US2158197A - Sewing machine - Google Patents

Description

May 16, 1939. J, H, PIKUL 2,158,197

SEWING MACHINE Filed Nov. 20, 1957 s Shets-Shet 1 INVENTORZ WJLQM,

A'i'ToRNEYs.

May 16, 1939. H,PIKUL sxawme MACHINE Filed Nov. 20, 1957 8 Sheets-Sheet 2 INVENTORII BY .1749. G44

ATTORNEYS.

May 16, 1939. J P|KUL 2,158,197

' SEWING MACHINE 1 Filed Nov. 20, 1937 8 Sheets-Sheet 3 Tl 1U Tl I I INVENTORI WMQQ ATTORNEYS.

y 16, 1939- J. H. PIKUL SEWING MACHINE Filed Nov 20, 1957 8 Sheets-Sheet 5 W w 1 m W d 2v T, w: g5 m v mfi l? Kiwi & I w a v%@ g g a W 2 6 w Y 4 k r a W W A & RMI QV H 1 E lip.

J. H. PIKUL SEWING MACHINE May 16, 1939.

Filed Nov. 20, 1957 8 Sheets-Sheet 6 9 6 ML m INVENTOR Z ATTORN EYB- w M A? no 4 n f 6 CV .1 MM 3 w a 2 z o ,2 a WW & 0 3 6 F N a 7 W. war V C? 0 "M d a a j W c i a J b a L 7 J. H. PIKUL SEWING MACHINE May 16, 1939.

Filed Nov. 20, 1957 s sheets-sheet 7 ATTO RN EYE.

Patented May 16, 1939 UNITED STATES PATENT OFFICE 2,158,197 SEWING MACHINE Joseph H. Pikul, Boston, Mass. Application November 20, 1937, Serial No. 175,651

7 Claims.

This invention relates to sewing machines and has for its principal object to provide mechanism wherein the exact amount of thread drawn from the supply for each stitch is automatically and accurately measured to the requirements without adjustment of the parts, and wherein all stitches are set in exactly the same manner irrespective of the conditions. The invention is applicable to a wide variety of machines designed to operate undervarying conditions, as, for example, machines for sewing on buttons in which the length of thread required for each stitch depends upon the thickness of the work or material to which the button is to be attached, the thickness of the button itself, the spacing of the holes therein, and the length of the desired neck of thread connecting the button with the material. It is also of great value in buttonhole machines (especially when operating upon soft material) in order to provide automatically for the correct amount of thread in accordance with the thickness of the material, the spacing of the stitches, and the depth of bight, thereby insuring the formation of a stitched buttonhole of smooth and even appearance without undue looseness or tightness of the stitches or bunching or puckering of the material irrespective of the character of the latter. Moreover in machines for sewing straight seams the thickness of the work, and consequently the amount of thread required for,successive stitches, sometimes changes from time to time as the stitching proceeds, as in sewing over folds in the work, attached tapes and the like, etc.

The usual practice, and that used heretofore in sewing machines in the handling of the needle thread, is to operate a take-up in conjunction with the needle and under sewing mechanism (i. e., the looper, shuttle, or other devices for handling the needle thread below the work), so that the take-up, on the descent of the needle, will supply thread to the needle between the tension and the needle. After the needle reaches the bottom of its stroke and starts upward, it throws out a loop which is engaged by the under sewing mechanism. At this time the take-up continues to give thread, so that the under mechanism can manipulate the loop it has taken from the needle to accomplish what any certain type of under mechanism is designed to do. The take-up thereafter draws back this loop of thread through the eye of the needle and sets the stitch,

