US2691949A - Shoe inseam sewing machine - Google Patents

Description

Oct. 19, 1954 H S 2,691,949

SHOE INSEAM SEWING MACHINE Original Filed June 12, 1951 Patented Oct. 19, 1954 SHOE IN SEAM SEWING MACHINE Otto R. Haas, Wenham, Mass, assignor to United Shoe Machinery Corporation, Flemington, N. J a corporation of New Jersey Original application June 12, 1951, Serial No. 231,082. Divided and this application October 15, 1952, Serial No. 314,812

4 Claims.

The present invention relates to improvements in machines for sewing shoes and more particularly to a wax thread inseam sewing machine similar to that illustrated in United States Letters Patent No. 2,359,662, granted October 3, 1944, upon application of A. R. Morrill and identical to that disclosed in an application for United States Letters Patent Serial No. 231,082, filed June 12, 1951, of which the present application is a divi- S1011.

The principal objects of the invention are to simplify and improve the operation of a machine for sewing a shoe and to render the machine more easily controlled, accurate and reliable in the performance of its operating devices on a shoe. Other objects are to avoid wastage of sewing thread and displacement of the thread from its guides while the machine is in stopped position through uncontrolled withdrawal of thread from the supply by the operator of the machine.

It is a common practice for an operator of a wax thread shoe sewing machine to withdraw and discard a length of thread before starting a new scam in order to insure that the thread in the new seam will have a fresh coating of unhardened wax without which a defective seam may be inserted. To facilitate withdrawal of thread while the machine is at rest it is usual to provide a sewing thread tension device with a brake drum and a brake shoe engaging it, which brake shoe is actuated at the end of a seam automatically to disengage the brake drum. Upon disengagement of the brake shoe from the drum the tension device is free to give up thread without restraint. If a sudden pull is exerted on the thread, overthrow will occur and excessive amounts will be withdrawn from the supply into the machine causing the thread to become displaced from its guides and possibly entangled with the moving parts of the machine. Failure of the subsequent sewing operation and breaking of the thread frequently follows such displacement and entanglement.

In carrying out the present invention a machine of the type referred to is provided with stitch forming devices including a thread tensioning traction member, a brake drum engaged by a brake shoe for retarding the traction memher and mechanism for actuating the brake shoe away from the drum at the end of a scam, in which a normally inactive auxiliary brake shoe is actuated at the end of a seam by the main brake shoe actuating mechanism as the main brake shoe is disengaged, so that a relatively light controlling tension will be imparted to the thread while the operator withdraws thread from the machine preparatory to starting a new seam. The invention is particularly advantageous when employed with an automatic shoe sewing machine in which the shoe is supported on a jack and is given its positioning movements without the attention of the operator. With such machine the main tension brake shoe is latched out of engagement with its drum at the end of a seam and is not released for engagement with the drum until the machine is restarted. With such automatic machine, the auxiliary brake shoe preferably is yieldingly connected to an arm which actuates the brake shoe so that the auxiliary shoe will engage the drum with a resilient pressure to prevent uncontrolled overthrow of the thread traction member connected to the drum as soon as the main brake shoe is disengaged from the drum at the end of a seam.

The several features of the invention consist in the devices, combinations and arrangements of parts hereinafter described and claimed, which together with the advantages to be obtained thereby will readily be understood from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a somewhat fragmentary detail view looking from the left of a machine embodying the invention and showing a main takeup lever, a stop arm of a stopping mechanism, a thread tensioning brake and mechanism controlled through the operation of these parts for releasing and applying the tension on the thread, the parts being shown in stopped positions; and

Fig. 2 is a similar view showing the same parts in running positions.

