US1304627A - Stitch-eobmctg- mechanism eor sewing-machines - Google Patents

Description

C. W. THOMAS. STITCH FORMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MN. 8. 1916; 1,304,627.

Patnted May 27, 1919.

WITNESSES." //Wl:'/V T70i EwuzsW 10/14/15 A45 M I, 10, 7.3M W5 ATTORNEY c. w. THOMAS. STITCH FORMING MECHANISM FOR SEWING MACHINES. APPLICATION FIL EU MN: 8 1916 I 1,304,627. Patented May 27, 1919.

2 SHEETS-SHEET 2.

INI/E/VTOR CARLYLE 'W. THQMAS, 01? BRIDGEIEORT, CONNECTICUT, ASSIGNOB. TO THE SINGER MAHUFACTUEING COMPANY, A CORPORATION OF JERSEY.

EEZQCH-FGRBEING MECHANISM FOR SEWING-MACHINES.

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Specification of Letters Patent.

Patented M y 27, 1919..

Application filed January 8, 1916. Serial No. 70,901.

- To all wkome'tmay concern:

Forming'hiechanisms for Sewing-Machines,

of which the following is a specification, referencebeing had therein to the accompanying drawings.

Q This invention relates to improvements in sewing machine stitch-forming mechanisms, more particularly that class of machines employing multiple needles in connection with multiple looptalcers wherein the needles are controlled to operate singly or together, and has for its object to control the slack of the bobbin-thread during the period that the needle, carrying the thread being concatenated with said bobbin-thread, is idle, such idle period occurring when the seams are to be continued at an angle to the previously formed lines of stitching.

The present invention is directed to improving the construction of under thread controlling mechanism represented by United States Patent No. 593,734, of November 16, 1897, to G. H. Colley, and differs from the device of the patent in the controller-spring being mounted and-actuated independently of the rotary movements of the bobbin, so that its limit of'action remains the same under all conditions of under thread supply, while in the patented device the thread-controlling action of the controller-spring depends upon the amount of thread carried by the bobbin.

Referring to the drawings which form a part of the specification, Figure 1 is a view in front side elevation of the front end portion of a sewing machine arm'bracket and bed-plate, ,the latter shown in section, equipped with one form of multiple needle stitch-forming mechanism and means for throwing one of said needle-bars out of action. Fig. 2. is a view in front end elevation of Fig. 1, except that it includes the bracket-arm and the bed-plate is shown in section transverse to that shown in the latter figure. Fig. 3 is a plan view of the loop taker shown at the right of the needle in Fig. 1 and its bracket or saddle, together with a like view of the cloth or throatplate. Fig. dis a view in central section of the present bobbin-case, the sameasis shown in Fig. 3, fitted with the present invention. Fig. 5 is a plan view of the present bobbincase, the controller-spring cap being removed to bring to view the controllerspring. Fig. 6 is an'edge View of Fig. 5. Fig. 7 is an inverted View of the bobbincase cap, together with a portion of the bobbin-stud and bobbin-thread illustrating the travel of the thread from the supply to and through the free end of the controller-spring. Fig. 8, views a, b, c andd show how the slack thread is formed and later controlled by the controller-spring. Fig. 9 is a specimen product illustrating angularly arranged parallel seams.

The present invention is herein shown and described as applied to a Singer 108W class machine fitted with multiple needlecarrying bars controlled to operate singly or together, substantially the same as ris represented by United States patent application of Herbert Corrall, Ser. No. 840,170, filed May 22, 1914, for improvements in sewing machines, but as the present invention is not limited in its application to any only such reference will be made to the elemerits comprising the latter as is necessary for a proper understanding of its construction and use.

