US1990796A - Stopping mechanism for sewing machines - Google Patents

Description

Feb. 12, 1935. A. R. MORRILL STOPPING MECHANISM FOR SEWING MACHINES Original Filed June 8, 1926 5 Sheets-Sheet 1 Feb. 12, 1935. A. R. MORRILL STCPPING MECHANISM FOR SEWING MACHINES Original Filed June 8, 1926 '5 Sheets-Sheet 2 iii-If 5 Sheets-Sheet 3 Original Filed June 8, 1926 Feb. 12,

m y un Feb. 12, 1935. A. R. MORRILL STOPPING MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 4 Original Filed June 8. 1925 Feb. 12, 1935. A. R. MORRILL 1,990,796

STOPPING MECHANISM F OR SEWING MACHINES Original Filed June 8, 1926 5 Sheets-Sheet 5 Fig. 9

I nvenifar Z2 WL Zness 6 g} 7 Patented Feb. 12, 1 93 UNITED STATES s'roPPmG MECHANISM FOR SEWING MACHINES Alfred B. Morrill, Beverly, Mass, assignor to United Shoe Machinery Corporation, Paterson, N. J., a corporation of New Jersey Original application June 8, 1926, Serial No.

Divided and this application October 12, 1933, Serial No. 693,285

16 Claims. (Cl. 112-219) The present invention relates to stopping mechanisms for sewing machines arranged to be brought to rest upon the occurrence of slack thread, and more particularly to novel and improved means for preventing a sewing machine having such a stopping mechanism from being stopped by the effect of slack thread as a new seam is being started. The invention also relates to novel and improved means acting automatically as the machine is brought to rest to relieve the tension on the thread, so that certain auxiliary operations may readily be performed without straining the thread. As herein disclosed, the invention is embodied in the automatic inseam sewing machine illustrated and described. in applicants'pending application Serial No. 114,441, filed June 8, 1926 on which Patent No. 1,952,770 issued March 2' 7, 1934, for improvements in Sewing machines, of which the present application is apdivieion. The several features of the present invention are not limited, however, to use in an automatic machine such as disclosed in said application, but may be embodied in sewing machines which are not automatic or in machines for performing other sewing-operations.

The several features of the present invention consist in the combinations and arrangements of parts hereinafter described and claimed. The features of the invention and the advantages secured thereby will be readily understood by those skilled in the art from the following description taken in connection with theaccompanying drawings, in which Fig. 1 is a view in front elevation of an automatic Welt shoe sewing machine embodying the several features of the invention Fig. 2 is a view in side elevation partly, broken away, of the sewing machine head, looking towards the left as viewed in Fig. 1; Fig. 3 is a detail sectional view in side elevation illustrating particularly the action of a switch cam on the lever through which the thread finger and thread cutter and holder are actuated; Fig. 4 is a detail view illustrating the mechanism through which the machine is stopped in case the thread breaks;

Fig. 5 is a view showing a portion of the mechanism illustrated in Fig. 4 in a difierent position;

' Fig. 6 is a sectional view along the line 66 of Fig. 5; Fig. 7 illustrates a part of the connections for bringing the machine to rest; Fig. 8 is a sectional view on an enlarged scale of certain parts of the driving and stopping mechanism of the machine; and Fig. 9 is a sectional plan view of a portion of the sewing devices.

The machine, as shown, is provided with stitch forming instrumentalities including a curved hook needle 2, a looper 4, a thread finger 6, a channel guide roll 2 a welt guide 10, a take-up 12, an auxiliary take-up 14, and a thread tension wheel 15. The shoe, indicated at 16, is supported upon a jack 17 arranged for movement to turn the shoe relatively to the operating means to transfer the point of operation about the shoe, and pattern cams 18 operate to impart work feeding and positioning movements to the jack. The general arrangement and operation of these parts are the same as in the machine of the patent to Laurence E. Topham and Alfred B. Morrill No. 1,616,714, dated February 8, 1927. The machine is provided witha driving and stopping mechanism which, at the completion of the sewing operation, or upon the occurrence of a misstitch, is automatically thrown into operation to disconnect the sewing and pattern cam mechanisms from the driving mechanism. The driving and stopping mechanism causes the machine to come to rest with the needle disengaged from the work at the limit of its retracting stroke, and the thread is severed at the end of a seam between the looper and the work. The thread is severed by the action of the -thread finger 6 which engages the thread extending from the looper, and moves rearwardly a greater distance than normal to force the thread against a knife 20 and hold the severed end of the thread remaining in the machine by pressing it against a springpressed gripping slide 22.

