US2562810A - Shoe sewing machine - Google Patents

Description

July 31, 1951 M. MUC 25623510 SHOE SEWING MACHINE Filed March 14, 194'? 2 Sheets-Sheet l INVENTOR.

/LW mm July 31, 1951 Filed March 14, 194'? M. MUC

SHOE SEWING MACHINE 2 Sheets-Sheet 2 IINVENTOR.

m5 l @VHA/Pu.

Patented July 31, 1951 2,562,810 p srioE sawnie Mannini:

Miioslav Muc, Slatinice, near Glomouc, Czecho- Slovakia, assignor to Bata, narodni podnik, Zlin,

- l Czechoslovakia Application March 14, 1947, Serial No. 734,754 In Germany December 1, 1942 Section 1, Public Law 690, August 8, 1946 Patent expires December 1, 1962 Cl. Ime-46) i Claims. l

' This invention relates to shoe sewing machines and in particular to machines for attaching the sole to the upper leather by means of a decorative welt or a false welt sewn around the edge of the sole.

OneI of the problemsencountered in sewing o n the welt which is usually fed from a large roll is to cut it off at the proper place so that when the sole has been sewn around the entire periphery, the two ends of the welt willL meet exactly.

The prior methods and machinery for cutting the welt have4 not been completely satisfactory. One technique which has been used is to control the operation of the cutting device in accordance with an impulse or control signal from the return of the beginning end of the welt already sewn on tothe sewing location. In one device of this type a special feeler is provided that is arranged independent of the guide member for the welt strip and upon traveling up against the beginning of the welt releases the cutting knife, by whose mechanically instigated movement against the guide member of the welt, the latter is cut olf.

This type of device has however many disadvantages. One drawback resides in the fact that the cutting knife has to be removed from its guide each time that it is sharpened. This is a very tedious operation and furthermore the knife must be readjusted into the exact position necessary for the correct cutting stroke whenever it is sharpened.

In another known automatic welt cutter of the impulse type, the cutting knife remains in a fixed position and is structurally combined with the guide member for the weltstrip into one piece. However, this arrangement is also unsatisfactory for the reason that continued resharpening of the knife ultimately renders the whole guide useless and it must be replaced.

The improved method according to the present invention permits elimination of the drawbacks mentioned and alsothe construction of anew satisfactory device for automatic cutting-off of the welt strip and is based on the fact that by the impulse given by theV traveling up on the beginning of the welt already sewed on, an automatic stroke of the guide member of the welt against an immovably mounted knife is released and thereby the welt is cut off. This process makes possible an advantageous combination of a number of actions in a single member, specilically the guide member of the Welt strip itself, that acts at the same time as feeler for feeling the welt origin and for releasing the stroke device against the fixed knife and preferably likewise forms a part of the feed device of the machine. The device serving for carrying on the method according to the invention therefore offers appreciable advantages over all constructions of welt cutting devices disclosed heretofore. A further advantage yielded by the invention is good visibility of the work place and convenient `exchangeability of the easily accessible xed knife, that can be easily adjusted.

Further advantages and features of the invention will be apparent from the following description of one constructional example in connection with the appended drawings.

. Fig. 1, a view in perspective, illustrates the whole apparatus of a cutting device for a duplex machine operating according to the invention.

Fig. 2, likewise a perspective View, shows the appertaining control mechanism on a larger scale.

Fig. 3 is a view in elevation of the working place during normal sewing.

And Fig. 4 is the same elevational view in the condition iust before the cutting olf of the welt.

The constituents of the sewing device carrying barbed needle I and the awl 2 already known per se are omitted from the drawings for the sake of clarity; these drive members can be constructed and arranged in any suitable way.

The needle I and the awl 2 describe reciprocating motions in a circular path through a slotv 3- in the customary support 4 for the piece of work 4a. In the direct neighborhood of the work support 4 is located the cutting knife 5 and aA foot e through the opening 'I of which is led the welt strip 8 taken from a receptacle that is not shown. The knife 5 is curved and adjustable, for instance anchored by means of a screw 9 rin a holder Ill that is carried by a bracket II. This' bracket Il is mounted to slide with all its con-V stituents on a pin l2 of the Xed machine arm I 3. The guide foot 6 of the welt 8 is likewise secured in a removable and adjustable manner inV a guide I4 of the lower arm of a two-armed lever I5, specifically by means of a screw I 6. The twoarmed lever l5 is mounted so as to turn-on a pin Il of the bracket I I already mentioned, which in addition carries a pivot I8 of the two-armed lever I9 likewise mountedto swing. Tothe upper arm of this lever IS is secured a projection 2li carrying the channel cutter 2l for cutting the sole groove receiving the seam, this projection 2D likewise carrying a toothed feeder foot 22 (cf. Fig. 3) for the stitch-like advance of the piece of work. The bracket II is given the ordinary reciprocating movement along the pin l2 for the purpose of stitch-like advance of the piece.

of work, the feeder foot 22 from above and the foot 6 from below alternately clamping and freeing the piece of work. The guide foot 6 in this connection thus performs the function usually performed by thework support in alternately clamping and releasing the piece of work for advancing the same.