Referring to the figures, 1 represents the sewing machine bed-plate upon which is mounted the bracket-arm comprising the arm-bracket 2 and standard 3 and into the head or free-end of said bracket-arm there is mounted to move vertically the needlebars 4 and 5 provided with the usual thread needles, said needle-bars being operatively connected, through the shaft-flange 6,- needlebar actuating link 7 and needle-bar actuating stud-eollar 8, with the main or needlebar actuating shaft 9. p

The stud-collar 8 is provided with two tubular openings, as 10, through which pass the respective needle-bars, the latter being provided with openings, as 11, in which is seated the teats, as 12, (the-openings l0 and 11 and teat 12 being shown singly and in dotted lines only, see Fig. 2) formed integral with the plunger-pins, as 13, provided with knurled nuts, as 14, and springs, as 15, '(one only of the latter being shown) which latter act to resiliently hold the teats 12 seated in the openings 11.

a spring, as'l6, seated at their lower ends on the stud-collar 8, their opposite ends being confined by collars, as 17, (one only of said springs and collars being shown) secured on said needle-bars, for a purpose later to bereferred to. Upon the upper surface of the head of the arm-bracket is secured by screw, as 18, guide-brackets, as 19, having their inner or free ends V-shaped, which latter track the V-shaped grooves, as 20, formed in the needle-bars, said brackets acting to hold the latter against accidental rotation when released from control by the teats 12 of the plungers -13.

21 represents a plate suitablysecured to the head of thearm-bracket and provided with suitably secured brackets 22 and 23 having openings, as 24 and as 25, respecti vely, (said openings being shown in dotted lines only,-see Fig. 1) and into said openings are mounted to move vertically rods 26 and 27 yieldingly held by springs, as 28, in their elevated positions, the lower ends of said rods carrying enlarged portions, as 29, provided with inclines, as 30, and slots, as 31, into which latter track the plunger-pins 13, the upper ends of each of said rods being provided with depressing brackets, as.

33, for a purpose later to be explained.

34 denotes a tubular post suitably secured upon the uppersurface of the bracket-armhead and into said post is housed to move vertically a pin or plunger35 (shownv in dotted lines only, see Fig. 1) carried by a needle-bar depressing cap 36, and to move said cap there is interposed between the base of the tubular post and the lower end of the pin 35 a spring 37, the movement of said cap being limited by a stop-pin 38 suitably secured in said post and tracking a slot 39, formed in said cap. 40 denotes the clothpresser carried by the cloth-presser bar 41 and 42 the needle thread take-up.

When it is desired to discontinue and later resume the stitch-forming-movements of one of the needle-bars, for illustration, the one located at the right in Fig. 1 the other being controlled in like manner, the operator, through the bracket 33, moves the rod 27 downward, and in doing so causes the incline 30 to act upon the nut 14 to withdraw the teat 12 of-the pin 13 out of engagement with the opening 11 in the needle-bar, thus permitting the spring 16 to elevate the needlebar slightly above its limit of upward stitch-forming movement where it remains with the teat 12 in contact with its solid portion until the opening is again brought into the field of movement of said teat by depressing the cap 36 when, owing to the rod 27 having been moved to its elevated position by its spring 28, the teat is permitted to again enter the opening 11 and transmit to the needlebar stitch'forming movements.

it is thought sufficient to refer to the loop- I takers, as 43, as being provided with looptaker shafts, as 44 (shown in dotted lines only, Fig. 1) operatively connected by bev eled gears, as 45, with a gear-shaft 46, which latter is operatively connected with the looptaker actuatin shaft 47 by gear members 48 and 49, WlllCh latter are of the ratio of two to one, thus giving to the loop-takers two rotations to one complete actuation of the needles, the loop-taker actuating shaft being operatively connected with the mainshaft 9. by means (not-shown) common to earlier constructions. 50 denotes the throat or needle-plate and 51 the feed-dog operated in a manner'common to many earlier varieties of sewing machines.

The bobbin-case comprises a' base portion 52 and cap 53, the line dividing said portions corresponding substantially with the upper wall 54 of the radial fin 55, which latter is journaled in a suitable guideway (not shown) formed in the inner wall of the loop-taker, as in earlier constructions,

the exception to the dividing line being arranged as noted above being the providing of the bobbin-case base with an upwardly extended portion 56, the upper free edge of which coincides with the base line '57-of the oval portion 58 of the bobbin-case cap and extending from-the point 59 to 60, best shown in Fig. 5. The bobbin-case base is provided with the usual central hub 60 into which is housed a spring-controlled plunger 61 whose upper end is provided with an en larged portion 62 which acts on a latch 63 1,95 hinged in the free end of said hub, said latch acting to hold the bobbin-case against accidental displacement, the thread-bobbin 64, provided with the mass of under thread 65, being inclosed in said bobbin-case to rotate' lo on said hub. The bobbin-case base is provided with the usual bobbin stops, as 66, and the throat-plate with the usual stoplugs, as 67, said stops and lugs acting to hold the bobbin-case against following the 5 rotary movements of the loop-taker, as in earlier constructions.

