US2160105A - Shoe sewing machine - Google Patents

Description

May 30, 1939. B. T. LEVEQUE I SHOE SEWING MACHINE Filed Dec. 20, 1957 5 Sheets-Sheet 1 May 30; 1939.

B. T. LEVEQUE SHOE SEWING MACHINE Filed Dec. 20, 1937 5 Sheets-Sheet 2 May 30, 1939. B, LEVEQUE 2,160,105

SHOE SEWING MACHINE Filed Dec. 20, 1937 5 Sheets-Sheet 5 May 30, 1939.

B. T LEVEQUE SHOE SEWING MACHINE 1937 5 Sheets-Sheet 4 Filed Dec. 20

May 30, 1939. B. T. LEVEQUE SHOE SEWING MACHINE Filed Dec. 20, 1957 5 Sheets-Sheet 5 Patented May 30, 1939 UNITED sm'rss PATENT OFFICE SHOE SEWING MACHINE Application December 20, 1937, Serial No. 180,701

22 Claims.

The present invention relates to shoe sewing machines and more particularly to presser-foo-t operating mechanisms therefor.

One object of the present invention is to profoot mechanism by which the presser-foot is clamped upon and released from the work during each work feeding and stitch forming cycle of the machine, and by which a predetermined clamping or squeezing pressure may be applied to the work regardless of variations in the thickness of the work.

Another object of the present invention is to provide simple and efficient means for lifting the presser-foot from the Work at the completion of a sewing operation to permit removal of the work and to place the parts in proper position for reception of a new piece of work.

With these objects in view the present invention comprises a machine including the improved presser-foot mechanism hereinafter described and particularly defined in the claims. The presser-foot mechanism illustrated in the drawings is designed primarily for use in the outsole shoe sewing machine disclosed in my pending application Serial No. 10,621, filed March 12, 1935, and all of the parts of the machine herein illustrated and not specifically described are the same in construction, arrangement, and operation as the corresponding parts of the machine disclosed in said application.

In the accompanying drawings Fig; 1 is an elevation partly in section of the presser-foot and operating mechanism therefor, with the parts in running position; Fig. 2 is a view similar to Fig.

1 showing the parts when the machine is stopped; Fig. 3 is a plan view of the parts shown in Figs. 1 and 2; Fig. 4 is a side elevation on an enlarged scale of the presser-foot and associated devices; Figs. 5 and 6 are views similar to Fig. 4 showing the parts in different positions; and Fig. '7 is a section on line 'i'! of Fig. 6.

The illustrated embodiment of the present invention comprises a presser-foot 8 secured to a '45 lever l0 which is pivoted at i2 on an arm or bracket I4 secured to a reciprocating feed slide or carriage It. Cooperating with the presserfoot is a work support [8 which is secured to the arm I4. Connected with a rod depending from the feed slide is an arm or link 22 which, as described in my co-pending application Serial No. 10,621, filed March 12, 1935, forms one arm of a toggle by which the feed slide is reciprocated. The work, which is indicated diagrammatically at Et in Fig. 1, is engaged between the presservide a simple and positively operating presserfoot and Work support. The stitch forming mechanisms including a curved needle and awl are operated through openings in the presserfoot and work support on the are indicated in dot-and-dash lines in Fig. 4.

The presser-foot is pulled yieldingly toward the work by a spring 26 secured at one end of the lever 10 and at the other end to an arm 28 pivotally mounted on the slide and adjustable by means of a bolt 30 which bears against the under side of the arm 14. For the purpose of applying to the work a squeezing pressure in addition to that afforded by the spring 26, there is provided a toggle mechanism comprising two arms 32 and 34 which are pivoted together on a stud 36. The arm 32 is pivoted on the rear of the presser-foot lever 0 at 33 and the lower end of the toggle arm 34 is pivoted at 40 on a sector-shaped plate 42 which in turn is journaled on a stud 44 carried by the feed slide. The stud 36' which forms the pivotal connection between the two toggle arms 32 and is connected by a ball and socket joint 46 with a rod 48 by which the toggle is operated. The sector 42 is wedge-shaped at its periphery, as indicated at 50, to be engaged by a looking or braking shoe 52 by which the plate may be held from movement. When not locked by the shoe 52, the sector 42 merely floats on its pivot, and any movement of the toggle will merely oscillate the sector without affecting the presserfoot. If the plate is locked by the shoe 52, the motion of the toggle is communicated directly to the presser-foot lever 10. Thus with the plate. locked, the presser-foot may be actuated topress or squeeze the work by straightening the toggle, as shown in Fig. 4, or to lift the presser-foot clear of the work by breaking the toggle, as shown in Fig. 5. In the operation of the machine, the sector 42 is held locked during the greater part of the cycle, and is only momentarily released to permit the presser-foot to be brought into yielding engagement with the work by the spring 26, as will hereinafter be described in detail.

