US1803978A - Automatic stop for sewing machines - Google Patents

Description

May 5, 1931. RQSEMAN I r 1,803,978

AUTOMATIC ST OP FOR SEWING MACHINES Filed March 27, 1928 v 2 Sheets-Shee t 2 .27 j i v a $5 17 f 10 9M4? H' h. I 7 f ir- J LII "T1 ATTORN EYS Patented May 5, 1931 LEO ROSEMAN, or NEWARK, New JERSEY AUTOMATIC s'ror ron snwme MACHINES Application filed March 27, 1928. Serial No. 265,124.

f UNITED. STATES PATENT orrica- This invention relates in general to sewing machines and more particularly to auxiliaries or attachments therefor, one object of the invention being to provide a combination of two or more stitch or revolution counting devices which cooperate to actuate a memher or device after a certain number of stitches have been made.

One of the important features of my inin vention is a combination of a plurality of devices for counting revolutions of the drive shaft of the machine or stitches made by the stitch-forming apparatus, said device coop crating in such a manner that when a predetermined number of revolutions or stitches has been made by the machine, operation of the machine is automatically stopped. The

invention includes a plurality of devices, one.

of which is movable in accordance with or Counts groups of stitches or revolutions, and

another of which moves in accordance withor counts single stitches, said devices coopcrating with each other and means for stopping operation of the machine so as to stop g. the machine after a predetermined number of revolutions or stitches has been made.

The invention is specifically advantageous.

4n work is a different size than that which the. machine has been set to operate on; and this.

eliminates mistakes in sizing the work and obviates the necessity for inspectors. Furthermore, if fasteners are to be sewed on the work,-the machine may serve to count the fasteners, or in other words sew a predetermined number of fasteners upon the work, since a certain number of'stitches are required for sewing each fastener and covering the work intermediate the fasteners. The invention is further advantageous .in that the machine will be stopped'in such a position as to serve as a gage for the beginning of the sewing operation on the following piece of work, for example, the machine may be stoppedafter each piece of work and upon beginning operation on the next piece the machine will make exactly the required number of stitches from the entering edge of the work to the first eyelet. Also the invention prevents overrunning of the machine afterthe point where it is desired to stop stitchingis reached, which reduces wastage of material and time.

Other objects are to provide an automatic stop mechanism of this character which may be adjusted to stop themachine at an inters mediate point in the making of a stitch or to make a fractional part of a stitch and to stop the machine when the needle is out of the work or in the work as may be desired;

and to provide an automatic stop mechanism which may be attached'to known types of sewing machinesfor the purposes hereinbefore described; to provide such a mechanism which is simple in construction and operation, rugged and reliable, and to obtain other advantages and results as will be brought out i by the following description.

In the accompanying drawings I have shown the now preferred embodiment of my invention, and while certain details of construction have been illustrated and will be described, it should be understood that this is primarily for the purpose of illustrating the principles of the invention and that many modifications and changes may be made in the details of construction without departing from the spirit or scope of the invention.

Referring to said drawings, in which corresponding and like parts are designated fill throughout the several views by the same reference ch aracters,

Figure 1 is a side elevation of an automatic stop mechanism for sewing'machines showing the same attached to a known type of machine and the mechanism set for operation.

Figure 2 is a top plan View of the mechanism shown in Figure 1.

Figure 3 is a fragmentary side elevation of the mechanism showing the same in the stoppincr position.

Figure 4 is a view similar to Figure 2 of the mechanism illustrated in Figure 3,

Figure 5 is a transverse vertical sectional view taken on the line 55 of Figure 3, and

Figure 6 is a vertical sectional view on the line 66 of Figure 5.

Specifically describing the illustrated embodiment of the invention, the reference character Ajdesignates a sewing machine of known type which includes the usual drive shaft B having the balance wheel C and pulley D thereon, the latter of which is connected by a belt E to any desired source of power, for example to a clutch on a main drive shaft which is actuated through a foot lever by the operator of the machine, as is well known in. the art.

