US2384488A - Shoe sewing machine and thread controlling device - Google Patents

Description

Sept. 11, 1945. r. F. ORR ETAL SHOE SEWING MACHINE AND THREAD CONTROLLING DEVICE Filed Aug. 20. 1945 2 Sheets-Sheet l Sept. 11, 1945. T. F. ORR ET AL 2,384,438

SEWING MACHINE AND THREAD CONTRQLLING DEVICE Filed Aug. 20, 1945 2 Sheets-Sheet 2 Eig.2

Patented Sept. 11, 1945 SHOE SEWING MACHINE AND THREAD CONTROLLING DEVICE Thomas F. Orr, St. Louis, Mo., and Leonard S. Curtin, Belmont, Masa, assignors to United Shoe Machinery Corporation, Flemington, N. J a corporation of New Jersey Application August 20, 1943, Serial No. 499,364

(Cl. il2--59) 5 Claims.

The present invention relates to high-speed shoe sewing machines and as herein illustrated is embodied in an improved thread-controlling and tension device for an eye-pointed needle sewing machine of the wax-thread type similar to that disclosed in United States Letters Patent No. 1,864,510, granted June 21, 1932, upon an application filed in the name of Bernard T. Leveque, and in United States Letters Patent No. 2,355,107, granted August 8, 1944, upon an application copending with the present application and filed in the names of Edward Quinn and Leonard S. Curtin.

The machine of the Leveque patent is provided with a treadle-controlied driving and stopping mechanism for disconnecting the needle from the main sewing shaft when the needle is disengaged from the work in the final sewing cycle oi a seam. The disconnection may occur while the machine is running at relatively high speeds so that the parts for disconnecting the needle are given an extremely quick motion. A thread cutter also is provided in the machine and actuated by the driving and stopping mechanism as the needle is being disconnected from the sewing shaft to sever the thread extending from the final stitch in a seam close to the eye of the needle. To avoid pulling the end of the thread from the needle eye or from the work when starting a new seam, a slack-thread pull-oil is employed in the patented machine, acting between a thread -waxing pot and a stationary dry-thread tension device located at the supply side of the wax pot. Such an arrangement is entirely satisfactory when good quality linen thread is available. When low quality shortiiber cotton thread is utilized for sewing, the ends 01' the dry fibers become broken on and wedged between themembers of the tension device, resulting in improper sewing operations. To avoid this difliculty a wet-thread tension device located between the wax pot and the work is required, the wax on the thread holding the fibers in place while moving over the wet-thread tension device.

As explained in the Quinn and Curtin patent above identified, the usual form of wet-thread tension device consists of a brake-retarded rotating wheel the periphery oi which is provided with thread-engaging tabs for securing the thread wound thereon against substantial slippage in spite of the lubricating qualities of unsolidified wax on the thread.

In order to avoid withdrawing the end of the thread from the eye of the needle or from the work while the pull-oil! device is acting in the machine of the Leveque patent, a one-way thread clamping lock is mounted between the pull-01f device and the wax pot. Due to the relatively rapid movement which may be imparted to the pull-off device by the driving and stopping mechanism while disconnecting the needle and to the ineffectiveness of a one-way clamping lock on thread to which wax has been applied, it is impractical to employ such a lock between the wetthread tension wheel and the needle in the ma.- chine of the Quinn and Curtin patent. Furthermore, if slack thread is provided by rotating the tension wheel in that machine before starting a new seam, some form of ratchet must be employed which preferably is of inexpensive and simple construction. With the use of a ratchet for rotating the tension wheel, the force oi reaction exerted by the ratchet on the wheel while the ratchet is being reset for a new operation may cause the wheel to take up thread suflicient in amount to oiiset the length provided at the beginning of a seam or to withdraw the thread from the needle eye.

