US1570769A - Stop mechanism for sewing machines - Google Patents

Description

Jan. 26 1926. 1,570,769

. e. w. NELSON s'roP imcmmsu FOR swims MACHINES Filed May 17; 1919 4 Sheets -Sheet 5 Jam 6} 1926- e. w. NELSON 5T0? MECHANISM FOR SEWING MACHINES 4 Sheets-Sheet 4 Filed May 1'7, 1919 ATTORNEY Patented Jan. 26, 1926.

UNITED STATES- 1,570,769 PATENT OFFICE.

GEORGE W. NELSON, OF CLEVELAND, OHIO, ASSIGNGR TO THE STANDARD SEWING MACHINE COMPANY, OF CLEVELAND, OHIO,

CORPORATION OF OHIO.

STOP MECHANISM FOR SEWING MACHINES.

Application filed May 17,

concern To all whom it may,

I, GEORGE W. NELSON,

Be it known that I v a citizen of the United States, and resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Stop Mechanism for Sewing Machines, of which the following is aspecification.

This invention relates primarily to stop mechanism for sewing machines and more particularly to stop mechanism for that class of sewing machines in which successive groups or series of stitches are made at separated points in the work, as, for example, in button sewing machines, such as disclosed in Letters Patent No. 1,252,931,

issued to me January 8, 1918.

The main object of the present invention is the provision of a simple and efficient 2 mechanism for automatically stopping the machine on the completion of predetermined series or groups .of stitches, quickly and without undue jar or strain on the machine parts. I

This and other objects to be hereinafter referred to are attained by the improve,- ments constituting my present invention, which in one embodiment thereof is illus trated in the accompanying drawings, in 9 which- Fig. 1, is a rear end elevation of a sewing machine embodying the invention, with the loose driving pulley removed and its supporting shaft in section, showing the parts in the positions they occupy during the normal operation of the machine and prior to the automatic stopping thereof.

Fig. 2, is a similar view showing the parts in the positions they occupy on the automatic stopping of the machine.

Fig. 3 isa rear side elevation of the machine. with the parts in positions corre sponding to those in Fig. 1.

Fig. 4. is a top plan of the rear end of the machine broken away, with the parts in positions corresponding to those in Fig. 2.

Fig. 5, is a section taken on the line '55 of Fig. 3, but showing the parts in positions corresponding to those in Fig. 2. In this view (Fig. 5) the outline of the adjacent end of the machine frame is shown by broken lines for the purpose of showing the relative position of the parts with respect thereto.

Fig. 6 is a section through the loose driv 1919. Serial No. 297,857.

ing pulley and certain associated parts of the starting and stopping mechanism, the section being taken in the line 6-6 of Fig. 2, in which the loose pulley is indicated by broken lines.

Fig. 7, is an inner end view of the driving and driven clutch members removed from the main shaft of the machine.

Similar reference characters indicate like parts in the several figures of the drawings.

The sewing machine here shown as equipped with my invention embodies a main frame comprising upper and lower portions, 2 and 3, suitably connected and adapted for the support of the various parts of the operating mechanism. Suitably journalled in the lower portion 3 of the frame is the main shaft 4, which extends lengthwise of said lower portion 3 and from which the several operating parts of the machine are driven through suitable connections, in the usual manner. This shaft 4 at its rear end projects beyond the adjacent end of the frame for the association therewith of my improved starting and stopping mechanism which will now be described.

