US1748052A - Chain-stitch sewing machine - Google Patents

Description

Feb.-25, 1930. R, BECKER '1,748,052

CHAIN STITCH 'SEWING MACHINE Filed Jun 22, 1927 4 Sheets-Sheet 1 Fe`b. 25, 1930. R. BECKER CHAIN STITCH SEWING MACHINE Filed IJune 22. i927 4 Sheets-Sheet 2A atroz nu# Feb. 25, 1930. R. BECKER 1,748,052

CHAIN STITCH SEWING MACHINE Filed June 22, 1927 4 Sheets-Sheet 3 Feb. 25, 1930. R BEKERl 1,748,052

CHAIN STITCH SEWING MACHINE Filed June 22; 1927 4 sheets-sheet Il Patented Feb; 25, v193()l UNITED STATESy PAT ENT OFFICE RUDOLPH BECKER, OF NORTH PLAINFIELD, NEW JERSEY, ASSIGNOR T0 THE SINGER MANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEU JERSEY Application filed .Tune 22,

' This invention relates to sewing machines and has for an object to provide a simplilied, quiet running mechanism for forming a chain-stitch seam, which mechanism is capable of high-speed operation.

In chain-stitch sewing machines it is usual toy provide a reciprocating needle for passing needle-thread loops through the work and a looper for presenting the 4needle-loops, or loops of an under thread enchained with the needle-loops, for entry by the descending needle.. In one known type o looper mechanism the looper is actuated by two cranks or eccentrics, one of which imparts to the sil looper loop-seizing and -shedding movements and the other of which gives the looper sidewise lor so-called needleeavoiding movements, whereby the looper passes along one side of the needle, seizes a needle-loop and moves to the end of its stroke; is then given a sidewise movement and is retracted along the other side of the needle-path.

In another known type of looper mechanism the looper is given its loop-seizing and -shedding movements in a single plane and a spreader is introduced to assist in positioning the thread-loop for entry by the needle.

l/Vith machines of the above types,kwhcre the looper is actuated by one or more simple crank motions, it is necessary to increase the amplitudes-of motion of the needle and looper suflicietly to secure the proper relative timy ing of these implements at two points in the stitch-forming' cycle, to "wit: a, when the looper seizesa needle-,loop and b, when the needle enters the loop positioned by the looper. f l

It has been proposed to reduce the amplil tudes of motion of the needle and looper by modifying the actuating mechanism so as to give the looper an irregular motion includ-l ing dwells and periods of rapid motion, but such irregular motion can only be secured by the use of cams, toggle devices, etc., which', complicate the actuating mechanism and are mechanically interior to simple vcrank-motions.

It has also been proposed lto solve' the problem of simplicity and high speed by providing two separately timed implements be- CHAIN-STITCH SEWING MACHINE 192'?.v Serial ANo. 200,592.

low the work, one a loop-taking implement which carries no thread and is crank operated and properly-timed to enter and detain the needle-loop, andthe other, a crank operated thread-carrying looper for passinga looper-thread loop through the needle-loop while held by the'loop-taker, after the needle has risen from the work; the thread-carrying looper being timed to present its loop to the descending needle. But little has been done toward developing machines involving the last above proposed method, and such machines as have been developed are unsatisfactory at high speeds for several reasons among which may be mentioned: 1. The 05 needle-loop is needlessly expanded or drawn out and causes undue reeving of' thread through the needle-eye. 2. In some cases the loop-taker is depended upon to drag the looper-thread loop through the needle-loop, which necessitates a harsh or sudden engagement of the loop-taker with the looper-thread, tending to unduly strain the latter. 3. The loop-taker twists the loops and thus introduces a tendency of such loops to kink or snarl while being drawn up. e

According to the presentv improvement there are provided separately timed looptaking and loop-presenting implements. The loop-taker has a slender thread-engaging portion which moves in the direction o its length and seizes a needle-loop without twisting or expanding such loop. The loop-presenter is preferably a simple two-motion thread-carrying blade which passes a loop of under-thread through the needle-loop and is timed to present the under-thread loop to the descendingneedle.