The present invention, therefore, has for an object the provision of a simplified and improved construction and arrangement of parts for providing a slack length of sewing thread sufiicient in amount to avoid withdrawing the end of thread from the eye oi the needle or from the work at the beginning of a seam inserted by a high-speed machine of the type referred to without the use of a separate thread clamping lock or of other means separate from the tension device, the operation of which would be adversely efi'ected by the presence of wax on the thread. More generally, the invention is intended to simplify the construction and improve the manner of operation in an eye-pointed needle sewing machine having a driving and stopping mechanism for disconnecting the needle irom the sewing shaft, a wet-thread tension device, and a thread cutter acting to sever the thread close to the eye of the needle at the end of a seam.

In the attainment of these and other objects, the present invention is embodied in a high-speed eye-pointed needle shoe sewing machine having a driving and stopping mechanism acting to disconnect the needle from the main sewing shaft of the machine with the needle in a position disengaged from the work, a thread cutter actuated automatically at the end of a seam to sever the thread close to the eye of the needle after the needle is disconnected from the sewing shaft, a rotary thread tension wheel, and ratchet means to be actuated by the driving and stopping mechanism when starting the machine in operation to provide slack thread by rotation of the tension wheel and to be reset thereafter by the driving and stopping mechanism before the thread cutter is actuated at the end of a seam. By resetting the tension-wheel rotating means before the thread cutter is actuated, there is no pomibility of withdrawing the severed end of the thread from the eye of the needle, so that the force of reaction on the tension wheel while the tension-wheel rotating means is being reset cannot cause the wheel to be rotated in a direction to take up thread and accordingly no special thread clamping lock or other moving parts are required. Where the tension-wheel rotating means comprises a pawl and ratchet member for rotating the tension wheel according to this feature of the invention, the pawl and ratchet member move together to rotate the tension wheel in a direction to provide thread, and the pawl moves over the ratchet member idly while being reset before the thread cutter actsattheend ofaseam.

Other features of the invention consist in a novel and improved thread-controlling and tension device of general utility and in certain constructions, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be apparent to those skilled in the art from the following description.

In the accompanying drawings,

Fig. 1 is a view in side elevation, looking from the right, of the forward portion of a shoe sewing and lasting machine, partly broken away, embodying the features of the present invention:

Fig. 2 is a view in left side elevation 01' the upper forward portion of the machine illustrated in Fig. 1;

Fig. 3 is a sectional detail view, on an enlarged scale, taken along the line III1II in Fig. 2, of the thread-controlling and tension device;

Fig. 4 is a detail view, taken in section along the line IV-IV in Fig. 3, of the tension wheel and the pull-ofl' pawl and ratchet of the tension device;

Fig. 5 is a detail view. on a still further enlarged scale, of the pawl illustrated in Fig. 4; and

Fig. 6 is a further detail plan view of both the pawl and ratchet.

The illustrated machine is a combined sewing and lasting machine and, so far as its stitchforming and lasting devices are concerned, is the same in construction and mode of operation as the machine disclosed in the patent to Leveque above referred to. The lasting operations are performed in part by a pair of work-gripping and feeding rolls 2 between which the upper and sole of a shoe are drawn into lasted relationship. For controlling the sewing operations and at the same time enabling the machine to be stopped abruptly while sewing at high speeds, the machine is provided with a driving and stopping mechanism for disconnecting the stitch-forming devices from their actuating mechanism. The tension device except as hereinafter described is the same as that of the corresponding device of the Quinn and Curtin patent- The illustrated tension device, as in the machine of the Quinn and Curtin patent, comprises a rotary thread-engaging tension wheel I mounted to receive one or more turns of thread while passing between a wax pot 8 and the stitchforming devices, which include a straight eyepointed needle I and a take-up ll mounted at the upper end of a reciprocating needle bar II. The periphery of the tension wheel is provided with thread-guiding tabs of well-known construction bent alternately in opposite directions forming crevices within which the thread is passed in order to insure an effective grip on the thread and to prevent slippage in spite of the presence of liquefied wax on the thread. The tension wheel is rotatably mounted upon a shouldered shaft I also rotatably supported in a sleeve-like bearing l8 secured by a set screw it within a hub at the upper end of an arm 20. The arm 20 is clamped at its lower end to a bracket adjustably secured on the machine frame at a position which will enable the thread to pass in a desired direction toward and from the tension wheel. The brake for the tension wheel consists of friction washers 22 backed by the end of the bearing l6 at one side of the tension wheel and by a washer 2! at the other side of the tension wheel. For applying pressure to the brake, the reduced and of the shaft II has coiled about it two springs, one 26 inside the other 28, wound in opposite di rections and of relatively different strengths. The outer spring 28 which is the weaker is compressed between the washer 24 and a thumb nut Ill threaded on the reduced end of the shaft II. The outer spring exerts a slight tension on the thread at all times. The inner spring 26 is compressed between the thumb nut 3|! and a. collar 32 held, when the machine is stopped, against a shoulder 34 on the shaft I4 and, when the machine is running, against the brake washer 24.