On the outer end of the shaft 4 is a loose driving pulley 5, which is held on the shaft means of a headed screw 6, threaded into the end of the shaft for removable connection therewith. This driving pulley is here shown as provided at its inner end with a projecting hub portion 7 having an annular recess 8, in which is received an expansible clutch member 9, of the split ring type, which can be expanded into frictional engagement with the adjacent wall of the driving pulley when the clutch is to be engaged, or can be contracted from frictional engagement with said wall when the clutch is to be released. This split ring 9 is carried in rotation with the shaft 4 through suitable connections, whereby, when it is expanded into clutching engagement with the as at 13, 13, and having a laterally projecting wedge member 14, extending between the opposing end walls 15, of the split ring 9. Byswinging the connector laterally in one direction, its said wedge member 14 will spread apart the engaging ends of the split ring 9 and force or expand the latter into frictional clutching engagement with the driving pulley, and by swinging the connector in the opposite direction to par-. tially withdraw its wedge member from between the engaging ends of the split ring, the latter will become released from its fast clutching engagement with the driving pulley. It will be understood, however, that connection between. the shaft and split ring should always be maintained so that said parts will always move in rotation together and in order to effect this the clutch releasing movement of the connector is limited by a suitable stop, such as the shoulder 16 (see Fig. 6), to prevent the complete withdrawal of the wedge member 14 from between the ends of the split ring.

In the present case, the connector is adapted to be swung laterally in a direction to advance its Wedge member 14 into wcdging position between the ends of the split ring. whereby to effect engagement of the clutch members, by means of a suitable spring, such as indicated at '17, which is seated in a pocket in the collar 10 with one end bearing againstthe inner side of the connector, as clearly shown in Fig. 6. As a means to move the connector against the pressure of this spring 17 and in a direction to withdraw its wedge member from wedging position between the ends of the split ring 9, whereby to release the clutch, I have provided a controller member 18 which is automatically operative at a predeter R'ElilElCl time in the operation of machineas at the conclusion of the sewing of a predetermined group of stitchesto engagethe connector and positively shift the same to its clutch releasing position. This controller 18 is here shown in the form of a lever mounted on a stationary pivot 19 onthe frame of the machine for movement in a plane transversely of the driving shaft. and as having an arm 20 adapted to be shifted, by rocking of the controller on its said p1vot, to and from an operative position in the path of the outer end2l of the connector 12 in its rotary movement about the axis of the driving shaft; said controller arm having aninner cam or inclined surface 22, which, upon the lowering of the controller arm to its operative position in the path of the connector arm 21, will engage the latter and force the connector laterally to its latch-releasing position. After the connector has been thus shifted to latch-releasing position, it continues its rotation a short distance under the momentum of the driving shaft until it comes into contact with a yielding buffer or stop device 23, which acts to bring the connector and connected shaft to a stop at a predetermined point in their rotation. This buffer is here shown as being carried by the controller and as being supported 'by' a spring 24 seated within a chamber 25 in said controller. On the controller arm directly above said buffer is a shoulder 26 over which the laterally movable connector arm 21 rides when advancing into engagement with the butter, and against which it is returned and held by the rebound of the buffer, as shown in Fig. 5. .In this way the machine is always brought to a stop with the parts thereof in the same definite predetermined positions. lVhen it is desired to again start the machine, the controller is rocked outwardly to a point beyond the path of the connector, as shown in Fig. 1, thereby releasing said connector and permittingit to be automatically shifted under the actionof the spring 17 to its wedging position for effecting engagement of the clutching members.

The controller is norn'ially held in its outward or. inoperative position, as shown in Fig. 1, by means of a suitable latch device 30, here shown in the form of a bolt slidably supported in a bracket 31 on the frame of the machine and having an upturned por tion at its outer end engaging the controller within a notch 32 thereon, as shown in Fig. 1. A spring 33, located on the bolt between a.collar 3st thereon and the adjacent end of the stationary bracket 31 (see Fig. 3), acts to yieldingly hold the bolt in its latching position until the completion of a predetermined series or group of stitches, at which time it. is tripped automatically to release the'controller and permit the latter being swung inwardly to its position for engaging the connector and shifting it to clutch-releasing position. hen the con troller is thus released by the latch, it is swung inwardly as described by means of a suitable spring, such as 35. which connects at one end with said controller and at its opposite end with a statioi'iary stud 4-6 on the machine frame.

