US1048210A - Buttonhole-sewing machine. - Google Patents

Description

E. A. READ.

`BUTTONHOLE SEWING MACHINE.

APPLICATION FILED Amm, 1911.

1,048,210. y Patented 1160.211912.

2 SHEETS-SHEET 1.

EW E Y ll I N r N i: l XQN E. A. READ.

BUTTUNHQLE SEWING MACHINE. l APPLICATION FILED AUG.- 5, 1911.

Patented Deo. 24, 1912.

2 SHEETS-SHEET 24 UNITED STATES PATENT OFFICE.

FRED A. READ, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE REECE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

BUTTONHOLE-SEWING MACHINE.

Specification of Letters Patent.

Application led August 5, 1911.. Serial No. 642,565.

To all 'whom it may concern.'

Be it known that I, FRED A. READ, a citi-4 This invention 'relates to buttonhole sew? ing machines of the type shown in Patent No. 655,637,y dated. August 7 1900, and has particular reference to'a mechanism for con;

trolling the moveme'nts of the feed shaft which drives the feed cam.

In machines of the above type the feed shaft is operated at different tlmes in the formation' of the buttonhole from each of. two different driving mechanisms, one of which operates to give the shaft a rapid rotary movement thereby to bring the work into position for the needle to operate thereon, and the other of which gives the shaft a slower intermittent rotary movement thereby to feed the work during the stitching of the buttonhole. The fast movement of the shaft is derived from. a rapidlyfrotating pulley loosely mounted thereon, but adapted to be clutched thereto and unclutched therefrom at the proper times by an'automatically-actuated clutch mechanism. The slow Aintermittent feeding movement of the feed shaft' is derived from a pawl and ratchet mechanism which is actuated at the proper times.

In the operation of the sewing machine the work is first clamped in position, and then the rapidly-rotating pulley is clutched to the feed shaft thereby to give the latter a quick feeding movement to bring the .work into posit-ion under the needle. When the work has reached this point said pulley is disconnected from the feed shaft and the pawl-and-ratchet feed mechanism is set in operation thereby to give the Work the slower intermittent feeding movement during thestitching of the buttonhole.

It is desirable that the feed shaft and the feed cam which it operates should be brought to rest at the time that the rapidly.

rotating pulley is disconnected therefrom and before the pawl and ratchet feed mechanism is set in operation, but with the sewing machines as heretofore made it has been dltlicult to secure this end owing to the momentum of the moving parts. Moreover, even when the rapidly-rotating pulley is unclutched` from the feed shaft and the latter is being operated by the pawl-and-ratchet mechanism, there is oftentimes sufficient friction between said pulley and the shaft so that the rapid rotation of the pulley tends to augment 4the' driving movement of the pawl-and-ratchet mechanism, and to cause the shaft to run ahead of the said mechanism, said pulley operating to give'a slight turning movement to said shaft during each intermission inthe operation of the pawl and ratchet. Whenever this happens the feed caml is operated faster than it was in-- tended to be, andV if such increased speed of the feed shaft occurs during the stitching of the last half or side of the buttonhole, as is not infrequently the ease, the stitches on said side will be more widely separated than on the other side, thus producing the undesirable result of a buttonhole with a less number of stitches on one side than on the other.

My present invention aims to provide a simple arrangement for controlling the operation of the feed shaft so as to prevent the undesirable results above described from occurring. i

In the drawings wherein I have illustrated a selected embodiment of my invention, Figure 1 is an underside view of a sewing machine such as shown in said Patent No. 655,637 with my improvements applied thereto; Fig. 2 is an enlarged section on the line :v -m, Fig. l; Fig. 3 isa section on the line .f1/ y, Fig. 2; Fig. 4 is a view similar to Fig. G of said Patent No. 655,637, but showing my improvements; Fig. 5 is a perspective view of part of the brake device.

In the drawings a indicates the bed of the sewing machine and b3 is the feed shaft provided with the usual worm t which meshes with and operates the feed cam This shaft b has loosely mounted thereon the pulley b" which is provided with a hub carrying a grooved collar 7118 that is operated by the clutch-controlling lever G. The pulley has rigid therewitha projection Grl5 which is ada'ited to engage a pin b1 carried by a han le b fast on the feed shaft b3 so that movement of the pulley longitudi nally of the shaft will brin the projection Gv' :nto engagement with t e pin'b` and thus clutch the pulley to the shaft. At the opposite endl of the feed shaft if? is a feed Patented Dec. 24, 1912.

mechanism designated generally at 3 and which includes an oscillatory pawl 51 operating on an internally-toothed ring 4].