The present machine is a further-development of that disclosed in my copending application Serial No. 137,863, filed September 7, 1926. In my prior machine the loop-taker is in the form of a continuously rotating ring supported by a circular raceway, while in the present .machine the loop-taker is in the form planes at the sameside of the needle-path 10U loop-presenter desired gauge or spacing between 'the' needles; the loop-taker and loop-presenter or looper elements being individually secured to parallel supporting studs carried by the respective shafts and-being adjustable lengthwise of such studs to suit the needle positions. As these elements may be made comparatively thin," they may be secu-red close together for narrow gauge requirements.

The machine is provided witha novel form .of multiple thread tension release connected to be operated by the presser-foot lifting- A novel form of multiple looper-l lever. thread guide is also provided to Yfacilitate easy threading and prevent entanglement of 'the looper-threads. I

In the accompanying drawings, Fig. 1 isl a side elevation, partly in section, of a sewing machine embodying the invention. Fig. 2 is a bottom plan view of the machine. Fig. 3v is avview of the rotary needle-thread takeup. Fig. 4 is a section on the line 4-4, Fig. 1. Fig. 5 is an end elevation of the cylinder-bed of the machine showing the stitching-forming mechanism; the needles just beginning their rising movement. Fig. 5a is aside view of the needles and loop-takers looking oppositely to the direction of feed at the time of the cycle shown in Fig. 5. Fig. 6 is a View similar to Fig. 5 but at a later stage Iin the stitchforming cycle; the needles rising above the work and the loop-takers detaining the needle-loops without having expanded such loops. Fi 6a is a side view of the parts shown in ig. 6 looking in the direction of feed. 'Fig 7 shows the stitch-forming elements with the needles at the top -of their stroke; the loopers having entered the ldetained needle-loops andthe loop-takers retracting. Fig. 8 shows the needles descending and the loop-takers and loopers-both retracting. Fig. 9 shows the needlesentering the looper thread-loops, the loopers retracting and the loop-takers reversing or at their' 4dwell point. Fig. 1()V is a perspective view of the looper carrier vwith one of the loopers 'removed. Fig. 11 is a perspective view of the looper removed from the looper carrier. Fig. 12 is a top plan view of the throatlate. Fig. 13 is a section. on-the line 13-13,'

ig. 12. Fig. 14 is a section on the line lll- 14,Fig. 12. Fig. 15 is atransverse section through the loop-taker driving shaft and the hub of the looper carrier. Fig. 16 is a -top .plan view of the multiple needle-thread tension device. Fig. 17 is a central transverse ,vertical section through the tension device.

Figs. 18 and 19 are perspective views of the tension release cam and cam-follower. Fig. 20 is a rear view of the machine bed showing the looper-thread .tensions and looper-'thread guide. Fig. 21 is a perspective view of the looper-thread guide removed from the Inachine, and Fig. 22 is a section on the line -22-22, Fig. 20. In the preferred embodiment of the invention illustrated, the machine comprises a frame having a. base 1 formed with a horizontally extending cylinder-bed 2. Rising from the base lis the standard 3 of the overhanging goose-neck 4 terminating in the head '5. Journaled in the goose-neck 4 is the'main.

shaft 6 carrying at its forward end the rovseize a needle-loop without expanding such loop.

' Clamped to the front end.of the hollow shaft 12 is the split collar 15 to which is fixed the stud, 16 in parallelism with the shaft 11 ;A

the-collar 15 and stud 16 constituting a carrier for the loop-presenters 17, in the form of thread-carrying loopers, the blades of which are. disposedin parallel planes substantially coincident with the planes of the loop-takers 14-the loopers 17 working close to the throat-plate 18. The rock- shafts 11, 12 are operated, respectively, b eccentrics 19, 20 on'the main-shaft, whic eccentrics actuate the pitmen 21,22 connected at their lower ends to cranks 23, 24 carried by the shafts 11, 12. vThe eccentric 19 is timed to cause the loop-takers to seize the-loops lof thread thrown ont by the rising needles, as

shown in Fi s. 5 land 5, and the eccentric 20 is -timedin ependently of the eccentric 19 to cause the loo ers 17 to retract and open the looper-thre loops 4at the proper moment to be entered by the points ofthe descending needles, asshown in Figs. 8 and` 9.