drawing at the same time new thread from the source of supply through the tension. It is of course understood that a great many varieties of material are sewn, from very thin material to very heavy material, and also that this may oc cur when sewing a continuous seam, because the material will frequently vary in thickness, depending on how the garment is made, and it may be necessary, due to folds, applied parts, or the like, to sew through two, three, four, or more thicknesses in one continuous operation. The amount of thread the take-up handles is, therefore, usually calculated for the average thickness of material. It follows then that on relatively thin work the take-up is handling too much thread, which allows a slack condition between the tension and the needle. Also, when the stitch is set, a very small amount of new thread will be drawn from the source of supply through the tension. When the material being sewn conforms to the amount of thread the take-up is handling, the'take-up, when it sets the stitch, will pull a larger quantity of thread through the tension. Therefore, to set the stitch accurately, the amount of tension on the thread will have to be changed as compared to thesetting when thin material is being sewn. If material heavier than the average is being sewn, the take-up will not supply sufiicient thread, and the needle consequently will try to pull thread from the source of supply through the tension when it reaches the bottom of the stroke. the thread must take in passing from the work down through the eye of the needle (when the latter .is below the upper surface of the work). and up again will cause a condition such that the very light tension is used, thus enabling the eye of the needle to pull thread from the source of supply. In this event, the stitching characteristic is unsatisfactory because the stitch cannot be set properly with a very light tension, In certain types of sewing machines, such as outsole stitchers, mechanisms have been devised to pull a certain amount of thread from the source of supply on each stitch, depending on the thickness oflthe material to be sewn. This amount of thread is subsequently given up to the stitching mechanism on the succeeding stitch. This type of mechanism is complicated, delicate of adjust? ment, and as a practical matter could not be applied to a sewing machine operating on various textures of cloth. Moreover, it does not compensate for variations in the length of stitch.

The present invention accomplishes the very desirable and long sought after result of so constructing a sewing machine that the amount of thread used on each stitch will be drawn from The sharp U-curve eye of the needlewill sever the thread unless a the source of supply by the needle eye in its cooperation with the material being sewn. The take-up action therefore handles just the amount of thread required for the stitching mechanism alone. In other words, the machine can be turned through one stitching cycle with the thread anchored at the throat plate and anchored at the tension, and the take-up motion' will allow the transfer of the exact amount of thread from one side of the needle eye to the other to accommodate the loop required by the under stitching mechanism, and when the needle again arrives at its uppermost position, the thread will be in exactly the same condition as when the cycle was started. The take-up motion is therefore of the constant amount necessary to handle the length of thread required in the formation of a stitch if no thread were used up in making the stitch. In accordance with the present invention, this result is accomplished by entirely releasing the tension at the proper time, so that the needle will, in its descent to the bottom of the stroke, pull directly from the source of supply a. length of thread automatically measured by the thickness of the material being sewn and the length of the stitch. If the material being sewn be thin, the eye of the needle reaches the top of the material after a longer descent than it would make if the material were thick. When the eye of the needle reaches the top of the material, the thread necessarily assumes its U-bend through the eye and thread is drawn from the source of supply. Therefore it is the needle in its cooperation with various types, kinds and thicknesses of work and length of stitch which pulls the thread from the source of supply, and the take-up, in its final action, simply sets the stitch. Consequently, all stitches can be set in the same manner and with equal tightness irrespective of the character and requirements of the work. Moreover, it becomes possible to make the tension device act as a thread clamp to exert a firm clamping pressure upon the thread when the take-up acts to withdraw a cast off loop from the loopers and to set the stitch, thereby better controlling these operations.

The foregoing and other objects and advantages of the invention will best be understood from the following description of an illustrative embodiment thereof shown in the accompany ing drawings, this, however, having been chosen for purposes of exemplification merely, as it will be obvious to those skilled in the art that said invention, as defined by the claims hereunto appended, may be otherwise embodied without departure from the spirit and scope thereof.

In sa'id drawings:

Fig. 1 is a side elevation, partly broken away, of a substantially complete button sewing machine embodying the invention.

Fig. 2 is a fragmentary plan view illustrating an attached button.

Fig. 3 is a fragmentary plan View, partly in section on the line 3-3, Fig. 1, of the mechanism for moving the needle laterally and part of the mechanism for synchronously oscillating the loopers.

Figs. 4 to 9 are detail views, partly in section and partly in front elevation, of the stitch-forming devices, showing the same in different positions.

Figs. 10 and 11 are sections on the lines Ill-10, Fig. 5, and Hl I, Fig. 6, respectively.

Figs. 12 to 20 are schematic views illustrating successive steps in a single stitch-forming cycle,

each view comprising, at the top, sectional perspective views of the thread clamp and take-up, and front elevations of their respective cams, and, at the bottom, a fragmentary perspective view of the stitch-forming devices, showing the latter in the positions corresponding to the positions of the thread clamp and take-up in the respective figures, and illustrating the relative timing of the movements of the parts.

