US1361871A - Sewing-machine - Google Patents

Description

J. KIEWICZ.

SEWING MACHINE.

APPLICATION FILED JAN-2.1919.

Patented Dec. 14, 1920.

3 SHEETS-SHEET 1.

firm/7X0 John K iewicz.

J. KIEWICZ.

SEWING MACHINE.

'APPLICATION FILED mm. 1919.

1,361,871, Patented Dec. 14, 192( v a SHEETS-SHEET 2.

John Kiewicz. 4 m 21m J. KIEWICZ.

SEWING MACHINE.

APPUCATION FILED JAN.2, 19w;

1,361 ,871 Patented Dec. 14, 1920.

3 SHEETSSHEET 3- I/fl MM? John Kiewicz UNITED STATES PATENT OFFICE.

JOHN KIEWICZ, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REECE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

SEWING-MACHINE.

Specification of Letters Patent.

Patented Dec. 14, 1920.

Application filed January 2, 1919. Serial No. 269,201.

To all whom it may concern: Be it known that I, J OHN Kinwicz, a (Hillzen of the United States, residing at Boston,

county of Suffolk, State of Massachusetts, have invented an Improvement in Sewing- Machines, of which the following description, in connection with the accompanying drawin is a s ecification. like characters IVhere the under thread is thus cut close to the work at the end of the stitching on a luittonhole, it is desirable that a suflicient length of under thread should be left pro truding' from the under thread mechanism that when the stitching is started again on another buttonhole the first stitch will be properly formed because if the thread end is too short, there is danger that it will be pulled through the work in tightening the first stitchjthus making an imperfect stitch.

It'is one of the objects of my present invention to provide a novel thread-pullingofi device which becomes operative automatically when the stitching on any buttonhole is completed to draw off from the source of supply a length of under thread before the thread is cut so that there will be left protruding from the under thread mechanism the required length to insure the correct formation of the first stitch.

Another object of my invention is to provide a novel thread-pulling-oiidevice which is arranged to be actuated by the actuator that controls the thread-trimming mechanism so that one actuator is sufficient to operate both the thread trimmer and the thread-pulling-ofi device.

Other objects of my invention are to imorove generally threae trimming and thread-pulling-ofl' devices for buttonhole sewing machines, all as will be hereinafter set forth. n

In order to give an understanding of my iuventioiu I have illustrated in the drawings a selected embodiment thereof which will now be described, after which the novel features will be pointed out in the appended claims.

In the drawings, Figure 1 is a side view of a buttonhole sewing machine embodying my invention;

Fig. 2 is a plan view of a part of the base frame with the clamps removed for the purpose of showing better the construction and operation of the pull-off device for the under thread;

Fig. 3 is an underside view of the bed plate showing theractuator forthe pull-off and thread-trimming devices;

Figs. 4 and 5 are plan views of the clamp plate showing the operation of the thread trimmer and the pull-off device.

Since my invention relates particularly to the means for pulling off the under thread and for cutting or trimming the thread. I have not deemed it necessary to illustrate herein a complete buttonhole sewing machine, but have contented myself with illustrating a suflicient portion of .the sewing machine to enable the invention to be understood.

1 indicates the bed plate of a sewing machine from which rises the head or overhanging arm 2 carrying the upper threadhandling mechanism which is herein shown in the form of a reciprocating eye-pointed needle 3 that is carried by the usual reciprocating needle bar l.

The bed plate 1 carries the work-holding means which is herein shown in the form of the usual clamp plate 5 that is slidably mounted in ways 6 formed on the bed plate land work clamps 7 which are pivotally mounted on the clamp plate 5. Situated beneath the bed plate 1 is the under-threadhandling mechanism which is indicated generally at 8 and which maybe of any suitable or usual type. In the type of sewing machine herein shown this under-threadhandling mechanism is carried by a turret which is rotatably mounted in suitable bearings carried by the depending portion 9 of the frame, said turret sustaining at its up- .per end the throat-plate 10 which is pro vided with an aperture 11 through which theunder thread 12 extends and through which the needle 8 passes when said needle descends through the work. The under thread mechanismis provided with the longitudinally of the ways 6 for feeding the work during the stitching operation and also for the purpose of carrying the work from stitching to buttonhole-cutting -posi-' tion at the end of the stitching operation by means of the usual main cam indicated generally at 14:, the connections between the clamp plate and the main cam being such. as are ordinarily employed in buttonhole sewing machines of this type. c

The parts; thus far described may have any suitable construction but for illustrative purposes they are shown as having substantially'the same construction as will be found in United States Letters Patent No. 1,188,944, dated June 27, 1916, or in my co-pending application Se. No. 203,899, filed November 26, 1917.

