US1894978A

US1894978A - Trimming mechanism for sewing machines

Info

Publication number: US1894978A
Application number: US534274A
Authority: US
Inventors: Frederic M Card
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1931-05-01
Filing date: 1931-05-01
Publication date: 1933-01-24
Anticipated expiration: 1950-01-24
Also published as: GB374696A; DE561962C

Description

Jan. 24, 1933. F. M CARD TRIMMING MECHANISM FOR SEWING MACHINES Filed May 1, 1931 2 Sheets-Sheet 4 1 Qwwawtov 55% firederzc M. Um'd TRIMM ING MECHANISM FOR SEWING MACHINES Filed May 1, 1931 2 Sheets$heet 2 fie dercc 1%. Card WaltTwooi a C? j z atkozmq Patented Jan. 24, 1933 ll eat em res PATENT ori ice rnnnnnro CARD, or nninenronr, CONNECTICUT, as'sreivon' To SINGER MANU FACTUBING COMPANY, or ELIZABETH, NEW JERSEY, A CORPORATION on NEW JERSEY TRIMMING MECHANISM Application filed May 1,

This inventionirelates to improvements in sewing machine trimmer mechanisms and has for its ObJQClL to improve the tr mmerblade supporting and actuating mechanlsm disclosed in W. A. Neely, No; 826,596, July at, 1906, to provide for more conveniently and accurately. effecting the trimming of the lower of super-posed plies of material in the operation of uni ling said plies by stitching.

With the above and other objects in view, as will hereinafter appear, the invention consists in the devices, combinations, and arrangements of parts hereinafter described 15 and claimed.

The several features of the invention and the advantages attained thereby will be readily understood from the following description of an embodiment thereof illustrated in the accompanying drawings, in which Fig. 1 is a front elevation of the bracket-arm and a portion of the work-supporting post of a sewing machine having the improved trimmer mechanism, which latter is shown partly in section. Fig. 2 is an end elevation of the trimmer mechanism, the bracket-arm and the throat-plate of the machine being shown in section. Fig. 3 is a side elevation of the edge-guide and its supporting means,

as viewed from the right in Fig. 1 and also of the keeper for yieldingly holding the trimmer-blade carrier in its inoperative position. Fig. f is a perspective view of the edge-guide and its supporting bracket. Fig. 5 is a perspective view of the trimmer knife and its carrier. Fig 6 is a horizontal section of the free end of the machine bracketarm, substantially in the plane of the mainshaft journaled in said arm.

The sewing machine illustrated in the drawings has a frame including a work-supporting post 1, and a standard. 2 for the usual bracket-arm 3 which terminates in a head l overhanging the post 1. Journaled for rotation inthe bracket-arm 3 is a main-shaft 5 carrying at one end a belt-pulley 6 opposite end a crank-disk? operatively connected by meansof a link 8 with aneedle-bar 9. i The needle-bar 9 carries at its lower end a needle 10 and is journaled for vertical rethe United States patent to SEWING MACHINES 1931. Serial No. 534,274.

ciprocation in a bushing 11 suitably fixed ,in the bracket-arm head 4. s Any suitable mechanism may be employed for cooperation with the needle in the forma tion of stitches, the work being preferably advanced by a feed-dog 12 of the lower fourmotion type projected through thethroat-e plate 13 upon the worlosupporting postin a raised portion of said throat-plate which, also provides a knife-guiding shoulder 14 Opposed to the feed-dog12 is a pressereroller. 15 carried by an. arm 16of a bracket 17 se}, cured upon the lower end of the usual spring, depressed presser-bar 18 movable endwise vertically in bushings, as 19, secured in the: head t of the bracketrarm. a

The under side of the. bracket arm 3 is formed with a flat faced boss 20providing a" seat for a trimmer-mechanism supporting bracket 21, detachably secured upon said boss and from which projects a horizontally. dis posed fulcrumstud 22 pivotally supporting the shouldered hub-sleeve 23 of a vertically depending swinging frame 24. The hub sleeve 23 is held on the fulcrum-stud by the head of a screw 22 threadedpinto the free! end of said fulcrum-stud. The swinging. frame 2 lis groovedto provide a radially ex! tending guideway 25 in which is fitted one member 26 of atwo-part carrier-block, said member 26 being secured in the guideway 25 i by a screw 27 for yerticaladj ustment toward and fromthe pivotal axis of the frame 2%. Fixed by a screw 29 in a transverse groove in the carrier-block member 26 is a complemental carrier-block member 30 which may be adjusted upon ,themember26 in the general direction ofthe swinging movements of the. frame 24, i. e, vcrosswise of the guideway 25. The carrier-block member 30 is forked at its lower end to, provide spaced arms32j spanned by a fulcrum-pin 33 pivotally sup-v porting an angular trimmer-blade holder 34:, 35. In the operative position of the swinging frame 24;, the armsof said holder is substantially horizontal, saidarm 34 carrying the shank36 of a trimmer-l'mife'having a depending, vertically disposed fin 3;? provided with a" cutting edge 38 directed oppositely to the direction of feed of the work.

