 26a a pulley 34 for a drive belt 36a, FIGURE 5, which travels over the pulley of a driving motor (not shown) and over the back of the driving pulley 3 for the pump in the case 2. The shaft portion extending between the bearings 27 and bushing 29 is provided with a crank which transmits motion throuhg the connecting rod 31 and arm 2, FIGURE 16, to a top shaft 33 parallel with the shaft 26. The shaft 33 carries at its forward end a crank pin 34 having fulcrumed thereto the middle portion of an arm 35, FIGURE 6. The rear end of the arm 35 is hinged by means of a pin 36 to a link 37, hinged in turn to the wall 1a of the frame by means of a pin 38. The forward end of the arm 35 is shaped to a fork 39 which is hinged by means of :a pin 40 to a slide 41 slidably mounted on a guide bar 42 stationarily arranged in the wall In of the frame. The slide 4-1 carries a needle 43, FIGURE 1, for forming the two-thread chain stitch in the manner to be described hereafter.

The length of the connecting rod 31 and arm 32 are such that on rotation of the main shaft 26 the top shaft 33 is swung through about 60. The position of the pivot 34 on the shaft 33 is in turn such that the pivot 34 is oscillated through about on both sides of a plane perpendicular to the guide bar 42 and containing the axes of the pivots 36 and 40 and the axis of the shaft 33. The arrangement is moreover preferably such that the spacing of the path of the axis of the pivot 4t and a line extending parallel with the said path and through the axis of the pivot 38 is twice the spacing of the axis of the shaft 33 and the above path and line. The spacing the axes of the shaft 33 and pivot 34 is preferably one sixth of the first mentioned spacing of the path of the axis of the pivot 40 and line extending through the axis of the pivot 38. With this arrangement the path of the slide 41, hence of the needle 43 are substantially rectilinear. With a stroke of about 25 mm. they do not depart by more than 1.5 to 2 microns from the truly rectilinear path of the region at which the siad path intersects the plane containing the axes of the pivots 36 and and the axis of the shaft 33, that is, the region at which this deflection is greatest. The differences in actual and theoretical paths of the abovementioned components do not affect correct operation of the mechanism effecting the needle movement or formation of the double-chain stitch.

Near the crank on the main shaft 26, which drives the connecting rod 21, a further crank is arranged to drive a connecting rod 43 which transmits motion to the device for trimming the work being sewn. The connecting rod 43 is hinged to a lever 44 which is keyed to a spindle 45, FIGURES l5 and 16. The spindle 45 extends parallel with the main shaft 26 and is likewise journalled within the frame 1. One end of the spindle 45 extends beyond the wall 1a and carries in front of the latter an arcuated arm 46, FIGURE 25, provided at its free end with a head 47 of square cross sectional shape extending parallel with the spindle 45. This head has mounted thereon for longitudinal displacement a first strap 48 formed beneath the head 47 with an incline 49 and a vertical land 50 for the top cutter 51 of L-shaped cross section to rest thereon, FIGURE 24. The cutter is secured to the strap 48 by means of a small auxiliary strap 52 fixed thereto by a screw 53. By loosening the latter the cutter 51 can be moved in the direction of its length in order to lower or lift its cutting edge 510. Since during this adjustment the edge 51a of the cutter is moved in the direction of the axis of the shaft 45, provision is made for adjustably positioning the strap 48 on the head 47 on the arm 46. The strap 4-8 is secured to the head 47 by means of a screw 54 The latter is screwed into a tapped seat in a pin 55 inserted into a longitudinal through hole in the head 47. The screw 54 extends first through a longitudinal slit 56 cut in the side wall of the head 47 opposite the arm 46. The members effecting the movements of the needle and top cutter 51 are correlated to move during operation of the machine in full synchronism and in the same directions.

The main shaft 26 carries on its portion between the crank driving the connecting rod 31 and support 29, FIG- URE 3, a further crank transmitting through a connecting rod 57 on an arm 53 provided with a spherical head an oscillatory movement to a cross shaft 59, FIGURE 8, mounted in bearings fitted in suitable holes in the side walls 1c and 1d of the frame. One end 59a of the shaft 59 extends beyond the side wall 10 which is formed at this region with a recess 60 closed by a tilting cover plate 61, FIGURES 2 and 13, and defined on its side facing the working table 3 by a cross wall 62 of the frame provided with an overhanging top portion 62a of L shape. The wall 62 and its overhanging portion 62a support the plate 8 and needle plate 14 and perform further functions which shall be described hereafter.