To thread the bobbin, the thread is led from the supply through the slotted notch e formed in.the rim of the bobbin-case cap 53,'th en beneath the suitably secured thread tension spring 9, back through the slotted notch it along the inner surface of the rim f, out through the slotted notch and from the latter through the thread-eye 69, from which 125 it is passed through the needle opening in the tl1roatplate.

Referring now to the features in construction more directly connected with the invention, 68 denotes a bobbin-thread control- 130 ler spring provided at its free end with a thread-eye 69, its opposite end being secured of movements of the stitch-forming mechanism relatively to the feed movements and manual manipulation of the fabric under the needles for effeeting'the angularlydirected seams of Fig. 9.

Referring to Figs. 8 and 9, 76 represents the right-hand and 77 the left hand seam; view a, Fig. 8, showing the seams advanced to their limit of parallel relationship in a. single direction, at which point the righthand needle '78 is placed out of action and the seam 77 continued for a distance correspondin to the distance between said seams, as represented in view I), Fig. 8, when the fabric is turned about the needle 7 9 in the direction indicated by the arrow, view c,

Fig. 8, in position to continue the seam 77 at right angles to the previously formed portion of the seam, and in this connection it is to be noticed that during the idle period of the needle 78 there has been drawn from the supply a. length 80 of free under thread extending from one to the other of the seams. when the machine is again put into action and the seam 77 advanced to a point in line with the seam 7 6, see view (5, Fig. 8, when the needle 78 is brought into action.

During the time that the seam 77 is being advanced from its previously formed angular portion to a point in line with the seam 76, the thread-controller spring has taken up the slack thread 80, see view (Z. Fig. 8, so that the needle 79 will commence its stitching operation under normal conditions.

It is to be understood that the tln'ead-controller spring is drawn to i s limit of torsional movement when first starting the seam formation and. so held during the stitching of a continuous seam except when, from any cause, slack is formed in the bobbin-thread.

Having thus set forth the nature of the invention, what I claim herein is:-

1. In a. stitch-forming mechanism for 'sewingn'lachines, the combination with a continuousl v rotating loop-taker and a stationary bobbin-case, the latter journaled in said loop-taker and provided with a thread-tension mechanism and a thread-bobbin, of a thread-controller spring carried by said bobbin-case and acting independently of said bobbin to resiliently resist the pull upon the bobbin-thread incident to seam formation.

2. In a stitch-forming mechanism for sewing machines, the combination with a con-- tinuously rotating loop-taker and a stationary bobbin-case, the latter comprising a base portion provided with a cap inclosing a. thread-bobbin and having a thread-tension mechanism, of a thread-controller spring carried by said cap and acting independently of said bobbin to resiliently resist the pull upon the bobbin-thread incident to seam formation.

3. In a stitch-forming mechanism for sewing machines, the combination with a continuously rotating loop-taker .and a stationary bobbin-case, the latter provided with a thread-tension mechanism, a thread-bobbin and a spring-pocket, of a thread-controller spring mounted in said pocket and acting independently of said bobbin to resiliently resist the pull upon the bobbinthread incident to .eam formation. v

4. In a stitch-forming mechanism for sewing machines, the combination with a continuously rotating loop-taker and a stationa'rybobbin-case, the latter comprising a base portion and a cap, said bobbin-case being provided with a thread-bobbin and a thread tension mechanism and said '-cap with a spring-pocket. of a threadcontroller spring mounted in saidpocket and controlled to resiliently resist the pull upon the bobbin thread incident to seam formation.

-5. In a stitch-forming mechanism for sewing machines including nniltiple'needles and continuously rotatingcooperating looptakers, each of the. latter being provided with a bobbin-case and each bobbin-case having a thread-tension. of a thread-controller carried by the respective bobbin-cases and acting independently to resiliently control. the slack of the bobbin-case threads when directing the parallel sean'i-formations at an angle to the previously formed seams.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

CARLYLE V. TH OM A S. Vitnesses Tirnononn JoRcnNsnx, Var. A. Sanrrnn.

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