US1756699A - Rotary-hook sewing machine - Google Patents

Description

April 29,1930. w. N. PARKES ROTARY HOOK SEWING MACHINE INVENTOR William MParkeJ A TORNEY Filed Aug. 11

i WT-":1 ESSEQ MQ Patented Apr. 29, 1930 UNETED STAE'ES Parser WILLIAM NELSON PAR-KES, OF BROOKLYN, HEX/V YORK, ASSIGNOR TO THE SING-ER MANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY ROTARY-HOOK SEWING MACHINE Application filed August -11, 1927.

This invention relates to improvements in sewing machines of the type employing a vertical axis loop-taker to cast needle-thread loops around a bobbin-carrier journaled in said loop-taker and confined to limited oscillations about its journal axis.

, The present invention has for its primary object to provide an improved construction for effecting an unobstructed passage for the needle-thread loops around the bobbincarrier of a vertical axis loop-taker, in so far as said needle-thread loops would meet with interference or resistance by the means employed for limiting the rotation of said carrier.

In accordance with the present improved construction, the bobbincarrier, as usual, has a peripheral bearing rib journaled in a raceway in the loop-taker, substantially as disclosed in my prior United States Patent No. 1,484,151, Feb. 19, 1924:. Above the'bearing rib the body of the bobbin-carrier is formed, at substantially diametrically opposite points, with a notch and a shoulder, the notch being entered by a stop-lug depending from the throat-plate and restraining the bobbin-carrier against rotation with the loop taker. The shoulder referredto is adapted to be engaged by a finger extending laterally from the upper end of a vertically disposed rock-shaft jour'naled in a bracket detachably secured to the underside of the machine cloth-plate and supporting the rotary loop-taker mechanism asa unit. At its lower end, said rock-shaft carries a lateral arm yieldingly held by a spring against an eccenv tric secured upon a loop-taker actuating shaft, journaled beneath the cloth-plate and rotated once for each complete reciprocation of the needle of the sewing machine. The loop-taker actuating shaft is journaled, at its forward end, in the detachable loop-taker bracket and is suitably geared with the vertical loop-taker shaft to impart two rotations to the loop-taker for each reciprocation of the needle. It will therefore be understood that while the loop-taker performs a multiple of rotations during each reciprocation'of the needle, the rock-shaft finger referred to engages the bobbin-carrier only once for each Serial No. 212,172.

needle reciprocation. As the movements imparted to said finger are very short and as its actuating eccentric is comparatively large in diameter, with a correspondingly small degree of eccentricity, it is evident that the construction described lends itself well to tion of rotation of the loop-taker, the sudden stopping of the bobbin-carrier by the throat plate stop-lug after oscillation of the carrier by the opener finger, coupled with the minimum of friction referred to, causes anincrease in a natural tendency of'the bobbin to rotate in a direction opposite to the direction of rotation of the loop-taker and therefore tends to keep the bobbin-thread taut, a condition enhancing the efficiency of the looptaker. p

In the accompanying drawings, Fig. 1 is a substantially central, longitudinal section of a portion of a sewing machine cloth-plate and its attached loop-taker mechanism bracket, and showing the usual reciprocatory needle at substantially the lower end of itsstroke. Fig. 2 is a top-plan view of the same portion of the cloth-plate, but omitting the throatplate, slide-plates and the feed-dog. Fig. 3 is a bottom plan, on a smaller scale, of the loop-taker bracket. Fig. 4 is a perspective view of the loop-taker detached. Figs. 5' and 6 are similar views of respectively the looptaker base and thebobbin-carrier. Fig. 7 is a perspective view of the bobbin-carrier auxiliary hook detached. Fig. 8 is a bottom plan View of the throat-plate. Fig. 9 is a side provement is shown as embodied in a sewing machine having the usual cloth-plate 1, the throat-plate 2 and, the slide-plates 3 and 4 at opposite sides of the throat-plate. Operating through suitable openings in the throatplate are the feed-dog and the reciprocatory needle 6.

Adjustably secured to the underside of the cloth-plate, by screws as 7, is the loop-taker bracket 8 sustaining the loop-taker mechanism in its assembled form as a detachable unit. Secured by a set-screw 9 in the bracket 8- is a bushing 10, in which is journaled the forward end of the loop-taker actuating shaft 11, which rotates once for each complete reciprocation of the needle. The actuating mechanism for the needle and the shaft 11 may comprise any usual properly timed construction, such as is illustrated, for instance, in the United States patent to J. C. Binge, No. 1,484,191, dated Feb. 19, 1924.