The end 59a of the shaft 59 has secured thereto by means of a collar and screw an arm 63 carrying an overhanging pivot to which one end of the link 64 is fulcrumed, the other link end being hinged to a bored spherical ball 65, FIGURE 9, on a cross pin 66 fitted at about mid height into a supporting arm 67 for the looper as which cooperates with the needle 43 for forming the double-chain stitch. The loopcr 68 is accommodated by a clearance beneath the needle plate 14 which is secured to the cross wall 62 and its overhanging portion 62a by means of screws 69 and 7%, FIGURE 2.

The arm 67 is mounted for oscillation on an arm 71 which is rotatable and axially slidable in bushings '72 and 73, FIGURE 9, carried by the frame 1. The arm 67 carrying the looper 63 is secured to the arm 71 by means of a collar clamped by a screw-74. The shaft 71 is axially displaceable by theaction of a fork 75, FIGURE 9, engaged between a collar 75 fast with the shaft 71 and a washer 77 on the bushing reaching within the strap securing the arm 67 to the shaft 71. The fork 75 is arranged at the end of a shaft '78, FIGURE 1, journalled in a bushing 79 fitted into the cross wall 62 of the frame. The shaft 73 carries a fork iii which is likewise clamped on the shaft 78 by means of a strap tightened by a screw 31 and hinged at its other end to a link 82, FIGURE 7, receiving motion from an eccentric 83 keyed to the main shaft 26 and arranged near the support 29 for the latter. Near the eccentric $3 an eccentric 34 is arranged which transmits motion through a connecting rod 85 to the mechanisms effecting movement of the feed dogs $6 and 87, FIGURE 2.

The big end of the connecting rod 85 is journalled on a sleeve 8?), FIGURE 3, which is eccentric to the axis of the shaft 26. The sleeve 88 is formed with an inner through bore larger in diameter than the main shaft 26. The sleeve 83 is moreover provided with a forward extension 89 provided with side flanges parallel with each other extending diametrically to the sleeve. The extension 8? which is consequently of L shape in cross section is slidably mounted in a diametrical guide in the face of the disc 84 turned towards the sleeve 88 and can be secured in a desired position in said guide by acting on a screw 94), the latter engaging through a washer 21 the extension 89 on the sleeve 88, FIGURE 3.

It is thereby possible to vary at will the eccentricity of the sleeve 83 t0 the axis of the shaft 26, hence the stroke of the connecting rod 85. The small end of the latter is hinged to a fork 92 secured to the shaft 93, FIGURES 3 and 6, mounted for oscillation in the walls 1:: and 1b of the frame. The shaft 93, which extends parallel with the shaft 26, has moreover secured to it an arcuated arm 94, FIGURES 11 and 12.

The arm 94 has slidably mounted thereon a slide 5 carrying on its side remote from the arm 94, a pivot to which a link 95 is hinged. The pivot extends beyond the link 96 and has articulated to its free end the top end portion of a curved arm 97, the bottom end portion of which is rotatably mounted on the free end of an arm 92*; extending transversely of the shafts 26 and 93. The arm 98 is moreover secured to an arm 99 extending parallel with the arm 26 and reaching to the outside through the wall 117 and carrying at this end a swing lever 100. The swing lever 11% is formed with a tapped hole receiving a screw threaded shank of a knob 1121 which is separate from the lever 19%) by a plate 192 supported by the wall 112 and formed with an arcuated slot 193 through which the screw threaded shank of the knob 1% extends. The center of curvature of the slot 103 is situated on the axis of the shaft 99.

