US2187235A - Sewing machine - Google Patents

Description

C. A. O. GRIP SEWING MACHINE Jan. 16, 1940.

2 Sheets-Sheet 1 Filed Dec. 5, 1938 INVEN 5% at \M Q N% v m m T1... 7 1 mm Jan. 16, 1940. c. A. o. GRIP 2,187,235

SEWING MACHINE Filed Dec. 5, 1938 2 Sheets-Sheet 2 I INVENIURIIY (9% am. 1 1v VAL, 6212M '4 i Patented Jan. :16, 1940 1 2,187,235 1 v sawmemcnmn Car-1A0. Grip, Newton, Mass, assignorto The Reece Button Hole, Machine company, Boston, Mass, a corporation of Maine Appiication Dcember 5, 1938,,SerialR-No. 243,968

\ 2 Claims, 21; iiz-a-ve 1 i This invention relates a buttonhole and similar 'sewingjmachin'es, and more particularly to the work holding and clamping mechanism employedinsuch machines; andis in the nature of 3 an improvement on the work clamping mochanism covered by an application filed December 1,

1938, by Joseph H. Pikuhserial NO. 243,311.

r In gsaid Pikul application is described a Sim-l plified work clamping mechanism wherein, .as um distinguished from' mechanisms heretofore em ployed for this general purpose, the fabric is tightlyv and securely held at substantially an pointssurrounding the stitching area i. e.; the

region in which the buttonhole or similar stitches I 15 are located), is evenly stretched or tensioned in all "directions, andflis properly positioned for the action thereon of thestitching and cuttinginstrumentalities! Said, mechanism comprises "a unitary work plate having an *Qpeniiigthere Y. o throughand a single complementary work clamping nemberadapted to enter said opening, clamp the interposed fabric between itself and the peripheral edge of thel'atter, and deflector defpresstheportion of the fabric withinsaid edge 1 into a position with its bottom surface {substantially flush with the bottom surface of the work i plate, thereby tensioning the same andpositicm ing it for the action of the stitching andcuttingf instrumentalities', said clamping ember having an "opening 'therethroughof such size and shape as LOJGXPOSG and enclose the stitching area and through which the stitchlngand cutting instru mentalities operate upon the depressed and tensinned portion of the fabric.

The mechanism r said applicationiisjeininente ly suitable and satisfactoryforuse in connection with relatively heavy, stiff, and inelastic or nori .stretchable'materials, such as leather and certain kinds of woven fabrics, but [it and highly stretchable "goods, such, forexaniple,

as knitted: fabrics, the proper tensioningfofthef material requiresa greater stretching thereof proper and even engagement of the jclamping member with the work. in order to ,preventjdisplacement or distortion of the latter. The prsto ent invention has for its objectlto provide a mechanism of this type which will satisfythese requirements. To this end, ,while retaining the unitary work plate and single cooperating clamping member 'ofsaid app1ication,}with their a'dso vantages, the present invention contemplates the hasbeen found qgm that, when operating upon relatively light, soft,

provision of a clampingmember comprising twof relatively. movable portions adapted respectively 1,

to clamp and securely hold the, work about the edge of the opening inthe work plate and thereafterto deflect, stretch, tension, and position the a same. The invention also includes improved meansfor mountingthe clamping member upon its carrier to cause its clamping fportion toenga e the work in a position substantially parallel to the latterirrespective ofthethickness therem of, While permitting said portionto adapt itself to irregularitiesin the workand to maintain its position of engagement during the subsequent stretching operation. r i r The foregoing and other objectsof the invention, together with means whereby thelatter may be carried into effect, will best be understood from the following description of an illustrative f embodimentlthereof shown in the accompanying drawings, this, however, having been chosen for m purposes of exemplification merely, as it will be obvious toth'ose' skilled in the art that theinvention, as defined bythe claims hereunto appended, may be otherwise? embodied without departing from its spirit and scope. t it i In saiddrawings: f

l 1. is a side levatiomypartly in sectiomgof a machine including work. clamping mechanism embodying the invention; I 1 a r Fig.2 is a plan View, partly broken away, of w the work clamping mechanism per se andassociated parts.

