US1763670A - Loop-taker mechanism for sewing machines - Google Patents

Description

' June 17, 1930-.

w. N. PARKES- LOOP TAKER MECHANISM FOR SEWING MACHINES Filed Jan' 15, 1929 2 Sheets-sheaf; l

SYN-M14450 I William MPa/kes June 17, 1930. w. N. PARKES LOOP TAKER MECHANISM FOR SEWING MACHINES 2 Sheets-Sh'eet 2 Filed Jan. 15, 1929 li-E-I a...

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WLLiamh Patented June 17, 1930 HUNH'EED STATES PATENT OF IcE 'f" WILLIAM NELSON PARKES, OF BROOKLYN, NEW YORK, ASSIGNOR- SINGER MANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A. CORPORATION OF NEW JERSEY LOOP-TAKER MECHANISM FOR SEWING MACHINES Application filed January 15, 1929. Serial No. 332,612.

This invention relates to j improvements in sewing machines in which a vertical-axis rotary loop-taker is disposed beneath the cloth-plate of the machine for cooperation with a vertically reciprocating needle in the formation of lock-stitches.

It is the object of the present invention to improve the quality of the sewing produced by a lock-stitch machine when operated at high speed and particularly in a sewing machine having a loop-taker in which is journaled a bobbin-carrier containing arelatively large mass of thread around which the needle-threadloops are cast by the loop-taker.

To the attainment of its object, the present invention is primarily directedto improved means for limiting the oscillation of the bobbin-carrier about the axis of rotation of the vertical-axis loop-taker in which said bobbin-carrier is journaled. Accordingly, the upper rim of an open-top bobbin carrier is provided with a shoulder positioned on the cast-off side of the loop-taker so as to be engaged by a stop-lug depending from the throat-plate of the machine to restrain the bobbin-carrier against rotation with the loop-taker. The throat-plate stoplug is 'spacedasubstantial distance from a line intersecting the throat-plate needle-ap erture transversely of the direction of feed.

In order to provide a passage for the needle-thread loop past said engaging shoulder and stop-lug, another shoulder upon the bobbin-carrier is intermittently engaged by a vibratory opener-finger to oscillate the bobbin-carrier in a direction opposite to the direction of rotation of the loop-taker. Because of the described location of the throat-plate stop-lug the needlethread loop is free to pass saidstop-lug at substantially the point where said thread loop is discharged upon the loop-taker spur or heel by the loop-taker beak, i. e., a substantial length of time before the actual setting of the stitch. The bobbin-carrier is limited in its reverse movementby the engagement with a third shoulder thereupon of a stop-finger supported upon the machine frame for adjustment-about the axis of rotation of the loop-taker.

In the accompanying drawings, Fig. 1 is a vertical section substantially on the axis of rotation of the loop taker and through a portion of the cloth-plate of a sewing .mach-ine containing the present improvement. Fig. 2 is a top plan view of a portion of the cloth-plate, with the usual slide-plate removed to expose the loop-taker. Fig. 3 is a sectional View of the loop-taker substantially on the line 33 of Fig. 2. Fig. 4 is a top plan view ofthe bracket supporting the adjustable stop-finger, for the bobbincarrier. Fig. 5 is a perspective view of the bobbin-carrier. Fig. 6 is a perspective view of the supporting post for the adjustable stop-finger. r

Referring to the drawings, the present improvement is shown as embodied in. a sewing machine having a cloth-plate 1, upon which is suitably secured a throat-plate 2 and the slide-plates 3 and 4, disposed at opposite sides of the throat-plate. The throatplate 2 is provided with the usual aperture 5 for a vertically reciprocatory needle 6, and with parallel slots, as 7, in-which operates a feed-dog v8 which may be actuated in any well-known manner to advancethe work. Opposed to the feed-dog is the usual pres'serfoot 9. d

Suitably secured. to the underside of the cloth-plate is a loop-taker bracket 10,, in which is fixed a bushing 11 constituting the journal for the" forward end of a horizontally disposed loop-taker actuatingshaft. 12 which rotates once only'for each complete reciprocation of the needle. Securedupon the end of the shaft 12 is a bevel-gear 13 in mesh with a similar gear 14 upon the vertically disposed loop-taker shaft 15. The shaft 15 is j'ournaled at its lower end in a bushing 16 and at its upper end in a bushing 17, both of which bushings are suitably fixed in vertically alined apertures invthe bracket 10. The gears 13 and Marc proportioned toimp-art two rotations 'to'the'shaft 15 for each rota-tion ofthe actuating shaft lDetachably secured with i-nthe tubular upper end of the shaft 15, for rotation there with, is the stub-shaft 18 of the inner looptaker body 19, which is cupped to receive a bobbin-carrier 20. The bobbin-carrier 20 is peripherally provided with an interrupted bearing-rib 21 journaled in a raceway constituted by a flange 22 at the upper edge of the inner body 19 and a flange 23 at the upper edge of the outer loop-taker body 24 secured upon and in peripheral contact with the inner body 19. It is to be understood that the inner body 19 and the outer body 24 together comprise the loop-taker proper, said outer body being provided with a loopseizing beak 25 and an oppositely directed loop-discharging spur 26.