The stopping mechanism is similar to that of I,

the machine of Patent No. 1,616,714 above referred to, and comprises a bell crank lever 24, the horizontal arm of which engages a cam groove 26 in a sleeve 28 from which the sewing mechanism and pattern cam mechanism are driven, and the vertical arm of which is provided at its lower end with a hole adapted to receive a lockingbolt 30. During the sewing operation, the locking bolt is held in retracted position. Said bolt is mounted in one end of a horizontally movable locking bolt carrier 32, the other end of which projects beyond the machine frame and is acted upon by a spring 34 which tends to move the carrier towards the left, as viewed in Fig. 1. At the end of the sewing operation, the locking bolt is released and is forced by a spring into the hole in the bell crank lever 24 as soon as the hole is brought into alinement with the locking bolt. Continued rotation of the sleeve 28 thereafter oscillates the bell crank lever in a direction to move the locking bolt carrier to the right, as viewed in Fig.v 1, against the tension of the spring 34. A partial return movement is permitted to the locking bolt carrier and then its return movement to the left is stopped by a latch. The lower end of the vertical arm of the bell crank lever 24 is now held stationary and continued rotation of the sleeve 28 moves the sleeve downwardly, thereby disconnecting main clutch members 36 and 38 between the sleeve 28 and the source of power, and bringing the machine to rest in a predetermined angular position, in which position the needle is retracted from the work; The'movement imparted to the locking bolt carrier 32 in stopping the machine rocks a bell crank lever 40, the vertical arm of which is forked and engages a flanged sleeve at the left hand end of the locking bolt carrier 32. The horizontal arm of the bell crank lever 40 is provided with a bevel gear segment arranged to mesh with a bevel gear segment carried by a lever 42 secured to a rock shaft 44 from which movement is imparted to the thread finger in severing the threads at the end of a seam.

The means for holding the locking bolt 30 in retracted position during the sewing operation comprises a lever 46 and a bevel gear segment on a lever 48 (see Figures 1 and 8) which cooperates with a segment on lever 46. Lever 48 is arranged to swing in a vertical plane and is pivotally connected to the upper end, of a vertical rod 50. Ihis rod is acted upon by a spring 52 Y which tends to raise the rod, and the rod is provided with a lateral projection 54 (see Fig. 7) which, during the sewing operation, is engaged by a spring pressed latch 56.

' When the stopping mechanism is to be operated, the latch 56 is automatically withdrawn from the projection 54 of the rod 50. The latch 56 is mounted to slide horizontally in guideways on the machine frame and is provided on its upper surface with a V-shaped notch opening towards the rod 50 which is engaged by a pin 58 projecting downwardly from the right hand end of a lever 60. This lever is mounted to swing in a horizontal plane,' and its movements either forwardly or rearwardly will cause the pin 58 to retract the latch 56, thereby throwing the stop mechanism into operation. To stop the machine at the end of a seam, the lever 60 carries a dog 62 arranged to be engaged by connections actuatedby the pattern cam mechanism after a complete rotation of the pattern cams.

' tion.

The thread finger 6 of the machine is formed on the forward end of a slide mounted to reciprocate in a guideway in the frame of the machine. This thread finger cooperates with the looper in supplying thread to the needle during each stitch forming cycle, and like the thread finger of the machine disclosed in Patent No. 1,616,714, is also utilized at the conclusion of the sewing operation as a part of a mechanism for severing and holding the thread between the looper and the work. The rear'end of the thread finger slide is provided with rack teeth 66 which are engaged by a gear segment 67 pivotally mounted upona pivot shaft 68. The hub of this segment is provided with spiral gear teeth meshing with corresponding gear teeth on the hub of a cam actuated lever 70 pivctally mounted upon a rock shaft 72. The lever 70 is provided with a cam roll '74 which, during the normal sewing operation ofthe machine is in engagement with a cam groove 76 formed in a cam disk 78 secured to the main sewing cam shaft 80 of the machine. The movements imparted to the thread finger by the cam groove 76 are merely sumcient to groove 82, the thread is held by the gripping' member 22 and carried across the fixed cutting blade 20 by the thread finger after it has been gripped between the finger and the slide 22.

For switching the cam roll 74 from the groove 76 to the groove 82, a switch cam disk 88 is provided which is mounted in the cam disk '78. The switch cam disk is provided with two grooves" 90 and 92 extending across the face of the disk and with a rib 94 separating the grooves.

