US2050790A - Sewing machine - Google Patents

Description

1, 1936. J. A. GOODMAN 2,050,790

SEWING MACHINE Filed April 11, 1952 asheew-sheet. 1

Aug. 11, 1936. .1. A. GCJODMAN 2,050,790

SEWING MACHINE Filed April 11, 1932 3 Sheets-Sheet 3 Patented Aug. 11, 1936 UNITED STATES zasa'zat SEWING MACHINE Jacob A. Goodman, Indianapolis, Ind.

Application April 11,

12 Claims.

This invention relates to sewing machines, particularly those adapted to seaming fabric articles.

It involves a method of controlling the tension on the sewing thread supplied to such machines and also tensioning and control mechanism adapted to readily vary the degree of tension on the thread over a definite range.

In sewing a series of stitches it has been customary to preliminarily adjust the tension on the sewing threads to a predetermined degree and operate the sewing machine continuously with this adjustment, with the result that all stitches will have the same characteristics, degree of tightness and appearance. My invention has in view the production of a series of stitches in which selected groups may have diiferent characteristics, different degrees of tightness or present a different appearance. With this in mind, I change the tension of the sewing thread at intervals during the sewing of the series of stitches. When operating with a plurality of sewing threads I vary the relative degree of tension between the several threads at intervals and thus change the stitch characteristic.

For this purpose I equip the machine with a plurality of thread tensioning units and supply means for rendering the various units effective and ineffective in predetermined order at the aforementioned interval. When a plurality of threads are used each thread is passed through one or more of said tension units. By rendering said units effective and ineffective selectively, not only can the tightness or looseness of the stitch of difierent groups of the series of stitches be controlled, but also the relative tension between the threads is variable to change the stitch characteristic.

An example of the application of my invention is to be found in my copending application, Serial No. 605,341, filed April 14th, 1932. In this application I show a sewed seam for a stocking which in portions of its length is flat, loose and elastic, and in other portions is tight and unyielding, and instill other portions is partially embedded under the fabric surface by a change in relative stitch tension between the respective yarns of the seam. V

The above described machine and method will be clear from the following detailed description of the invention and the accompanying drawings of whichi Fig. 1 is a side elevation of a portion of the sewing machine to which my invention is applied;

showing the arrangement of tension units;

- Fig. '2 is a plan view with parts broken away 1932, Serial No. 604,578

Fig. 3 is a perspective takenfrom the rear right of the machine showing the new tension mechanism and the instrumentalities for manipulating them;

Figs. 4, 5, and 6 are diagrammatic views showing the respective tensions obtainable by the embodiment shown in Figs. 1, 2, and 3.

Figs. '7, 8, 9, and 10 show one embodiment of the type of sewing that is obtainable by the mechanism of Figs. 1, 2, and 3.

As best seen in Figs. 1 and 2 the sewing machine is one that is commonly used in seaming full fashioned'stockings and comprises in its essential elements the fabric feed discs I and. 2 and the stitch forming mechanism consisting of the needle 3 and the interlooping element, a looping finger 4. Element 5 is a chaining finger. The fabric feed mechanism and the stitch forming mechanism are driven in synchronism from driving mechanism enclosed in the housing 6. The mechanism thus far described is old and is shown in the patent Onderdonk, No. 1,197,055.

Briefly stated, the operation of the sewing machine is as follows: The needle 3 passes a thread through the fabric edges extending above the discs I and 2 and the looping finger 4 carries a thread to each end of the needle travel there to interloop the two threads. When an interloop is being formed at one end of the stroke, the previously formed interloop at the other end of the stroke is being drawn taught against the fabric and the chaining finger 5.

The sewing threads emanate from suitable sources of supply, not shown, and pass through tension mechanism and guide eyes to be hereinafter described. The respective threads are threaded through the respective stitch elements in a manner well known and clearly shown in the above-mentioned patent.

The needle thread passes through the thread guide 8 and. then successively through the ten sion units 9 and I0, which in the preferred embodiment comprise conventional disc tensioning elements. After the tension unit In, the yarn passes through the disc tension I I and from there through thread guiding means including the guide eye I2 to the eye near the point of the needle at I3. Between the respective tension units 9 and I0 and the disc tension I I are thread hold-down pins I5 which function to hold the thread in proper position between the discs. The tension units 9 and II) are similar to conventional disc tensions such as the element II, as is clearly shown in the drawings, and are equipped with adjusting means comprising springs I6 and The disc tensions ii and 2| are of themselvesold on the machine but in the present embodiment are adjusted to a very light degree of tension. The tension exerted by the discs and 2| is approximately the same and is only sufficient to enable the stitch mechanism to properly intercooperate. The respective tension units 9, i8, and 28 are adjusted to about the same degree of tension and each exerts about as much tension as is exerted by the tension discs similar to and 2| on machines not equipped with my invention.

