US2397588A - Shoe sewing machine - Google Patents

Description

April 1 4 F. ASHWORTH EI'AL 2,397,533

' SHOE 'SEWING MACHINE Original Filed Feb. 2, 1942 2 Sheets-Sheetl 72 70 VENTURE imh ' April 2,1946.

F. ASHWORTH El'AL SHOE SEWING MACHINE 1 Original Filed Feb. 2, 1942 2 Sheets-Shae 2 Patented Apr. 2, 1946 SHOE SEWING MACHINE Fred Ashworth, Wenham, and Carl F. Whitaker,

Beverly, Mass., assignors to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Original application February 2, 1942, Serial No. 429,206. Divided and this application August 13, 1943, Serial No. 498,484

14 Claims.

The present invention relates to improvements in work-feeding and guiding means for shoe sewing machines and is herein illustrated as embodied in a high-speed lockstitch sewing machine of the hooked needle type, as disclosed in the present inventors United States Letters Patent No. 2,271,611, granted February 3, 1942, and constructed and arranged to sew the outsole and welted upper of a Goodyear welt shoe.

In .outsole shoe sewing machines of the clamp feed type, inequality of spacings between stitches may be produced by variation in the position at which a shoe being operated upon is presented to the machine by an operator. Forcing a shoe against the forward face of the work support or against the back gage of a stitcher with an irregular pressure or holding the edge of the outsole in presenting the shoe to the machine at a slight angle to the natural line of feed, as is often the practice, in order to maintain the edge of the outsole against the back gage with less physical effort, causes the back gage of the machine to impart an outward component of movement to the outsole, thus rendering it easier for the operator to hold the work in position. When the edge of the outsole is given an outward component. of movement by the back gage, due to the practice of holding the edge of the outsole at an angle with relation to the line of feed, the seam also tends to follow a line not exactly parallel to the line of feed, especially when there is an abrupt curvature along the edge of the outsole. As a result, the back gage will exert a feed choking drag on the work which may become excessive if the angle at which the edge of the shoe outsole at the point of operation is presented is relatively large. Also due to the angular relation of the seam line to the line of feed, the needle may be looped improperly and the operations of others of the stitch forming devices may be adversely aflected.

The particular objects of the present invention are to provide a construction for a high-speed lockstitch outsole shoe sewing machine in which accurate and equal feeding movements will be imparted to the work during sewing'and in which the difliculties referred towill be avoided. In general, the objects are to simplify and improve the actuating mechanisms of an outsole sewing machine in a manner to insure accurate forma tion of stitches both in length and in uniformity with which they are set in the substance of an outsole where the machine is operated at high or moderate speeds, and to prevent irregularity in sewing operations of previous machines in which such irregularity has resulted from vibration, lost motion in the parts, or from other associated causes.

With these and other objects in view, a feature of the present invention contemplates the provision, in a high-speed outsole shoe-stitching machine, of a mechanism for actuating the work support and presser foot to exert a continued rearward pull at right angles to the line of feed on the outsole near the point of operations throughout and during feeding movements, thus avoiding the necessity of forcing the shoe against the back gage with an irregular feed choking pressure. Consequently, when the shoe is presented to the machine with the edge of the sole at the point of operation more nearly parallel with the line of feed than has been the practice heretofore, a substantially uniform pressure of the sole edge against the back gage may be maintained without Variation ordinarily caused by uncertain manipulations of the operator either in pressing the shoe rearwardly or in turning the shoe into a position with the sole edge out of line with the feed line to cause the feeding movement of the shoe to assist in pressing the sole edge against the back gage. The embodiment of this feature of the invention, as hereinafter described, is in a machine in which there is an arcuate movement of the work support and presser foot and a proper timed relation between the workclamping mechanism for the presser foot and feed-actuating mechanisms. When properly arranged and timed, the pressure of the presser foot is centralized on the work and the point of cen-' tralized pressure moves rearwardly and away from the needle while the work is clamped and is being fed. During back feeding movement, the parts of the work support and presser foot which cause the clamping pressure to be centralized move forwardly toward the needle, the presser foot then bein raised from the work. To centralize the clamping pressure, in accordance with this feature of the invention, the surfaces of the work support and presser foot are relatively inclined in the direction of work feed to cause the greatest clamping pressure to be exerted at a location on the seam side of the needle.