The latch device may be tripped by any suitable means. Preferably the tripping means is operated from the main shaft 1 through a cross-shaft 37, driven from said main shaft by gearing (not shown), by means of which a relatively slow rotary movement is imparted to this cross-shaft. On the completion of a predetermined group of stitches, the cross-shaft is intended to bring into operation a releasing device. This releasing device is shown as carried by a disk 38 on the end of the cross-shaft and is in the form of a radial pin 39, slidable in and out of operative position and suitably held in place. When projected into operawhen such contact takes place.

the po i ion as sh n, i is brough on each complete rotation of the cross-shaft, into engagen' ent with the inner end of the latch bolt 30, and moves the latter lengthwise in a direct-ion to disengage its outer end from the notch 32 of the controller, as shown in Fig. 2, whereupon the parts will act'to release the clutch .in the manner previously described. The disk 38 is here shown as provided with a second radial pin 39 which may be employed in combination with the first pin to effect a release of the clutch on every one-half rotation of the cross-shaft, or, if not so employed, may be set back into the disc out of operative position. A swinging plate 40 normally covers, this latch tripping means.

To start the machine following the release of the clutch as described, the controller is swung from its operative or connector-engaging position, shown in Fig. 2, to its inoperative or connector-releasing position, shown in Fig. 1, in which latter position it is caught and held by the latch 30. This movement of'the controller to its inoperative posit-ion is adapted to be effected by manually operated means. Such means as here shown comprises a lever fulcrumed on the stationary stud 46 and arranged with one arm l7 extending beneath an arm 48 of the controller for. engagement therewith, and its other arm 49 extending to a suitable position for connection with the treadle (not shown), or other similar operating device.

When the controller 18 is operated to shift the connector to clutch-releasingv position, said connector, as heretofore described, continues its rotation a short distance under the momentum of the driving shaft until it is brought to a stop by contact with the buffer23. As this momentum is very considerable when the machine is being operated at. high speed, it is desirable to employ a suitable braking device that will be operative to come into action immediately upon the release of the clutch and so retard the speed of the machine before contact of the connector arm 21 with the buffer- 23 as to prevent injurious jar or strain on the parts The braking device here employed for such purpose comprises a brake band 50 which co-operates with the collar 10 on the drive shaft adjacent its inner end (see Figs. a, 5and 6). This brake band is connected at one end to a fixed in 51 on the frame of the'machine, and at its opposite or loose end has connection with suitable means for tightening and releasing the same in co-operation with the releasing and engaging of the clutch ,de vices. These means, as here shown (see Fig. 5), comprise a rod 52 which connects at one .end with the brake band adjacent its loose end, as at 53., and extends loosely through an opening in the supporting stud to a point yon h a er, where it carries a coiled spring 54 which expands between the fixed stud 46 and a suitable shoulder 55 on the rod to exert an outward pressure on the latter, whereby it will operate to hold the brake band in braking engagement with the collar 10; the said shoulder 55 on the rod against which the spring. bears being here shown in the form of an adjustable nut for the purpose of adjusting the action of the spring and thereby the brake, as may be desired. A second rod 56 connects at one end with the brake band at 57, and at its opposite end has connection with the controller 18 by extending loosely through an opening in a flange 58 thereon and being provided with an adjusting nut 59 engaging the rear side of said flange, as shown. This connection between the brake band and the controller is such that when the controller is in position to release or disengage the clutch, as shown in Figs. 2 and 5, it will permit the springactuated rod 52 to draw the brake band into braking engagement with the pulley 10 on the drive shaft, and when the controller is swung outwardly to effect engagement of the clutch, as shown in Fig. 1, it will act to simultaneously release the brake band by drawing the same slightly backward against the pull of the rod 52.

The sewing machine here illustrated as equipped with my improved starting and stopping mechanism, is, as before stated, a chain-stitch sewing machine of the type adapted for forming successive groups or series of stitches. In this type of machine it is customary to sever the thread on the completion of a group of stitches by suitable means under the control of the'operator, and it ha therefore been found desirable that provision should be made for certain necessary manipulation of the thread, to wit: that means be employed for pulling off from the source of supply a sufiicient length of thread to permit the forming of the first stitch of a series without drawing down the end of the thread below the upper surface of the work, and that the length of the thread beyond the needle eye at the beginning of the making of such a series of stitches should be determined in order that there may be no substantial excess thread beyond what is necessary for the formation of the first stitch. Means for effecting su'ch manipulation of the thread are disclosed in my aforesaid. Patent, No. 1,252,931, and comprise a thread-restraining device or thread-clamp for clamping the thread upon the completion of a series of stitches, and a pull-off device I for drawing off from the source of supply a sufficient length of thread for the first stitch of a new series; these thread-restraining and pull-off devices being automatically operated in the performance of their functions after one series of stitches has been completed and the action of the needle-bar mechanism is substantially finished and before the next series is started.