Fig. '7 is a section taken subst-antially onthe 0 line 1 1mg. 6. i a i i l Referring to Fig. 1, the invention is shown as applied to a buttonhole or similar machine of a well knowntype comprising a stationary bed frame i'5rcarrying the lworkclamplng mechanism, 5 hereinafterdescribed, and'a movable stitch frame i or head It carrying the'stitchingmechanism as well as cutting mechanism for cutting the buttohiiole or the like. The stitch: frame [6 is1movf able longitudinally over the bed frame [5 to bring-the" stitching and cutting mechanisms alternati vely into operative relationship with the work, and also longitudinally or laterally orboth to position thestitcheshin accordance with the i work to ,be performed, by means of mechanism 26 through which the needle I9 passes to cooperoperated by a main cam l1 carried by the stitch frame l6 and rotated by a feed shaft l8 likewise carried by said frame. This mechanism is well known in the art, being shown, for example, by the patents to Reece, No. 240,546, April26, 1881, and No. 655,637, August 7, 1900, and many others,

and requires no detailed description herein.

The stitching mechanism comprises .a needle l9 carried by a needle bar 20, and looper mechanism l4 which may be substantially as shown in .the patent to Grip, No. 1,905,854, April 25, 1933,

said needle bar and looper mechanism being carried respectively by upper and lower turrets 2| and 22 rotated in unison at the proper time by gear segments 23 and 24 carried bya rock shaft 25 operated by the main cam H as further described in the Reece patents above referred to. The lower turret 22 also carries a throat plate ate with the looper mechanism. The needle bar is reciprocated vertically and vibrated laterally in its turret 2| from suitable cams on a stitchmg shaft 21 through mechanisms generally indicated at 28 and 28a, respectively, andwhich may be substantially as shown and described in the'patent to Reece, No. 1,991,627, February 19, 1935'. The looper mechanism carried by the turret .22 is likewise operated from the stitching shaft 21 by mechanism generallyindicated at 29 and which may be substantially as shown and described in the patent to Grip above referred to andin the patent to Dunnell, No. 1,935,083, November 14,1933.

The cutting mechanism comprises upper and lower cooperatingcutting elements 30 and3l, the former of which is carried by a lever or arm 32 operated at the proper time from the main scribed in the Kiewicz patent above referred to and inthe patent to Hill, No. 713,764, November 18, 1902.

It will be understood that, in machines of this character, suitable mechanism is provided whereby the machine, when started, will perform its operative cycle and then automatically stop, said cycle including; first, a closing'of the'work clamp to clamp the work, then a movement ofthe stitch frame from a cutting position in which the cutting elements are adjacent ,the stitching area, into a stitching position in which the stitching instrumentalities are adjacent said area, a stitching operation ofla. character determined by the design of the feed mechanism, a return of the parts into cutting position, and, finally, the

- opening of the work clamp to release the work,

said cycle also including a. cutting operation which may be'performed either before or after the stitching operation accordin'gto the design or adjustment of the machine.

Except as hereinafter pointed out, or as they enter into combination with parts hereinafter "describedthe mechanisms above referred to speicifically form no part of thepresentinventmn and may be asshown and descr b din the p ents referred to, or otherwise, as will be well I understood by those skilled in the art.

oted, said plate having slots 43 through which the lower ends of said arms project for detachable connection with the rocker 36, permitting removal of said arms with the work plate. At its underside, the work plate 33 is grooved, as shown at 44, to receive ,the'throat plate 26 and lower cutting element 3| and permit movement of said thereof, being secured in this position by a spring pressedlatch 4'! as shown-in Fig. 2. Cooperating with the work plate 33 is a single clamping member 48 carried by and between the arms 34.