The said machine also includes the usua needle bar F and other cooperating parts of a stitch forming mechanism, the needle bar being driven from the drive shaft B in the usual manner.

My invention is shown as an attachment for such a machine and consists of a worm 1 fast secured to the drive shaft B and with which meshes a worm wheel 2 fast on a counter-shaft 3 journalled in bearingsl and 5 secured to the frame of the machine A. The worm wheel 2 extends through an opening 6 in the frame of the machine A whereby the shaft 3 is driven from the drive shaft B. The ratio of the gearing 1, 6 is to cause one revolution of the shaft 3 for each fifteen stitches made by the sewing machine, but it will be understood that this ratio may be changed as desired.

Mounted upon the upper end of the coun-,

ter-shaft 3 to rotate therewith is a disc 7 upon which is adjustably mounted a cam tappet 8 to cooperate with a stop bar 9 which is arranged to move into and out of the path of a stop lug 10 on the balance wheel C. The tappet 8 is rotatable about the axis of the shaft 3 relative to the disc 7 and is releasably held fast to the disc by any suitable means such as a set screw 11 threaded into a block 12 slidably arranged in a slot 13 in the top of the disc 7 concentric with the shaft 3.

The stop bar is formed in two pieces 14 and 15 the first mentioned of which is horizontally slidable in suitable bearings 16 on a bracket secured as by screws 18 on the top of the frame of the machine A. The thrust link 15 is pivotall connected about a horizontal axis at 19 to the end of the part 14 and has its free end rounded as at 20 to be engaged by the corresponding rounded end of the tappet 8. The thrust link 15 is normally influenced into the path of the tappet 8 by tension springs 21 and 22, the latter of which also withdraws the end of the stop bar 9 from the path of the stop lug 10.

In operation of the apparatus so far described it will be observed that the tappet 8 will rotate in a horizontal plane once for each fifteen stitches, and the stop bar 9 is normally withdrawn from possible contact with the stop lug 10, and is normally disposed in the path of movement of the tappet 8. Accordingly when the tappet reaches the curved end 20 of the part 15 of the stop bar 9, the stop bar will be pushed horizontally and moved into the path of the stop lug 10 which will engage the stop bar and thus stop the drive shaft B and the stitch making mechanism.

To again start the machine the thrust link 15 of the stop bar 9 is pushed upwardly against the influence of the spring 21 out of the path of the tappet 8, so that the spring 22 will hold the stop bar 9 out of the path of the stop lug 10.

Preferably the top of the tappet 8 is beveled at 23 and the bottom of the free end of the thrust link 15 is beveled at 24 to facilitate slipping of the link 15 upwardly out of the path of the tappet. As shown in the drawings the thrust link 15 is so manipulated by a push rod 25 vertically slidablein a bearing 26, and in accordance with the invention this push rod is associatedwith means for holding the thrust link 15 out of the path of the tappet 8 for a period of time necessary to permit a pre-determined number of stitches to be made, said means releasing the thrust link 15 after said stitches have been made so as to stop the machine. This means includes a setting disc 27 mounted on a stub shaft 28 rotatable in the bracket 17, said disc being fast secured to a ratchet 29 which is in turn keyed upon said shaft 28. With the ratchet 29 cooperates a pawl 30 normally influenced into engagement with the ratchet by a spring 31, and pivoted at 32 on the end of an arm 33 rotatable on the stub shaft 28. The arm 33 is oscillated through a link 34 connected to an eccentric strap 35 on an eccentric 36 fast secured to a shaft 37 which is rotated by a spiral gear 38 meshing with another spiral gear 39 on the counter-shaft 3. The shaft 37 and the bearing 5 for the shaft 3 are carried by a base plate 40 secured to the base of the machine A. r The push rod 25 has a fol lower roller 41 which rides upon the periph- I cry of" the setting' disc 27 which normally holds the thrust link 15 out of the path of the tappet 8 to permit operation of the machine. The periphery of said setting disc is provided with a notch 42 into which the roller 41 may fall at a certain point in the rotation of the setting -disc so as to release the thrust link into the path of the tappet and stop the machine as above described.