The thread-clamp and pull-off devices here shown are of the same construction and operation as those of my aforesaid patent; the threadclamp, indicated at a, being located. on the face-plate of the machine and comprising fixed and movable clamping jaws, ($0 and 61, between which the thread If is led in its passage from the thread supply to the needle, and the pullcfl', indicated at being located on the upper part of the arm or frame for engaging the thread between the thread supply and said clamp and being in the form of an angle lever having an rip-turned threadengaging finger 62. These thread-clamp and pulloft devices, also as in my aforesaid patent, are both directly controlled by a single controlling member in the form of a rod 63 mounted to slide in suitable guide-ways on the arm of the ma chine, such as indicated at (34, 65 and 66. and having operative connection with said devices, whereby, upon movement of the rod 6 in a forward direction, it will operate the thread-clamp to clamp the thread and thereafter operate the pull-off to pull a predetermined length of thread from the spool or other source of supply to provide for the formation of the first stitch of a new series. A reverse movement of the rod will cause said devices to assume their normal positionsi i. e., the thread-clamp in open or unclamping position, and the pull-oft back from the normal path of the thread.

In accordance with my present invention, I have provided an improved means for automatically controlling the action of the rod 63 and associated parts from the automatic stop mechanism hereinbefore described. This means, as here shown, embodies a main actuator. in the form of a cam on the collar 10 carried by the main drive-shaft, and atrai'ismitter for imparting movement to the rod (33 and associated parts from said actuator 70. which includes an elbow lever 71 pivoted to a bracket 72 on the machine frame with one arm in a position for engaging the rear end of the rod 68, and a rod 73 pivoted to the other arm of said elbow lever and depending therefrom to be engaged at its, lower end at predetermined times by the actuator cam 70. This transmitter rod adjacent to its lower end passes through a guide slot 74 in a bracket stud 75 on the machine frame, which slot extends transversely of the cam 70, as clearly shown in Fig. 4-. In the operation of the machine, as when sewing a group of stitches, the rod 7?) is held by a spring 76 towards the inner end of said slot and at one side of the path of the cam 70, as shown in Fig. 3, in which position it is inoperative to actuate the rod 63 and thread-controlling means associated therewith. l i hen, however, the machine is to be brougl'it to a stop by the action of the stop mechanism upon the completion of the sewing of a group of stitches, the rod 73 is shifted by automatic controlling iszeans to bring its lower end into the path of the cam 70, whereby it will be engaged by the latter and raised suficiently te rock the connected elbow-lever 71 into engageinent with the end of the rod 63 and impart the necessary longitudinal movement to the latter to operate the thread-clamp and pull-off devices in the manner hereinbefore described. The earn 70 is so timed as to impart the described operative upward stroke to the rod 73, just prior to the stopping of the machine, as will be clear by reference to Fig. which shows the parts in position with the machine stopped and with the rod 73 resting on the high part of the cam 70.

As a means for so shifting the rod 73 to position for engagement by the cam 70, the controller 18 is provided with a second arm 7 8 at the inner side of its clutch-controlling arm 20, which is provided with a cam or inclined surface 7 9 adapted, upon the swinging of the controller 18 to clutchreleasing position, to be brought into engagement with the lower end of the rod 73 and force it laterally to its operative position in the path of the cam 70, as shown in Fig. l. Upon the backward or outward movement of the controller for permitting engagement of the clutch, its arm 78 will thereby be withdrawn from engagement with the rod 73, as shown in Fig. 1, where upon said rod will be moved laterally to its inoperative position under the action of the spring 76, and the rod 63 will be permitted to be returned to its normal or inoperative position under the action of a suitable spring, such as the spring 80, in terposed between the stationary lug 65 and a block 81 on said rod.