The trimmer-knife shank 36 is slotted to receive a securing screw 39 and a steadying pin 40, whereby the blade 87 may be adjusted toward and from the line of seam formation. The other arm 35 of the trimmer-blade holder is bent upwardly at the trimmer-blade side of the carrier-block member 30 into substan- 'tial parallelism therewith and is acted upon by a spring 41 in a direction to yieldingly urgetheknife-fin 37 downwardly toward the throat-plate to an extent limited by the head of a screw 42, passing through a slot in the upper end of the holder-arm 3 3 and thread ed through the member 30 to which is ad justably secured by a lock-nut'43,the' spring.

41 being coiled about the shank of said screw.

42 between the holder-arm 85 and the member 30. i r

The swinging. frame 24 is releasably latchedto a vertically depending rock-lever l 44, fulcrumed upon the swinging-framehub 23 forfvibratory movements'about an aXis coinciding with the axis of swinging movement of saidfr'ame 24. The rock-lever 44 is c0nn'ected by a link 45f'with a crank-arm 46 clamped upon a horizontally disposed rock:

. shaft 47 journaled in bearing lugs 48 atthe I rear side of the machine bracket-arm 3. Se-

cured upon the rock-shaft 47 is another,

gmCiflIlk-ELIIH 49'which is forked'to straddle an f eccentric 50 upon the main-shaft 5. The rocklever 44 terminates at its lower end in a segmentalguide-bracket 51 projecting from opposite sides of said rock lever in an are having gs the'fulcrum-axis of said rock-lever as its center of curvature, said guide-bracket 51 being preferably slidablyengaged by the adjacent face of the swinging frame 24.

Yieldingly projected from the swinging aplframe 24, by a spring 53,:is a latch-bar 54 slidingly disposed in a socket 55' in the frame 24,said latch-bar beingedapted to enter a keeper-aperture 56 in the rock-lever 44,

whereby the trimmer-frame 24 may be releasg lably locked to said rock-lever. t

- Means is provided for conveniently retracting the latch-bar 54 from the keeper-aperture 56. To this end, the latch-bar has a laterally extending pin 57 projecting through. a soshorizontally disposed slot 58 in the frame 24,

said pin 57 enteringa slot 59 in a vertically directed arm'GO of a release-lever 60, 61 fulcrumed intermediate its ends upon a pivotscrew 62threaded into the frame 24. The 'desu pending otherarm 61 of the release-lever is widenedto form a thumbspiece opposed to an adjacent finger-piece. 63 extendingintegrally from the trimmer-frame '24. TB grasping both'thethumb-piece 61 and the oo finger piece 63, not only may the latch-bar 54 be readily disengaged from the rock-lever 44, but the frame 24 may be thereby convenientlyfswung forwardly beyond the latching position thereof for the purpose of manua allytrimming the lower ply margin in ad- Vance of the needle, preparatory to sharply turning the work as-for instance in stitchmg corners. Furthermore, the opposed thumbpiece, 61 and finger-piece 63 provide convenient means for swinging the 'unlatch'ed frame 24 rearwardly out of operative position, the latch-bar 54 riding theguide-bracket 51 during movement of said frame into and out of operative position. 'When the frame 24 is thrown rearwardly out of operative position it-is held in its inoperative position ,by a

keeper comprising a bent spring 64 which 1 engages the elongated head of the screw 27, as

shown in Figs. 2 and 3 of the drawings. In the present instance, the spring 64 is secured lower presser-bar bushing 19.

It is important to properly direct theupper plyor plies of material, with whichthe lower bya screw 65 upon a collar 66 fixed upon the trimmed ply or plies. are to be unitedby stitches, in order that said upper material plymay not be marred by thetrimniing knife and'to insure vthat the lower ply margin is. severed along the desired line with respect seam formation as well asfordifi'erent thicked ge-guiding fin '67 disposed closely adjacent to the needle-path depends vertically from a.

shank 68, bent laterally'awayl from the line of scam formation and detachably secured upon the forwardly extending end of an arm 69 .pivotally supported by a: screw 70 upon a vertically disposed member 71 of an angular bracket-71, 72. Theother member 72 of said bracket is secured bya screw 73 in 'a recessed seat provided in a supporting block 74, for horizontal adjustment of said member 72 crosswise of the line of seam forms} tion, Integral with the supporting block 74 is a split collar? 5 clamped by axscrew 76 for vertical and also angular adjustment upon the lower reduced end of the needlebar bushing 11. The rearward end of the edge-guidecarrying arm 693s rounded and is provided withspaced'notches 77 and 78 adapted to be yieldingly engaged by a V- shaped portion of a spring 79 for holding said arm in, operative and inoperative posi-' tions into which it may be swung about the .screw 70. The spring 79 is suitably fixedby screws 80, upon the bracket-'inember 71.]

