US1575112A - Sewing machine - Google Patents

Description

March 2 1926. 1,575,112

-:' A. B. FOWLER SEWING MACHINE Original Filed Oct. 21, 1920 2 Sheets-Sheet 1 March 2 1926. 1,575,112

A. E3. FQVVLER SEWING MACHINE Original Filed Oct. 23., 1920 2 SheetsSheet 2 Patented Mar. 2, 1926.

UNITED STATES PATENT OFFICE.

ALFRED B. FOWLER, OF BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MACHINERY CORPORATION, OF IPATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SEWING MACHINE.

Application filed October 21, 1920, Serial No. 418,451. Renewed March 5, 1925.

To all whom it may concern:

Be it known that I, ALFRED B. FOWLER, a citizen of the United States, residing at Beverly, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to sewing machines and more particularly to wax thread chain stitch inseam shoe sewing machines, although certain features of the invention are applicable to other types of sewing machines.

In applicants co-pending application filed of even date herewith, Serial No. 418,450 a wax thread chain stitch inseam shoe sewing machine is illustrated and described which is provided with a main take-up for drawing thread from the supply and for exerting strain on the thread while the needle is in its forward position, and for giving up thread during the thread measuring move ment of the thread arm, the looping movement of the looper and the first part of the retracting movement of the needle. The machine is also provided with a spring pressed. auxiliary takeup for exerting a strain on the thread during the latter part of the re tracting movement of the needle. In the operation of sewing machines, particularly of this type, it has been found that the strain which must be exerted on the thread to produce the best results varies with the speed at which the machine is operated, a greater strain ordinarily being required to produce a tight seam when the machine is operated at a low speed than when the machine is operated at a high speed. To secure this resultin the machine of said co-pending application, means is provided for varying the tension. of the auxiliary take-up spring, the tension of the spring beingincrcased upon a reduction in the speed of the machine and being decreased upon an increase in the speed of the machine.

An object of the presentinvention is to provide novel and improved; means in a sewing machine for regulating the strain cut that the effect of thus varying the duration of the strain is to increase the amount of effectiveness of the strain. The preferred embodiment of the invention is provided with a high speed driving mechanism, a low speed driving mechanism, and means for adjusting said stitch setting mechanism upon shifting from the high to the low speed driving mechanism to increase the duration of the strain upon the thread, and upon shifting back to the high speed driving mechanism to decrease the duration of the strain, the variation in the duration of the strain being such as to result in the desired tightness of seam being secured at both speeds. The present embodiment of the invention is provided with a main take-up for exerting a strain on the thread and for drawing thread from the supply when the needle is in its advanced position, and for providing slack or free thread for the stitch forming devices, and is further provided with a spring pressed auxiliary take-up that tends to be urged in one direction to exert a strain on the thread during the retracting movement of the needle. The auxiliary takeup is provided with a stop'for limiting the movement thereof in said direction, and with means acting upon a reduction in the speed of the machine to raise the stop to allow a greater movement of the auxiliary take-up in said direction during the retract ing movement of the main take-up. It will be apparent that the effect of thus raising the stop at this time is to lengthen the path of travel of the thread and, hence, to decrease the amount of slack or free thread provided by the main take-up for the stitch forming devices, so that during the retracting movement of the needle the needle will cooperate sooner with the auxiliary take-up to exert a strain on the thread. Preferably,

scribed and claimed, the advantages of which will be obvious to those skilled in the art.

The several features of the invention will be clearly understood from the following description and accompanying drawings, in

' which Figure l is a front elevation of the head of a wax thread chain stitch inseam shoe sewing machine embodying the features in their preferred form; Fig. 2 is a side elevation on an enlarged scale of a portion of the head of the machine with a side of the casing removed; and Fig. 3 is a detailed sectional view taken on the line 33 of Fig. 2

of a portion of the mechanism for control ling the strain exerted on the thread.