The mechanism for operating the presser-foot toggle comprises the rod 48 which at its rear end is connected by a ball and socket joint 54 with an arm 56 having a hub 58 secured on a rock shaft $0. Also secured on the shaft 00 is 2. depending arm 52 having a slot 64 in which is adjustably secured one end of a link 66. The slot 64 provides for adjustment of the motion of the toggle. The link 06 is connected to a bell crank 68 journaled on a stud l0 and having an arm provided with a cam follower 12 received in a cam groove 14 of a presser-foot operating cam HS on the cam shaft Tl. As shown in Fig. 1, the cam follower 12 is in its extreme left-hand position whereby through the connections above described the toggle arms 32 and 34 are straightened (Fig. 4) to apply squeezing pressure to the work by the presser-foot. This is the position of the parts during feed of the work. After about 30 degrees motion of the cam shaft from the position of Fig. l, the cam follower 12 is moved to the right by the portion indicated at a of the cam, thereby operating through the above-described connec tions to break the toggle to the position of Fig. 5, whereby the presser-foot is lifted clear of the work. Before describing further the operation of the lift cam, the connections for operating the lock will next be described.

The presser-foot lock comprises the wedgeshaped peripheral portion 58 of the sector 42 and the braking or looking shoe 52 which, as shown in Fig. 5, is shaped to engage tightly with the wedge 50. The shoe is pivotally mounted on a pin i8 which extends outwardly from, but eccentric to, a rock shaft 88 jcurnaled in a bracket 82 on the feed slide. The construction is such that counter-clockwise rotation of the rock shaft 8i] as viewed in Figs. 1 and 2, moves the shoe into braking engagement with the sector (Fig.1) and clockwise rotation moves the shoe out of engagement with the sector (Fig. 2). Secured to the rock shaft 88 is an arm 98 having a stud 92 connected by a ball and socket joint 94 with a reciprocating rod 96. As shown in Fig. 1, the rod 96 is threaded at its rear end to receive an ad.- justable nut 93 against which bears a boss are extending outwardly from an arm W2. The boss iflfi has an opening sufficiently large to permit universal movement of the rod 96 to accommodate the lateral motion of the feed slide. The boss is yieldingly pressed against the nut 98 by a spring H34 retained on the rod by a nut 1st whereby the spring pressure may be adjusted.

The arm I62 constitutes one arm of a bell crank pivoted on the rock shaft 60, the other arm H38 of the bell crank being connected by a link lit with an arm H2 of a bell crank which is freely pivoted on a rock shaft M, the other arm HE of the bell crank carrying a cam follower roll 5 I8 received in a cam groove I26 of a locking cam I22. As shown in Fig. 1, the locking cam groove is circular except for a short region indicated at P23 by which the cam follower H8 is moved momentarily to the left and back again. It will be seen that during movement of the follower 5 i8 to the left, under the influence of the portion MS of the cam, the rod 86 is moved to the right, as viewed in Fig. 1, thereby rocking the shaft 80 clockwise to move the braking shoe 52 away from the peripheral edge 59 of the sector plate 42. This action momentarily unlocks the presserfoot, and places the presser-foot entirely under the action of the spring 26. The sector 42 adopts a position depending on the thickness of the work.