While, as above suggested, the invention is applicable to a wide variety of machines, it is, for convenience, herein illustrated in connection with a button sewing machine of the general type described in an application Serial No. 60,616, filed January 4, 1936, by Franklin A. Reece.

Referring to Fig. 1, the frame or casing of the machine comprises a base or bed 10 and an overhanging head H supported therefrom by an upright housing portion 12 enclosing the principal parts of the operating and controlling devices. The frame or casing together with various brackets and other attached minor parts collectively afford the necessary enclosures, supports, bearings, etc., for the various moving parts. The bed 10 carries a work plate 13 upon which the material W to which the buttons are to be attached is supported and against which it is clamped by a combined presser foot and button clamp 15 for holding the individual buttons B and positioning them for the operation of the sewing instrumentalities.

The main driving and controlling instrumentalities include a main power shaft 16.journalled in the head H and to which power is supplied through a belt pulley H; a vertical cam shaft 18 journalled in suitable bearings in the housing 12, driven through worm gearing 25 from the main shaft 16, and carrying a cam I29 for controlling certain of the movements of the stitchforming instrumentalities; and a horizontal looper shaft I9 journalled in the base 10.

The stitch-forming mechanism as shown is of the general type described in the Dahl Patent No. 862,238, August 6, 1907, although operating with a single needle thread. This, mechanism includes an eye pointed needle 80 carried by a needle bar 8| mounted for vertical or longitudinal reciprocation in the head 1|, a pair of loopers 82 and 83 (Figs. 4 to 11) and cooperating loop spreaders 223 and 224 on a looper carrier 84 secured to the looper shaft 19 adjacent its forward end, and a cam plate 228 for operating the loop spreaders as the looper shaft and looper carrier are oscillated. The loopers are formed with thread engaging shoulders 2, while the loop spreaders, which are pivoted to the looper carrier and are normally held withtheir operative ends closely adjacent their corresponding loopers by springs 226, are formed with tail portions 230' adapted to engage bevelled edges 229 of the cam plate to actuate said loop spreaders to spread the loops, as hereinafter explained.

The sewing or needle thread t is supplied to the needle from a suitable source, not shown, through a tension device or thread clamp 85 (Fig. and suitably arranged guides on the head and the needle bar, shown, for example,

at 86 and 81, under the control of a take-up 88 operated by a cam 422 on the shaft Hi, all as hereinafter more fully explained. The needle bar is vertically reciprocated from the main shaft 16 by any suitable means, as, for example, a crank pin carried by a disc 89 on said shaft and connected by suitable linkage 9| to a collar 92 on said needle bar, and is moved laterally between successive descents to cause it to pass alternately through different holes hl, M (Fig. in a button B held by the button clamp. Means for thus laterally oscillating the needle may be of any well known type common in the button and button hole sewing machine arts. As herein shown, however, the needle -bar BI is guided adjacent its upper end in a bearing 93 carried by a flexible metallic disc 94 suitably clamped in a recess 95 in the upper end of the head", this mounting of the needle bar guide being such as to permit the needle bar a limited swinging movement about the point of intersection of its axis with the plane of the disc 94. Adjacent its lower end the needle bar is guided in abearing 96 similarly mounted by means of a disc 91 in a carrier member 98. The carrier member 98 (see also Fig. 3) is pivoted at I01 in the head H to swing in a horizontal plane, thereby oscillating the needle bar laterally as above described, said swinging movement being effected through a link II3 connecting said carrier member with a lever I22 pivoted at I23 in the head and carrying a cam follower I25 engaging a cam groove I21 in the top of the cam The looper shaft 19 and looper carrier 84 are oscillated to cause the loopers 82 and 83 and their associated loop spreaders 223 and 224 alternately to enter successive needle loops, as the needle rises from its lowest position, and spread' and position the same to be entered by the needle upon its subsequent descents, as more fully described in the Dahl patent above referred to. As herein shown, the looper shaft 19 is oscillated from the main cam I29 through suitable connections including a link I98 (Figs. land 3) connected at I9I with one end of a lever I93 fulcrumed at its opposite end at I94 in the housing 12 and having intermediate its ends a cam follower I95 engaging a cam groove I91 formed in the side or periphery of the cam I29. The connections between the shaft 19 and link I90 are not shown and described in detail herein as specifically they form no part of the present invention and are fully disclosed in the Reece application above referred to.