The sewing machine illustrated in the drawings is provided with a curved hook needle 2, a needle carrier i, a looper 6, a thread arm 8, a back gage 10, a back rest or hunter 12, and a thread tcnsioning device comprising a tension wheel 1%. The machine is also provided with a high speed driving mechanism comprising a pulley 16 mounted on the driving shaft 18 of the machine and a low speed driving mechanism comprising a worm wheel 20 mounted on the driving shaft. The high speed driving mechanism is thrown in upon the depression of a rod 22 connected with a treadle mechanism at the base of the machine, and is thrown out and the low speed driving mechanism is thrown in upon the rod being released. The rod 22 is connected with the driving mechanisms through an arm 24; secured to one end of a rock shaft 26 that carries a forked arm 28 engaging a clutch sleeve 30 mounted to slide on and rotate with the driving shaft 18. When the treadle rod 22 is released to throw out the high speed driving mechanism and to throw in the low speed driving mechanism, the upward niovement of the arm 2% which is effected by means of a torsion spring 31 connected with the arm, is limited by the engagement of a stop lug 32 thereon with the lower end of a latch lever 34 pivoted on the frame of the machine. Ata predetermined point in the rotation of the driving shaft after the low speed driving mechanism is thus thrown in, the latch lever 34 is released from the stop lug 32 by a cam carried by the driving shaft allowing the arm 24 to be further carried upwardly by its spring which shifts the clutch sleeve 30 into position so that upon the completion of a predetermined number of degrees of rota tion of the driving shaft after the latch lever 3% is released, the low speed driving mechanism is thrown out, and stopping devices act to stop the shaft in a predetermined angular position. in sewing about the toe of a pointed toe shoe, it is desirable that the machine shall be run at a uniformly low speed, and it will be apparent that this may be accomplished in the illustrated machine by the operator releasing the treadle rod 22 only suliiciently to throw in the low speed driving mechanism without rendering the stopping devices of the machine active, and that upon again depressing the trcadle rod 22 the driving mechanism may be shifted back to high speed. The parts above described may be and preferably are the same as the corresponding parts of the machine illustrated and described in applicants copending application Serial No. 298,589, filed May 21, 1919, to which reference may be had for a full and complete description of the same.

The main take-up comprises a thread truck 36 mounted on the free end of an arm 38 projecting from a sleeve 40 which is loosely mounted on a stud shaft 12 secured to the frame of the machine. The main takeup is actuated by an arm projecting upwardly from the sleeve d0 and having its free end pivotally connected with a cam actuated link 4-6. The auxiliary take-up which is interposed between the main takeup and the tension wheel lei comprises a thread truck 48 mounted on the free end of an arm 50 projecting from a sleeve which is loosely mounted on the sleeve 40 of the main take-up. The auxiliary take-up arm 50 is urged upwardly by a coiled spring 5% connected therewith until a projection thereon abuts against the lower end of an abutment 56. The thread passes from the tension wheel over the thread truck 48, beneath a thread truck 58 loosely mounted on the auxiliary takeup sleeve 52, over the thread truck 36 of the main take-up, and thence through the looper to the work.

The thread handling devices of the ma chine illustrated in the drawings are so arranged and operated that the main take-up acts to exert a strain on the seam and to draw oti thread for the next loop from the tension wheel when the needle is in its forward position and extended through the work. The main take-up then falls during the bread measuring movement of the thread arm, during the looping movement of the looper, and during the first part of the retracting movement of the needle. During the latter part of the retracting movement of the needle, it exerts a pull on the thread to tighten the preceding loop, such pull moving the auxiliary take-up arm 50 away from the abutment 56 against the tension of the auxiliary take-up spring 5%.