With this configuration of the component parts the lever 1% can be brought to a stable position which consequently also applies to the slide 95 on the arm 94, to thereby determine the length of stroke performed by the link 26 on oscillation of the arcuated arm 94. For the purpose of checking the extent of the stroke performed by the link 95 the plate 1632 is provided with a graduated scale 104, FIGURE 4, having cooperating therewith a pointer 105 carried by the lever 1th The other end of the link as is mounted for oscillation on a pivot 1% fast with the feed dog holder bar 107, FIGURE 12. The latter extends transversely of the main shaft 26 and is adjacent a further feed dog holder bar 1% which is similar to the former. The bars 107, 168 are each formed with a bottom bell crank projection 1637a, 1380, respectively. These projections define guides fitted on a sleeve 1119 keyed to the portion 2611 on the main shaft 26, which is slightly eccentric to the shaft axis. Consequently, on rotation of the main shaft 26 the bars 1&7, 1198 are simultaneously lifted and subsequently lowered, their ends remote from the feed dogs being of fork shape at 1137b and 108b, respectively. The forks encompass a block 11%) mounted for oscillation on an eccentric pivot 111 fast with the pivot 112 rotatably supported in the wall In of the frame and normally retained in a desired position by a screw 113, FIGURE 8.

a *0 The bar 1% is connected by means of a piovt 114 and a link 115 to an arm 116, FIGURE 11, secured to the shaft 5 3. The arm 116 is arcuated and formed with a slot 117 having slidable therein a pivot 118 which can be retained in a desired position. The pivot 118 has hinged thereto a link 115. The bars 1&7, 1133 reach by their ends opposite the forks 1197b, 1193b into theclearance beneath the needle plate 14 in which the looper 63 is arranged, any movement of the bars in a lateral direction being prevented at this region by the provision of hell cranks 119, 123 secured to the frame, FIGURE 8. The bar 1137 has secured thereto a three feed dog 85, the bar 1618 having secured thereto a double feed dog 37. The feed dogs 36 and 37 are situated at the elevation of their corresponding openings formed in the needle plate 14, which is further formed with a hole 121, FIGURE 2, for the needle 43, which is offset from the edge 14a of the plate remote from the wall 1!) of the frame, and with a recess 122 opposite the region of the machine at which the device for trimming the work being sewn is arranged.

The main shaft as slightly extends beyond the bearing 28 fitted into the frame wall 1b. The projection on the shaft 25 has keyed thereto a cam 123 secured to the shaft 26 for angular. staggering with respect to the shaft. The top of the cam 123 extends through a slot cut in a bracket 124- carrying on its top face pins 125, 12s for guiding the thread which is supplied to the looper 68. The bracket 124 has, FIGS. 2 and 3, superposed thereon a frame-shaped spring 127 adapted to press the thread travelling over the pins 125, 126 against the surface of the bracket 124 and top of the cam 123. The cam. is shaped to stretch or release, respectively, the thread according to the position taken by the looper 68 with respect to the needle 43 during formation or" the double-chain stitch. The bracket 124 is mounted for displacement in height. This displacement can be effected by loosening the screws 128 engaged by eyelets 129 fast with the bracket. With this adjustment the length of the looper thread section between the pins 125, 126, hence the tension of this thread can be varied.

The device for cutting the material being sewn, the movable top cutter 51 and supporting and driving members therefor have been previously described, further comprises a cutter which is stationary during sewing, but can be adjustably positioned in the manner described hereafter.

The stationary cutter 136 is in the form of a thin blade, the shank 131m of which is received by a groove of square cross sectional shape, cut in the side face 131a of the support 131, FIGURES 19, 22 and 23. The groove is closed by a plate 132 secured to the face 131a by screws 133, the shank of the cutter 13% being secured in the resulting seat through the interposition of an inverted L -shaped cotter 134.

The cotter 134 is pressed against the cotter shank by a screw 135 screwed into a tapped hole in the forward face of the support 131. The hole is a through hole and connects with the inside of the groove receiving the cutter shank 131:: as well as the cotter 134. The support 131 carries at its rear face a pin 136 which upon assembly of the support 131 on the machine fits into a through hole in the portion 62a of the cross wall 62 of the machine frame and is fixed in a desired position in the said hole by means of a screw 137, FIGURE 20. The support 131 has a hole 13?, FIGURE 22, bored therein, receiving a pin 139, FIGURES l9 and 20, extending parallel with the hole receiving the pin 136 and secured to the portion 62a by means of a screw 14 4 The support 131 is constantly urged in the direction of the free end of' the pin 139 by a spring 14-1 biassing a head 142a on a pin 142 received by a hole 1 :3 in the portion 62a, extending parallel with the pin 139, FIG. 20.