The upper arm of the lever i carries a ball pivot 23 of the draw-bar 24, the opposite end of which is likewise hung by a ball pivot 25. This ball pivot 25 changes over into a cylindrical pin 26 (cf. Fig. 2) on which engages, on the one hand, the fork 21 of a draw-bar 28 and on the other hand a rail 29 that for instance has a U-prole and is guided so as to slide in the recess 3U of a bracket 3| mounted in a fixed fashion in the machine frame. In the lower part of the recess 30 of the bracket 3| is provided an inclined slot 32, in which roller 33 is laid and pressed by a spring 34 against the narrow side of the slot, this roller thus clamping the rail 29 in the recess 36; the release of the lock constituted by members 32, 33, 34 is accomplished by pressure on the roller 33 by means of a bolt 35 against the influence of the spring 34. This bolt 35 is governed by the projection 36 of a two-armed lever 31, that is mounted so as to turn on a pin 38 of the bracket 3| and by means of a roller 39 is actuated by a cam 4U provided on the main shaft 4| of the machine. The parts 42 and 43 of the cam track 40 correspond to the locked position of the roller 33 while the projection 44 causes the release of the lock members 32, 33 and 34.

Besides the cam 46, an additional cam 45 is provided that has a deep notch 46 and a slight projection 41. This cam 45 acts on the roller 48 of a three-armed lever 49, that can turn on a pivot 5U mounted fast in the machine frame (Fig. 1). The roller 48 is held in engagement with the cam 45 by a spring 5| hooked to the lower arm 52 of the lever 49. To the upper arm 53 of the lever 49 is secured a pivot 54 on which the draw-bar 28 with a long recess is suspended. The drawbar 28 is constantly drawn to the right by a spring 52 hooked on the one hand in the pivot pin 26 and on the other hand in the pivot pin 54, the long recess 55 furnishing play for the guide foot 6 agreeing with the thickness of the welt 8 (Figs. 3 and 4). The highest position of the guide foot 6 is determined by the striking of a bolt 13 against the end of a groove 14 in the bracket 3| Fig. 2). In order that the lock, comprising members 32, 33 and 34 of the rail 29 can be held in the released position independent of the position of cam 40 or of its projection 44 (for reason to be explained later), an angle lever 51 furnished with a pawl 66 is placed in front of the bolt 35 or the projection 36 of the lever 31, this angle lever being capable of turning on the pin 58 of a supporting plate 59 secured to the bracket 3|. The upper arm of the angle lever 51 is provided with a fork 60 in which an adjustable bolt 6| (Fig. 1) of the draw-bar 24 engages.

In order' to be able to set the cutting device entirely out of operation for any desired length of time, the lower arm of the three-armed lever 49 is provided with a stop 62 (Fig. 1) on which the pawl 63 comes to rest, this preventing the lever 49 from swinging out under the iniluence of the spring 5|. The pawl.63 is mounted so that it can turn on a pivot 64 mounted in the machine frame and is shifted by means of a linkage system comprising members 65, 66, 61, 68, 69 and 10 by a bowed member 1|, the latter being controlled for instance by a knee of the operator serving the machine. This entire lever system is under the influence of a spring 12 so that as long as no force is exerted on the knee-bow member 1| from outside, the pawl 63 is in engagement with the stop 62 and the cutting device is thus out of operation.

The method of operation of the device described is as follows:

During sewing, the cam shaft 4| receives a turning motion in the direction Si (Fig. l) whereby the needle and the awl 2 describe the normal working movements and sew the welt strip 8 to the upper part and the sole 4a of the shoe being made. The lateral movement of the projection 20 carrying the feeder foot 22 necessary for this and of the foot 6 takes place with the help of the bracket to which this movement is transmitted in the ordinary way from the cam shaft through a device not shown.