Buttonhole sewing machines of this type are usually constructed so-that when they are set in'operation the work clamps 7 are first closed onto the work to indicated in dotted lines Fig. 1, thereby clamping the latter to the clamp plate 5, and the buttonhole cutter, if oneis used, is actuated to cut the buttonhole after which the clamp plate is moved toward the front of the machine to carry the work from buttonhole-cutting to stitching position. The stitch forming mechanism is then set inoperation and the stitching proceeds down one side of the buttonhole and back along the other side, the clamp plate 5 being given the appropriate feeding movement to feed the work properly. At

the end of the stitching operation on the buttonhole the sewing machine is brought to rest with the needle 3 raised and the work clamps 7 are then released to unclamp the work, after which the clamp plate is given a move- I ment to carry the work from stitching to buttonholecutting position. After this cycle of operations has been completed, the

machine is brought to rest The sewing machine herein illustrated is provided Wlth tread-trimming mechamsm which s carried by 'the clamp plate 5 and operates to cut the under thread close to and mechanism comes unclamped.

beneath the work when the stitch-forming to rest and the work is This thread-trimming device is somewhat I Y similar to that illustrated in my co-pending application, Se. No. 203,899, andeomprlses two thread- cutting jaws 15 and 16 which are pivotally connected together at 17 and p are slidably mounted on the clamp plate 5.

Each'jaw has an inclined slot formed in its rear end, said slots being indicated at- 18 and 19, respectively,-said slots receiving a pin 20 carried by a lever 21 which is pivoted at 22 to the clamp frame 5. The threadcutting jaws are capable of bodily movement toward and from the throat-plate 10 and are guided in their movement by a swinging arm 24, one end of which is pivotally connected to the pivotal pin 17 and the other end of which is pivoted to the clamp plate at 25. This arm 24 plays between two stops 23 and 53 which limit its swinging movement and thereby limits the reciprocating movement of the jaws. 'The thread-trimming devices are situated on the upper side of the clamp plate but occupy a position beneath the work 10 when the work is applied vices normally-occupy a retracted position shown in Fig. 4: during the stitching operation and are yieldingly held in such position by means of a spring 26, which-acts on a pin or projection 27 extending from the lever 21. The action of this spring 26 normally holds the pin 20 at the left-hand ends of the slots 18 and 19, as seen in Fig. at whereby the jaws 15 and 16 are held in their open position. When the cutting jaws are in their retracted position they are situated in front of the throat-plate or stitching point, as shown in Fig. 4, and hence do not interfere with the stitching operation. When the stitching on the buttonhole has been completed and the work-clamps 7 are released,;the lever 21 is -swung toward the throat-plate and during the first part of the swinging movement'of the lever, the open jaws 15 and 16 will be moved bodily toward the'throat-plate until the arm 24 strikes the stop 23, at which time the cutting edges 28 of said jaws are situated over the throatplate 10 so that the under thread and the loop of upper thread that is retained by the looper will be situated between the cutting edges. Further swinging movement of the lever 21 will carry the pin 20 to the righthand end of the slots 18 and 19, thus closing the cutting aws and severing both the under threadand the loopof upper thread, as seen in Fig. 5; This form of thread-cutting device is substantially the same as that illustrated in my co-pendingapplication Se. No.

the main cam 14. This main cam is provided with a hub 37 which depends through the camhousing 38 and to which the arm 36 is secured. The main cam 14 and consequently the arm 36 make one complete revolution for each buttonhole, and the parts are so designed and timed that the roll 35 will actuate the lever 30 at the point in the cycle of operations when the sewing on the buttonhole has beeen completed and just as the work clamps 7 are released. The movement of the actuator 30 operates the lever 21 there by to move the thread-trimming devices into operative position and actuate them to trim the thread, as above described.

1 In order to pull off from the source of supply a sufficient length of under thread to provide for forming properly the first stitch when the sewing machine is started in operation, I have provided a pull-off lever 39 which is pivoted at 40 on the end of the bed plate 1 and beneath the clamp plate This pull-off lever 39 is acted upon by a pulling spring 41 which normally holds it in its full line positions Figs. 2 and 4. The end 42 of the lever is situated close to the throatplate 10 and is provided with a thread-engaging notch 43 and said lever is so shaped and constructed that when it is swung from the full to the dotted line position, Fig. 2, the end 42 thereof will be carried beneath the throat-plate 10 and the notch 43 will be brought against the portion of the under thread 12 leading from the under thread mechanism up through the throat-plate.