By means of the above structure the cutter cooperating with the movable top cutter 51 on the device for cutting the material being sewn can be properly positioned. In actual practice the position of the movable cutter 51 is first selected and is held in a somewhat lowered position in which its substantially vertical portion 51b, FIGURES 24 and 25, is beneath the top edge of the cutter 130, while the screw 137, FIGURE 20, is loosened. The support 131 is moved under the action of the spring 141 till the cutter 130 abuts the abovementioned portion 51b of the cutter 51; The screw 137 is then tightened in order to prevent any further movement of the support 131 together with the cutter 130.

As will be seen from FIGURES 3 and 27 the cutting device comprising the cutters 51 and 130, is so constructed and arranged as to act in a plane which is more or less offset towards the edge 14:! of the needle plate at the region past the hole 121 in the direction of feed of the work' being sewn with respect to the hole 121 through which the needle 43 can extend through the plate 14, as well as to its corresponding hole 144 in the presser foot 11, FIGURE 27. This arrangement, by virtue of which the edge of the material being sewn and out after the double-chain stitch seam has been formed, is advantageous, in that cutting or trimming can be effected along very narrowly curved paths, and the work is fed in an extremely safe manner on account of the fact that a feed dog 86a can be arranged beneath the plate 14, at the region ahead the hole 121, FIGS. 2 and 27, for the needle 43 the said feed dog 86a being displaced towards the edge 14a of the plate 14 with respect to the hole 121 in the latter. It is thereby possible to employ the speedy one-needle sewing machine for performing work which could heretofore be effected only by arm machines suitable for sewing by a doublechain stitch seam shirt cuffs, ladies garments and the like.

The positioning of the cutting device displaced towards the machine inside with respect to its conventional arrangement in one-needle machines, necessitates a special structure of the cutting device as well as of the means for removing cuttings or waste from the material cut by the device.

The support 131 is larger in thickness on the side of the groove receiving the cutter 130 and is formed between its portion to which the cutter 136 is secured and the pin 136, with a recess 145, FIGURE 23, the provision of which permits oscillation of the arm 67 of the looper 68 when the latter is moved in the direction of the edge 14a of the needle plate 14. The support has moreover superposed thereon and fixed thereto by means of a screw 146, FIGURES 19 to 23, an eyelet presser strap 147 acting as a brake for the needle thread 148,

FIGS. 29 to 32, during the upward movement of the needle.

The device for discharging cuttings comprises a U- shaped channel 148 of pressed sheet metal secured to the support 131 for the cutter 131 by means of a screw 149, FIGS. 27 and 28. The channel 148 has two parallel walls 148a, 1481) perpendicular to the axis of the main shaft 26, and a bottom wall 1480, the top portion of which is substantially vertical, its top end being slightly bent backwardly and inclined in the direction of the side wall of the machine starting from about mid-height. The top edge 148d, FIGURES l4, l and 17, ends at an elevation such as to clear a full downward movement of the cutter 51 and avoid interfering with the movement of the arm 46. The wall 148a is formed with holes 159, 151 for the screw 149, FIGURE 17, which is threaded into a tapped hole 152, FIGURES 19 and 22, in the support 131 and secures the channel 148 to the support, and for the screw 135 clamping the cutter 130, respectively.

The top portion 148:: of the wall 148a of the channel, FIGS. 27 and 28, is inclined towards the needle plate 14 and forms together with the triangular section 148 of the wall 1480 and tongue 148g inclined towards the latter a lateral channel conveying cuttings to the actual discharge channel 143. After attachment of the channel to the support 131, the inclined portion 148a is superposed on a bevel 153 on the support and cotter 134, FIG- URES 21 to 23. The lateral channel moreover reaches into a recess 122 in the needle plate 14, without protruding from the top face thereof, and is formed with a slot 14811 through which the cutter extends.