The operation of the parts above described will now be explained. In Figs. 1 and 4, the presserfoot is shown clamped or squeezed on the work, the locking sector being engaged by the braking shoe 52 and the toggle arms 32 and 3% being straightened. This is the position of the parts during feed of the work. After about thirty degrees rotation of the cam shaft from the position of Fig. l, the feed motion by that time having been completed, the portion a of the operating cam groove reaches the cam follower 12, thereby moving the follower to the right and breaking the presser-foot toggle as previously described. The sector plate still remains locked. The resulting position of the parts is shown in Fig. 5, the presser-foot being then lifted clear of the work. At this time, the back feed of the presser foot and work support is accomplished through the connection 22. After the back feeding operation, the lock 52 is released by engagement of the portion !23 of the locking cam with the looking cam follower H8. This momentary release frees the presser-foot and permits it to be pulled into yielding engagement with the work by the spring 26. In the short interval when the brake shoe is released, the presser-foot toggle is par tially straightened by virtue of the fact that a portion b of the operating cam groove T l arrives at the cam follower 12, thereby moving the follower slightly to the left. This movement of the toggle does not affect the presser-foot which is then unlocked but simply resets the toggle in preparation for the squeezing pressure which is to be applied shortly afterward. This position of the parts is shown in Fig. 6, the lock being off and the toggle being in a position intermediate to its straightened and wide-open positions. At this time the sector 4'2 has assumed a position depending on the thickness of the work. A slight further rotation of the cam shaft moves the looking cam follower H8 to the right, thereby moving the brake shoe 52 into engagement with the periphery of the sector plate 42. After a short further rotation of the cam shaft, the portion 0 of the cam arrives at the cam follower '52, moving the follower to its extreme left position, which is the same as that indicated in Fig. 1. This again straightens the toggle and brings the parts to the position shown in Fig. 4:, namely, that in which the work is clamped or squeezed between the presser-foot and the work support. This position of the parts is retained until the portion a of the cam it again acts on the follower 12, a distance of nearly three-quarters of a revolution during a part of which the work feed is again effected.

The presser-foot locking mechanism, as above described, operates to apply to the work a definite squeezing or clamping pressure which is independent of variations in the thickness of the work. During the period in which the presserfoot is unlocked, the presser-foot and the sector assume positions determined by the work thick ness, and thereafter the definite motion of the toggle results in the application of the same squeezing pressure, regardless of how the work may vary in thickness. This feature is important, since the work should be clamped under a definite predetermined pressure sufficient to hold the work during the feeding and stitch forming cycles, but preferably below the pressure at which the work will be marred. Furthermore, the presser foot is always lifted a definite distance above the work for the back feeding operation. These results are attained in the present invention by simple and positively acting devices of small weight, which may be satisfactorily operated at the necessary high speed of modern sewing machines.

The machine is provided with means for automatically lifting the presser-foot from the work at the completion of a sewing operation to release the work and to place the parts in readiness for receiving a new piece of work. The releasing means is connected with the starting and stopping cams of the machine which are of the same character as described in my co-pending application above referred to and which will be hereinafter briefly described.

The releasing means comprises a lifting lever I30, the end of which overlies the toggle link 32 at its pivotal connection 38 with the presser-foot lever It. The lever I36 is secured to a rock shaft I32 journaled in a bracket i3 l extending upward 1y from the machine frame. The lever 936 is held during the stitching operation in its upper or inactive position by a spring we connected between the rear end of the lever and the bracket. When the lever is depressed, as shown in Fig. 2, it engages the link 32 and acts in a direction to lift the presser-foot. Slightly before the lever I30 acts to lift the presser-foot, it is necessary to release the brake shoe 52 from the sector 52 and to this end, there is also connected to the rock shaft l32, a release lever l38 having at its end a cam roll M to engage a cam M2 depending from the rock shaft 88. The rock shaft 813, as previously described, carries the eccentric pin 78 on which the brake shoe 52 is mounted so that clockwise movement of the cam H52 by the roller it,

as viewed in Figs. 1 and 2, releases the brake shoe and thereby permits the lever Hill to depress the presser-foot lever and the whole toggle assembly. The rotation of the rock shaft fit by the cam Hi2 pulls the actuating rod 95 to the right and this action is permitted by the spring 55 3 which is compressed as shown in Fig. 2.