From the beginning of the sewing operation on a piece of work up to just before completion of the sewing over the entire periphery of the shoe sole 4a, the cutting device of the welt strip 8 remains set out of operation since the pawl 63 holds the stop 62 fast, as already described earlier. When the sewing operation has almost reached the end, the operator presses the knee bow 1| to the right (according to Fig. 1) so that with the aid of the lever system already described, the pawl 63 is brought out of engagement with the stop 62 and then all the requirements for the cutting off of the welt at the required moment are met, i. e. upon traveling up of the foot 6 on the Welt origin already sewed on.

The cutting operation proceeds as follows:

Upon each rotation o f the cam shaft 4|, that corresponds to a stitch, the projection 44 of the cam 40 effects a release of the lock (32, 33, 34) of the rail 29. This releasing action is obtained by upward movement of roller 39, which causes the projection 36 of the two-armed lever 31 to be forced in the direction S3 (Fig. 2), thus caus ing the bolt 35 to be pressed against the locking roller 33. The latter is thus pushed back against the influence of the spring 34 and the rail 29 is freed. If at this moment, the foot 6 however is not pushed down at the same time, i. e. the foot assumes the position shown in Fig. 3, the projec tion 36 of the lever 31 goes right back to its original position after the projection 44 of the cam 4U has turned past and the roller 33 again blocks the sliding movement of the rail 29 to the left. Thus in this case, even with released pawl 63, the roller 48 of the lever 49 cannot follow the cam track 45 and the recess 46 since the lever 49 cannot swing out, because of the firmly locked rail 29. The same operation is repeated at each stitch as long as the foot 6 slides along the surface of the piece of work still not covered by the welt strip 8, as according to Fig. 3, during the reverse movements of the feeder device.

Just before the completion of the sewing op? eration, the moment is finally reached when the foot 6 rides up on the beginning of the welt 8' already sewed on; Fig. 4 shows this moment. Since the cam position is adjusted so that the foot 6 describes its reverse movement in rela-tion to the piece of work at a time in which the rail 29 is just liberated under the influence of the projection 44 of the cam 4U, then upon the depressing of the foot 6, due to its traveling up on the beginning of the welt 8, the draw-bar 24 withthe rail 29 and the draw-bar 28 are pushed to the left (Fig. 1) against the pull of the spring 5|, the long recess 55 of the draw-bar 28 sliding Qn the Pin. 54 Qi the lever 5.3 and the pin 6l of' y 5 the .draw-.bar f2s shifting the forky 0 vinto Athe position shown in Fig. 2 by solid lines 'In this position the pawl dii rests Vagainst the projection t that has just taken up its position releasing the lock (-32, 38, .54) of the rail 2.9. Meanwhile u the foot 5 has traveledcompletely upon the beginning of the welt, the pivot Si .and with it likewise the fors t@ remains in the position shown in Fig. 2, even when the projection 114 ofthe cam de has run past the roller Sil so that the latter o,

into the position shown bydotted lines in Fig.`

4. The cutting-off of the welt strip B occurs during this swinging, since it is moved down forcibly by the foot against the edge of the knife 5. The moment of cutting off is thereby adjusted exactly to the welt beginning already sewed on. The operator can then finish sewing the remaining stitches and after lifting off the feeder foot 2c can remove the piece of work from the machine.

The foot 5, after the welt strip 8 is cut off, is lifted again by the cam 45, so that the draw bars 2d and 28 go back to their original positions, the pin 5i of the pull rod 24 putting back the fork 69 iikewise into the original position shown by dotted lines in Fig. 2. The projection 36 is thus freed and can be shifted again to the left until the roller 3S of the lever 3l rests on the cam 4l] and the lock 32. 33, 34 goes into operation as soon as the roller 39 leaves the projection 44 of the cam it. The working operation is then completed and can be repeated in the same way with the next piece of work.

A main feature of the device according to the invention is to be found in the fact that guide foot 5 does a whole series of tasks; it serves as guide member for the welt strips, as an aid to the feed device of the duplex machine and finally as a feeler for feeling the beginning of the welt and for releasing the cutting device.

In conclusion, it will now be evident that the novel method of cutting @if the welt according to the invention is predicated upon an impulse instigated by the return of the beginning end of the welt which results in a forced stroke of the ,guide member for the welt 8 against a xed knife 5. Furthermore, it will be understood that while the illustrated machine for carrying out the novel method of cutting off vthe welt is to be preferred, changes in the construction of the machine parts as well as substantially different machine arrangements may be effected without departing from the spirit and scope of the invention.