5 With this construction it will be observed that the setting disc 27 will be rotated in the direction of the arrow with a step by step motion by the pawl 30, link 34 and eccentric 36. Backward rotation of the setting disc is limited by a stop pawl 43. The ratio of the gearing is such that one complete revolution of the setting disc 27 corresponds to 375 stitches formed by the sewing machine, although obviously this ratio may be changed as desired. As illustrated the disc is graduated by the figures 44 to correspond to the groups of stitches, the zero point representing the stop position and also the three-hundred and seventy-fifth stitch. Upon the disc is coaxially rotatably mounted a setting lug 46 which is frictionally adjustable through the spring 45, and the shaft 28 is provided with a handle 47. Should it be desired to automatically stop the sewing machine after 60 stitches have been made, the setting lug 46 will be adjusted over the figure 60 on the setting disc 27. The setting disc will then be rotated in the direction of the arrow until the setting lug 46 engages the follower roller 41. The 30 machine is then started in operation, the thrust link 15 being held out of the path of the tappet 8, and operation continues until the setting disc has been rotated by the pawl 30 to bring the notch '42 beneath the follower roller 41, whereupon the spring 21 pulls the thrust link 15 into the path of the tappet 8, which, upon engaging said thrust link moves the stop bar 9 into the path of the stop lug 10 and stops the machine. To again start 49 the machine the operator again rotates the setting disc 27 by the handle 47 until the stop lug 46 engages the follower roller 41, whereupon the operation is repeated.

To stop the machine after any multiple of fifteen stitches, for example seventy-five or three hundred and sixty, the setting lug 46 is set at the corresponding figure on the disc 27. for example 75 or 360. Preferably the disc 7 is also graduated by figures 48 to represent fifteen stitches so that by adjustment of the tappet 8 relative to said disc 7 the mechanism may be set to stop the machine at any number of stitches between the respective groupsrepresented by the figures 44 on the setting disc 27. For

example, should it be desired to stop the ma-' chine after 66 stitches, the stop lug 46 would be set atf60 and the tappet 8 would be set so at 6 corresponding tosix stitches. This causes the tappet 8 to rotate a distance corresponding to six stitches afterthe thrust link 15 has been moved into stop position, or

I in other words, the thrust link 15 is moved 55 into the path of the tappet a period of time corresponding to six stitches before the tappet reaches its stop position.

The mechanism may also be adjusted to stop the machine with the needle in or out of work or after a fraction of a stitch has been made, and this is shown as accomplished by adjustably mounting the stop lug 10 on the balance wheel C as by a threaded stud 49 on the lug 10 arranged in a slot 50 in the balance wheel and having a thumb nut 51. thereon. Obviously, bysliding the lug 10.

by the hand through the handle 47. Mecha- I nisms for this purpose may comprise a ratchet 52 fast on the shaft 28 with which cooperates a toothed bar 53 pivotally connected at one end as at 54 to one arm of a bell crank lever 55 pivotally mounted at 56 on the base of the machine. The other arm 57 of the bell crank lever depends to a point beneath the machine in convenient relation to one knee of the operator, so that by lateral movement of the knee the bell crank lever may be oscillated. The toothed bar 53 is heldin, engagement with the ratchet 52 by a spring 58, and a spring 59 serves to return the bell crank lever to its normal position after operation by the operators knee. The ratchet 52 and the bar 53 are so related that when the arm 57 of the bell crank lever is moved in the direction of the arrow the setting disc 27 is moved in the direction of the arrow on Figure 1, which serves to locate the setting lug in starting position relative to the roller 41. An adjustable stop screw 60 serves to limit movement of the bell crank lever and the extent of rotation of the setting disc 27 can thereby be regulated. When the arm 57 of the bell crank lever is released by the operator the spring 59 returns the bell crank lever to normal position, and backward rotation of the ratchet 52 is prevented by the pawl 43.