To render the action of the main take-up,

.the auxiliary take-up and the needle reliable and uniform under all conditions of sewing, means are provided which insure that the pull exerted upon the thread by the needle during the latter part of its re tracting movement shall always be against the resistance offered by the auxiliary tension spring 54 and not against the resistance offered by the tension wheel 14:. To secure this result the needle carrier 4 is provided with a cam surface 60 to cooperate with the end of an arm 62 projecting from the auxiliary take-up sleeve 52. The cam surface- 60 acts to positively raise the auxiliary takeup and to hold the auxiliary take-up in raised position during the action of the main take-up in setting the stitch, so that during the latter portion of the taking up action of the main take-up the auxiliary take-up is practically locked in a position in which the arm 50 of the auxiliary takeup is nearly in contact with the abutment 56. As the main take-up moves to give up thread, however, the retracting movement of the needle carrier moves the cam surface 60 away from the path of the end of the .arm 62 leaving the auxiliary take-up free to be moved against the tension of the spring 54 so that whenthe needle exerts a pull on the thread during the latter part of its retracting movement the auxiliary take-up can yield to the required extent without bringing up against a positive stop so as to cause any strain to be exerted on the thread in addition to that caused by the spring 54 of the auxiliary take-up. The parts of the main take-up and the auxilary take-up above described are of the same'construction and mode of operation, except as hereinafter described, as the corresponding parts of the machine illustrated and described in the co-pending application filed of even date herewith, hereinbefore referred to.

In themachine illustrated in the drawings during the retracting movement of the main take-up, the auxiliary take-up arm 50 is raised by the spring 54 against the abutment 56 and the abutment is so positioned that a certain amount of slack or free thread is provided during the thread measuring movement of the thread arm, the looping movement of the looper and the first part of the retracting movement of the needle or until the needle has retracted sufficiently to cooperate with the auxiliary takeup spring to exert a strain on the thread. It will be apparent that by raising the abutment 56 the path of travel of the thread may be increased and, consequently, the amount of slack or free thread provided as above described for the stitch forming devices may be decreased. The effect of thus decreasing the slack or free thread obviously is to increase the amount oreffectiveness of the strain on the thread as the needle and take-up will act sooner to tension the thread during the retracting movement of the needle, and hence the duration of the strain at this time will be increased. As the machine illustrated in the drawings is provided with a low speed driving mechanism for driving themachine at low speed, means is provided for raising the abutment 56 upon shifting from the high to the low speed driving mechanism to such position that the amount or effectiveness of the strain exerted on the thread may be increased such a degree as to compensate for the reduction in the speed of the machine, resulting in the desired uniform tightness of stitch being obtained at both speeds. To this end the abutment 56 comprises a rod which is screw threaded through an aperture in a cross bar 64, the rod being adapted to be adjusted in the aperture and locked in adjusted position by a lock nut 66. The cross bar is mounted to slide on a pin 68 secured to the frame of the machine, and is urged upward-' ly against nuts '70 threaded onthe upper end of'the bar by means of a spring 72 coiled about the pin and interposed between the bar and the frame. The cross bar 64; is connected by a cord 74: with a lugTG secured to the arm 24,- the cord 74 being connected to the lug by a block 78 secured on the end of the cord extending through an aperture in the upper end of the lug 76, and provided with a head 79 at its lower end. lVith this construction it will be ap parent from an inspection of the drawings that upon depressing the treadle rod 22 to throw in the high speed driving mechanism the lug 76 on the arm 2- will act through the head of the block 78, cord 7 and cross bar 64 to lower the abutment rod 56, and that upon releasing the treadle rod 22 sufficiently to throw in the low speed driving mechanism without rendering the stopping devices active, the cord 74 will be released to permit the spring to move the abutment rod to its raised position, which position is such that the requisite increase in the strain exerted on the thread is obtained in accordance with the reduction in the speed of the machine.

In the illustrated machine the outer end ofthe spring 54 is secured to a screw 30 which is adapted to be adjusted and locked in adjusted position by means of lock nuts 82.

lVhile it is preferred to employ the specific construction and arrangement of parts illustrated and described, it is to be under-- stood that this construction and arrangement is, not essential except so far as specilied in the claims, and may be changed or modified without departing from the broader features of the invention.

The nature and scope of the presentinvention having been indicated and amachine embodying the .several teatures of the tion, high and low speed driving mechanisms,-mechanism for exerting a strain on the thread, and means forshitting from the high to the low speed driving mechanism and for simultaneously adjusting said mechanism for exerting a strain' on the thread to increase the duration of said strain.