Secured upon the end of the shaft 11 is a bevel-gear 12 which meshes with a similar gear 13 upon the vertically disposed looptaker shaft 14 journaled in suitable bearings provided in the bracket 8. The gears 12 and 13 are proportioned to impart two rotations to the shaft 14 for each rotation of the shaft 11. Detachably connected with the shaft 14 for rotation therewith is the stub-shaft 15 of the inner loop-taker body 16, which is cupped to receive a bobbin-carrier 17. The bobbin carrier 17 is peripherally provided with an interrupted bearing rib 18 journaled in a raceway constituted by the flange 19 at the upper edge of the inner body 16 and the flange 20 at the upper edge of the outer looptaker body 21 secured upon and in peripheral contact with the inner body 16. It is to be understood that the inner body 16 and the outer body 21 together comprise the loop-taker proper, said outer body being formed to provide a loop-seizing beak 22 and the inner body being provided with a nose 23 disposed rearward of the point of the beak 22 and func tioning to deflect the inner limb-of the needlethread loop into the thread-clearance opening 18 provided by the interruption inthe bearing rib.

The bobbin-carrier 17 is substantially bottomless, its base comprising a narrow bobbinsupporting flange 24 in the present construction formed by a flat ring suitably secured as by soldering or welding to the lower edge of the bobbin-carrier wall; Projecting from the ring or flange 24 is'an' auxiliary hook 25 disposedbetween the walls of the inner looptaker body 16and the bobbin-carrier17, said hook-.25 acting to engage-and rapidly spread the needle-thread loop seized by the loop takerbeak. 22. This feature of the presentconstructionforms the subject of my patent application Serial No; 212,175, filed August 11, 1927. Sustained within the bobbin-can rierjby the flange-24 is a' bobbin 26 of any suitableconstruction. Above the bearing rib 1*8Zthe1b0bbin earrier 17 is or may be provided with aperturesand a, tension device substantially as described in my prior Patent No. 1,484,151 hereinbefore referred to, said bobbin carrier body above its bearing rib being additionally provided with a notch 27 and a shoulder 28 substantially diametrically opposite to the notch 27. The notch 27 is loosely entered by a stationary stop-lug 29 depending from the throat-plate 2 to confine the bobbin-carrier to limited oscillation upon its loop-taker journal, it being observed that, the notch 27 is located above and at oneside of the thread-clearance opening 18 in the bearing rib 18.

In order to oscillate the bobbin-carrier in a direction opposite to the direction of rotation of the loop-taker, for the purpose of providing a free thread-passage for the needle-thread loop past the stop-lug 29, the shoulder 28 is intermittently engaged by an opener-finger 30 having a hub 31 suitably secured upon the upper end of a vertically disposed rock-shaft 32. The rock-shaft 32 is journaled in a bearing-bushing 33112166. in the bracket 8 and is transversely apertured for the reception of an actuating arm 34 adjustably secured to said rock-shaft by a set-- screw 35. At its free end, the arm 34 is provided with a grooved roller 36 engaging the circular face of a comparatively large eccentric 37 secured upon the rotary shaft 1 1. Surrounding the bushing 33 is a coil-spring 38, one end of whichengages the arm 34 to yieldingly hold the roller 36 in contact with the eccentric 37, while the other end of the spring 38 enters'an aperture in a collar 39 adjustably secured upon the bushing 33 to vary the tension of the spring. It will be evident from the foregoing description that the opener-finger 30 has a relatively slow motion of approach to the shoulder'28 and is therefore particularly suitable for high speed operation of the machine.

As the loop-taker beak 22 is disposed very close to the throat-plate, there is a possibility that in chaining-off, i. e., in the operation of the threaded machine in the absence of work, the thread-chain thus formed may sag into the path of movement of the loop-taker beak. To avoid this contingency, there is provided a segmental, tapering guard-finger 40 over lying the portion of the path first traversed by the loop-taker beak after seizure of the needle-thread loop. The finger 40 extends laterally from its shank 41 adjustably secured by means of a screw 42 upon the machine frame below the slide-plate 3. The shank 41 is provided with a needle clearance notch 43, the wall 44 of said notch constitut ing a stationary abutment for the needlethrea'd loop seized by'the loop-taker, thereby forcing' the loop more rapidly down the inclinededge of the beak to spread said loop. This guard-finger forms the subject of my patent issued September 17 1929, under No. 1,728,506. WVhen employing the gua'rd-fim ger in connection with a hemstitching machine, it may additionally be provided with a piercer aperture 45.