The connections between the levers H33 and E33 and the starting and stopping cam include a lever M6 which is also secured to the rock shaft I32. The lever MS has a curved cam surface Hi8 and at its extreme end a flat portion itil. The cam surface is engaged by a roller on one arm I52 of a three-arm lever which is pivoted on a fixed part of the machine at E54. The second arm I56 of the lever forms one link of a toggle of which the other link i555 is connected to an arm 150 secured to the rock shaft M. The third arm I82 of the three-arm lever is connected by a link Hi l with the starting and stopping lever. Secured to the frame of the machine is a bracket H55 having adjustable limit bolts I58 and W8 to engage the arms 1.32 and I52 respectively and thereby to limit the motion of the three-arm lever in either direction.

The starting and stopping lever comprises a bell crank pivoted on the shaft it and having two arms H2 and 5M which are in different planes. The arm H2 has a stopping cam follower H8 adapted to be engaged by the stopping cam H8 and the arm i'l l has a starting cam follower E88 to be engaged by a starting cam E82. The starting and stopping cams are mounted on a hub splined to the cam shaft and arranged for movement along the cam shaft by a yoked arm i843 secured to a rod Hit which is connected to the foot operated treadle. By means of the yoked arm Hit, either the stopping cam l'lfi may be brought into the plane of its follower H6 or the starting cam I82 may be brought into the plane of its follower 18$. The conditions for stopping are shown in Fig. 2, wherein the cam has thrown the follower I15 to the right, thereby turning the arms 152, i555 and H62 in a counter-clockwise direction. against the limit stop lit. This action straightens the toggle E55), E58, thereby rocking the rock shaft l Ml counter-clockwise. The shaft .1 It is a control shaft which, as described in my up, the looper, and other thread manipulating and work feeding devices of the machine, in a manner to bring all such parts to rest in predetermined positions. Byvirtue of the inertia of the parts and the straightening of the toggle, the follower H6 is thrown clear of the cam H8. The counter-clockwise motion of the arm .l52 lifts the cam arm 9% and thereby depresses the release arms 536 and I38 to lift the presser-foot into the position of Fig. 2, as heretofore described. The arm Mt remains supported by the engagement of the arm |l52 with the flat surface 558. The cam shaft may continue to rotate for several revolutions, but in doing so, it merely operates the toggle cam to break and straighten the presser-foot toggle. The toggle is entirely ineffective since the presser foot is then held in raised position.

To reset the parts for a subsequent sewing operation, the treadle is operated to move the yoked arm ltd in such a manner as to place the starting cam H82 in the plane of its follower i229. When the follower is engaged by the cam, the arm li t is moved down into the position of Fig. 1, thereby rocking the three-arm lever I52, use, 562 clockwise against the limit stop its. As a consequence of this action, the toggle W8 is broken, thereby rocking the control shaft i l clockwise to reconnect the various thread manipulating and feeding devices with the driving mechanism. The cam follower lflfi is thrown clear of the cam N32. The clockwise motion of the arm i522 brings its end under the curved portion of the cam arm Hi6, thereby permitting the lifting and release levers fail and 138 to be raised into their upper or inactive positions by the spring Est, as shown in Fig. 1. From a comparison of Figs. 1 and 2 it will be observed that the presser foot release lever E36 will move out of engagement with the presser foot lever before the roller M8 on the lever i323 is disengaged from the cam M2 which controls the operation of the locking shoe. Accordingly, the presser foot is immediately drawn into engagement with the new work by the spring 25 at a time when the presser foot toggle is straightened. This action is permitted because thesector 42 is then free, but immediately thereafter the M2 is released and the sector is locked. On the first engagement of the presser foot with the new work, there is no provision for applying squeezing pressure in addition to the pressure afforded by the spring 25, but none is necessary because no work feeding motion is accomplished at that time. Fig. 1 shows the relative positions of the parts immediately after operation of the starting cam and it will be seen that the toggle is shortly to be broken to lift the presser foot in preparation for the back feeding motion. After the first back feed, and until the stopping cam again operates, the presser-foot is under the control of the spring 26 and the presser-foot toggle for the normal sewing operatiomas previously described.

