US2564678A - Shoe sewing machine - Google Patents

Description

Allg- 21, 1951 J. DILGER sHoE SEWING MACHINE Filed NOV. 16, 1949 Fig I Inventor John L. ou

Patented Aug. 21, 1951 SHOE SEWING MACHINE John L. Dilger, Reading, Pa., assignor to United fShoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application November 16, 1949, Serial No. 127,606

The present invention relates to sewing machines and is herein shown and described as embodied in a machine for lasting stitchdown shoes -3 Claims. (Cl. 112-34) similar to that disclosed in United States Letters l Patent Nos. 1,864,510, granted June 21, 1932, and 1,972,023, granted August 28, 1934, both upon applications of Bernard T. Leveque, in which a straight eye pointed needle is employed with a rotary loop taker to form a chain stitch seam.

In the machines in the patents referred to, a main sewing shaft of each machine is disconnectably connected to the needle to enable the needle to be brought to rest out of engagement with the Work during continued rotation of the sewing shaft. The loop taker which cooperates with the needle in forming the stitches is mounted directly on one end of the sewing shaft so that it continues its rotation after the sewing shaft is brought to rest. In so doing, the final loop of thread carried through the Work by the needle is disengaged from the loop taker. Such disengagement is a disadvantage if it is desired to resume sewing after having brought the sewing shaft to rest, inasmuch as the final loop formed before stopping the machine will not then be enchained with the rst loop in restarting it and the continuity of the seam will be broken.

An object of the invention is to provide simple and effective means for enabling a machine similar to that of the patents referred to to be broughtv to rest reliably in the middle of a seam without causing a break in the enchaining operations by' the loop taker. In this way, a continuous tight seam is formed and a lasting operation momentarily interrupted can be resumed without possibility of irregularity resulting from improperly enchained stitches. A further object of the invention is to provide an attachment for existing machines of the class described which is readily adapted for application to such machines in a convenient manner without the necessity of dismantlement of the machines.

To these ends, the present invention resides in a chain stitch or similar class sewing machine having work clamping and feeding means, an eye pointed needle and a rotary loop taker both actuated by a main sewing shaft, a clutch for driving the shaft and means operating in stopping the machine to disengage the clutch and to disconnect the needle during continued movement of ther sewing shaft and loop taker, in which a brake is provided for stopping the machine to bring the main sewing shaft to rest without disconnecting the needle therefrom, the brake consisting of a spring pressed plunger on a clutch actuating collar arranged to be rendered operative when the clutch is disengaged and inoperative when the clutch is engaged. With such arrangement the main sewing shaft may be brought promptly to rest without disconnecting the needle from the shaft. Accordingly, the loop taker remains in proper operating relationship with the needle so that a loop of thread will not be cast olf the loop taker in stopping temporarily without being enchained with the succeeding loop of thread.

Other features of the invention consist in certain constructions, combinations and arrangement of parts as hereinafter described and claimed, the advantages of which will be apparent to those skilled in the art from the following description and accompanying drawings, in which Fig. 1 is a detail View in side sectional elevation of portions of a machine embodying the features of the present invention and illustrating the manner of operation of the machine upon a stitchdown shoe;

Fig. 2 is a sectional detail View in front elevation on an enlarged scale of the needle and loop taker in the machine of Fig. 1 illustrating their operative relationship in sewing and Fig. 3 is a detail view of the brake and clutch collar of the machine illustrated in Fig. 1.

The machine of the present invention is intended for operation on a stitchdown shoe having a sole 4 attached to a last 6 upon which is loosely mounted a shoe upper 8. The margin of the upper and the edge of the sole 4 are clamped in engagement with each other by a pair of clamping and feeding rolls I0 and I2 acting intermittently between the formation of successive stitches to feed and pull the out-flanged margin of the upper into lasted relation with the sole 4. To secure the parts operated upon together, a seam is formed between the bite of the rolls and the last 6 by a straight eye pointed needle I4 and a rotating loop taker I6 acting at opposite sides of the work to form a chain stitch seam. The loop taker I6 is secured to one end of a main sewing shaft I8 about which the feed roll I2 rotates and the sewing shaft has a central crank portion 20 surrounded by a socket at the lower end of a connectend. During operation of the machine the connections thus described reciprocate the needle in proper timed relation to the loop taker, causing cooperative action of the needle and loop taker to form a chain stitch seam. When the machine is stopped under normal actuating conditions, the two bell-cranks 26 and 30 which normally move together as a single unit are .disconnected at a point in the final sewing cycle at which the needle is at its highest point f travel out of engagement with the work.