Referring to Figs. 1 and 12 to 20, the tension device 85 comprises two oppositely dished resilient disks 350 and I mounted on a rod 352 guided for longitudinal moment in a bushing 353 having an enlarged and recessed upper end upon which the lower disk 350 is supported,-said bushing being in threaded engagement with the top of the head 1|, whereby its vertical position thereon can ;ment of the nut 355. Intermediate its ends, be-

tween the dished portions of the disks 350 and 35 I,

' the rod 352 is formed with an enlargement 351 of slightly less length than the space between said dished portions. At its lower end, the rod 352 is formed wtih a head 358 which engages an edge cam 359 on the main power or needle shaft 16, said head being held in engagement with said cam by a spring 360 interposed between saidhead and a shoulder on the bushing 353; The thread t is received between the marginal portions of the disks 350 and 35I ,and when the rod 352 engages a high portion of the cam 359 and is moved thereby into the position shown in Fig. 13, the enlargement 351 lifts the disk 35I away from the disk 356, thereby releasing the thread. When the rod 352 engages a low portion of the cam 359, the spring" 369 moves it into the position shown in Fig. 12, whereupon the enlargement 351 releases the disk 35I and permits the latter to be pressed toward the disk 350 by the spring 356, thereby clamping the thread or squeezing the same between said disks with a pressure determined by adjustment of the nut 355. The cam 359 is formed with two.

low portions a and b and two high portions 0 and d. The shape of the cam and its angular position on the needle shaft 16 are such that when the ,needle starts downwardly from its uppermost position, the rod 352 is in engagement with the low portion a, thereby clamping or squeezing the thread between the disks 358 and 35I. When, or just before, the needle enters the work, the rod 352 is engaged by the high portion 0, thereby releasing the thread, the shape and position of said portion 0 being such as to cause the thread to be in released condition when the needle enters work of the maximum thickness which the machine is intended to operate upon. When the needle approaches its lowermost position, the rod 352 engages the low portion ,b, thereby clamping or squeezing the thread between the disks 350 and 35I When, or just before, the needle reaches its lowermost position, the rod 352 engages the high portion d1, thereby releasing the thread until the needle has started upwardly and its point has reached approximately the position shown in Fig. 17, after which the rod 352 engages the low portion a, thereby causing the thread to be clamp or squeezed between the disks 356 and 35I and to be thus held until the needle has reached its uppermost -position and has moved downwardly into a position adjacent thework, as above explained.

The take-up 88 comprises a three-armed lever pivoted at 4I4 atthe top of the head 1I, said lever having an uprightarm 4I6 formed with an opening or perforation 424 through which the thread passes between the tension device and the needle, a second arm 4I8 connected by a spring HQ with a pin secured to the wall of the head, and a third arm 420 engaged by the upper end of a plunger 42I slidably mounted in the top of the head and engaging at its lower end the periphery of the cam 422 on the main power or needle shaft 16. The cam 422 is formed with a descending portion e that causes the take-up to give up thread to the needle during the major portion of the descent of the latter, a short ascending portion f operative, as the needle approaches its lowermost position, to cause the take-up to withdraw a cast off loop from the loopers, as hereinafter explained, said ascending portion 1 being connected by a concentric portion g with a second ascending portion It operative, as the needle reaches approximately its highest position, to cause the take-up 4 to set the stitch.