During the sewing operation, the pull-off lever 39 is in its retracted or full-line position, Fig. 2, but at the end of the stitching operation and before the thread-trimming device is actuated to cut the thread, said lever is swung from its full to its dotted line position Fig. 2, during which swinging movement the notch 43 engages the under thread 12 and draws off a length from the source of supply, it being understood, of course, that the thread is at this time connected to thework. Immediately after this required length of under thread has been pulled from the source of supply, the threadtrimming device is actuated, as above 'described, to cut the under thread.

In order to simplify the mechanism, I have provided a construction wherein the pulling-off movement of the pull-off lever 39 is effected by the actuating. lever 30 so that said lever 30 operates both the pulloff lever, and the thread-trimming device. For this purpose the pull-off lever 39 is provided with the tail or extension 44 which normally extends beyond the tail 33 of the lever 21, the end of the extension 44 being formed with the cam surface 45 with which the upstanding part 32 of the lever 30 normally has engagement. Hence during the initial movement of the actuating lever 30 the part 32 operates on the cam surface 45 thereby to swing the pull-oft lever 39 from the full to the dotted line position. and pull off the required length of under thread from the source of supply. The inner face or edge 47 of the extension 44 has such a shape that after the end 32 of the lever 30 has passed the corner 46, said lever can return toward its normal position under the influence of the spring 41 thereby letting up on the under thread. The relative position of the tail 33 of the lever 21 and the cam surface 45 of the extension 44 is such that the end 32 of the lever 30 will engage the tail 33 immediately after it has passed the corner 46 so that as soon as the under thread has been pulled off and then the pressure of the pull-off on the under thread has been released, the thread-trimming device is moved into position to engage the thread and then'is actuated to sever the thread.

The advanta e derived from thus releasin c; 23

tion, means to produce a relative work-feeding movement between the work-holding means and the frame carrying said stitchforming mechanism, a thread-trimming device carried by the work-holding means and operating to cut the under thread beneath the work at the completion of the sewing operation, a pull-off device mounted'on said frame and adapted to pull off a length of under thread from the source of supply, and

an actuator common to both devices.

2. In a sewing machine, the combination with a frame, of stitch-forming'mechanism carried by the frame and adapted to concatenate an upper and an under thread, work-holding means constructed to hold the work clamped during the stitching operation, means to produce a relative work-feeding' movement between the work-holding means. and the frame carrying said stitchforming mechanism, a thread-trimming device carried by the work-holding means anl operating to cut the under thread beneath the work at the completion of the sewing operation, a pull-off device mounted on said frame and adapted to pull off a length of under thread from the source of supply, and

-an;actuator common to both devices'and arranged first toactuate the pull-offrdevice and then subsequently toloperate the trimming device.

3. In a sewing machine, the combination with stitch-forming mechanism for c0ncatenating an upper and an under thread, of work-holding means, a main cam for producing a relative feeding movement .between the stitcheforming mechanism and work-holding means,'a thread-trimming doe vice carried by the work-holding means, a pull-olf device supported independently of the worl-r-holding means and arranged to pull oil" a length of under thread from the source of supply, an actuator constructed to actuate first the pull-oif device and then the threadtrimming device, and means rigid with the main cam for operating said actuator. l a

12. in a sewing machine, thecombination with stitch-forming mechanism for concatcnating an upper and an under thread, of

work-holding means, a main cam for producing a relative feeding movement between the stitch forming mechanism and work holding means, a thread-trimming device carried by the work-holding means for cut ting the under thread beneath the work, a pull-off device supported independently of the worlcholding means and arranged to pull ofl a length of under threadfrom' the source of supply, a lever adapted by its swinging movement to actuate first the pulloil and then the thread-trimming device, and means associated with the main cam for actuating said lever.

In a sewing machine, the combination with work-holding means, of stitch-forming mechanism for concatenating an upper and an under thread, a main cam for producing a relative feeding movement between the stitch-forming mechanism and work-hold ing means, a pull-elf device adapted to pull. oii a length of under thread from the source of supply, a thread-trimming device separate from the pull-off device, a pivotallymounted actuating lever adapted during its turning movementfirst to actuate the pulloil device and then to operate the, trimming device, and means associated with the main cam to operate said lever.