The discharge channel 148 connects with the outside through an opening 154, FIGURE 14, cut in a tilting lid 155 closing from the outside the recess 60, FIG- URES 1 and 8, in the frame wall 10. The bottom edge of the lid 155 is formed with two tabs 155a, 155b, FIG- URE 13, having extending therethrough a rod 156 secured to the tab 155b on the lid 155, slidably mounted in a cover plate 157 secured by screws to the frame wall 1c. A helical spring 158, coiled on the rod 156 is interposed between a stop 159 secured to the rod and a tab 157a on -'the cover plate 157. The lid 155 is thereby constantly urged in the direction of the plate 14. In order to clear by its edge 155c the other machine component parts arranged at this region beneath the plate 14, more particularly the looper arm 67 and looper, the end of the rod 156 remote from the tab 155b rests on the tip of a screw 161 threaded into a tubular guide 161 for the end of the rod 156 fast with the cover plate 157,'FIGURE 27. The lid 155 is moreover provided with a projection 155d forming a hood preventing at the same time as the tongue 143g on the channel body the tip of the looper 68 from interfering with the cuttings discharged through the channel 148. The lid 155 is moreover provided with a projecting rib 162 variable in height situated beside the wall 143!) of the channel 148.

The manner of forming the double-chain stitch seam on the improved machine can be easily understood from FIGURES 29 to 32.

Since the row of stitches is offset to the inside with respect to the edge B of the work T being sewn the work is assumed for clearness of representation to be transparent. For this reason the needle 43 and looper 68 and their respective threads 148, 164 are shown in full lines. It should be recalled that the looper 68 acts beneath the working table 8,1FIGURE 1. FIGURE 29 shows the needle 43 withdrawn from the work T the moment it has completed its upward movement. The feed dogs 86, 87, FIGURE 2, move the work on each feed stroke in the direction of the arrow 169 by an extent equalling the desired stitch length.

As the needle again moves upwardly the looper 68 retains a loop from the needle thread 148 and is then situated behind the needle working path.

The looper 68 then moves forward towards a position situated in a plane, FIGURE 30, in front of. the needle working path 43. The needle 43 moves downwardly through the work T and is inserted into the loop formed by the looper thread 164, the needle passing the looper.

situated behind the needle working path. FIGURE 32 shows the looper 68 in an advanced position into the eyelet formed from the needle thread 148. The needle has been withdrawn from the work T and moved upwardly, the looper being approximately in a position from which it starts its return movement during which the looper retains the needle thread loop. The needle 43 and looper 68 then resume their positions shown in FIGURE 29, and a fresh working cycle is started.

The general structure of the fundamental component parts of the improved machine is such that the machine is easily and quickly converted to a one-needle machine effecting the so-called safety stitch, that is to a machine of the type disclosed by US. patent application Ser. No. 180,996, new Patent No. 3,145,672.

In order to effect this conversion the needle bar is equipped with a further needle displaced to the needle 43, adapted to form the one-needle stitch seam, as well as with two loopers essential for this type of stitch. One looper shall be secured to the arm to be substituted for the arm 63 carried by the shaft 59 and shall be provided with a pin for connecting thereto the link 64. The other additional looper shall be slidably mounted in a pivot oscillating in a bushing fitted into a seat 164, FIGURE 1, in the frame wall 10 within the recess 60. The bottom end of the latter looper shall be operated by suitable leverages driven by a shaft parallel with the shaft 59, journalled in bushes fitted into holes closed by plugs E and 166 in the frame walls and 1d.

This shaft, FIGURE 8, parallel with the shaft 59 shall be driven from a crank 168, FIGURE 3, specially provided on the main shaft 26.

Of course, in the case considered the needle plate 14 and certain parts of the trimming device shall be replaced. The addition of the two loopers for the one-needle stitch shall necessitate a displacement of the trimming region ahead the needles, which requires a shorter support for the bottom cutter and longer arms on the oscillating shaft operating the top cutter. The lid 155 shall be replaced by a lid without an opening 154.

The resulting machine can in turn be used simply as a one-needle machine. To this end it will be sufiicient to suppress the needle 43 and looper 68.

It will be understood that various constructional details can be widely varied within the principle of this invention Without departing from the scope thereof.