The bobbin-carrier 20 is open at its top and is substantially bottomless, its base comprising a narrow, internal, bobbin-supporting flange 27. Extending outwardly and upwardly from the bobbin-carrier base is an auxiliary hook 28 disposed between the inner loop-taker body and the bobbin-carrier, said hook 28 acting to direct toward the bottom of the bobbin-carrier a limb of the needlethread loop initially caught by the nose 29 afforded by one end of the interrupted bearing-rib 21. Sustained upon the flange 27 within the bobbin-carrier is a bobbin 30, which may be of any suitable construction but contains a larger quantity of thread than has been usually employed in high speed machines of the present type.

The bobbin 30 is latched against accidental upward movement out of its carrier by a bobbin-retainer 31, which is secured upon the outer side of the bobbin-carrier below its bearing rib and has a spring-tongue 32 extending through an opening in the bobbin-carrier wall. The tongue 32 terminates at its free end in a lip positioned to normally overhang the outer edge of the bobbin. Because of the yielding character of the spring-tongue 32, the lip 33 may be readily deflected outwardly by the act of inserting or removing a bobbin.

Upon the cast-off side of the loop-taker, the bobbin-carrier 20 is formed with a flange 34 above the bearing-rib 21, said flange being provided in its inner side with a clearance recess 35 for the bobbin-latch. The flange 34 terminates at one end in a stop-shoulder 36 rising from an adjacent portion 37 of the bobbin-carrier upper edge which lies below the upper flange of the bobbin to provide for convenient access to said bobbin for removal thereof. Intermediate its ends, the flange 34 is intersected by a bobbin-thread slit 38 inclined downwardly in the direction of rotation of the loop-taker. At its end opposite to the stop-shoulder 36, the flange 34 is bent outwardly to provide a stop-shoulder 39, substantially equal in width to that of the bearing-rib 21.

Bridging the thread-slit 38 and suitably secured upon the outer side of the flange 34 is a bobbin-thread tension-spring 40 of which the upper side extends above said flange and therefore serves as a guard which prevents entrance of the needle-thread loop into the thread-slit 38. Above the bearing-rib 21 and beginning substantially from the nose 29 thereof is an inclined flange 41 which serves to initially direct a limb of the needle-thread loop over the upper side of the bobbin. This flange 41 terminates abruptly in a shoulder 42 which defines the other end of the depressed portion 37 of the bobbin carrier.

In order to restrain the bobbin-carrier 20 against rotation with the loop-taker, the throat-plate 2 is provided with a depending stop-lug 43 at the edge nearest the loop-taker axis, said stop-lug being spaced a substantial distance from a line extending transversely of the throat-plate through the needle-aperture thereof. This stop-lug 43 is adapted to be engaged by the bobbin-carrier stop-shoulder 39, thereby limiting rotation of the bobbin-carrier in one direction. The lug 43 and shoulder 39 are intermittently separated to provide clearance for the needle-thread loop, this being effected by oscillating the bobbin-carrier in a direction opposite to the direction of rotation of the loop-taker. To this end, the shoulder 42 of the bobbin-carrier is intermittently engaged by a vibratory opener-finger 44 secured by a screw 45 upon the upper end of a vertically disposed rock-shaft 46 suitably journaled in the bracket 10. Adjustably secured upon the lower end of the rock-shaft 46, by means of a screw 47, is an arm 48 having a ball-joint connection at its free end with a pitman 49 provided with a strap 50 embracing an eccentric 51 upon the actuating shaft 12.

The oscillation of the bobbin-carrier under the action of the opener-finger is limited by a stop-finger 52 positioned to engage the bobbin-carrier stop-shoulder 36. The stopfinger 52 is detachably secured by a screw 53 upon a head 54 at the upper end of a post 55 rising from a supporting bracket 56. Preferably, the post-head 54 and the upper end of the rock-shaft 46 are constructed in such a way as to insure returning the stopfinger 52 and the opener-finger 44 to a predetermined position upon their supporting members, after having been swung out of operative position to remove or insert the loop-taker and/or the bobbin-carrier. An expedient of this character is illustrated in Fig. 6 of the drawings in connection with the post 55 and is also employed with the rock-shaft 46, although not shown in detail in the drawings. It will be observed that the post-head 54 is formed with a flange 57 which is cut away upon diametrically opposite sides to provide alined recesses, as 58,

- bushing 17 in which the loop-taker shaft is journaled. This mounting of the bracket 56 provides for adjustment of the stopfinger 52 about the loop-taker axis, said bracket being secured in adjusted position tot-he bracket 10 by a screw 60 passing through an arcuate slot 61 in the bracket 56.

The novel features of the present construction disclosed but not claimed in this application form the subjects of separate applications filed by me on January 15, 1929, with Serial Nos. 332,610; 382,611; and 332,613.