3. A sewing machine having, in combination, stitch forming devices, a take-up, a spring for urging the take-up in one direction to exert a strain on the thread, and means acting upon a variation in the speed of the machine for adjusting the take-up to vary the duration of the strain while the tension of said spring remains constant.

i. A sewing machine having, in combination, stitch forming devices, mechanism for exerting a strain on the thread, and means acting upon a variation inthe speed of the machine for adjusting said mechanism to Vary the duration of the strain.

5. A sewing machine'having, in comhination,-stitch forming devices, a take-up tending tomove in one direction to exert a strain on the thread, -a stop for limiting the movement of the take-up in such direction, and means for adjustingthe position of the stop to vary the amount of said strain upon a change in the speed ofthe machine.

6. A sewing machine having, in combination, stitch forming devices, a take-up, a

spring for urging the take-up in one direction to exert a strain on the thread, a stop for limiting-the movement ofthe take-up in such direction, and means for adjusting the stop to increase the amount of said strain upon a reduction in the speed of the machine.

7. A. sewing machine having, in combination, stitch forming devicespa take-up tend ing to move in one direction to exert a strain on the thread, astop for limiting the movement of the take-up in such direction, and means for adjusting the stop to increase saidstrain upon a reduction in the speed of the machine, and for adjusting the stop to decrease said strain on the thread upon an increase in the speed of the machine.

8. A sewing machine having, in combination, stitch forming devices including a needle, a main take-up mechanism for exertmg a strain on the thread while the needle is inits forward position, an auxiliarytakeup mechanism for exerting a strain on the thread during the retracting movement of the needle, and means for adjustingsaid auxiliary take-up mechanism to increase the path of travel of the thread to increase the strain thereby exerted on the thread upon a reduction-in the speed of the machine.

9. A sewingmachine having, in comhination, stitch forming devices including a needle, a take-up mechanism for exerting a strain on the thread during the retracting movement of the needle, and means acting upon a change in the speed of the machine for adjusting the take-up mechanism to increase the duration of said strain.

lOaA sewing machine having, in combination, stitch forming devices, .a take-up mechanism for exerting a strain on the thread, .and means acting upon. a reduction in the speed of the machine to adjust the take-up mechanism to lengthen the path of travel of the thread, and acting upon an increase in the speed of the machine to adjust said mechanism to shorten the path of travel of the thread.

11. A sewing machine having, in combination, stitch forming devices, mechanism for exerting a strain on the thread, and means acting upon a variation in the speed of the machine to adjust said -mechanism to vary the amount of said strain .while the intensitythereof remains constant.

12. A sewing machine having, in combination, stitch forming devices, mechanism for exerting a strain on the thread, and means actingupon arcduction in the speed of the machine for deflecting the thread from itsnormal path of travel to increase the amount of said strain.

13. A sewing machine having, in combination, stitch forming devices, mechanism for exerting a strain on the thread, and

vmeans acting upon a variation in the speed of the machine to adjust said mechanism to vary the path of travel or" the thread.

14. A sewing n'i.acliine having, in combination, high and low speed driving mechanisms, means for shifting from the high to the low speed driving mechanism, stitch forming devices, mechanism for exerting a strain on the thread, and means acting upon bina-tion, stitch forming devices including a needle, a main take-up mechanism for exerting a strain on the thread While the needle is in its advanced position, an auxiliary take-up mechanism for exerting a strain on the thread during the re'tractingmovement of the needle, and means acting upon a variation in the speed of the machine for adjusting said auxiliary take-up mechanism to vary the duration of the strain exerted thereby.

17. A sewing machine having, in combination, stitch forming devices including a needle, a take-up mechanism for exerting a strain on the thread, and means acting upon a reduction in the speed of the machine to adjust the take-up mechanism to increase the duration of the strain and acting upon an increase in the speed of the machine to adjust the take-up mechanism to decrease the duration of the strain.

18. A sewing machine having, in combination, stitch forming devices, a take-up mechanism for exerting a strain on the thread and for providing slack or free thread for the stitch forming devices, and means acting upon a variation in the speed of the machine for adjusting the take-up mechanism to vary the amount of slack or free thread provided for the stitch forming devices.

ALFRED B; FO'VVLER.

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