The means for disconnecting the bell-crank 26 from the bell-crank 30 comprises a latch 38 Yfixed to a pivot 40 rotatable ina sleeve .on aY downwardly extending arm of .thebell-crank 38 and adapted to hook over a pin 42 on a downwardly extending arm of the bell-crank 26. The latch is held in engagement with the pin 42 vby an arm 44 secured to the pivot 40 and by a spring 46 stretched between the arm and a fixed member ,in the machine. When it is vdesired todisconnect .trolled rockshaft 52 rotatable in the machine frame. The arm 50 also is provided with a notch v."4 which slips over the sleeve on the bell-crank 30 when the needle bar is at the top of its stroke, thus locking the needle bar inits highest position.

The rockshaft 52 has connected to it an arm 56 fixed to one end thereof and provided with a swiveling eye 58 to which is clamped the upper end of a treadle rod 60. The lower end of `the treadle rodis pivotally connected to a treadle 62 fulcrumed at .64 in the frame of the machine. Betweenits ends the treadle rod is surrounded by a ,coil spring 66 compressed between a perforated projection 68 .of the machine frame and a .clamp collar on the treadle rod acting to raise the treadle rod against its own .weight and to move the rockshaft 52 into a position where the needle is disconnected from the sewing shaft. The spring 66 also is constructed to overcome the force of thelatchspring 46, in addition to raising the treadle rod and rotating the rockrShaft 52.

To start themachine in operation, the treadle 62 is depressed against the force of the spring 66, rocking the shaft 52, and disengaging the pin 48 from the tail of the latch 38 so that the latch yieldingly moves into the path of oscillation of the pin 42. As soon as the sewing shaft begins to rotate, the bell-crank 26 is oscillated and the pin 42 is engaged by the latch to reciprocate Vthe needle.

To rotate the sewing shaft I8, the shaft is surrounded by a driving pulley 12 rotating loosely on the shaft and having an linternal conical surface engaged by a driven member 'I4 arranged to rotate with the shaft but slidably mounted therein for engagement with the driving pulley. The driving pulley and the driven member I4 comprise a clutch actuated by a clutch collar 'i6 surrounding the hub of the driven member 'I4 and held from rotation with the sewing shaft by a yoke 'I8 secured to a rockshaft80 rotatable in a fixed bracket 82. The rockshaft 80 also has secured to it a forked arm 84 through the fork of which the treadle rod 60 passes. To retain the clutch members disengaged, the arm 64 is held raised yieldingly by a compression spring 86 supported by a projection from the bracket 82. Above the arm 84 on the treadle rod is a clamp collar 88 located to provide lost motion with relation to the arm 84 so that in starting the Ina.-

without disconnecting the needle is advantageous when it is necessary to adjust manually the relationship of the upper and sole of a shoe at an intermediate point during the sewing of a stitchdown seam, particularly when sewing about the toe of a shoe in which diiiiculty is encountered in Y distributing the fullness in the outflanged por- Anected thereto a friction member.

-tions of the upper. As thus far described the present machine is the same as that of the patents above referred to.

In bringing the machine to rest without disconnecting the needle, the inertia of the parts may cause the work to be carried beyond the desired stopping point. Frequently, the operator in his attempt to stop will release the treadle Vunintentionally by excessive movement beyond the point where the needle is disconnected from the sewing shaft. When the needle is thus disconnected, the loop taker continues independent rotation with the sewing shaft so that when the Ymachine is restarted the loop of the stitch formed before stopping is released from the loop taker without being enchained with the newly formed stitch. In some instances also, the sewing shaft carried by the needle from said beak so that, upon restarting, the loop taker may miss entirely that needle loop and cast off the loop indicated at 92 of the previous stitch without enchaining it.

vIn the illustrated form of the invention, the sewing shaft I8 is restarted in its independent rotation and is brought to rest promptly after releasing the treadle 62 toV or beyond a midposition in which vthe needle remains connected to the sewing shaft I8 without possibility of reverse movement of the sewing shaft. For this purpose the clutch collar 'I6 has yieldingly con- The friction member is mounted on a pair of attened surf aces .94 on the collar to which are screwed side wings of a block 96 provided with an offset perforated lug within which is slidably mounted a spring pressed plunger 98. The plunger 98 has a recess carrying the friction member in the form of a button |00 arranged to engage a braking surface on a disc |02 forming a hand wheel secured to the main sewing shaft I8.