The operation of the stitch-forming mechanism in the attachment of a button B is illustrated in Figs. 4 to 11. As above explained, the needle 80 is vibrated laterally between successive descents, causing the same to pass alternately through different holes hl and k2 in the button, by the cam groove I21 (Fig. 3) in the cam I29, the looper shaft 19 and looper carrier 84 being oscillated in synchronism with the operations of the needle by the cam groove I91, Fig. 1. At the beginning of the attaching operation, the needle descends through one of said holes, for example, thehole hI shown at the left in Fig. 4, and through the work W, the looper carrier at this time moving toward the right from its extreme position toward the left. The needle then rises, leaving behind it a thread loop I, as shown in Fig. 5., The continued movement of the looper carrier toward the right causes the end of the looper 82, as well as the end of the corresponding loop spreader 223 (which at that time is immediately above said looper as shown in Fig. 10), to enter said loop. The needle continues to rise and the looper carrier continues to move toward the right, causing the loop I to be caught by the shoulder z of the looper 82 and carried into a position below the hole 712 as shown in Fig. 6. During this movement the tail 239 of the loop spreader 223 engages the left bevelled edge 229 of the cam plate 228, causing said spreaderto be rocked about its pivot and carrying its end away from the looper 82, thereby spreading said loop as shown in Fig. 11. The needle 88 is then moved laterally toward the right and again descends, this time passing through the hole b2, and its descent passes through the loop Z, the looper carrier slmultaneouslymoving toward the left to cause the looper 82 and loop spreader 223 to release said loop which is thereupon drawn up about the needle and out of the path of the loopers, as shown in Fig. '7. The needle then rises, leaving behind it a second loop 1 which, as the looper carrier 84 continues its movement toward the left, is immediately entered by the looper 83 and loop spreader 224 in a maner similar to the engagement of the loop I by the looper 82 and spreader 223 as above explained. Continued movement of the looper carrier into its extreme position toward the left causes the loop I to be spread by the spreader 224 and caught by the shoulder a of the looper 83, so as to be carried into and held in a position i1. which the needle will pass therethrough during its next descent through the hole hl, thereby completing the first stitch which is set by a final operation of the takeup acting to draw the loop I tightly up against the work after the needle has risen from and released said loop. These operations are continued to form a group of stitches s, Fig. 2, of a numb-er determined by the shape of the cam grooves I21 and I91.

A single stitch-forming cycle corresponding to one complete reciprocation of the needle (down and up), for example, the cycle immediately following the one last described, is illustrated more in detail in Figs. 12 to 20. The needle being in its substantially uppermost position, as shown in Figs. 9 and 12, and having been moved laterally into a position to pass through the hole hi, commences its descent, the thread being clamped by engagement of the head 358 with the low portion a of the cam 359, and the take-up 88 moving forwardly to release the thread to the needle by engagement of the plunger 42! with the descending portion e of the cam 422. As the needle eye is about to enter the work, as shown in Fig. 13, the head 358'is engaged by the high portion 0 of the cam 359, thereby opening the thread clamp and releasing the thread, the clamp preferably remaining open until the needle has descended through the hole hl, through the work W, and through the spread loop Z into substantially the position shown in 14. By reason of the complete release of the thread during this period, the needle is enabled to draw from the supply a length of thread automatically and accurately measured in accordance with the spacing of the holes hl, 11.2,

the thickness of the button B, the thickness of the work W, and the length of neck n connecting the button with the work. As the needle advances from the position shown in Fig. 14 to that shown in Fig. 15, the looper 83 and loop spreader 224 move toward the right to relase the loop I as shown in Fig. 15. -At this time the head 358 is engaged by the low portionb of the cam 359, thereby causing the thread to be clamped, after Which the plunger 42l is engaged by the ascending portion f of the cam 422, causing the take-up 88 to move from the broken line to the full line position in Fig. 16, and thereby withdraw the loop Z out of the path of movement of the loopers and up about the needle as shown in Fig. 16, this operation being assisted by the continued downward movement of the needle. Meantime the needle has descended to substantially its lowermost position and thereafter rises to leave behind it another loop F as shown in Fig. 1'7. Since, during the latter part of the descent of the needle, the thread has been firmly clamped and has been subjected to the action of the take-up, it is placed under a substantial tension and has been resiliently stretched to a certain extent. In order to prevent this tension, and the consequent stretch of the thread, from interfering with the throwing out of the loop I, the clamp is opened to release the thread, as soon as the loop I has been drawn into the position shown in Fig. 1 6, by engagement of the head 358 with the high portion (1 of the cam 359. Meantime, the looper carrier 84 has been moving toward the right and, when the loop Z has been sufficiently opened by the rise of the needle, the looper 82 and loop spreader 223 enter said loop as shown in Fig. 18. At this time the head 358 is engaged by the low portion a of the cam 359, causing the thread to be clamped, the loop spreader 223 is operated to spread the loop Z as above explained and as shown in Fig. 19, and, after the needle has risen from the work, the