To enable the inner brake spring 26 to be rendered ineffective, the tension wheel shaft II is moved endwise and is threadedly received in the hub of a controlling arm 36, a check nut 38 being provided to lock the shaft to the arm. One face of the hub on the arm is formed with a cam Ill cooperating with a projection 42 at one end of the sleeve bearing l5 so that, when the arm 36 is rocked in one direction, the cam will move away from the projection 42 causing the spring 28 to draw the shaft H endwise until the shoulder 34 engages the collar 32 and moves it away from the washer 24. When the shoulder 3t engages the collar 32, expansion of the spring 26 is stopped and the pressure of the spring 26 on the tension wheel brake is relieved. Thus, the force of the stronger tension spring 26 is rendered ineifective, the weaker spring 28 only acting on the brake. The purpose of the weaker spring 28 is to prevent excessive stripping of thread from the machine when the machine is stopped. When the arm 36 is moved in the opposite direction, the cam 48 will climb up the pro jection l2 compressing the spring 28 slightly and bringing the collar 32 to bear against the washer 24. The heavy tension spring 26 is thus rendered eifective to act on the tension wheel brake and to impart a sewing tension to the thread.

In stopping the machine of the Quinn and Curtin patent and oi the Leveque patent at the end of a seam. the thread is automatically severed by a thread cutter 21 close to the eye of the needle and, unless a length of thread is provided so as to become slack at the eye of the needle, when the machine is started in a new sewing operation, the severed end of the thread may become withdrawn from the needle eye. The operator thus must give special attention to the amount of slack thread available or a new threading operation may be found necessary.

To avoid the difllculty of frequently rethreading the machine of the present invention and to provide slack thread at the needle suflicientin length for the P p r formation of the first stitch in a scam. the tension wheel 4 has secured to one side a dished washer N the flanged edge of which is formed with a series of ratchet teeth engaged by a pawl 48. The pawl 40 is constructed of relatively thin resilient sheet metal having a disk-shaped portion integrally attached thereto. The disk portion of the pawl is perforated to recelve the tension wheel shaft It and is made fast to the washer 24 so that, when the washer is rotated, it will impart a corresponding movement to the pawl. To rotate the pawl. the washer N and the disk portion of the pawl are formed with aiined slots within which is fitted a key It slidably mounted in a suitable keyway in the shaft ll. When the shaft, which has secured to it the arm II, is rotated with the arm, corresponding movement is imparted to the pawl inaddition to the lengthwise movement oi the shaft. The pawl and ratchet washer are so arranged that the tension wheel will be rotated. to provid slack thread when the machine is started in operation on a new seam.