When no back gage is employed to guide the edge of an outsole being operated upon, it is customary to shape the work support in a wedge form which will readily fit into the crease between the welt and upper of a shoe. When a forward and rearward movement, in addition to the feeding movement, is imparted to the work support, it has been found desirable in the machine of the surface of the work support and is so arranged that the thrust of the work-engaging surfaces of the work support exerts substantially equal pr essures against both the welt an-d'upperwhile sewing along the shank of a shoe;

When the work support and'pr'esser feet are actuated in the manner just outlined and a back gage not moving with the work-'support'is. pro

vided for guiding the edge of anoutsole past'the point of operation of the stitch-forming devices,

there is a tendency for the movements of the work support to cause the lower corner of the welt i-riashoe to-become wedged between the work support and the gage. In order to prevent the welt from becoming wedged between the work support and gag'ein the present form of the machine; the gage constructed with angularly disposed su'rfaces, one or which-guides the welt alo g that surface en'g' agejdby the work support.

eature consists of agaf'ge having a lip upon w" lithe-surface of the weltrests and the work support-is provided with a shoulder formed at that side ofthe point of operation of the stitchfor evices first'engaged by the work durin Baek feedof the-work support, thus enabling the wirk engaging surfac'e of the lip to be located as close as possibleto'thework-supporti-ng' surfa e of the Work support. Etherfeatures or the invention consist in the novel 'aiid improved devices; combinations and arrangements of parts hereinafter described and claimed, .the ad-vantages of which will be readily understood --by-- one s-k-ill'ed-- in the art from the following'description taken in connection'with the accompanying drawings illustrating one emb'odi r rren't of the invention.

the drawings; Fig." 1 is-a View iri'front elevation of apart of an outsol'e sho'e' -sewing iinachine embodying the features of the present invention;

c 'Fig:2'isa view'in-sid'e elevation of a portion of the work supportand: presser foot'of' the machine'illustrated in Fig. togetherwi'th the novel bak' -gage;

Fig; ais'a-plan' view of the worksupport and ac age;

Fig. 4* is a'detailview; partly in section, ofthe work support carrier; its mounting shaft and feed ac'tuating mechanism;

5 is ad'iagrammatic-plan viewonan enlarged scale illustrating the -man-ner of obtaining-a;-rearwa rd'-pull on the work during work toya d operand-t es that -'i llustrated and described m inventors application Serial No. 429,206, filed February 2, 1942, (Patent No. 2,354,729, granted August 1, 1944), of which the present application is a division. The machine is equipped with a curved hook needle 2, a curved awl 6, a thread case 6 mounted within a shuttle ortloop taker, needle-threading mechanism including a looper 8 and a thread finger Ill, a work support 12, a

presser foot l4, back gage I6 and other stitchforming devices similar to those of the above patents, except as hereinafter pointed out. The general arrangement 7 of the machine is as usual, with thesewingj shaft I8 located behind and above the poi-nt 'of operation of the stitch-forming devices and substantially parallel to the line of the seam formedth'ereby.

The'work is ted in the illustrated machine, as

inthema-chine of Patents Nos. 1,824,063 and 2,271,6-1-1 by the movement of the work support and presser foot while clamping the work. As

on the main sewing'shaft I 8;a-cain lever-lfi; a

link- ZB 'connecti-ng'the --lever with the central joint of'apair of togglelinks 3ll an d '32; The togglel-ink 3fl i'spivotallymounted on a yoke 34 andthe other link connected-to a rearward ly extendinga'rm on'a-fe'ed carriage having'alugfor the pivotal mounting 22 for the presser foot lever 20; present feed carriage differs slightly from that of Patent No; 2271;61'1 in that the present carriage is formed as a single-integralpiece whereas the carriage ofthe said patent isformed in two parts clamped together on an inclined pivot shaft correspondingto'the shaft- 3'81 Thepivotshaft 38 is rotatably supported in bearings in the machine frame and is held fromlengthwisemovementby As has been stated, an important feature of the invention relates-to an arrangernent ofthe work support and-presser'foot acting asfa unit toexert a continued"rearward-pull at right-angles to the line of feed on the outsole of a shoe adjacent-thepoint ofsewing operations. In the embodiment of this feature; the' work 'support [2, which is of U-shape; is clamped'to parallel portions of the feed carriagetfi and has a table portion *formed along -its work-engaging surface with a raised-portion 42 at'the extreme left end of the -work engaging su-rfaceyasshown'in'Fig. 3, for causing the pressure exerted onthe work tobe centralized at a mid-point'suchas 44" (Figs. 4 and 5) on the portion '42 as the work is clamped by the presser foot; the Work-engaging surfaces of the work support and-presser f'oot-"beingel-sewhere inclined away from each other in 'a'direction' opposite to tha t of work'feed. While the workengagingl surfaces of both work support-and presser foot may beinclined-for this purpose, the present machine is illustrated'as-havingthe workengagi ng surface of the work supporoonly inclined. Inc-lining the work-engaging surfaces of the work support and" presser foot awayfrom each-othen-im a-' direction opposite to that of worlc feed provides ameans for enabling the pressu e on the work tobe centralized at the mid point" 54; During success-ive-'feeding movements The particular construction of the of the work support, the movements imparted to the work, unless otherwise prevented, are substantially the same as the movements of the midpoint 44, this being the center of greatest work clamping pressure.