The respective tension units 9, l0 and 20 are adapted to be rendered ineffective by a plurality of control elements, one for each tension unit, and comprising pins 23, 24,25, and 26 which are movable from a position away from the'discsto positions where their beveled ends 21 enter between the discs and spread them apart. The control units are interconnectedto be readily operated in unison. Thus the predetermined tensions on. the.

respective threads can be readily obtained or changed as required for producing any particular type of stitch variation desired. The description of the preferred embodiment of mechanism for accomplishing this follows.

The pins 23 to 26 are mounted on a common arm 28. Set screws 29 hold the respective pins in proper relationship to the tension units to perform their functionv as hereinafter described. The pins 23, 24, and 25 are adjusted to: positions above their respective discs 9., Land 2|],

all pins being about the same distance from the discs. The pin 26 is adjusted to a position below the disc l0.

Thebar 28 is adjustably mounted by set. screw 30 on the upright slide arm 3|. The arm .3| is adapted to slide up and down through'the fixed guideway 32 mounted on the machine housing 6. The cam 33 is mounted to pivot on the screw 34 fixed to the upright slide arm 3|. The

cam 33 has a finger 35 for manually rotating the- Three. cam positions cam on its pivot pin 34. are determined by projections 36, 3'1 and 38. on the cam periphery which projections are adapted to seat in the notch 39 of the cam follower 4.0 which is integral with the fixed guideway bracketv 32. The cam operates in opposition to' the spring 4| mounted on the upright guide arm 3|.

When the projection 36 is seated in the. notch 39 the bar 28 is at its lowermost position. The projection 31 determines the intermediate position of the bar and the projection 38 determines the uppermost position of the bar. When the bar 28 is at its lowermost position the pins 23,

24 and 25 have been inserted between the tension discs of the respective tension units 9, l8, and' 28 and therefore all tension units are rendered ineffective. When the bar 28 is at its. uppermost position the pin 2.6 has been entered between the discs of. the tension unit. l8 and this unit is therefore renderediineffective. Whenthe. bar.

28 is in its intermediate position no pins are between tension unit discs.

In Figs. 4, 5, and 6, respectively, I show diagrammatically the effect of the pins on the discs for the three positions 36, 31, and 38 of the cam 33. It will be recalled that the disc tensions II and 2| are very light and only sufficient to enable the stitch mechanism to operate satisfactorily. Thus, when the projection 36 is seated in the notch 39 the tension units 9,, l8, and 2,0 are ineffective and sewing is done with very little tension on the threads. This will produce a flat, loose stitch such as is shown at in Fig. 7 and in cross-section in Fig. 8. The discs will thenhave the relationship indicated diagrammatically in Fig. 4.

When the projection 38 is seated in the notch 39 the pins and disc assume the relationship illustrated in Fig. 6 and the tension unit l0 will be rendered ineffective. This leaves the tension units 9 and 20 effective and they exertatension on the respective threads that will produce-firm tight stitches such as are. shown at 46 in Fig; 7 and in cross-section in Fig. 9. If the. tension units Sand 28 exert approximately the same de-- gree of tensionthe. stitch will :be balancedaaviththe concatenations 41 approximately oppositely spaced on each side of the stitch asshown in Fig. 9.

When the projection 31 is seated in the notch. 39 the pins and discs have the relationship shown, in Fig. 5 and all tension units-are effective; This will produce a tight stitch such as shown .at 4.9

in Fig. 7. and in cross-sectionfin Fig. 10.v It willv be noted that since the discs 9 and 20 exert a; balanced tension on the respective threads toproduce the balanced stitch of Fig. 9, by renderingv the disc l0 additionallyefiective. onthe needle thread, the'needle thread has been given an es. pecially great amount of tension. This causes; the drawing of the concatenations 50 in Fig. 1| v close together and brings the sewn. fabric 5| close around the needle thread at 5.2 to. embed the thread under the fabric surface. This. is. clearly seen in Fig. 10 ascompared to Fig. 9.