To avoid any tendency for the tension wheel to be rotated in a reverse direction so as to unthread the needle, the connections for actuating the arm l! in the present machine are adjusted to cause the pawl and ratchet members to be rotated relatively and to reset the'pawl on the ratchet before the thread is severed at the end of a seam. In this way that portion of thread connecting the work with the tension wheel prevents the wheel from being rotated in a reverse direction. The arm 36 is directly non-yieldingly connected to a control member for the driving and stopping mechanism so that a pawl resetting movement will be imparted to the arm before the drivin and stopping mechanism has had an opportunity to stop the machine at the end of a seam. the other hand. the mechanism for actuating the thread cutter comprises a lost-motion connection between the thread cutter and the driving and stopping mechanism.

The connections for moving the arm 35 to actuate and reset the pawl 45 comprise an adjustable horizontal link 5li pinned at one end to the arm 38 and at the other end to a bell-crank lever 52 iulcrumed on the machine irame, a vertical link 54 being connected between the lever 52 and an arm 56 iastened to a treadle-controlled rockshait II inside the machine frame. Outside the frame, the rockshaft 58 has attached to it an arm 80, and a treadle-actuated rod 52 passes loosely through an eye at the free end of the arm in. When the treadle rod 52 is depressed, a notched arm 64 on the rockshaft 58 inside the machine frame is moved away from a sleeve on a downwardly extending arm of a needle-actuating bell crank 58, freeing the needle-actuating mechanism tor reciprocation. At the same time, the bell crank 56 is connected to a continuously oscillating bell crank 68 to start the sewing operations. When the sewing operations are started, the connections between the treadlecontrolled rockshait 58 and the tension-wheel controlling arm 35 rotate the tension wheel suiliciently to provide slack thread at the eye of the needle, thus enabling proper formation of the first stitch in a seam. This movement of the arm 30 also eflects a sewing tension on the thread by causing the inner sewing tension spring 26 to act on the tension-wheel, thus causing it to produce an effective sewing tension on the thread. The return movements or the parts to reset the pawl it thus described are effected by a coil spring 89 (see Fig. 1) surrounding the treadle rod. These return resetting movements cause the spring II to become ineflective.

The mechanism for actuating the thread cutter includes an arm ll secured to the treadle-controlled rockshait ll, a hook I! pivotaliy connected at one end to the arm II, with its hooked end surrounding a stud ll projecting from a rocking member ID having a number oi arms one or which is connected to the thread cutter. The hook I! is so arranged that it causes movement or the rocking member It only during the ends of the movement imparted to the hook it, the hook at other times being disengaged from the stud H or sumciently displaced as to be inetlective in moving the rocking member ll. The rocking member I! is also a part of a toggle including a downwardly extending arm or the member and a spring link I! connecting the rocking member with a pivoted support member on which one 0! the work-gripping and feeding rolls 2 is rotatably mounted. the spring link connection causing the work to be gripped yleldingly by the rolls. The same arm of the rocking member II also is connected through a vertical link It to a lever l2 iulcrumed at M on the machine irame with an arm underlying one end of a spring-actuated lever 86 to which the thread cutter 21 is secured, these parts being the same in construction and mode of operation as in the machine of the Leveque patent. The purpose of the spring link II is not only to move the feeding rolls 2 together but also to lock the rocking member II in its actuated position either when the machine is stopped or during sewing. Accordingly, the toggle formed by the rocking member 16 and the spring link is adjusted to move past centers in one direction or the other. During sewing, the connections between the rocking member ll hold the thread cutter out of engagement with the thread, and at the end of a seam enable the thread to be severed by the thread cutter. The connections for moving the ratchet and brakecontrolling arm 38 are so adjusted that substantially all the necessary movement is imparted to the arm in either direction before the rocking member 16 of the thread cutter mechanism is shifted from its position.