Referring to Figs. 4 and 5, the pressure-(ten tralizing portion 42 is indicated by a somewhat D-shaped outline and is located on the work support at the seam side of the needle and awl paths so that in feeding the work it moves from the full-line position to the dot-dash line position always further away from a point 45 formed by the intersection of a line 46 passing through the center of the pivotal mounting shaft 38 at right angles to the line of feed indicated at 48, the line of feed passing through the needle and awl paths. The needle and awl paths are coincident in the illustrated machine at the location of the awl 4. The awl 4 is located at the trailing side of the intersection 45, or at the left as viewed from the front of the machine, the pressure-centralizing point 44 on the work support being located still further to the left of the awl away from the intersection 45. As a result of the swinging movement of the work support about the shaft 38, the pressure centralizing point 44 moves appreciably out of the line of feed along an arcuate path 50 and rearwardly by a distance 52 in feeding the work. Since the work is clamped by the Work support and presser foot during feeding movement, a rearward pull is exerted on the Work itself. Back-feeding movement of the work support and presser foot occurs when the clamping pressure of the foot is released from the work so that during back-feeding movement the pressure-centralizing portion 42 of the work support moves from the dot-dash position to the full-line position and with a forward thrust against the shoe being sewn through the distance 52. In the full-line position of the pressure-centralizing portion 42, the work is again clamped so that the rearward pull which is directed at right angles to the line of feed is continued from one sewing cycle to another, the awl being projected into and holding the work during each back-feeding movement.

The rearward pull of the work support and presser foot on the work has further desirable results due to the inclination of the pivotal mounting shaft 38 for the feed carriage, as indicated in Fig. 6. In sewing about the shank of a Goodyear welt shoe 54, shown in Fig; 7, and about the entire marginal portion of other types of shoes, a front surface 56 of the work'support disposed at an angle to the work-supporting and pressure-centralizing surfaces serves as a gage against the outer last-supported surface of the shoe upper indicated at 58. In a Goodyear welt shoe, the hoe is presented by the operator in the position shown with the upper against the gage surface 56 and with the projecting margin of welt 60 on the work-supporting surface. The angle of the pivotal mounting shaft 38 is such that the forward thrust movement of the work support during back feed of the. work support causes the gage surface 56 and the work-supporting surface of the table portion on the work support to be urged wtih equal pressures against both the upper and welt within the crease of the shoe while the clamping pressure of the presser foot is released. The inclination of the shaft 38 for this purpose is selected at an angle which will cause a line 62 bisecting the angle between the work gage and supporting surfaces on the table portion of the work support to intersect the axis of the shaft 38 at right angles, the forward thrust of'the work support when so arranged being exerted along this line.

In order to enable the operator to hold the work against the back gage with little or no muscular effort, according to present day practices, a shoe is presented to the machine with the edges of the welt and outsole substantially out of parallel to the line of feed 48. During feeding movements of a shoe so presented to the present machine, there is a tendency to choke or retard the feeding movement of the shoe whenever a back gage for guiding the rearward edges of the work is employed. With the present construction and mode of operation, the rearward pull exerted by the work support and presser foot on the work enables the operator to present the work with the sole edge more nearly parallel to the line of feed than possible heretofore, and at the same time, to hold the work against the back gage without substantial muscular effort.

As a means for accentuating the effects of rearward pull on the work, the feeding and backfeeding movements are so proportioned that the time of feed is relatively long, as compared with the time of back feed. When the machine is operating at high speeds, the inertia of a shoe is easily overcome during the relatively slow feeding movement and after the clamping pressure on the work is released, the relatively quick backfeeding movement enables a new clamping grip to be obtained on the work before any substantial forward movement of the work is possible.