It will be observed from the foregoing that the disc 7 and cam 8 are in effect a revolution or stitch counting device, said parts counting single revolutions up to 15 and the setting disc 27 with its driving mechanism serves to count groups of revolutions or stitches each of which groups comprises 15 stitches. These two devices so cooperate that the stop bar 9 is actuated to stop the machine after a predetermined number of revolutions or stitches have been made. In this connection, it should be remembered that a predetermined number of stitches are produced for each revolution of the driving shaft of the machine and that one revolution of the disc 7 corres onds to fifteen stitches made by the stitch orming mechanism F.

While I have shown and described one embodiment of my invention in a sewing machine, it will be understood that the invention'is applicable to man different specific uses without departing rom the spirit or scope of the invention. 7 Having thus described my invention, what I claim is pre etermined number of stitches have been made, comp-rising means for counting stitches singly, means for counting stitches by groups each of an equal number of stitches, said means for stopping operation of said stitch-forming mechanism being controlled by cooperation of said two stitch.

counting means.

2. The combination with a stitch forming mechanism of two means relatively movable .in fixed paths, the complete travel of one of said two means corresponding to a given number of stitches, and the complete travel of the other of said two means corresponding to a number of stitches which is a multiple of said given number, and means operated jointly by said two means when each thereof reaches a certain position in its path of movement tostop operation of said stitchforming mechanism.

3. The combination set forth in claim 1 wherein the second-mentioned counting means is adjustable to vary the stoppin of said stitch-forming mechanism after di erent numbers of stitches have been made.

4. The combination set forth in claim 2 with the addition of means for varying the extent of travel of the second-mentioned means.

5. The combination set forth in claim 2 with the addition of means for varying the said position of the first mentioned means to vary the stopping of the stitch-forming mechanism after difierent numbers of stitches have been made.

6. The combination with astitch forming mechanism, of means for automatically stopping operation of said mechanism after a predetermined number of stitches have been made,- comprising means for counting singly 7. The combination with a stitch forming mechanism, of a member to be actuated after a predetermined number of stitches have been made to perform upon actuation thereof, a predetermined operation, means for countmg stitches sing'ly,lmeans for counting stitches by groups each of an equal number of stitches, and means foractuating said member controlled by cooperation of said two stitch counting means.

8. The combination set forth in claim 1 wherein the second-mentioned counting means includes a rotatable disc, and with the addition of a stop member adjustable thereon but movable therewith to abuttingly engage a part of the last-named means for adjusting and setting the mechanism to vary the stopping of said stitch-forming mechanism after different numbers of stitches have been made.

.9. The combination with a stitch-forming mechanism having a driving shaft, of auto,

mat-ic stop mechanism comprisin means for interrupting rotation of said she. t, an operative connection including a movable part actuated by said shaft between said means and said shaft to actuate said means to stop said shaft, said operative connection being so related to said shaft as to actuate said means once for a certain number of stitches, said interrupting means including a. movable element cooperating with said part of said oper- I ative connection, means for manipulating said movable element to vary the moment of interruption of rotation of said shaft, and means movable at a speed having a certain relation to the speed of movement of said movable part of said operative connection for actuating the last-named means.

10. The combination with a stitch-forming mechanism having a rotatable shaft, of stop mechanism comprising means for interrupting rotation of said shaft, an operative 'con-.

nection including a rotatable part between said shaftand said interrupting means to actuate the latter, said interrupting means including a movable element cooperating with said rotatable part of said operative connection to control the actuation of said interrupting'means through said operative'connection, and means including arotatable member movable at a speed different than but in certain relation to themovement of'said rotata-ble part of said operative connection to actuate said movable element.

11. The combination set forth in claim 9 wherein said movable part of said operative connection is adjustable in steps of stitches from one to said certain number to vary the moment of stopping of said shaft, and the automatic stop mechanism comprising meansauo for interrupting rotation of said shaft, an

operative connection between said interrupting means and said shaft for actuating said interruptin means once for a certain number of stitc es, said interrupting means including a movable part cooperating with said operative connection, means for manipulating said movable part of said interrupting means to control actuation of said interrupting means by said operative connection, and means for actuating the last-named means to stop the machine after a number of stitches equal to a multiple of said certain number.

LEO ROSEMAN.

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