What I claim is:

1. A one-needle sewing machine comprising a side wall, a working table, a needle plate on said table, a main driving shaft, extending below said table, means for supporting the needle and for moving it towards and away from said table, a looper beneath said table, means for supporting and for moving said looper synchronously with the movements of the needle to form a double-chain stitch seam, a work feed device, and a device comprising a lower stationary cutter and a top movable cutter, means for actuating the top cutter for cutting the edge of the material of the work being sewn after the material is already sewn a device for discharging cuttings from the work being sewn, comprising a main U-shaped channel chute perpendicular to the main shaft interposed between an opening in said side wall situated on the inlet side of the work being sewn, and a region in which the top movable cutter of the trimming device acts, an inclined auxiliary transverse channel in communication with said main channel and extending in the direction of the needle and inclined towards the main channel, said auxiliary channel having its higher end in the region of the stationary cutter of the cutting device.

2. Machine as claimed in claim 1, comprising a support for the bottom cutter, means securing said U-shaped channel to the support for the bottom cutter of said cutting device, said auxiliary channel having a longitudinal recess in the bottom thereof for accommodating variable positioning of the bottom cutter.

3. Machine as claimed in claim 1, comprising a looper arm and in which said support for the bottom cutter extends towards the longitudinal middle plane of the machine beyond the region of the needle plate, said needle plate comprising a plate having ahole for the needle, said support having on the remote side of the U-channel a recess for said looper arm to extend through during oscillation of the looper in the direction of the channel.

4. Machine as claimed in claim 1, including a tiltable cover plate having an opening at the top portion thereof aligned with said main U-shaped channel whereby said channel opens to the outside through said opening, said cover plate being disposed covering a recess in said side wall of the machine frame, said cover plate being provided in proximity to an edge thereof adjacent the needle with a bracket-like projection defining in conjunction with the auxiliary channel a clearance within Which the looper tip reaches during the longest looper stroke towards the U-shaped channel, in order to clear it from any cuttings discharged through said channel.

References Cited by the Examiner UNITED STATES PATENTS 1,016,590 2/12 Weis 112-122 1,139,093 5/15 Woodward 112-122 1,544,606 7/25 Seymour 112123 1,977,505 10/34 Chudner 112-l22 JORDAN FRANKLIN, Primary Examiner.

ROBERT V. SLOAN, Examiner.

Claims (1)

1. A ONE-NEEDLE SEWING MACHINE COMPRISING A SIDE WALL, A WORKING TABLE, A NEEDLE PLATE ON SAID TABLE, A MAIN DRIVING SHAFT, EXTENDING BELOW SAID TABLE, MEANS FOR SUPPORTING THE NEEDLE AND FOR MOVING IT TOWARDS AND AWAY FROM SAID TABLE, A LOOPER BENEATH SAID TABLE, MEANS FOR SUPPORTING AND FOR MOVING SAID LOOPER SYNCHRONOUSLY WITH THE MOVEMENTS OF THE NEEDLE TO FORM A DOUBLE-CHAIN STITCH SEAM, A WORK FEED DEVICE, AND A DEVICE COMPRISING A LOWER STATIONARY CUTTER AND A TOP MOVABLE CUTTER, MEANS FOR ACTUATING THE TOP CUTTER FOR CUTTING THE EDGE OF THE MATERIAL OF THE WORK BEING SEWN AFTER THE MATERIAL IS ALREADY SEWN A DEVICE FOR DISCHARGING CUTTINGS FROM THE WORK BEING SEWN, COMPRISING A MAIN U-SHAPED CHANNEL CHUTE PERPENDICULAR TO THE MAIN SHAFT INTERPOSED BETWEEN AN OPENING IN SAID SIDE WALL SITUATED ON THE INLET SIDE OF THE WORK BEING SEWN, AND A REGION IN WHICH THE TOP MOVABLE CUTTER OF THE TRIMMING DEVICE ACTS, AN INCLINED AUXILIARY TRANSVERSE CHANNEL IN COMMUNICATION WITH SAID MAIN CHANNEL AND EXTENDING IN THE DIRECTION OF THE NEEDLE AND INCLINED TOWARDS THE MAIN CHANNEL SAID AUXILIARY CHANNEL HAVING ITS HIGHER END IN THE REGION OF THE STATIONARY CUTTER OF THE CUTTING DEVICE.

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