Any link mechanism is subject to wear and looseness in its pivotal connections after long continued use and to offset the effects of wear and lost motion in the work-feeding mechanism of thepresent machine, the rearwardly extending arm of the feed carriage 36 is acted upon by a plunger 64 slidable in a passage in the machine frame and backed by a compression spring 56. The spring 66 is retained in the passage of the frame by a cap screw 68. By reason of the relatively long feeding movement imparted to the feed carriage by the feeding mechanism, it is possible for a light spring acting on the plunger 64 to take up all of the backlash in the feeding mechanisms even when the machine is operating at high speeds.

The back gage is similar to that of the machine disclosed in Patent No. 2,271,611 and is located with the trailing end of its work-engaging edge, or of that portion of the edge from which the work recedes, in close proximity to the portion 42 of the work support which acts to concentrate the pressure on the work, as indicated in Fig. 3.

With the end of the back gage so located, the operator is enabled to guide the work more effectively and to change its position easily while presenting the work to the machine.

To prevent the outer lower corner of the welt from becoming wedged or out between the work support and the back gage as the work is compressed by the presser foot, the present back gage is provided with a lip 10 having a, horizontal work-engaging surface substantially parallel to the work engaging surface of the work support in front of the vertical work-engaging portion of the back gage, as' shown in Figs. 2 and 3. The angularly disposed surfaces formed by the lip 10 and the vertical edge-engaging surface of the back gage provide a trough through which the outer lower corner surfaces of the welt travel. To enable the lip to approach as close as possible to. the work-engaging surface of the work supprt,;thfe work-supports 'cutrawayiatrlkto forrma: shouldertmi Duringzbackefeedflnovement ofizthe work support, the shoulder :l'4 rmovesit'owardcthe lipron the backgager-andsraisesgthe:;edge:of :the welt onto the surfacexof theaworkksupport. 7

- The nature :and scoperot .ithe iinventionzhariug. been indicated: and la iparticuia'r embodimentzoi the: invention .havingrwbeenix describeditwhat is claimed is::

1 An outsole-;shoe=sewing:rmachine having-Am combination, stitch-formingidevicesmaz workzsupport and; a 'presser foot roriclampingi amlifeeding the work, and lmeangfor actuating the work support: and: Lpresser foot to r cause them; toexertqa continued :pu'll: ion the zworkudirectedi rearwardly of. the" linexoi the-:"seam ,duringzsuccessive --wtork feeding movements.

1 2; An ;outso1ecshoereserving-machine" having, in combination, stitch-tormingdeviceai a; work support and a presserfootzforclamping and feeding the work, a carriage lUIiiW-hichi the workzsupport and: presseri fioot are mountedvto moves as a unit during workfeed, andfimeans for imparting: a. rearward movement t0.:l7h85081'1':i3g81 duringfeed andzaforward movement:duringibackiifeedi-of the: work support and spresser; footzcto cause :a con-l tinned rearwardpuii'ito besexertedtontheswork at rightangles. .tothe line. of: the: seam'ithroughou-t successive workefeeding movements; 7

31 An outs'ole shoeesewing: machinerihaving; incombination, stitch-forming; devices:includimg; a needle, a work: support and a. presser foot shaped to exert acentralized clampingpressureomthe Work, a carriage onwhich: the workxsupp'or't and presser foot are mountedto move as a unit, a shaftabout which the carriage oscillates through a curved path during workufeed," and. mechanisms for actuating the presser foot, and carriage in timed relation to cause the work t'o: b'e clamped while those parts which centralize the: clamping pressure move rearwardly of a-line. extending in the direction of feed and to: release theworlnfrom the grip of the presser foot: during. the return. movements.

4-. An outsole shoe-sewing-machine-having,in combination, stitch-torming devic'es; a carriage, a shaft about which the carriage isxmountedifoi: oscillation, and a work-feeding supportwand a work-clamping presser foot on the: carriage :having work-engaging. surfaces shape'd 'to centralize the clamping pressure ata-position; witlrrespect to'the carriage shaft in which a rearward pullwill' the needle.

V 6'. An outsole 'shoe-sewing machineuhaving, in combination, stitcheforming. devices; artwork;- feeding support, a work-clamping ,presser. foot, and mechanisms for actuating .thevwork support and presser foot at righttangles to the lin'ezot feed to cause them; to exert a:relativelyasljow realize ward pull on the work during'zfeeding:movements and a relatively ,qu'i'cki forward thrusttagainst the. work during back-feeding'.movements;

