US2103478A - Sewing machine - Google Patents

Description

Dec. 2s, 1937. l 'E UTZ Y 1 2,103,478

' SEWING MACHINE Filed June 25, 1955 5 sheets-sheer 1 1 l' 11 i i m @Q Tm qu I m m 1 H I w FM l v i1 'E im i WITNESSES: I INVENTOR:

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WQ. M v l I JA TTORNEYS.

F. LUTZ SEWING MACHINE Dec'. 2s, 1937.

Filed June 25, 1935 4 5 Sheets-Sheet 4 u INVENTOR: 'raric L11/E5 ATTORNEYS WI TNESSES:l y@

Dec. 2s, 193:1.v F, UTZ 2,103,478

SEWING MACHINE Filed June 25, '1935 5 sheets-sheet 5 Vam FRA

WITNESSES- f 'Patented De.2s,1937

SEWING MACHINE lFrederick Lutz, Stuttgart, Germany, assigner to Es PATENT ori-ice Union Special Maschinenfabrik, G. m. b. yH.,

Stuttgart, Germany 'application June 25, isaspseriai No. 28,314 A 1s claims. (ci. 11a- 162) 'Ihis invention relates to sewing machines, particularly to sewing machines` for forming overedge seams, including both plain and scalloped or, 'shell stitch seams, either from one or from several threads." t

My invention sfdirected toward simplifying and structurally refining 'machines of the kind referred to with a .view toward making possible their operation at higher speeds than feasible' heretofore, and thereby attaining a correspondingly increased outputfrom them. These 'advantages I secure in part asherein fter set forth, through provision of stltch forming mechanism wherein threeinstrumentalities cooperate to perform all the necessary functions for hich four elements were required heretofore. ese instrumentalities'include a reciprocating needle, a non-thread'carrying 'hook loopr to draw loops of the needle threadfbelowthe throat plate of the machine, and a latch looper adapted to engage the needle thread above the throat plate and to draw loops of said thread around the edge of the fabric and through previously formed loops, `withincidental casting of such loops from its Ig5 shank and then to' take the loops from the hook looper before re-engaging the needle thread above the throat plate in successive repetitions of the stitch forming cycle.' In addition, my invention 'f provides smoothly-operating. dynamically-balanced parts for actuating the hook loop- `er and the latch looper in such manner as to .draw only the required amount of the .needle 35 dispense with`thespecial and complicated com-` pensating thread take-ups used in louper-sewingl thread in predetermlning tight seam loops of a definite size. As. a consequence. I am able to machines of ordinary construction.

Another object of my invention isvto provide for the delivery of an auxiliary thread in such a 4o way that 1t 'will be taken only by the nach moper along the edge of the plain or shell stitch seam produced in the machine.

Another obect of my invention is to make it 'i possible to vary the timing of the feed means for adaptation of the sewing machines to the for mation 4either of plain or shell stitch seams.

50 This I secure, alsoas hereinafter more fully explained, by providing simple actuating parts for the machine so that they are conveniently accessible for the purposes of ready interchange.

Other objects and attendant advantages of this ing been-broken awayv to expose the mechanism at the interior. Fig. II is a 'view drawn to a larger scale and lshowing the front elevation of the lower portion of the machine.

' Fig.' III'is a fragmentary view likewise drawn to a larger scale, and showing the lower' front portion of the machinein plan with the worksupporting plate removed.'

Fig. IV is a detail sectional view taken as indicated by the arrows IV-IV in Fig. III and 'showl ing, in part, the means for actuating the latch louper.- t

Fig. V is a detail sectional view taken as indicated by the arrowsV-V in Fig. III, and showing the means for actuating the feed dog of the machine.

Figs. VI-X are fragmentary perspective views showing how the needle and theyhook and'the latch loopers cooperate in forming a plain overedge seam with the needle thread alone.

Fig. 2H is a detail sectional view showing how the needle and the two lloopers cooperate in forming'an overedge seam with the needle thread and an auxiliary thread.,

Figs. X11-XV illustrate different forms. of seams capable of being formed with my improved sewing machine.