The present trimming mechanism. in coin-f mon with that. of the Neely Patent No;

826.596, has the advantage of severing the work in a directionparallel with the direc tion of feed, thereby obviating the choppy appearance of the trimmed edge resulting from employing an under-ply trimmer swinging in an are about a vertical axis. It

will be understood that as the pivotal axis of the trimmer-blade carrying frame is disposed ve tically above the knife blade in its work-severing position and is removed a considerable distance from said knife-blade, the latter acts to sever the work in a substantially straight line.

The arrangement of the trimmer-blade carrying frame in sliding engagement with its actuating rock-lever and the elongated pivot bearings therefor provide a degree of rigidity conducive to accurate performance and long wear. The adjustable yielding feature of the knife blade provides for readily accommodating materials of different thicknesses and the edge-guide supporting means is of a character such as not to interfere with free handling of the work.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine having a frame including a work-support and a bracket-arm overhanging the work-support, stitch-forming and work-feeding mechanisms, a trimming mechanism comprising a vertically disposed rock-lever having a horizontal-axis fulcrum upon said bracketarm, means for rocking said lever, a vertically depending frame ournaled coaxially with the fulcrum of and disposed adjacent to said rock-lever for swinging movements substant ally parallel with the line of feed, a trimmer blade carried bysaid swinging frame and having a vertically disposed work-severing fin provided with a cutt ng edge opposed to the direction of feed, and a latch releasably connecting said swinging frame and rock-lever.

2. In a. sewing machine having a frame including a work-support and a bracket-arm overhanging the work-support, stitch-forming and worlnfe'eding mechanism, a trimming mechanism comprising a vertically disposed rock-lever having a horizontal axis fulcrum upon said bracket-arm, means for ipcking said lever, a swinging frame journaled coaxially with the fulcrum of and disposed adjacent to said rock-lever, a trimmerblade holder carried by said swinging frame for adjustments in directions substantially parallel with the direction offeed and radially of said swinging frame, a trimmer-blade carried by said swinging frame and having a vertically disposed work severing fin, and a latch releasably connecting said swinging frame and lever.

3. In a sewing machine having a frame including a work-support and a bracket-arm overhanging the work-support, stitch-forming and work-feeding mechanisms, a trimming mechanism comprising a vertically disposed rock-lever having a horizontal-axis fulcrumupon bmckt aria, rocking said naled coaxially with the fulcrum of, and disposed adjacent to said rock-lever, atrimmer:

blade carried by said swinging frame, a latch r-eleasably connecting said swlnging' frame lever, a swinging frameejour-y and rock-lever, a latch-operating lever pivotally mounted upon said swinging frame and having a thumb-piece, and afinger pieceextension on the swinging frame opposed to said thumb-piece. X

a. In a sewingmachinehaving a frame in-L cludinga work-support and abracket-arm overhanging the work-support, stitch-form lng'and work feedmg mechanisms, a ,tI'lIllming mechanism comprising a supporting bracket upon the under side of said bracket, arm and carryinga horizontally disposed. fulcrum-stud, a vertically depending swings, ing-frame having a hub-sleeve pivotally mounted upon said fulcrum-pin, a trimmers blade carried by said swinging frame and having a vertically disposed work-severiiiig fin, a. rock-lever 'f'ulcr'umed coaxially with said swinging frame and depending in slidable contact with said swinging frame, means for vibrating said rock-lever, a latch releasably connecting said swinging frame and rock-lever, and means for holding said swinging frame in an inoperative position disconnected from said rock-lever.

5. In a sewing machine having a frame including a work-support and a bracket-arm overhanging the work-support, stitch-forming and work-feeding mechanisms, a trim-' ming mechanism comprising a vertically disposed swinging-frame having a horizontal axis journal upon said bracketarm, means for swinging said frame, a trimmer-blade holder overhanging the work-support and pivotally carried by said swinging frame, a trimmer-bladecarried by said holder and having a vertically disposed work-severing fin, a spring acting upon said holder to yieldingly urge said trimmer-blade fin toward the work-support, and means for limitin the work-support approaching movement of the trimmer-blade fin under the action of said sprin 6. In a sewing machine having a frame including a work-support and a bracket-arm overhanging the work-support, stitch-forming and work-feeding mechanisms, a trimming mechanism comprising a vertically dis with said holder-supporting member, a trimmer-blade having a depending work-seversaid trimmer-blade.

7 Ina sewing machine having a vertically reciprocatory I needle and a work-feeding mechanism, the combination with a'trimmlng mechanism including a trimmer-blade having a depending fin provided with a cutting edge opposed to the direction of feed for trimming the under of superposed plies of'material adjacent to the outer'edge of the overlying ply,'of' means for guiding the overlying ply of material comprising an arm carrying a" depending edge-guiding fin overhangin the work-support adjacent to the pathoi the needle, a bracket secured upon the bracketarm ofthe machine and providing a pivotal support for said arm, and means for latching V saidarmin operative and inoperative posi- 'tionsupon said bracket.

= In testimony whereof I have signed m name to this specification, f V

5 FREDERIG M. CARD.