plunger 42! is engaged by the ascending portion spect to the thickness of the thread, may be such that, when the head 358 is engaged by a high point of the cam 359, the thread will either be completely released or subjected to only a light tension, depending upon the character of the work. On some types of work, particularly heavy work, some tension is not objectionable and may be beneficial, whereas in sewing light silks, for example, complete release is desirable in order to avoid any tendency to puckering. Also, for some classes of work, additional light tension devices, common to the art, may be provided at suitable points along the path of the thread. In any event, however, the release of the thread should be at..least suflicient to permit the needle to draw thread from the supply, as above described, and to lay it across the face of the work Without any substantial resilient stretch.

I claim:

1. In a sewing machine, in combination, stitchforming devices including a needle and cooperating .loop handling means, means for reciprocating said needle to cause the same to penetrate and withdraw from the work, a take-up, means for operating the same when the needle has passed through a previously formed loop during its work penetrating movement to withdraw said previously formed loop from the loop handling means, a thread clamp for the needle thread, and means for operating said clamp to clamp the thread during the operation of the take-upand to release the same when the needle is at the limit of its penetrating movement.

2. In a sewing machine, in combination, stitchforming devices including a needle and cooperating loop handling means, means for reciprocating said needle to cause the same to penetrate and withdraw from the work, means for relatively moving the needle and work to cause the needle to penetrate the work at difierent points upon successive reciprocations, a take-up, means for operating the same when the needle has passed through a previously formed loop during its work penetrating movement to withdraw said previously formed loop from the loop handling means, a thread clamp for the needle thread, and means for operating said clamp to clamp the thread during the operation of the take-up and to release the same when the needle enters the work.

3. In a sewing machine, in combination, stitchforming devices including a needle and cooperating loop handling means, means for reciprocating said needle tocause the same to penetrate and withdraw from the work, means for relatively moving the needle and work to cause the needle to penetrate the work at different points upon successive reciprocations, a take-up, means for operating the same when the needle has,

passed through a previously formed loop during its work penetrating movement to withdraw said previously formed loop from the loop handling means, a thread clamp for the needle thread, and means for operating said clamp to clamp the thread during the operation of the take-up and to release the same when the needle enters the work and also when the needle is at the limit of its penetrating movement.

4. In a sewing machine, in combination, a needle, means for reciprocating the same to cause it to penetrate and withdraw from the work, means for relatively moving the needle and work to cause the needle to penetrate the work at different points upon successive reciprocations, a take-up, means for operating the same to set the stitches, a tension device or thread clamp for the needle thread, and means for operating said device to clamp the thread when a stitch is set and to release the same during at least a portion of the work penetrating movement of the needle.

5. In a sewing machine, in combination, stitchforming devices including a needle and cooperating loop handling means, means for reciprocating said needle to cause the same to penetrate and withdraw from the work, means for relatively moving the needle and work to cause the needle to penetrate the work at difierent points upon successive reciprocations, a take-up, means for operating the same to set the'stitches, a thread clamp for the needle thread, and means for operating said clamp to clamp the thread when a stitch is set and to release the same when the needle enters the work and also when the needle is at the limit of its penetrating movement.

6. In a sewing machine, in combination, stitchforming devices including a needle and cooperating loop handling means, means for reciprocating said needle to cause the same to penetrate and withdraw from the work, means for relatively moving the needle and work to cause the needle to penetrate the work at different points upon successive reciprocations, a take-up, means for operating said take-up when the needle has passed through a previously formed loop during its work penetrating movement to withdraw said previously formed loop from the loop handling'means and again to set the stitch when the needle has withdrawn from the work, a thread clamp for the needle thread, and means for operating said clamp to clamp the thread during the aforesaid operations of the take-up and to release the thread when the needle enters the work.

'7. In a machine for sewing on buttons, in combination, a work clamp for holding a button and positioning the same with respect to material to JOSEPH HQPIKUL.

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