' As herein shown, the sewing machine of my invention comprises a main shaft whichismjournaled in the lower part of the machine, and which is provided at one end with a pulley 2 for coordination by means of aibelt (not shown) with a suitable source of power.. Mounted on the main shaft i is an eccentric 3 whereof the upwardlyextending rod 4 is pivotedto a lever 5 by which reciprocating motion is imparted to the needle bar t of the machine. A pendant arm l of the lever itis relied upon to actuate the non-thread carrying hook looper 8 which operates lbeneath the throat plate of the machine, to draw a loop from the needle thread, for presentation to the latch looper as later on explained, the intermediate connections including a link 8a, and an os.

cillating arm .8b on a rock shaft 8c which is f obllquely arranged as shown in Fig. IlI so that the hook end of said looper swings at an angle the feed element and by allocating said parts in 1H) is secured a crank it, which, through a link II and a rocker arm IIa, actuates the latch looper carrier I2. A yoke I3 affords 'journal support for an obiiquely-disposed oscillating shaft I4 whereto the latch looper carrier I2 is fixed, said yoke being in turn secured to another shaft I5, which, see Fig. II, is located beneath the main shaft I, and oscillated laterally through engagement of a fork I 6 thereon with a rotary cam rI1 on the main shaft I. vThe latch looper is indicated at I8, and, as shown, has a curved body or shank with a hook end adapted to be closed by a pivoted latch after the manner of a knitting machine needle. Incident to rotation of the main shaft I, the latch looper I8 is 4bodily osciilated substantially at right angles to the swing of the hook looper 8 (see Fig. III) toward and away from the seaming needle by action of the rotary cam I1 upon the yoke I3, and concurrently moved up and down through inuence of the crank Il upon the arm IIa on the oscillating shaft I 4 which supports the latch looper carrier I2, these combined motions causing the hook end of the latch looper to trace a short arc around the -edge of the fabric in a manner more clearly set forth hereinafter.

An eccentric I9 on the main yshaft I communicates motion, through a link 2l), to a rocker 2i by which the feed bar of the machine is horif zontally reciprocated, said feed bar being moved up and down at the ends of its horizontal strokes in opposite directions by the action of the ciri cumferential cam groove 23 of a rotary cam 24 which revolves about a vertical screw Istud 24a threaded into the base of the machine and which is driven by means of a worm gear couple 25, 25 from the main shaft I, see Figs. III and V. As shown, the cam groove 23h is engaged by a 4stud 21 'at the end of. the lever 28,`which latter is fulcrumed for free oscillation on the rock shaft I5, and connected with the feed bar 22 by means of a link 29. 'I'he feed dog 38 on the bar-22 is thus actuated to intermittently progress the fabric across the work support of the machine for-`seaming by the needle. Attention is directed to the fact that the gear wheel '26 is located in an interval between the main shaft I and the feed bar rock shaft 2Ia, and betweenV the feed barl link 20 and the feed bar 22,Y where it is conveniently accessible from above, and

further to the fact that the rotary cam 24 isy made separate from the gear wheel 26 and secured thereto by two screws 28a, see Fig. III. 'I'his construction permitsiready interchange of the parts when the timing of the feed mechanism is to be altered in adapting the machine for scallop or shell stitch seaming as presently described.

As shown in Figs. VI-X the throat plate 3! of the machine provides a fixed stitch tongue 35 which is aligned in the direction of feed and over which loops of the needle thread are formed by the hook and latch looers 8 and I8 in the manner about to be' disclosed.

The operation of the'machine in making a plain overedge seam is as follows:

By the combined action of the eccentric III lformation of several stitches.

seam loops of a predetermined size without the need of additional means to absorb excessive slack occasioned bythe movements of the loopers as in prior art sewing machines. The stitch forming cycle begins as shown in Fig. V'I when the latch looper I8 is in fully advanced position relative to the needle with its hook end above the throat plate 34 immediately adjacent the path of said needle. As the needle 3| descends, it lays its thread 31 into the hook of the Ilatch looper I8 as shown in Fig. VII, while said latch looper, in `moving, downward in close proximity to the stitch tongue'35 draws a loop 31a of said thread around the edge oi' thefabric and through two previously' formed hook and latch looper loops 31h and 31e temporarilyheld on said stitch tongue after the manner shown in Fig. VIII. As'` the latch looper I8 completes its outward and downward movement, its latch closes over the new loop 31a, with incidental casting `oi the two old loops 31D andy 31e as shown in Fig. IX, this occurring just about the time that the needle 3i reaches its lowermost position. As the needle 3l starts its ascent, the' hook looper 8 engages the needle thread 31 also as shown in Fig. IX, and, in moving away from the needle, draws a loop 31d angularly crosswise of thebottom of the stitch tongue 35, while the latch looper."

begins to move upward toward the needle through said loop 31d, thereby taking said loop as shown in Fig. X, the needle in the meanwhile ascending to its uppermost position concurrently with the latch looper for repetition of the stitch forming cycle. With the feed dog 30 timed to function once for each stroke of the needle 3i as ordinarily, a plain overedge seam such as shownjin Fig. XII is producedas a result of the cooperation of the hook and latch looper 8 and I8 with said needle as above described. f

By providingv a feed eye 38 on the needle bar 8 of the machine, as shown in Fig. XI, to feedan auxiliary thread 39 so that it may be taken by the latch looper I8 when the latter moves upward to take the needle yarn 31,'it is possible toproduce an overedge seam such as is shown in Fig. XIII having an edge fringe thickened by the additional loops 39a of said auxiliary thread. In this connection it is to be noted that the hook looper 8 never engages the auxiliary thread 39; and it is for this reason that the loops 39a formed from said thread arrange themselves along the edge of the stitching.