The feeding mechanism comprises the feed-dog 25 mounted on the feed-bar 26 which is pivotally supported at -27 by a crank-arm28 on the feed-lift`rock-shaft 29. Connected tothe feed-bar at 30 is a link 31 which is connected at 32 to a crank-arm 33 on the feed-advancing rock-shaft 34. The' and within the cylinder-bed 2 and at their rearward ends carry crank-arms 35, 36 which are connected by pitmen 37, 38 to the feedeccentrics 39, 40 on the main-shaft 6; the feed-advancing eccentric 40 being -of the known adjustable type to enablev the stitchlength to be regulated.- A

lThe throat-plate 18 is formed with feeddog slots 41 and needle-holes 42 withinv each of which is preferably provided a depressed shelf -43 having an mclined front edge 44 which deflects to one side the llooper-thread leading from the looper-eye to the last stitch,

thus assisting in causing the looper-thread` to bow away from the looper-blade to open the looper loop for entry by the descending needle. This throat-plate construction is substantially the same as that shown in the U. S. patent to DeVoe No. 1,254,214 of January 22, 1918.

The thread-engaging portions or beaks of the loop-takers 14 and loopers-17 reciprocate in paths at the same side of the respective needle-paths and parallel with the line of feed, hence the loop-takers need have no lateral swells 'for expanding the needle-loops or shifting such loops laterally to the other side of the respective needle-paths, as would (be necessary if the loopers and loop-takers operated at opposite sides of the' respectiveA needlepaths. The loop-takers and loopers are two-motion reciprocating members; that is, they have loop-seizing and loopprising the spaced parallelv isks 7 between which is located the 'stationary stri per plate 45 having the thread slot 46. A ent wirey thread-guide` 47 properly positions the needle-threads at either side of the take-up disks 7 for action by the latter.

A thread-nipper i also preferably pro- -vided' for arresting t e feed of the needle'- thread during the .setting of the stitches. v This nipper comprises anipper-seatl 48 and nipper-head 49. The nipper-seat 48 1s yieldingly mounted in a recess 50 1n thewside of the arm 4, being backed by the coil' springs 51. The outward movement of the'se'at 48 under the influence -of the springs 51 is limited by the holdingscrews 52.", 713hje'1nipperhead 49 is'ixed to the reciprocating rod 53 journaled transversely of. the larm v`'4 and formed between its ends with a yoke 54 ern'-4 'simultaneous separation of h'eddin movements but no sidewise or so-calle bracing the eccentric follower 55 driven by the eccentric 56 on the main-shaft 6.

The needle-threads lead from the supplyv to the thread-nipper through^a multiplethread tension device comprising a plurality of thread-tensions 57 mounted on the supporting plate 58 which is held spaced from andcfixed relative .to a primary supporting plate 59 by means of four corner-posts 60, the plate 59 being carried by a bracket 61 screwed to the top of the arm 4. Slidably mounted on the corner-posts 60 between the plates 58, 59 is the movable plate 62having mountedI on its inner face a disk 63 'formed on its-exposed face, Fig. 18, with the diametrically. opposed cam elevations 64. Mounted in the bracket 61 is a rock-shaft 65 to oneiend of which is fixed the 'flanged Circular head 66 having cam-depressions 67 receiving the elevations 64 of the disk 63 which are maintained in engagement with the head 66 by means of the bow spring 68, F ig.l 16, which is secured between its ends tothe plate 58 and presses upon the movable plate 62. When the shaft 65 is rocked the inclined surfaces of the depressions 67 force the movable plate 62 away from the plate 59'and `cause the plate 62 to engage the several tension release pins 69 which effect the the tension disks of the several' pairs. e

The shaft 65 is operated by the' usual crank-arm 70 and link 71 connected to the usual lifting lever 72 for the presser-font 73.

t is desirable that the looper-threads run freely in this machine and it is preferredto guide them separately from the looper-thread tensions 74 tothe loopers 17. To .this end the 'rear side of the bed 2 is formed withra longitudinally disposed groove 7 5in which is removably disposed a multiple threaduide tubev comprising three U-,shaped tro'ug S76 disposed side-by-side and secured together, as by soldering, to constitute a unit'whlch 1s held in the groove 75 by means of the vtransverse retainer wires 77 fastened tothe cylinder-bed by screws 78. No looper-thread take-up is required. y