The nature and scope of the invention having been indicated, and a specific form of the invention having been described, what is claimed is:

- 1. A shoe sewing machine having, in combination, a presser-foot, means for moving the presser-foot yieldingly into engagement with the work, a presser-foot lock including a floating member movable with the presser-foot to a position. determined by the thickness of the work, means for locking the floating member, a toggle connected with the presser-foot, and for operating the toggle when the floating member is locked to squeeze the work and to lift t e presser-foot clear of the work.

2. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presser-foot lock including a pivoted floating member, a toggle connected between the presserfoot lever and the floating member, means for locking the floating member, and a toggle actuating mechanism operating when the floating member is locked to straighten the toggle to squeeze the work and to break the toggle to lift the presser-foot clear of the work.

3. A shoe sewing machine having, in combination, a presser-foot, means for moving the presser-foct yieldingly into engagement with the work, a presser-foot lock including a floating sector movable with the presser-foot to a position determined by the thickness of the work, means for locking the floating sector, and means for operating the presser-foot when the floating sector is locked to squeeze the work and to lift the presser-foot clear of the work.

4. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presser-foot lock including a pivoted floating sector, a toggle having two links, one of which connected with the presser-foot lever and the other with the floating sector, means for moving the presser-foot yieldingly into engagement with the work and acting to set the sector in a position determined by the thickness of the work, means for locking the sector, and toggle actuating means operating when the sector is locked to squeeze the work and to lift the presser-foot clear of the work.

5. A shoe sewing machine having, in combination, a presser-foot, means for moving the presser-foot yieldingly into engagement with the work, a presser-foot lock including a pivoted floating sector, connections between the presserfoot and the sector to move the sector to a position determined by the thickness of the work, a locking shoe for the sector, mechanism for engaging the locking shoe with the sector, and means operating when the sector is locked to operate the presser-foot to squeeze the work and to lift the presser-foot ciear of the work.

6. A shoe sewing machine having, in combination, a presser-foot, means for moving the presser-foot yieldingly into engagement with the work, a presser-foot lock including a pivoted floating sector, connections between the presserfoot and the sector to move the sector to a position determined by the thickness of the work, a locking shoe, an eccentric mounting for the locking shoe, and means for operating the eccentric mounting to move the locking shoe into or out of engagement with the sector.

'7. A shoe sewing machine having, in combination, a presser-foot, presser i'oct iever, a presserfoot lock including a floating member, a toggle having arms connected with the presser-foot lever and the floating member, means for locking the floating member during the greater part of the cycle. of operation of the machine and for momentarily unlocking the floating member at one point in the cycle, a spring for yieldingly moving the presser-foot into engagement with the work when the floating member is unlocked, and actuating means for the toggle to set the toggle in a predetermined position when the floating member is unlocked, to clamp the presser-foot on the work immediately after the floating member is locked, and thereafter to lift the presserfoot clear of the work while the floating member remains locked.

8. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presserfoot lock including a pivoted sector and a locking shoe to engage the periphery of the sector, a toggle having arms connected to the presserfoot lever and the sector, means for locking the sector during the greater part of the cycle of operation of the machine and for momentarily unlocking the sector at one point in the cycle, a spring for yieldingly moving the presser-foot into engagement with the work when the sector is unlocked, and actuating means for the toggle to set the toggle in a predetermined position when the sector is unlocked, to clamp the presser-foot on the work immediately after the sector is locked and thereafter to lift the presser-foot clear of the work while the sector remains locked.

9. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presserfoot lock including a pivoted sector, operating means for the presser-foot connected with the sector, a locking shoe cooperating with the periphery of the sector, and means for moving the shoe into or out of engagement with the sector.

10. A shoe sewing machine having, in combina tion, a presser-foot, a presser-foot lever, a presserfoot lock, means for operating the presser-foot lock to lock and release the presser-foot with relation to the work periodically during a sewing operation, stopping devices, a normally inactive lifting lever associated with the presser-foot lever, a presser-foot lock release member, and means operated by the stopping devices to actuate the lock release member and the lifting lever to raise the presser-foot from the Work.

11. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presser-foot lock, means for operating the presser-foot lock to lock and release the presser-foot with relation to the Work periodically during a sewing operation, stopping devices, a lifting lever normally out of engagement with the presser-foot lever, and means operated by the stopping devices to actuate the lifting lever to raise the presser-foot, said means having provision for releasing the presser-foot lock.

12. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lock, a lock operating member to lock and release the presserfoot periodically during a sewing operation, the member having a yielding connection to permit independent release of the look, a normally inactive lifting lever associated with the presserfoot, a stopping cam, and connections from the stopping cam to the lifting lever and the lock to release the presser-foot and raise it from the work.

13. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presser-foot look, a normally inactive lifting lever associated with the presser-foot, a starting and stopping lever, and connections from the starting and stopping lever to the lifting lever and the presser-foot lock to release the presser-foot and to raise the presser-foot.

14. A shoe sewing machine having, in combition, a presser-foot, a presser-foot lock, a presserfoot lifting lever, a lock release lever, an operating arm for simultaneously operating the hfing lever and the lock release lever, starting and stopping devices, and connections therefrom to the operating arm. v

15. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lock, a presserfoot lifting lever, a lock release lever, an operating arm for simultaneously operating the lifting lever and the lock release lever, a starting and stopping lever, and connections between the starting and stopping lever and the operating arm.

16. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lock, a presserfoot lifting lever, a lock release lever, an operating arm for simultaneously operating the lifting lever and the lock release lever, the operating arm having a cam surface, starting and stopping devices, and connections therefrom to the cam surface of the operating arm.

17. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lock including a pivoted sector and a shoe movable into and out of engagement therewith, means for normally moving the shoe periodically with relation to the sector during a sewing operation, an independent lock releasing lever, a normally inactive presserfoot lifting lever, an operating arm for the lock releasing lever and the presser-foot lifting lever, starting and stopping devices, and connections therefrom to the operating arm.

18. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lever, a presserfoot lock including a pivoted sector, operating means for the presser-foot connected with the sector, a locking shoe cooperating with the periphery of the sector, means for periodically moving the shoe into and out of engagement with the sector, independent releasing means for moving the shoe out of engagement with the sector, a normally inactive presser-foot lifting lever, stopping devices, and connections from the stopping devices to the releasing means and the lifting lever.

19. A shoe sewing machine having, in combination, a presser-foot, means for moving the presser-foot yieldingly into engagement with the work, a presser-foot lock including a pivoted floating sector, connections between the presser-foot and the sector to move the sector to a position determined by the thickness of the work, a locking shoe, an eccentric mounting for the locking shoe, means associated with the eccentric mounting to move the locking shoe periodically into and out of engagement with the sector, independent releasing means associated with the eccentric mounting for moving the shoe out of engagement with the sector, a normally inactive lifting lever associated with the presser-foot, stopping devices, and connections between the stopping devices and the releasing means and lifting lever.

20. A shoe sewing machine having, in combination, a presser-foot, a presser-foot look, a presserfoot operating cam, connections between the cam and the presser-foot to move the presser-foot periodically with relation to the work, a locking cam, connections between the locking cam and the lock to operate the lock periodically in timed relation with the presser-foot, a presser-foot lifting lever and a lock release to unlock and lift the presser-foot independently of the presserfoot operating cam and the locking cam.

21. A shoe sewing machine having, in combination, a presser-foot, a presser-foot lock, a lock operating member, a presser-foot locking cam, connections between the cam and the lock operating member to lock and release the presserfoot periodically, a stopping cam, connections between the stopping cam and the lock to release the lock, the lock operating member having yielding means to permit release of the lock independently of the operation of the stopping cam, and means controlled by the stopping cam for lifting the presser-foot.

22. A shoe sewing machine having, in combination, a presser-foot, a pivoted presser-foot lever, means for operating the presser-foot in a normal work holding and feeding cycle, a lifting lever overlying the presser-foot lever and out of engagement therewith during the normal cycle, stopping devices, and connections from the stopping devices and the lifting lever to move the lifting lever into engagement with the presserfoot lever to lift the presser-foot.

BERNARD T. LEVEQUE.

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