During sewing, it is common practice for the operator to vary the position of the treadie-controlled rod II in order to control the sewing speed or the machine, the rod 82 also being connected with a clutch-controlling lever (not shown) The movement of the treadle rod 62 in this way will have no eflect on the sewing inasmuch as it is insuflicient in extent. to impart a full-length movement to the tension wheel arm 36. Any rotation of the tension wheel by movement of the arm 38 during sewing is insuflicient to produce slack thread and defective stitches since continual movement or the thread toward the needle occurs at a rate greater than any possible rotation of the tension wheel by the connections to the tension-controlling arm I.

The nature and scope of the invention having been indicated and the machine embodying the several features having been specifically described, what is claimed is:

1. A shoe sewing machine having, in combination, stitch-iorming devices including an eyepointed needle, mechanism for actuating the stitch-forming devices, driving and stopping mechanism for disconnecting the needle from the actuating mechanism in a position with the needle disengaged Item the work. a thread cutter actuated by the driving and stopping mechanism to sever the thread at the end 01' a seam close to the eye of the needle after being disconnected from the actuating mechanism, a rotary tension wheel having thread-engaging means about its periphery, and ratchet means for the tension wheel actuated by the driving and stopping mechanism when starting the machine in operation to provide slack thread at the needle sufficient in length for the proper formation oi the first stitch of a seam, said ratchet means being arranged to be reset before the thread cutter is actuated at the end of a seam.

2. A shoe sewing machine having, in combination, stitch-forming devices including an eyepointed needle, mechanism for actuating the stitch-forming devices, driving and stopping mechanism for disconnecting the needle from the actuating mechanism in a position with the needle disengaged from the work, a thread cutter actuated by the driving and stopping mechanism to sever the thread at the end of a seam close to the eye of the needle after being disconnected from the actuating mechanism, a rotary tension wheel having thread-engaging means about its periphery, pawl and ratchet means for rotating the tension wheel to provide a length of slack thread sufiicient for the first stitch in a seam, and connections actuated by the driving and stopping mechanism in starting the machine in operation to rotate the tension wheel in a direction to provide slack thread and to rotate one member of the pawl and ratchet means in the other direction at the end or a seam before the thread cutter is actuated in preparation for a new slack thread providing rotation of the tension wheel.

3. A shoe sewing machine having, in combination, stitch-forming devices including an eyepointed needle, mechanism for actuating the stitch-forming devices, driving and stopping mechanism for disconnecting the needle from the actuating mechanism in a position with the needle CERTIFICATE Patent No. c

disengaged from the work, a thread cutter, a lost-motion connection between the driving and stopping mechanism and the thread cutter tor actuating the thread cutter when the needle is being disconnected, pawl and ratchet means for rotating the tension wheel to provide a length of slack thread sufllcient for the first stitch of a seam, and non-yieldingly attached connections between the driving and stopping mechanism and the pawl and ratchet for causing the tension wheel to be rotated in a direction to provide slack thread and in a direction to reset the pawl and ratchet for a new operation before the thread cutter is actuated at the end or the previous seam.

4. In a thread-controlling and tension device for sewing machines, the combination with a rotary thread tension wheel, a friction brake for the wheel, pawl and ratchet means for rotating the wheel to provide slack thread, mechanism for actuating and resetting the pawl and ratchet means, and means actuated by movement of the pawl and ratchet means while providing slack thread to apply the friction of the brake on the wheel and while being reset for a new slack thread-providing movement to relieve the triotion 01 the brake on the wheel.

5. In a thread-controlling and tension device for sewing machines, the combination with a rotary thread tension wheel, a friction brake for the wheel, a pair of springs for causing the brake frictionally to engage the tension wheel, pawl and ratchet means for rotating the wheel to provide slack thread, mechanism for actuating and resetting the pawl and ratchet means, and means actuated by movement of the pawl and ratchet means while providing slack thread to render one of the springs efiective and while being reset for a new slack thread-providing movement to render said spring ineffective.

THOMAS F. ORR. LEONARD S. CURTIN.

OF CORRECTION.

September 11, 1915.