A rotary cam 2l with a differently formed groove 23, or worm gears 25, 26 of a different ratio may be employed to change the timing of the feed dog 30 so as' to shift the fabric after the With use 'of the needle thread 31 only there results a scallop or shell stitch'seam such as is shown in Fig. XIV; while, by using both the threads. 31 and 39 with changed operation of the feed dog 30, it is possible to form a scallop or shell stitch seam such as is shown in Fig. XV, with the added loops 39a of the lauxiliary thread doubled with the edge loops formed from the needle thread. Due to the ready accessibility of the gearing 25, 26 and the cam 24, the change from one condition of operation to the other can obviously be accomplished with comparative ease and a minimum loss of time.

Having thus described my invention, I claim:

1. A sewing machine comprising a reciprocating needle; a non-thread-carrying looper to draw loops from the needle thread at one side of the fabric being seamed; and a latch looper to draw v 2,103,478 N loops from the needle thread at the other side of the fabric, and, after drawing'such loops, to take the loops from the first mentioned looper.

2. A sewing machine comprising a reciprocating needle; a non-thread-carrying looper to draw loops from the needle thread at one side of the fabric being seamed; a latch looperlto draw loops from the needle thread at the other side of the fabric, and, after drawing such loops, to take the loops from the rst mentioned looper; and means to actuate the two loopers to draw only suiiicient thread for tight seam loops of the desired size.

` 3. Asewing machine comprising a reciprocating needle; a xed stitch tongue; a non-threadcarrying looper to draw loops from the needle thread beneath the stitch tongue; a latch looper the needle thread above the stitch tongue, and,

.` of the desired size.

. tive beneath the throat plate; means for actuatyafter drawing such loops, to vtake the loops from the first mentioned looper; means for actuating the first mentioned looper to draw only suillcient thread for seam loops of the desired size; and means for actuating the latch looper such that its hook end describes Va short arc around the edge of the stitch tongue likewise for seam loops 5. A sewing machine comp- 'sing a reciprocating needle; a-throat plate; a hook looper opera-1 ing the hook looper to draw loops from the needle thread; a latch looper; and actuating means for moving the latch looper to draw a loop of the needle thread above the fabric, around the fabric 'edge and through a pairof previously formed loops thereon with incident casting of said loops, ,A

and then to take the-loop' from the hook looper aforesaid before reengaging .the needle thread above the throat plate in -initiating another stitch forming cycle.

6. A sewing machine 4comprising a reciprocat.

ing needle; a throat plate affording a stitch tongue; a hook` looper operativeV beneath the throat plate; means for actuating the hook looper to draw loops o f the needle thread under the stitch tongue; a latch looper; and means for actuating the latch looper so that its hook end traces an arc angularly tothe direction of feed and in close proximity to the edge of the stitchtongue, and in so moving', engages the needle thread above the throat plate to draw a loop therefrom downward varound the edge of the fabric and through previously formed loops on 'its shank, with vincidental casting of such previous loops, and thereafter takes the loop from the hook looper before reengaging the needle thread above the vthroat plate to initiate another stitch forming cycle.

'7. A sewing machine comprising a reciprocating needle; a throat plate; a hook looper operative beneath the throat plate; means for oscillating the hook looper to form loops from the needle. thread; a latch looper; a carrier for saidv latch .looper; a laterally oscillating support to which said latch looper is pivoted with capacity for up and down movement; and means for oscillating the support and for concurrently swinging the latch looper about its pivot axis on thesupport whereby it is caused to draw a vloop from the needle thread above the throat plate, around the edgev of the fabric and through two previously formed loops' thereon with incident casting of. said loops, and then to take the .loop from the hook looper aforesaid before re-engaging the needle thread above the throat plate in initiating another stitch forming cycle.