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

1. In a sewing machine provided with a throat-plate having a needle aperture, a reciprocatory needle, a vertical-axis rotary loop-taker complemental to said needle in the formation of lock-stitches, a bobbin-carrier journaled in said loop-taker provided with spaced stop-shoulders upon the loop cast-off side of the path of rotation of the looptaker, a stop-lug depending fromthe throat-plate engaged by one stop-shoulder to prevent rotation of the bobbin-carrier with the loop-taker, and an adjustable stopfinger independent of said throat-plate engageable with the other'shoulder of the bobbin-carrier to limit rotation of said carrier in a direction opposite'to the direction of rotation of the loop-taker.

2. In a sewing machine provided with a throat-plate having a needle-aperture, a reciprocatory needle, a vertical-axis rotary loop-taker complemental to said needle inthe formation of lock-stitches, a bobbin-carrier journaled in said loop-taker rovided with three spaced shoulders upon t e upper edge thereof, a pair of said shoulders being disposed upon the loop cast-off side of the path of rotation of the loop-taker, a stop lug depending from said throat-plate engageable with one of said pair of shoulders to limit oscillation of the bobbin-carrier in one direction, a stop-finger separate from said throat-plate engageable with the other of said pair of shoulders to limit oscillation of the bobbin-carrier in the opposite direction, and an opener-finger engageable with the remaining shoulder to provide a free passage for the needle-thread loop past the throat-plate stop-lug.

3. In a sewing machine, a reciprocatory needle, a vertical-axis rotary loop-taker complemental to said needle in the formation of lock-stitches, a bobbin-carrier journaled in said loop-taker, a bobbin disposed within said bobbin-carrier, said bobbin-carrier having a flange on the'loop cast-off side of the loop-taker which extends above said bobbin and an adjacent portion disposed below the upper side er the bobbin terminating in a shoulder, an opener finger positioned to intermittently engagesaid shoulder to slightly oscillate the bobbin-carrier in a direction opposite to the direction of rotation of the loop-taker, spaced stop members engaging opposite ends-of said flange to limit the'extent of oscillation of the bobbin-carrier in opposite directions, and means for-adjustably securing one of said stop-members.

4. In a sewing machine, a reciprocatory needle, a vertical-axis rotary loop-taker compiemental to said needle in the formation of lock-stitches, a bobbin-carrier journaled in said loopaaker, means for restraining saidbobbin-carrier against rotation with the loop-taker, a bracket secured in fixed position for adjustment about the axis of rota-v tion of the loop-taker, and a stop-finger car- :ried by saidbracket in position to engage the bobbin carrierto limit its movement in a direction opposite to-the direction of rotation of the loop-taker. r V

5. In a sewing machine, a reciprocatory needle, a vertical-axis rotary loop-taker complemental to said needle in the formation of lock-stitches, a bobbin-carrier journaled. in said loop-taker, means'for restraining said bobbin-carrier against rotation with the loop-taker, a bracket supported for adjustment about. the axis of rotation of the looptaker, a vertically directed post carried by said bracket, and a stop-finger removably secured in a predetermined position upon said post to engage the bobbin-carrier to limit its movement in a direction opposite to the direction of rotation of the loop-taker.

6. In a sewing machine, a reciprocatory needle, a vertical-axis rotary loop-taker complemental to said needle in the formation of lock-stitches, a bobbin-carrier journaled in said loop-taker, a bobbin disposed within said bobbin-carrier, said bobbin-carrier having a flange on the loop cast-off side of the loop-taker which extends above said bobbin, a bobbin-thread tension-spring upon said flange, an opener-finger positioned to intermittently engage and slightly oscillate the bobbin-carrier in a direction opposite to the direction of rotation of the loop-taker, spaced stop-members engaging opposite ends of said flange to limit the extent of oscillation of the bobbin-carrier in opposite directions, and means for adjustably securing one of said stop-members.

7-. In a sewing machine provided with a throat-plate having a needle-aperture, a reciprocatory needle, a vertical-axis rotary flange having a threading slit vextending from the upper edge of the flange and inclined downwardly in the direction of rotation of the loop-taker, a bobbin-thread tension-spring secured upon said flange above the bearing-rib, said flange terminating in a stop-shoulder directing the bobbin- I thread upwardly from the tension spring and thence to the throat-plate needle-aperture in substantially the plane of the under side of said throat-plate, and means engaging said stop-shoulder to restrain the bobbilrcarrier against rotation with the loop-taker.

8. In a sewing machine having a throatplate provided with a needle-aperture, a reciprocatory needle, a vertical-axis rotary 1oop-taker coinplemental to said needle in the formation of lock-stitches, a bobbin-carrier journaled in said loop-taker having a pair of stop-shoulders, a stop-lug depending from said throat-plate spaced a substantial distance from a line extending transversely of the throat-plate through its needle-aperture said stop-lug being positioned to engage one of said bobbin-carrier stop-shoulders, and a stationary stop-element independent of the throat-plate positioned to engage the other of said stop-shoulders.

In testimony whereof I have signed my name to this specification.

\VILLIAM NELSON PARKES.

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