THOMAS P. ORR, ET AL.

It is hereby certified that error appears in the printed specification t of the above numbered patent requiring correction as follows: Page 3, fir: column, line 71, after "tension-wheel" insert the word --brake--; and tta the said Letters Patent should be read with this correction therein the the same' may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of January, A. D. 19kt).

(Seal) Leslie Frazer First Assistant Commissioner of Patents.

actuated by the driving and stopping mechanism to sever the thread at the end 01' a seam close to the eye of the needle after being disconnected from the actuating mechanism, a rotary tension wheel having thread-engaging means about its periphery, and ratchet means for the tension wheel actuated by the driving and stopping mechanism when starting the machine in operation to provide slack thread at the needle sufficient in length for the proper formation oi the first stitch of a seam, said ratchet means being arranged to be reset before the thread cutter is actuated at the end of a seam.

2. A shoe sewing machine having, in combination, stitch-forming devices including an eyepointed needle, mechanism for actuating the stitch-forming devices, driving and stopping mechanism for disconnecting the needle from the actuating mechanism in a position with the needle disengaged from the work, a thread cutter actuated by the driving and stopping mechanism to sever the thread at the end of a seam close to the eye of the needle after being disconnected from the actuating mechanism, a rotary tension wheel having thread-engaging means about its periphery, pawl and ratchet means for rotating the tension wheel to provide a length of slack thread sufiicient for the first stitch in a seam, and connections actuated by the driving and stopping mechanism in starting the machine in operation to rotate the tension wheel in a direction to provide slack thread and to rotate one member of the pawl and ratchet means in the other direction at the end or a seam before the thread cutter is actuated in preparation for a new slack thread providing rotation of the tension wheel.

3. A shoe sewing machine having, in combination, stitch-forming devices including an eyepointed needle, mechanism for actuating the stitch-forming devices, driving and stopping mechanism for disconnecting the needle from the actuating mechanism in a position with the needle CERTIFICATE Patent No. c

disengaged from the work, a thread cutter, a lost-motion connection between the driving and stopping mechanism and the thread cutter tor actuating the thread cutter when the needle is being disconnected, pawl and ratchet means for rotating the tension wheel to provide a length of slack thread sufllcient for the first stitch of a seam, and non-yieldingly attached connections between the driving and stopping mechanism and the pawl and ratchet for causing the tension wheel to be rotated in a direction to provide slack thread and in a direction to reset the pawl and ratchet for a new operation before the thread cutter is actuated at the end or the previous seam.

4. In a thread-controlling and tension device for sewing machines, the combination with a rotary thread tension wheel, a friction brake for the wheel, pawl and ratchet means for rotating the wheel to provide slack thread, mechanism for actuating and resetting the pawl and ratchet means, and means actuated by movement of the pawl and ratchet means while providing slack thread to apply the friction of the brake on the wheel and while being reset for a new slack thread-providing movement to relieve the triotion 01 the brake on the wheel.

5. In a thread-controlling and tension device for sewing machines, the combination with a rotary thread tension wheel, a friction brake for the wheel, a pair of springs for causing the brake frictionally to engage the tension wheel, pawl and ratchet means for rotating the wheel to provide slack thread, mechanism for actuating and resetting the pawl and ratchet means, and means actuated by movement of the pawl and ratchet means while providing slack thread to render one of the springs efiective and while being reset for a new slack thread-providing movement to render said spring ineffective.

THOMAS F. ORR. LEONARD S. CURTIN.

OF CORRECTION.

September 11, 1915.

THOMAS P. ORR, ET AL.

It is hereby certified that error appears in the printed specification t of the above numbered patent requiring correction as follows: Page 3, fir: column, line 71, after "tension-wheel" insert the word --brake--; and tta the said Letters Patent should be read with this correction therein the the same' may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of January, A. D. 19kt).

(Seal) Leslie Frazer First Assistant Commissioner of Patents.

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