8. A sewing machine comprising a reciprocatying needle; a throat plate; a hook looper operative beneath the throat' plate; means for oscillating the hook looper about an axis oblique to the direction of feed to engage the needle thread and draw loops therefrom; a latch looper; a' support for the latch looper oscillating laterally about an axis aligned inthe direction of feed; an oblique axis on the support whereto the latch looper is secured with capacity for up and down movement incident to being swung ,at substantially right angles to the movement of the hook looper;

and means for oscillating the support and for concurrently rocking the latch looper' on its pivot axis so that it is caused to draw a loop from the needle thread 'above the throat plate around the edgeof -the'fabric and through two previously formed loops on its shank, with incident casting of such loops, and then to take the loop from the hook looper aforesaid before re-engaging e the needle thread above the throat plate in initiating another stitch forming cyclesV 9. A sewing machine comprising a needle bar with a reciprocating needle carrying a seaming thread; an eye on the needle bar for Aguiding an auxiliary thread; a throat plate; a hook looper operative beneath the throat plate; means for actuating the hook looper to draw loops from the needle thread below the throat plate; a latch looper; and actuating means for moving the latch looper to concurrently draw loops from the needle and auxiliary threads above the throat plate| through previously formed loops thereon with incident casting of the latter loops, and. then forwardly and upwardly to take the loop from the hook looper aforesaid before re-engaging the needle thread and the auxiliary thread above the for actuating the hook looper to draw loops from Y the needle thread around the bottom of the stitch tongue; a latch looper; and actuating means for moving/the latch looper downwardly and outwardly away from the needle above the throat plate to draw a loop of the needle thread around the stitch tongue and through a pair of previt ously formed loops thereonwith incident casting of the latter loops, then forwardly and upwardly to take the loop from the'hook looper aforesaid before re-engaging the needle thread above the throat plate.

11. A sewing machine comprising a reciprocating needle; a non-thread carrying looper for drawing loops from the needle thread at one side of the fabric being seamed; a latch looper for drawing loops from the needle thread at the other side of the fabric, and, after drawing such" loops, taking the loops from the rst mentioned looper; and means for feeding an auxiliary yarn so as to be taken by the latch looper at the same time that the latter engages the needle thread.

12. In a sewing machine comprising a reciprocating needle, a feed dog, and means for reciproeating the feed dog horizontally; the combination of a non-thread carrying looper for drawing loops from the needle thread at one side of the fabric -being seamed, a latch looper for drawing loops cating needle, a feed dog, means for reciprocating rocates the feed dog horizontally; the combina- 'i the feed dog, a rotary shaft, and a rocker actuated by an eccentric on the shaft for reciprocating the feed dog horizontally; the combination of a non-thread carrying looper for drawing loops from the needle thread at one side of the fabric being seamed, a latch looper for drawing loops from the needle thread at the other side of the fabric, and, after drawing such loops taking the loops from the first mentioned looper, means whereby the. two loopers are operated from the shaft aforesaid, a rotary cam driven by gearing from the shaft, and a lever operated by the rotary cam moving the feed dogl up and down.

14. In a sewing machine comprising a reciprocating needle, a rotary shaft, a feed dog, a rocker actuated by an eccentric on the shaft which reciption of a non-thread carrying looper for drawing the loops from the needle thread at one side of the fabric being seamed, a latch looper for drawing loops from the needle thread at the other side of the fabric and after drawing such loops taking the loops from the first mentioned looper, connections whereby the two loopers are operated from the`rotary shaft, a rotary cam on said shaft, a lever operated by the rotary cam for moving the feed dog up and down,-a worm gear to which the rotarycam is detachably secured, and a worm on the main shaft for driving the worm wheel.

15. In a sewing machine, a reciprocating needle, a transversely reciprocating thread manipulating element cooperating with the needle at one i side of the fabric being sewed, and a transverselyreciprocating latch looper cooperating with the needle at the other side of the fabric in the formak tion of stitches.

16. In a sewing machine, a reciprocating needle, a transversely reciprocating thread manipulating element cooperating with the needle at one side of the fabric being sewed, a transversely-reciprocating'latch looper cooperating with the needle at the other side of the fabric in the formation of stitches, and means for advancing the fabric relative to the needle each time only after several actuations of the needle, the thread manipulating element and the looper to determine formation of shell stitch effects.

17. A sewing machine comprising a reciprocating needle; a non-thread carrying looper for drawing loops from they needle thread at one side of the fabric being vseamed; a latch looper for drawing loops from the needle thread at the other side of the fabric, and, after drawing such loops, taking the loops from the first mentioned looper; means for feeding an auxiliary yarn so as to be taken by the latch looper at the same time that the latter engages the needle thread; and means for advancing the fabric relative to the needle each time only after several actuations of the needle and the two loopers whereby the formation of shell stitch effects is determined.

18. In a sewing machine comprising a reciprocating needle, a feed dog and means for horizontally reciprocating said feed dog in synchronism with the needle; the combination of a non-thread carrying looper cooperating with the needle at one side of the fabric being sewed, a latch looper to cooperate with the needle at the opposite side of the fabric, and means for imparting lift movements to the feed dog such that the fabric is advanced each time only after several actuations of the needle and the two loopers whereby the formation of shell stitch effects is determined.

FREDERICK LU'IZ.

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