The machine illustrated in the drawings is constructed for sewing the inseams of Goodyear welt shoes and comprises a frame 2, housing welt sewing and driving and stopping mechanisms. The driving and stopping mechanisms act in stopping the machine to reverse the operating devices before bringing them to rest. The operating devices for sewing are arranged to insert a chain stitch seam and include a curved hook needle d movable in the line of feed to assist in feeding the work, a thread traction or tension wheel 5 mounted on a shaft 8, a work feeding channel guide H}, a welt guide I2 movable toward and from engagement with an upper, indicated at M, of a Goodyear welt shoe to sew a welt it in the guide to the upper which is supported on a last it, securing the upper in lasted relation with the sewing rib along the margin of an insole 2!] also mounted on the last. As the operation progresses 3 the stitches of the inseam pass through the insole, the upper and welt.

Besides the stitch forming devices just referred to, a main takeup 22 is supported intermediate its length on a pin 24 secured in the machine frame, the thread passing from the traction member or tension wheel 6 under a guide pulley 26 on a stud 28 in the frame and over a pulley 30 on the forward end of the takeup 22. The thread tension wheel shaft 8 is rtatable in the machine frame and carries at one end a drum 32 engaged by a main brake shoe 34 actuated against the drum under variable pressure through a brake lever 38 on which the shoe 34 is mounted. For exerting a pressure on the brake shoe the brake lever carries an adjusting screw 38 to one end of which is connected a tension spring 40 stretched between the screw 38 and a link 42 connected with the takeup lever 22.

To enable thread to be drawn readily from the machine after it has been brought to rest the drum 32 is released from the brake shoe 34. In restarting the machine the shoe 34 is held disengaged from the drum 32 for at least one sewing cycle after which it is caused to reengage the drum. While the brake shoe is disengaged from the drum the thread may be withdrawn freely from the machine by the operator so that there is no possibility of entanglement or displacement in the thread from its guide pulley 26. Also in starting a new seam intermittent pull of the thread produced by the takeup may cause the tension wheel to spin providing an excessive supply of thread so that the first stitch of a seam will occasionally be loose and the seam may not be started properly.

To insure proper control of the thread while the brake shoe 34 is disengaged from the drum 32, particularly in starting a new seam, in accordance with the invention, a light yielding resistance is applied to the rotation of the tension wheel during this time of operation of the machine. To this end the tension wheel brake drum 32 is engaged along its under surface by an auxiliary brake shoe 44 actuated by the same mechanism which is employed to disengage the main brake shoe 36 from the drum, the auxiliary shoe swinging on a fixed pivot 45.

To disengage the main brake shoe 34 from the drum as the stitch-forming devices are brought to rest at the end of a seam, connections are provided with a driving and stopping mechanism in the machine. Those connections include an adjustable screw 48 carried at the end of the brake lever 36 and engaged by an L- shaped arm 50 secured to a rockshaft 52 rotatable in the machine frame. Also secured to the rockshaft 52 is a downwardly extending arm 54 arranged at its lower end to be engaged by an abutment on a lock bolt carrier 55 acted upon by a coil spring 58 comprising a part of the stopping mechanism of the machine. In bringing the machine to rest at the end of an operation on a shoe the lock bolt carrier is initially given a forward movement, that is, toward the right away from the full line position of Fig. 2 to the dot-dash position. The initial forward movement of the lock bolt carrier causes the shaft 52 to be rocked in a counterclockwise direction moving the arm 53 toward the set screw 48 on the brake lever 36. The shaft 52 also has secured to it a stop arm 50 provided at its lower end with a roll 62 movable into engagement with the periphery of a cam disk 64 carried by a sewing cam shaft 35 from which the stitch-forming devices are actuated. During sewing operations the sewing cam shaft normally rotates in a counterclockwise direction, the roll 62 being held out of engagement with the cam disk. As the machine is brought to restat the end of the seam normal rotation of the shaft 65 is terminated and the rotation is reversed for a short distance. roll '32 is pressed against the disk and enters a stopping cam groove 68 so that the roll as it reaches the bottom of the groove rocks the shaft 52 still further in a counterclockwise direction to the position of Fig. 1 to disengage the main brake shoe 34 from the drum 32. At the same time that the main brake shoe 34 is disengaged from the drum a forwardly extending arm 10 on the rockshaft 52 moves upwardly and a pawl 'H on the arm is engaged by a latch 12 rotatably supported on the pivot 45.