The button |00 engages the hand wheel disc I02 when the clutch is disengaged from driving relationship. When the clutch collar 16 is actuated to engage the clutch, the button |00 is disengaged from the hand wheel disc. To `disengage the friction button from the disc upon engagement of the clutch the forward end of the plunger 98 passes through a restricted opening in the block 96 and is provided with stop means Vcomprising a pair of check nuts |04 threaded With the construction described, the spring pressed plunger 98 causes the friction button |00 to engage the hand wheel disc with a substantially uniform braking pressure to bring the sewing shaft promptly to rest when the clutch is disengaged. For this reason there is a definite response in the action of the machine to the release by the operator of the treadle to a mid-position. The likelihood of disconnecting the needle by eX- cessive treadle release therefore is greatly reduced. Furthermore, after the sewing shaft has been stopped, the frictional force of the button on the hand wheel disc prevents reverse rotation of the sewing shaft.

The application of the block and plunger to the clutch collar 16 requires no other changes in the construction of the machine and few additional adjustments. The only requirement for effective operation of the braking plunger is that the spring 86 must produce a greater force than that produced by the yielding action in the plunger to prevent the plunger from effecting adversely the disengagement of the clutch.

The invention having thus been described what is claimed is: l

1. A chain stitch sewing machine having work clamping and feeding means, an eye pointed needle and a rotary loop taker cooperating to form a seam in the Work, a main sewing shaft, a disc on the main sewing shaft, a clutch for driving the main sewing shaft, a clutch actuating collar surrounding the shaft, a yoke connected to the clutch collar for shifting the collar axially of the sewing shaft and for preventing rotation of the collar with the shaft and connections with the sewing shaft for actuating the needle and loop taker, in combination with a spring pressed plunger on the clutch collar arranged for engagement with the disc when the clutch collar is actuated to disengage the clutch and for disengagement from the disc when the clutch collar is actuated to engage the clutch.

2. A chain stitch sewing machine having work clamping and feeding means, an eye pointed needle and a rotary loop taker cooperating to form a seam in the work, a main sewing shaft, a disc on the main sewing shaft, a clutch for driving the main sewing shaft, a clutch actuating collar surrounding the shaft, a yoke connected to the clutch collar for shifting the collar axially of the sewing I shaft and for preventing rotation of the collar with the shaft, means operating in stopping the machine to disconnect the needle from the shaft during continued movement of the shaft and loop taker, and a treadle rod for actuating the yoke and the disconnecting means, in combination with a spring pressed plunger disposed on the clutch collar in parallel relation to the sewing shaft and arranged for engagement with the disc when the clutch collar is actuated to disengage the clutch and stop means on the plunger for disengaging the plunger from the disc when the clutch collar is actuated to engage the clutch.

3. A chain stitch sewing machine having work clamping and feeding means, an eye pointed needle and a rotary loop taker cooperating to form a seam in the work, a main sewing shaft, a disc on the main sewing shaft, a clutch for driving the main sewing shaft, a clutch actuating collar surrounding the shaft, a yoke connected to the clutch collar for shifting the collar axially of the sewing shaft and for preventing rotation of the collar with the shaft, means operating in stopping the machine to disconnect the needle from the shaft during continued movement of the shaft and loop taker, and a treadle rod for actuating the yoke and the disconnecting means, in combination with a spring pressed plunger disposed on the clutch collar in parallel relation to the sewing shaft and arranged for engagement with the disc when the clutch collar is actuated to disengage the clutch, spring means of greater force than produced by the spring of the plunger for actuating the yoke to disengage the clutch and a lost motion connection between the treadle rod and the yoke to enable the clutch to be disengaged before the needle is disconnected from the sewing shaft.

JOHN L. DILGER.

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

UNITED STATES PATENTS Number Name Date 1,972,023 Leveque Aug. 28, 1934 2,454,710 Meyers Nov. 23, 1948

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