To review the operation of the invention briefly, if the machine is running, the latch 30 will be operated upon the completion of a predetermined group of stitches, by the tripping device 39, to release the controller 18, whereupon the latter will be rocked under the action of the spring 35 to swing its cam arms 20 and 7 8 into position to engage, respectively, with the connector-arm 2i and the rod 73, the engagement with the connector operating to shift the latter for effecting release of the clutch, and the engagement with the rod 7 3 operating to shift the latter for effecting the operation of the thread-clamp and pull-oil devices. Such movement of the controller under the action of the spring 85 also operates to permit spring 54 to apply the brake 5O substantially simultaneous with the release of the clutch. To restart the machine for the sewmg of the next group of stitches, the controller 18 is swung outwardly by the lever to disengage its arms from the said connector-arm 21 and rod 73, whereupon the connector will be automatically operated by the spring 17 to effect engagement of the clutch, and the rod 7 3 will be shifted to its inoperative position to permit the threadclamp and pull-off devices to reassume their normal positions. a

What I claim is:

1. In a stop motion, the combination with a driven shaft, of a driving clutch member loose thereon having a recess in one end, a split clutch ring within said recess, connector pivotally connected with the shaft for rotation therewith and having a wedge member projecting between the adjacent ends of the clutch ring, means yieldingly holding said connector in position with its wedge member expanding the clutch ring into engagement with the driving clutch member, and a controller cam automatically movable to a position in the path of rotation of the connector for shifting the latter to release the clutch at a predetermined time in the operation of the machine.

2. In a stop motion, the combination with a driven shaft, of a driving clutch member loose thereon having a recess in one end, a split clutch ring within said recess, a connector pivotally connected with the shaft for rotation therewith and having a. wedge member projecting between the adjacent ends of the clutch ring, means yleldingly holding said connector in position with its wedge member expanding the clutch ring into engagement with the driving clutch member, and a controller cam mounted on a stationary pivot and being movable to and from a position in the path of rotation of the connector for shifting the latter to release the clutch.

3. In a stop motion, the combination with a driven shaft, of a driving clutch member loose thereon having a recess in one end, a split clutch ring within said recess, a connector pivotally connected with the shaft for rotation therewith and having a wedge member projecting between the adjacent ends of the clutch ring, means yieldingly holding said connector in position with its wedge member expanding the clutch ring into engagement with the driving clutch memher, and a controller cam mounted on a stationary pivot and being movable to and. from a position in the path of rotation of the connector for shifting the latter to release the clutch, said controller having a yielding buffer for receiving the impact of the connector and also a stop co-operating with said buffer for bringing the connector and connected shaft to a stop at a predetermined point in their rotation.

4:. In a control means for power sewing machines, the combination in the driving means, of a tight pulley and a loose pulley, a friction clutch between the said tight pulley and loose pulley with. means for actuating the said clutch, a brake means for the said tight pulley, a stop lugon the said tight pulley, a pivoted stop arm with buffer means for the said tight pulley, an actuating rock shaft for controlling the said buffer stop arm, connections to the said stop arm from the said rock shaft to swingthe said buffer and stop arm to and from engaging position, actuating means for said rock shaftto start said machine, and release means to stop the same, as specified.

5. In a control means for power sewing machines, the combination in the driving means, of a tight pulley, a clutch means for said pulley, a brake means for the said pulley, a. stop lug on said pulley, a pivoted stop arm with buffer means for the said pulley, an actuating rock shaft for controlling the said buffer stop arm, connections to the said stop arm from the said rock shaft to swing the said buffer and stop arm to and from engaging position, actuating means for said rock shaft to start said machine, and release means to stop the same, as specified.

Signed at Chicago, in the county of Cook, and State of Illinois, this 24 day of April, A. D. 1919.

GEORGE W. NELSON.

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