To actuate the auxiliary brake shoe 44 from the main brake shoe mechanism, additional connections are provided. At an intermediate point on the arm 10 is mounted a pivot for a perforated block 14 comprising one end of a yielding link. Extending through the perforation in the block '54 is a machine screw '76 threaded into a clevis l8 surrounding and pivotally connected to a portion of the auxiliary brake shoe 44. Engagement of the arm 73 with thelatch 12 causes the main brake shoe 34 to be held disengaged from the drum 32 during the insertion of the first stitch of a new seam in a manner more fully set forth in Patent No. 2,359,662. At the same time the auxiliary brake shoe is pressed against the drum 32 to impart a yielding braking action so that a light tension will be imparted to the thread while withdrawing it. The braking action of the auxiliary shoe 4-4 is sufficient to prevent overthrow of the tension wheel in starting a new seam or when withdrawing thread manually while the machine is at rest.

For actuating the auxiliary brake shoe 44 yieldingly against the drum 32 the machine screw it is surrounded between the clevis l8 and the block. 14 by a compression spring 85. When the shaft 52 rocks in a counter-clockwisedirection at the end. of a seam the auxiliary brake shoe moves from the position of Fig. 2 to that of Fig. 1, the block 14 sliding on the machine screw '16 and moving away from the head thereof. In the operation of the brake shoe mechanism either the main brake shoe or the'auxiliary shoe are thus operative at all times, the auxiliary shoe maintaining a control of the tension on the thread when the machine stops and preventing overthrow of the tension wheel when the main brake shoe is disengaged from the drum 32.

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

l. A shoe inseam sewing machine having stitch forming devices including a thread traction member, a brake drum connected to the traction member, and a main brake shoe engaging the drum and mechanism for actuating the brake shoe out of braking engagement with the drum at the end of a seam, in combination with an auxiliary brake shoe connected to and actuated by said mechanism into engagement with the brake drum as the main brake shoe is disengaged from braking engagement with the drum.

2. A shoe inseam sewing .machine having During reverse rotation of shaft 66 the stitch forming devices including a take-up lever and a thread traction member, a sewing cam shaft, a brake drum connected to the thread traction member, a main brake shoe engaging the brake drum, suitable connections for actuating the stitch forming devices during sewing by rotation of the cam shaft in one direction and in the opposite direction todisengage the brake shoe from the brake drum including an arm, a pawl on the arm and a latch engaging the pawl to hold the brake shoe disengaged from the brake drum, in combination with an auxiliary brake shoe yieldingly connected to the pawl carrying arm for preventing uncontrolled rotation of the brake drum when the machine is brought to rest.

3. A shoe inseam sewing machine having stitch forming devices including a thread traction member, a brake drum connected to the traction member and a main brake shoe engaging the drum, driving and stopping mechanism for bringing the machine to rest at the end of an operation on a shoe and connections between the stopping mechanism and the brake shoe for actuating the brake shoe out of braking engagement with the drum at the end of a seam, in combination with an auxiliary brake shoe also connected to the stopping mechanism for actuation into engagement with the brake drum as the main brake shoe is disengaged from engagement with the drum.

4. A shoe inseam sewing machine having stitch forming devices including a take-up lever and a thread traction member, a sewing cam shaft, a brake drum connected to the traction member, a main brake shoe engaging the brake drum, driving and stopping mechanism connected to the sewing shaft operative in stopping the machine toreverse the sewing shaft and connections between the stopping mechanism and the main brake shoe to disengage the shoe from the brake drum, including an arm, a pawl on the arm, a latch engaging the pawl to hold the brake shoe disengaged from the brake drum, in combination with an auxiliary brake shoe engaging the brake drum for preventing uncontrolled rotation of the brake drum when the machine is brought to rest and additional connections between the stopping mechanism and the auxiliary brake shoe including a yielding link for disengaging the brake shoe from the brake drum during forward rotation of the sewing shaft.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,451,918 Meyer Apr. 17, 1923

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