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

1. In a sewing machine, a reciprocatory needle, a vertical-axis loop-taker performing a multiple of rotations during each reciprocation of the needle, a bobbin-carrier journaled in said loop-taker, stationary means for restraining said bobbin-carrier against rotation with the loop-taker, a movable finger adapted to impart a short oscillation to the bobbin-carrier in a direction opposite to the direction of rotation of the loop-taker, and means for actuating said finger to oscillate the bobbin-carrier once only for each needle reciprocation.

2. In a sewing machine, a reciprocatory needle, a vertical axis loop-taker provided with a raceway, a bobbin-carrier having a body provided with a peripheral bearing rib near its top journaled in said raceway, said bearing rib being interrupted to form a thread-clearance gap, the body of the bobbincarrier above said bearing rib being provided with a stop-notch disposed at one side of said bearing-rib gap, a stationary stop-member positioned to enter said stop-notch to restrain the bobbin-carrier against rotation with the loop-taker, a bobbin within said bobbin-carrier, and means for slightly oscillating the bobbin-carrier once only for each needle reciprocation in a direction opposite to the direction of rotation of the loop-taker to thereby provide a free thread-passage past said stop-member.

3. In a sewing machine, a reciprocatory needle, a cloth-plate, a bracket detachably secured to the underside of said cloth-plate, and a loop-taker mechanism sustained by said bracket for detachment therewith as an assembled unit, said loop-taker mechanism comprising an actuating shaft rotating once for each needle-reciprocation, a vertical-axis loop-taker shaft performing a multiple of rotations for each needle reciprocation, driving connections between said shafts, a loop taker secured for rotation with said looptaker shaft, a bobbin-carrier journaled in said loop-taker, an opener-finger adapted to oscillate the bobbin-carrier once only for each needle-reciprocation in a direction opposite to the direction of rotation of the looptaker, and means for actuating said openerfinger from said actuating shaft.

4:. In a sewing machine, a cloth-plate, a reciprocatory needle, a vertical-axis looptaker performing a multipleof rotations for each needle-reciprocation, a bobbin-carrier journaled in said loop-taker, means for restraining the bobbin-carrier against rotation with the loop-taker, an actuating shaft journaled beneath said cloth-plate rotating once for each needle-reciprocation, an openerfinger adapted to oscillate said bobbin-carrier once only for each needle-reciprocation in a direction opposite to the direction of rotation of the loop-taker, a vertical-axis rockshaft carrying said finger, and operative connections between the rock-shaft and said actuating shaft for actuating said openerfinger.

5. In a sewing machine, a cloth-plate, a reciprocatory needle, a vertical-axis looptaker performing a multiple of rotations for each needle-reciprocation, a bobbin-carrier journaled in said loop-taker, means for restraining the bobbin-carrier against rotation, with the loop-taker, an actuating shaft journaled beneath said cloth-plate rotating once only for each needle-reciprocation, an openerfinger adapted to oscillate said bobbin-carrier onceonly for each needle-reciprocation in a direction opposite to the direction of looptaker rotation, a vertical-axis rock-shaft carrying said finger, an arm carried by said rock-shaft, an eccentric upon said actuating shaft, and a spring yieldingly holding said arm in operative engagement with said eccentric.

6. In a sewing machine, a reciprocatory needle, a vertical-axis loop-taker, a bobbincarrier ournaled in said loop-taker, means for restraining the bobbin-carrier against ternal raceway around the top of its side wall, a bobbin-carrier provided with an in terrupted bearing rib journaled in said raceway, said bobbin-carrier having a centrally open base constituted by a narrow internal flange provided at the bottom of the bobbincarrier wall, and means for oscillating said bobbln-carrier once only for each needlereciprocation in a direction opposite to the direction of loop-taker rotation.

In testimony whereof, I have signed my 5.

name to this specification. 1 v

WILLIAM NELSON PARKES. I

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