, which is geared tothe shaft 636, all as shown and described insaid Patent No. 655,637. This feed mechanism 3 is called into play at the proper time and operates to give the shaft 636 a slower intermittent rotary movement during the stitching operation.

In the operation of the device when the machine is first started the buttonhole is cut by usual mechanism and the pulley 627 is then clutched to the feed shaft 63G thereby to give said shaft a rapid rotation which moves the stitch-frame and feeds the work into position for the `stitching operation with a quick movement. Vhen the work is in proper position for the stitching operation the pulley 627 is unclutched from the feed shaft and the pawl-and-ratchet feed mechanism 3 is brought into play to give the shaft the requisite slow intermittent movement for stitching purposes. The parts thus far described are or may be all as shown in said Patent No. 655,637 and form no part of the vpresent invention, and reference may be had to said patent for a more complete description of the operation thereof..

As stated above it is desirable that the feed shaft 636 and the feed cam should be brought to rest instantly at the time that the drivlng -pulley 627 is unclutched from the feed shaft in order that the intermittent pawl-andratchet -feed mechanism 3 may operate properly to givedthe feed shaft its intermittent feeding moiifment during the stitching operation. This is frequently a somewhat difficult accomplishment, and moreover, as stated above, even when the pulley 627 is ruiming loose on the feed shaft 636 it frequently happens that at certain points in the stitching operation there will be suliicient friction between the pulley and the shaft so that the latter will be fed forward by the pulley, thus causing :the feed shaft to run` ahead of lthe`pawl-and-ratchet feed mechanis and producing the undesirable result of a b tton-hole in which the stitches are not evenly spaced.- In order to overcome this diiiiculty, I have provided a. novel brake arrangement which is applied to the feed shaft 636 and which operates to prevent said shaft from running ahead of the paWl-andratchet feed mechanism 3, and also operates to bring the shaft to rest instantly that the pulley 627 is unclutched therefrom.

In carrying out my invention I apply nto said shaft 6se or to a sleeve fast thereon a collar '4 which may be clamped to the shaft in any, suitable way as by making said collar .a s )l t collar, as seen in Fig. 2, it being provied with a clamping screw 5 by means of which it may be clamped firmly to the shaft 636. This collar is provided with a recess G in one end in which is receiveda split spring washer 7. This washer 7 bears against a plain washer 8 which set-s against a shoulder 9 formed on the cam casing 10 through which the shaft 636 extends. The collar d will be set up against the shoulder 9 with more or less pressure, and as a result the spring washer 7 will provide-a constant frictionA lbetween the collar which rotates wit-hnthe shaft and the stationary shoulder 9, said friction acting as abrake or drag on the shaft 636. I find in practice that this friction is suiicient to prevent the shaft 63G from over-running when the pulley 627 is disconnected at the end of the quick feeding movement4 and also that it is sufficient to prevent the pulley 627 from augmenting the action of the feed mechanism 3, and it thereby prevents any increase of speed in the feed shaft 636 during the stitching of the buttonholedue to the action of the pulley 627. With my improvement on thesewing machine the stitches in the buttonhole will be formed uniformly with the same number on each side thereof.

Havingfully described my invention what .I claim as new and desire to secure by Letters Patent is 1. In a .buttonhole sewing machine, the combination with a frame having a shoulder, of a lfeed shaft, a feed cam operated thereby, two separate driving mechanismsA for operating` said ,feed shaft, one of which is adapted to drive the shaft faster than the other, a collar fast on -the shaft but adjustable longitudinally thereof, and a resilient friction washer confined between the collar and said shoulder and operating to prevent over-running of Ithe feed shaft.

2. In a buttonhole sewing machine, the combination with a frame having a shoulder, of a feed shaft, a feed cam operated thereby, means to operate the driving'shaft at two different speeds, a recessed collar fast on said shaft adjacent said shoulder, a washer mounted on the shaft and bearing against said shoulder, and a split spring Washer occupying the recess` f the collar and engaging theliirst-named washer, said washers provlding a suflicient frlctional resistance to 4prevent the overrunning of the feed shaft. v

In testimony whereof, I have signed my namev to this specification, in the presence of two subscribing witnesses.

FRED A. READ.

Witnesses:

Louis C. SMITH,

BERTHA F. I-IEUsER.

@epics of this ptiteut may beobtai'ed for five cents each, by addressing lLhe Gemmissioner of Patents,

i y Washington, D. C.

Images