I have described my invention as applied toa specific. machine for producing .a specific stitch.. Obviously my invention is not so limited. I;have. described a specific selection of thread tension-e ing for different groupsv ofstitches ofa series: of stitches. This selection was made to producethe particular construction as described in my. copending application. It constitutes merely one embodiment of the invention., Obviously .other selections can be made .to produce different=.worl :v within the spirit andscope of my invention. I therefore do not wish to limit myself ;to. the; specific. embodiment disclosed. herein but myinvention is of more generic application and is of the scope of the appended claims.

What I claim is; a

.1. In a machine for sewing witha needle; andan interlooping thread, a plurality of pairs of. tension discsfor each thread adapted to sliding 1y clamp the respective threads, spreading pins: for certain pairs of discs, control means common. to all of said pins to selectively actuate the-various. pins between their respective disc pairs torelieve the tension exerted by the respectivediscs, said control means being operative through the various pins to render the tension discs on themseveral threads operative and inoperative both :simultaneously and independently.

2. In a machine for sewing. with a. needle..and an interlooping thread, variable tension means.

for each thread, said tension means comprising one or more tension elements for each thread, a control unit for each tension element, selectively operating mechanism for the control units operating said units in groups to release different numbers of tension elements at different times.

3. In a machine for sewing with a needle and an interlooping thread, variable tension means for each thread, said tension means comprising one or more tension units for each thread, a control unit for each tension unit, operative mechanism for the control units for placing them in one position to render a predetermined selection of tension units effective, another position to render all tension units effective, and in a third position to render all tension units ineffective.

4. In a fabric seaming machine, means for sewing with a needle and an interlooping thread, variable tension means for each thread, said ten sion means comprising one or more tension units for each thread, a control unit for each tension unit, operative mechanism for the control units for placing them in one position to render a predetermined selection of tension units effective, another position to render all tension units effective, and in a third position to render all tension units ineffective.

5. Thread tensioning means for a sewing machine comprising a plurality of opposed discs for sliding clamping engagement on the thread, a control element for the discs to selectively render one or more of said discs effective and ineffective, cam and follower mechanism including a pivotal plate, cam edges on the plate, and a cam follower having a surface engageable with the cam edges of the Plate, means actuatable by the cam and follower mechanism and connecting'with the control element for operating the latter, and manually operative means for turning the cam plate.

6. In a fabric seaming machine, tension mechanism for a seaming thread adapted to vary the relative tension thereon comprising a plurality of tension elements engageable with the thread and selective control means engageable with the various tension elements for selectively varying the tension exerted on the thread, said control means operating on different groups of tension elements at different times.

'7. In a sewing machine, thread tensioning mechanism comprising a plurality of independent thread tensioning elements, and selective control means for cooperating with the various tensioning elements and operable at one time for releasing less than the whole number of tension elements from the thread and also operable at another time for releasing a different number of tension elements from engagement with the thread.

8. In a machine for sewing with a needle thread 5 and an interlooping thread, variable tension means for each thread, said tension means comprising one or more tension units for each thread, a control unit for each tension unit, and a selector mechanism for the control units operating said control units in selective groups for rendering a predetermined selection of tension units effective at one time and operating for rendering another predetermined different selection of tension units effective at a different time.

9. In a sewing machine for sewing with a plurality of threads, tension mechanism comprising one or more tension elements for each of the several threads, and a selective controlling means operating through said tension elements 20 for applying tension to the respective threads, said controlling means operating on the tension elements in groups and releasing different numbers of tension elements at different times.

10. In a fabric seaming machine, means for sewing with a needle thread and an interlooping thread, separate variable tension means for the several threads, said tension means comprising one or more tension units for each thread, a control unit for at least certain of the tension units, and a selector mechanism for the control units operating said control units selectively in groups so that different numbers of tension units are rendered operative at different times.

11. In a fabric seaming machine, two thread stitch forming mechanism, tensioning means for each of the threads, and selective control means cooperative with the tensioning means for selectively adjusting the relative tension of the re spective threads, said control means operating to reduce the tension on both threads simultaneously and also operating to reduce the tension on one thread without reducing the tension on the other thread.

12. In a machine for sewing with a needle thread and an interlooping thread, tension means for both threads comprising a multiplicity of tension elements, and unitary control means for the tension elements of both threads operating to selectively engage different of said tension elements at different times to vary in their relation to each other the tension on the respective threads.

JACOB A. GOODMAN.

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