6. In a sewing machine, the combination '7. In a sewing machine'of the type 0011- structed to sew a short seam and then come to rest, the combination :with a frame, of workholding means movably mounted thereon, means to give s'aidwork-holding ried icy-the work-holding means, and means common to both devices to actuate them.

, s 8. In a sewing machine of the type constructed to sew a short seam and then to come to rest, the combination with a frame,

of work-holding means, movably mounted thereon, means tc give said work-holding means a feeding movement, stitch-forming means constructed to concatenate an upper and an under: thread, a pull-off device ,mounted on the frame and adapted to pull off a length of under thread from tl c source c-f supply, a thread-trimming device for cutting the under thread beneath the work carried by and movable with the work-holding means, an actuating'lever common toboth devices, and means to actuatevsaid lever at the end of a sewing operation.

9. In a sewing machine, the combination with a frame having a bed plate portion, of worleholding moans, s'lida-bly mounted thereon, a stitch-forming mechanism for concatenating an upper and anunder thread and including a throat-plate through which the threads pass, a pull-off device mounted on the bed plate to swing in a horizontal plane and adapted by its swinging movement to pull off a length of under thread,

said device having a cam surface, an actuating lever adapted by its swinging movement to wipe over said cam, surface thereby to actn ate the pull-oil device and then to release the latter, and a spring to return the pull-off device to normal position.

it). In a sewingmachine, the combination with a frame having a bed plate portion, of work-holding means slidably mounted thereon, a stitch-forming mechanism including a throat-plate through which the threads pass, a pull-off member pivoted to the bed plate beneath the workrholdingmeans and adapted to swing in a horizontal plane and by its swinging movement to pull off a length of under thread, one end of sald member projecting beyond the end of the bed plate,

and an actuating lever pivoted to the frame and adapted to engage the projecting end of the pull-off member.

11. In a sewing machine, the combination with a frame having a bed plate portion, of work-holding means slidably mounted thereon, stitch-forming mechanism including a throat plate through which the threads pass, a pull-off member pivoted to the bed plate beneath the work-holding .means and adapted to swing'm a horizontal plane and byits swinging movement to pull off a length of under thread,:ione end of said member projecting beyond the end of the bed plate, a thread-trimming device car- 'ried by the work-holding means, and an actuating lever pivoted to the frame and adapted by its swinging movement to engage the projecting end of the pull-off lever thereby to actuate the latter and then to actuate the thread-trimming device.

12. In a sewing iachine, the combination with stitch-forming mechanism for concatenating an upper and an under thread, of work-holding means for holding the work clamped during the stitching operation, means to produce a relative feeding movement between the stitch-forming mechanism and the work-holding means, a thread-trimming device carried by the work-holding means and operating to out the under thread beneath the work at the completion of the stitching operation, a pull-off device adapted to pull off a length of under thread from the source of supply and supported so that there is a bodily relative movement between it and the trimming device during the workfeeding movement, and an actuator common to both devices.

13. In a sewing machine, the combination with stitch-forming mechanism for concatenating an upper and an under thread, of work-holding means for holding the work clamped during the stitching operation, means to produce a relative feeding movement between the stitch-forming mechanism and the work-holding means, a thread-trimming device carried by the work-holding means and operating to cut the under thread beneath the work at the completion of the stitching operation, a pulloff-device adapted to pull off a length of under thread from the source of supply and supported so that there is a bodily relative movement between it and the trimming device during the work-feeding movement, and an actuator common to both devices, and arranged to actuate'first the pull-off device and then to operate the trimming device.

1a. In a sewing machine, the combination with a frame, of work-holding means movably mounted thereon, means to give said work-holding means a feeding movement, stitch-forming mechanism constructed to concatenate an upper and an under thread, a pull-off device mounted on the frame and adapted to pull off a length of under thread from the source of supply, and a thread-trimming device carried by and movable with the work-holding means for cutting the under thread beneath the work at the end of the sewing operation.

15. In a sewing machine of the type constructed to sew a short seam and then come to rest, the combination with a frame, of work-holding means movably mounted thereon, means to give said work-holding means a feeding movement, stitch-forming means constructed to concatenate an upper and an under thread, a pull-off device mounted on the frame and adapted to pull off a length of under thread from the source of supply, a thread-trimming device can ried by the work-holding means and adapted to cut the under thread beneath the work, and means common to both devices to actuate them.

In testimony whereof I have signed my name to this specification.

JOHN KIEVV 1C7.

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