The stitch-formingl cycle is performed substantially as' follows. The 'needles 10 rise, Figs. 5 and 5", to throw out their loops which are seized and detained, but are not expanded,

by the loop-takers 14. The needles continue to rise and the loopers 17 advance closely above the loop-takers, Figs. 6 and 6, in planes substantially coincident with the planes of the respective loop-takers. The loopers 17 .enter the needle-loops and pass to theend lof their stroke, Fig. 7, while the loop-takers recede and deposit their loops on the loopers. The loopers 17 recede, Fig. 8, and throw out their thread-loops for ,entry by the descending needles, Fig. 9. The descending needles,

' together with the take-up 7, tighten the preloop to carry a loop oi under thread through the needle-loop for entry by the descending which the ,loop-taker has a loop-engaging needle.l

2. The combination set forth in claim 1 in portion disposed substantially wholly at one side o'f the needle-path. v

3. The combination set forth in claim l in which the loop-taker and looper are arranged to operate in substantially coincident planes wholly at the same side of the needle-path.

4. The combination set forth in claim 1 in" cluding feedino mechanism and' with the l loop-taker and looperarrange'd to operate in paths parallel to the vertical plane through the line'of feed. Y

5. The combination with multiple-needle mechanism, of a complement of loop-takers and a complement of loop-presenters, separate supports on which said complements are rigidly mounted, each of said loop-takers and loop-presenters bein adjustable circularly and longitudinally o its respective support. 6. In a`V sewing machine, 1n combination, feeding mechanism, multiple-needle mechai v nism, a pair of separated rocker-studs, a comf loop-taker.

plement of loop-takers, one 'for each needle, mounted on one of saidstuds to suit the; gage.

4of theneedles, and a complement of looppresenters, one for each needle, mounted on the other of said studs, each loop-presenter cooperating with its respective` needle and 7. In a sewing machine, in combination, a reciprocating needle, a pair of telescopically arranged rock-shafts, a collar secured to the outer of such shafts, a stud carried by said collar in spaced parallel relation'with the inner of such shafts, and loop-taker and looppresenter members secured one to said stud and the other to the innerrock-shaft.

8. A chain-'stitch sewing machine having, in combination, feeding mechanism, a "reciprocating needle, and looper mechanism comprisingl a to-and-fro moving loop-taker and a' to-and-fro' moving loop-presenter, the

llatter carrying an under-thread and each Y making one complete to-and-fro movement for each complete reciprocat-ionof the needle, the thread-engaging portions of said looptaker and loop-presenter operating in sub- 9. The combinationwith ai-reciprocatin needle and a throat-plate, of separately time two-motion oscillatory loop-taker and looppresenter elements each making one complete oscillation for each complete reciprocation of the needle, said loop-taker and loop-presenter having beaks extending in opposite directions and operating in paths at the same side of the needle-path and entirely below the throatplate.

10. y,The combination with a reciprocating needle, and eeding mechanism, of sepirately timed two-motion oscillatory loop-ta er and thread-carrying loop-presenter elements hav-- ing oppositely directedbeaks operating in` paths at the same side of the needle-path and parallel to the line of feed, said loop-taker and loop-presenter elements beingtimed to make .onecomplete oscillation for each complete reciprocation of said needle. f

11. A sewing machine having a frame including a'bed, a'hollow standard and hollow overhanging bracket-arm, 'a main-shaft journaled in said bracket-arm, two eccentrics carried by said main-shaft at the upper end of said hollow standard, a reciprocating needle connectedto be operated by saidvmain-shaft, loop-taker and loop-presenter elements, looptaker and loop-presenter operating Y roekshafts'journaled in said bed, and two pitmen connections within said standard between said rock-shafts' and said eccentrics.

:'jIn testimonfy7` whereof, I have signed my name to this specification.

RUDOLPH BECKER.

stantially lcoincident p'anes entirely at the same side of the needle-path and substantial ly parallel to the line of feed. Y

4 las

Images