The cam lever '70 is moved by rotating the rock shaft 72 having at one end a gear member,

96' which engages a corresponding segment on the lever 42. The shaft '72 is rocked by the stop mechanism at the conclusion of the sewing operation at a predetermined point in the cycle of operations. The lever '70 is connected with a spring 98 tending to swing the lever about the shaft 72 in a clockwise direction. The shaft "'72 is provided with a pin 100 which projects radiallythrough a circumferential slot in the hubbf the lever 70, the slot being of suflicient length .to allow for the oscillation of the lever '10 durthe sewing operation, the pin 100 engages the right hand end of the slot in the hub of the lever '72 and swings the lever in a counter-clockwise direction, this action taking place at the time in the cycle of operations of the sewing mechanism when the roll 74 of the lever '70 is slightly below the center of the switch disk 88. During the continued rotation of the shaft 80, t he roll '74 travels along the cam groove 82 until the cam shaft is stopped in the position indicated in Fig.

3. The outward movement of the upper end of the lever 70 produces a sufficient movement of the thread finger to cause the thread to be cut and held. When the sewing mechanism is again thrown into operation, the cam roll 74 of the lever 70 passes along the groove 90 of the switch cam into the cam groove '76.

The auxiliary take-up 14 comprises a roll, over which the thread passes on its way from the main take-up 12 to the looper 4 and is mounted for limited movement on the upper end of a pivoted arm 102 actuatedto tension the thread by a spring 103.

To stop the machine upon the occurrence of a mis-stitch, a slide 104 is arranged to be reciprocated during each stitch forming cycle of the machine by means of a cam actuated lever 106 (see Fig. 4), the rear end of which engages a cam on the cam shaft 80 of the sewing mechanism and the front end of which is connected by a link 108 to the horizontal arm of a bell crank horizontally extending arm of which engages the upper end 01' a thrust rod 116. The-lower end of the thrust rod 116 rests upon the horizontal arm of a-bell crank lever 120, the vertical arm of which engages the lever 64 of the mechanism for throwing the" stop mechanism into operation.

hereinbefore described.

The arm 102 of the auxiliary take-up is provided with an abutting surface 122, which as the auxiliary take-up rises and falls during the formation of each stitch on account of the varying tension on the thread is moved into and out of the path of movement of the slide 104. The movements of the slide 104 are timed with rela tion to the stitch forming cycle so that the forward movement of the slide takes place while a suilicient tension is exerted on the thread to raise the auxiliary take-up against the spring 103 into a position in which the surface 122 is out of the path of movement of the slide. In case of a mis-stitch, due to breaking of the thread or for other cause, the tension on the, thread will be relieved and when the slide 104 makes its forward movement, it will engage the surface 122 on the arm of the auxiliary take-up. This will stop the movement of the slide and continued downward movement of the forward end of the cam lever 106 will rock the three-arm support slack due to an extra length being drawn from the supply or while the end of the thread is held by the operator instead of by the thread holder, the illustrated machine is provided with means which acts during the first stitch forming cycle to hold the auxiliary take-up in its raised position. In the illustrated construction, this means comprises a rod 124 (see Fig. 3) the forward end of which is arranged to engage an arm 126 secured to the pivot stud of the arm 102 of the auxiliary take-up and the rear end of which is arranged to engage the cam lever 70 which actuates the thread arm. As has been described, the'roll 74 of the lever 70 is in the outer cam groove 82 when the sewing mechanism stops and remains in this groove during the first cycle of operations of the stitch forming devices in sewing the next shoe. While the roll 74 remains in the groove 82, the lever '70 is in a position in which the rod 124 holds the auxiliary take-up raised, so that the mis-stitch stop mechanism can not be thrown into operation. A spring 128 surrounding the rod 124 acts on a collar 130 secured to the rod to hold the rod normally in a position in which the auxiliary take-up is free to move.

The thread finger, during the last cycle of operationsoi' the stitch forming devices, moves to the rear a considerable distance from its normal position and consequently draws out more thread vices to the arm.. To provide the requisite extra" amount of thread and to relieve the strain which would otherwise be caused by'the thread finger during its abnormal movement at the conclusion of the, stitch forming operation, a pull-oil is provided in the illustrated machine arranged to engage the thread between the tension wheel 15 and the work, which pull-cit is thrown into operation from the stop mechanism to pull of]? a supply of thread for the thread finger to operate upon. This pull-oil is indicated in Fig. 2 at 132 and comprises a pin mounted at the upper end of a lever 134. The other arm 01' this lever is connected by a link 136 to an arm 138 secured to the shaft '72, which shaft is actuated from the stop motion at the conclusion of the sewing operation, as has hereinbefore been described.

The nature and scope of the present invention having been indicated, and an embodiment of the several features of the invention having been specifically described, what is claimed is:

1. A sewing machine having, in combination, stitch forming devices including a yielding auxfl iary take-up, means controlled from the aux- 2 iliary take-up for stopping the machine, and means independent of the thread for holding the auxiliary take-up raised during the first stitch forming cycle in starting the machine.