"7; Arr outsole. shoe-sewing: machineh'aving, in combination zastitcl'r-fiormingt'z devices; I a workaaomse feedingzsupportuhaumg; a table portion: formed with work-engaging surfaces disposed a-txan acute angle to enter; the crease :betweenthe Welt and upper :of ;.a shoe; a; Work-clamping; presser .foot; a carriage on which the worksupport .and :presser footsare-mounted to-move as a unit, a shaft formingz-amaxis: about ,whi'chthe work support oscil-v lates duringzwork feed, the workesupporting surface: of the work; support and the :work-clamping, suriacezof :the presser. foot being shaped to centralize: theccl'ampingpressure at one side of a line perpendicular to both said axis and the lineof theseam'throughout' the feeding movement of the work'support andpresser foot, and a mecha nism for; actuating the carriageeat right angles tonthetline of feed to cause the worksupport .to berathrust-galong: that part adjacent the centerrof clampingvpressure into the crease between the welt andiuppenthe axis of the work support beingrdisposed to cause the thrust to "be exerted in thezrdirection ofa line approximately bisecting the :angle:of the. work-engaging surface of the worksupport. r V 8': An outsole shoe-sewingmachine,having, in combination; stitch-forming. devices, a work supportand a'presser foot for clamping and feeding the -work, a carriage on which the work support and" presser foot are mounted to moveas. a unit duringwork feed, mechanism including-a train of connections for actuating the carriage first-with a relativelyslow-feeding movement andthen with airelatively quick back-feedin movement, and yieldingmeans acting on the carriage in the direction ofrthe feeding-movement to take up lost motion in the connections. j

19'... An outsole shoe-sewingmachine having, in combination,stitchaforming devices, a work 'supe port and a pressersfoot for clamping and feeding the work, aback .gage having a work-engaging edge with its 'trail-ingend extending past the point of'xoperation :of the stitch-forming devices, and means on therworksupport and ,presser foot ,for concentrating thepressure on thework along the Work-engaging surfaces of 'thework, support and presserzfoot in close proximit to the. trailing end on the work-engaging edge of the back gage;

10. outsolev shoe sewing machine having, in combination; stitch-formin devices, a work, supporit andapresser footjfor clamping and feeding the work,"albackgageprojecting above the work supporting; :surface. of the work support for guidingsthe edge of thework onthe. work support and having; a-: work-engaging edge with its trailing: end extending-ypast the point of operation of the stitch-eforming; devicesg. means on the work support-rand presser foot for I COHCSH OI'atiHgwthG' pressureionthezwork along the work-engaging surfacesiof the-work support and presser foot in close proximity'wo the'trailing end on the work-em gaginguedge of the b-ac'kgage, and means for actuating thevwork support; and presser, foot to cause themrto eXertaconti-nued rearward pull n the-work;v against the back: gage.

11; Ariro'utsoleshoe-sewing machine having, in'

combination, stitch-forming :devices, a: work .support-and-a presser. foot forclampingandfeeding. the'work, a stationary: gagenhaving, angularlydisposedrsurfaces OneiOf which projects above the worlosupporting surface of the, Work supportior guiding the edge: andzzsupport-engaging surfaces, respectively; of-theiwork. on thework support past the point .of: operation-of. Ithestitch-forming devicesntorprevent the from becoming wedged between the wonky-support :andgageduring feedingrmovementsfofithe support. V

12. An outsole shoe-sewing machine having, in combination, stitch-forming devices, a work support and a presser foot for clamping and feeding the work, a stationary gage projecting above the work supporting surface of the work support for guiding the edge of the work past the point of operation of the stitch-forming devices, and a lip on the gage acting in advance of the work engaging surface of the work support to guide the supportengaging surface of the work to prevent the work from becoming wedged between the work support and gage during feeding movements of the support.

13. An outsole shoe-sewing machine having, in combination, stitch-forming devices, a work support and a presser foot for clamping and feeding the work, a stationary gage for guiding the edge of the work past the point of operation of the stitch-forming devices, a lip on the gage for guiding the support-engaging surface of the work to 20 prevent the work from becoming wedged between the work support and gage during feeding movements of the support, and a shoulder formed on the work support at the side of the point of op- 14. An outsole shoe-sewing machine having, in

combination, stitch-forming devices, a work support and a presser foot for clamping and feeding the work, means for actuating the work support and presser foot to cause them to exert a continued rearward pull on the work, an edge gage having angularly disposed surfaces one of which projects above the work supporting surface of the work support to guide the edge and another of which is substantially parallel to the work. engaging surface of the work support to guide the support-engaging surface of the work past the stitch-forming devices and to prevent the work from becoming wedged by the rearward pressure between the support and gage durin feed.

FRED ASHWOR'I'H. CARL F. WHITAKER.

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