In accordance with the present invention, the

clamping member 48 comprises a head 49 pivoted at 5!! to the arms 34 and comprising a tubular portion 5| and a separate work clamping portion or element 52. v

a The tubular portion 5|, which is adapted, when the clamping member is depressed, to enter the opening in the work plate 33, and through which the stitching and cutting instrumcntalities operate, may be formed integral with the head 49 or may comprise a separate sleeve permanently secured, as by brazing, to said head. It is of such size and shape as to enclose the stitching area and to receive within the confines of its inner periphery all of the stitches positioned by the feeding movements of the stitch head and the rotation of the turrets in accordance with the character of the work to be performed; The particularmachine herein shown is arranged to sew oval buttonholesdisposed parallel with the edge of the goods, the stitch feeding movement of the stitch head being entirely or chiefly in a direction transverse tothe machine, and the tubular member 5| is accordingly of approximately oval shape with its longest dimension transverse .to the machine, as is also the opening 45 which, while slightly larger in size, corresponds generally in shape'with said tubular member. To the same end, the lower cutting element 3| comprises a transversely disposed knife to cooperate with a transversely disposed cutting block or anvil 30 carried by the lever 32. It will, of course, be understood that, for sewing buttonholes or the like of other forms, work plates (or the surface of the workfplate and aboutthe edge of the opening 45 substantially continuodsly throughout a region completely surrounding. the stitching areas The clamping element52 is carried by headed plungers 53 guided in the head 49, said element being normally held inthe positionshotvh in Figs. 3,14 andtbyrsprings 54 sufiicient strength toexert an adequate clamping surrounding said plungers and interposed between said element and the inner ends of recesses formed in the said head. ithetsprings .54 are of pressureupon said clamping element.

The Work W having been positioned on the work plate 33, with the clamping member 48 elevated as shown in Fig. 3,. the clamp operating t mechanism is operated to depress said clamping the head lflcauses the tubular portion 5| thereof, operating through the clamping element 52, to

enter the opening 45 (the springs 54 yielding for this purpose), ultimately depressing said work into said opening into a position with itsbottom surface substantially flush with the bottom surface of the work plate andtherefore with the tops of the throat plate 26 and cutting element l 3], as shown in Figs. 1 and 5. Consequently,

the movements of the throat plate and cutting element. into and out of operative position, i. e., into and out of register with the opening 45, need. beonlyin a plane parallel with the work plate, said members, however, being in close proximity to the work whenbrought into operative position. This subsequent downward movement of the tubularportion 5|, after the work has been 4o firmly clamped by the clamping. element 52;acts to-stretch the work across the open lower end of said tubular member like a drum head, thereby work evenly notwithstanding the arcuate rtiovement of the ends of the arms by which the clamping member is carried, and in order to insure such even engagement, means are preferably provided for yieldinglyjfixing the angular position of the clampingmember on its pivot, so

adapted to engage and clamp the'WorkW upon as toi cause the. element 52 to occupy a position parallel to the work plate at the time of its en- ]gagement with, work of average thickness. As shown, such means comprises spring pressed plungers 55 guided in enlarged portions 56 of the 3 arms 34 and engaging the head 49 at opposite sides, respectively, of the axis of the pivots 50. i

The plungers55 are backed by springs 51 which may be adjustably tensioned by abutment screws 58, thereby balancing the, pressures exerted by such springs in such a way as to determine the angular position of the head 49 about its pivots. The clamping element 52 is thereby caused to engage the upper surface of the work evenly at all points about the stitching area, but the springs 51 are capable ofvyielding to permit saidclamping element to accommodate itself to variations in thicknessof, and irregularities in the work, as

' where the latteris of greater thickness at one side of the buttonhole than the other, and also to compensate for the slight additional angular movement incidental to the final depression of the tubular portion 5| into the opening 45 to stretch, tension and position that portion of the work which is to be operated upon. I claim: U

1. In a sewing machine having stitching mechanism, work clamping means comprising a work plate and a clamping member having alined openings through which the stitching mechanism operates, said member comprising a portion adapted to clamp the work about the opening in saidwork plate and a portion adapted to depress the work into said opening, a carrier upon which said member is movably mounted, and means for yieldingly positioning said member on said carrier to cause the work clamping portion thereof to engage the worksubstantially parallel to said work plate.

2. In a sewing machine having stitching mechings through which the stitching mechanism which said member is carried at opposite sides,

anism, work clamping means comprising a work. plate and a clamping member having alined openadequately tensioning the same in all directions. The pivotal mountingf5ll "of the l clamping 1 member 48 on the arms permits the clamping 1 element 52 to engage the upper surfaceof the and adjustable spring pressure devices carried l bysaid armsandengaging said member at oppol site sides of the axisof said pivots for normally, ,maintaining said member in a predetermined angular position with respect to saidaxis.

' CARL A10. GRIP.

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