2. A sewing machine having, in combination, stitch forming devices including a take-up, a yielding member for actuating the take-up to maintain a tension on the thread, connections controlled by the take-up when the tension is released for stopping the machine, and means for preventing the machine from being stopped by a lack of tension in starting a new seam.

3. A sewing machine having, in combination, stitch forming de'vices including a' take-up, a yielding member for actuating the take-up to maintain a tension on the thread, connections controlled by the take-up when the tension is released for stopping the machine, and means for preventing the take-up from affecting the connections in starting a new seam and for causing the take-up to again exercise control over said connections after the seam is started.

4. A sewing machine having, in combination, stitch forming devices including a main take-up, an auxiliary take-up for maintaining a tension on the thread, connections controlled by the auxiliary take-up when the tension is released for stopping the machine, and means for preventing the machine from being stopped by a lack of tension in starting a new seam.

5. A sewing machine having, in combination, stitch forming devices including a main take-up, an auxiliary take-up for maintaining a tension on the thread, connections controlled by the auxiliary take-up when the tension is released for stopping the machine, and means for preventing the take-up from effecting the connections in starting a new seam and for causing the take-up to again exercise control over the connections after the seam is started.

6. A sewing machine having, in combination, stitch forming devices including a main take-up, an auxiliary take-up operating through a limited range of movement to maintain a tension on the thread, a member operated once during each stitching cycle of the machine to intersect the range of auxiliary take-up movement, connections to said member for stopping the machine when the member engages said take-up in a position at the lim t of its thread tensioning move-' g is ' ment, and means for holding the auxiliary takeup out of said position when the tension is re-- leased at the beginning of a new seam.

tion at the limit of its thread tensioning movement, and means actuated on stopping the machine for holding the auxiliary take-up out 01' said position when the tension is released.

8. A sewing machine having, in combination, stitch forming devices including a main take-up, an auxiliary take-up, operating through a limited range of movement to maintain a tension on the thread, a member operated once during each stitching cycle of the machine to intersect the range of auxiliary take-up movementyconnections to'said member for stopping the machine when themember engages said take-up in a position at the limit of its thread tensioning move ment, means for providing an extra supply of thread on stopping the machine, and means for holding the auxiliary take-up out of said limiting position when the tension is released at the beginning of a new seam.

9. A sewing machine having, in combination,

stitch forming devices including a main take-up,

an auxiliary take-up operating through a limited range of movement to maintain a tension on the thread, a member operated once during each stitching cycle of the machine to intersect the range of auxiliary take-up movement, connections to said member for stopping the machine when the member engages said take-up in' a. position at the limit of its thread tensioning movement, a 'pull-ofi arranged to be inoperative during'sewing, connections for actuating the pull-off on stopping the machine to provide an extra stitch forming devices including av hook needle,

machine, means acting automatically on stopping the machine to draw thread from the looper and sever the thread extending to the work while the work is retained in operative position in the machine, and means for relieving the strain on the thread between the looper and the work during the operation of the thread drawing means.

13. A sewing machine having, in combination, stitch forming devices including a hook needle, a looper and a thread tension for maintaining a strain on the thread during operation of the machine, means acting automatically on stopping the machine to draw thread from the looper and sever the thread extending to the work while the work is retained in operative position in the machine, a pull-01f arranged to be inoperative during sewing, and connections for actuating the pull-off on stopping the machine to supply thread to the thread drawing means.

14. A sewing machine having, in combination, stitch forming devices including a hook needle, a looper and a thread tension for maintaining a strain on the thread during operation of the machine, means acting automatically on stopping the machine to draw thread from the looper and sever the thread extending to the work while the work is retained in operative position in the machine, a pull-off between the looper and the thread tension arranged to be inoperative during sewing, and connections for actuating the pull-off on stopping the machine to supply thread to the thread drawing means before the thread issevered.

15. A sewing machine having, in combination,

stitch forming devices including a hook needle, a looper, a thread finger, and a thread tension for maintaining a strain on the thread during operation of the machine, means acting automatically on stopping the machine to cause the thread finger to draw an extra supply of thread from the looper and engage the thread with a thread severing knife, and means for relieving the strain on the thread between the looper and the work during the extra thread drawing movement of the thread finger.

16. A sewing machine having, in combination, stitch forming devices including a hook needle, a looper, a thread finger and a thread tension for maintaining a strain on the thread during operation of the machine, means acting automatically on stopping the machine to cause the thread finger to draw an extra supply of thread from the looper and engage the thread with a thread severing knife, a pull-off between the looper and the thread tension arranged to be inoperative during sewing, and connections for actuating the pull-oiT on stopping the machine to supply thread to the thread finger before the thread is severed.

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