1. In a sewing machine for use in the manufacture of shoes, the combination with stitch forming mechanism acting to secure a welt progressively around a shoe, of a welt guide for dil recting the welt into proper position on the shoe upper in advance of the sewing point, means supporting the welt guide to allow an initial motion thereof upon contact with the return of the beginning end of the sewn on welt, a stationary knife positioned adjacent the guide, and means conditioned in response to the initial motion of said guide for effecting an additional motion 6 .thereof tobring the weltfagainst and-becutjhy vsaid knife.

2. In a sewing vmachine for use in the manufacture of shoes, the combination with stitch forming mechanism acting to .secure a `welt progressively around a shoe, of a welt guide fordirecting 'the welt into proper position on the shoe upper in advance `of the sewing point, Ameans supporting said welt guide to permit an initial downward motion thereof upon contact withthe return of the beginning `end of the sewn on wel-t, a stationary knife positioned below said welt,

vand means conditioned in response to the initial motion of said guide for effecting a further down- `ward motion thereof to bring the welt against and be cut by said knife. y

3. A sewing machine as defined in claim 2 and further including means locking said last named means in an inoperative position and a manually actuated device for releasingv said locking means. l

4. In a sewing machine for use in the manufacture of shoes, the combination with stitch forming apparatus to secure a welt progressively around a shoe, and a reciprocatory feed device for feeding the shoe past the sewing point, of a welt guide for directing the welt into proper position on the shoe upper in advance of the sewing point, said welt guide also constituting a feeder foot of the feed device, means supporting said welt guide to allow an initial downward motion thereof upon contact with the return of the beginning end of the sewn on portion of the welt, a stationary knife positioned below said welt, mechanism conditioned by the initial motion offrsaid guide for effecting further downward motion thereof to bring the welt against and be cut by said knife, and means controlled in timed relation with operation of said feed device for determining the operating moment of said mechanism.

5. In a sewing machine for use in the manufacture of shoes, the combination with stitch forming apparatus to secure a welt progressively around a shoe and a reciprocatory feed device for feeding the shoe past the sewing point, of a welt guide for directing the welt into proper position on the shoe upper in advance of the sewing point, said welt guide also constituting a feeder foot of the feed device, means supporting said welt guide to effect a downward motion thereof upon contact with the return of the beginning point of the sewn on portion of the welt, a stationary knife positioned below said welt, mechanism conditioned by initial motion of said guide for effecting further motion thereof to bring the welt against and be cut by said knife, a manually actuated device for rendering said mechanism incapable of operation, and means controlled in timed relation with the operation of said feed device for also holding said mechanism inoperative except when said welt guide occupies its rearmost position in the feed stroke.

6. A sewing machine as defined in claim 5 wherein said welt guide is supported by a pivoted lever and said mechanism for depressing said welt guide is constituted by a spring loaded lever system connected to said pivoted lever.

'7. In a sewing machine for use in the manufacture of shoes, the combination with a stitch forming apparatus to secure a welt progressively around a shoe and a reciprocatory feed device for feeding the shoe past4 the sewing point, of a welt guide for directing the welt into proper position on the shoe upper in advance of the sewing point, said welt guide also constituting thereof upon contact with the return of the beginning point of the sewn on portion of the welt, a stationary knife positioned below said Welt, a spring loaded mechanism for further depressing said welt guide and Welt subsequent to the initial movement thereof to bring the welt against and be cut of! by said knife, a device alternately locking and unlocking said mechanism as the sewing progresses, means actuated in response to an initial depression of said guide to secure said locking device in its unlocked position, and means controlled in timed relation with the operation of said feed device for 'determining the exact operating moment of said mechanism.

8. A sewing machine as dened in claim 7 and further including a manually operated release for said spring loaded mechanism.

9. A sewing machine as defined in claim 1 wherein the last said means is comprised of a cam having a depression in the cam track, said cam being driven by a cam shaft of the sewing machine, a cam roller mounted on one arm of 8 a. pivoted lever connected in the spring loaded mechanism, and the latter is freed for operation when said roller rides down into the depression in the cam track.

10. A sewing machine as defined in claim 7 wherein said mechanism includes a rail reciprocating in a slotted portion of a stationary member of the sewing machine, and said rail is alternately locked and unlocked relative to said slot by means including a cam and cam roller, the cam being driven by a cam shaft of the machine in such manner that the rail is locked and unlocked once for each stitch taken by the machine.

MUC, MILOSLAV.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,774,498 Ashworth et al. Sept. 2, 1930 2,022,754 Ashworth Dec. 3, 1935 2,225,812 Wennerlund Dec. 24, 1940

Images