US1299402A - Looper mechanism for sewing-machines. - Google Patents

Description

A. H. DE VOE.

LOOPER MECHANISM FOR SEWING MACHINES.

APPLICATION FILED DEC. 1. 1916.

1,299,402. Patnted Apr. 1,1919.

WITNESS: INVENTOR TORNEY TED s rn'rns rn'rnn'r orricn.

ALBERT H. DE VOE, OF WES'ITIELD, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

LOO PER MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Application filed December 1, 1916, Serial 'No. 134,254.

of New Jersey, have invented certain new and useful Improvements in Looper Mechanisms for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to asewing machine of the class employing a thread-carrying looper which cooperates with a needle in making a double chain-stitch.

To facilitate the threading up of a threadcarrying looper it is convenient to have means of some sort affording access to the eyes therein. A device which afi'ords access to loopers is shown in my prior Patent No. 1,256,880, issued February 19-, 1918. In said patent the thread-carrying loopers were withdrawn from their rearmost retracted position to a position nearer the operator and spaced farther from the throat-plate. The finger-lever at the end of the machine for effecting this withdrawal of the looper was locked against movement excepting when the looper was in its rearmost retracted position by means of a detent-pin engageable with a recess in a disk fast on the mainshaft.

In said device it was necessary to turn the main-shaft to a certain position in a stitching cycle and by constantly pulling upon the finger-lever to feel for the recess in the disk on the main-shaft in which the detent-pin could be forced and held by movement of.

improve the above mentioned construction bv facilitating the finding of the position in which the pin and recess register, while retaining substantially all of the advantages of the old construction. This has been accomplished by mounting the segmental plate of the old construction for bodily movement in the direction of the axis of the detent-pin. V

Briefly the construction may be described as comprising a fulcrum-shaft eccentric of bearing bosses journaled in the frame of the machine to one of which is secured a fingerlever carrying a segmental-plate having in one face a pocket adapted to permit .a detentpin under the thrust of a coiled spring being held in a position clear of a recess in a disk on the main-shaft of'the machine, said segmental plate having a pin projecting from its other face which has a limited sliding movement in a boss carried by the lever and pocketing a-spring of greater strength than-the spring about the detent-pin, thus urging the segmental plate in a direction opposite to that in which the detent-pin is urged by its coiled spring.

The invention also consists in further de- Patented Apr. 1, 1919. I

tails of construction that will appear from the following description of the embodiment of the invention illustrated in the accompanying drawings, in which Figures-1 and 2 are perspective views of the device, respectively, in working relation and in detail partly in section.

The invention is applicable to either a single ormultiple-needle stitching mechanism. It is shown applied to a multipleneedle machine and excepting the segmental plate is the same in its essential details of construction as that found in my previously mentioned patent. Briefly needles 1 cooperate with loopers 2 actuated. by an inclined crank 3 on the main-shaft 4 to which suitable thrust flanges or disks 5 and 6 are fixedly connected at opposite ends of the crank. In the left-hand disk 5 near its periphery a recess 7 is provided for a purpose to be described later. Embracing the inclined crank 3 is a strap 8 at one end of a -pitman 9 whose other end is connected by a at the rear ends thereof, are given endwise position, the boss 13-of the fulcrum-shaft 12 is rotated by a finger-lever 20 secured thereto by a set-screw 21 in the hub 22of the lever. Shifting the lever'2O from a horizontal to a vertical position results in moving the fulcrum shaft 12 about the axis of boss 13 through an angle of'approximately 90 thereby lowering and retracting the loopers from their normal cyclical paths of movement. In the inner face of a segmental plate 23 carried by the lever is provided a pocket 24 adapted to permit a detent pin 25 under the thrust of a coiled spring 26 to be held in a position clear of the recess 7 in the disk 5 integral or fast on the main-shaft of the machine, when'the finger-lever is in substantially a horizontal position. Projecting from the outer face of the segmental plate .is a pin 27 which slides in a boss 28 integral with the finger-lever, said pin having a fiat head 29 which is adapted to limit the inward movement of the segmental plate away from its seat 30 on the finger-lever. In the boss 28 is pocketed a spring 31 of greater strength than the spring 26 coiled about the detent-pin 25 that urges the segmental plate in a direction opposite to that in Which the detent pin is urged by its coiled spring. The

length of the slide-pin 27 is such that when the finger-lever is in a horizontal position the spring 31 in the boss cannot move the segmental plate a sufficient distance in overcoming the spring coiled about the detent pin which is at this time seated in the pocket 24 to move the detent-pin into the disk-recess 7 should it happen to be in register with the pin. But when the finger-lever has been moved from a horizontal or normal position throwing the end of the detent-pin out of the pocket 24 the movement of the segmental plate under the action of the spring 31 in the boss is suflicient to forcethe end of the pin into therecess in the disk when said recess is brought into register with the pin by turning the main-shaft 4.

In operation the main-shaft is first turned to a position in which the loopers are near their retracted position when the detent pin and the recess in the disk of the main-shaft will be somewhere near a registering position, the finger-lever is thrown out of its normal horizontal position, and finally the main-shaft is manipulated until the detent pin snaps into locking relation with the disk on the main-shaft under the dominating action ofthe relatively strong spring carried by the boss integral with the finger-lever. To unlock the main-shaft the finger-lever'is merely thrown to a horizontal position when I the detent-pin snaps back into the socket of the segmental plate out of the recess in the disk on the main-shaft. It will thus be seen that the old construction of the previously mentioned patent has been improved by enabling the operator to readily find the position of the machine in which it is locked and in which the loopers may be most readily threaded.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, in combination, a reciprocating needle, a looper, actuating means for imparting operative movements to said needle and looper, means whereby saidlooper may be shifted from normal operative position .to a position favoring easy threading thereof and operable during at least a considerable part of a stitch-forming cycle, and means acting to lock said actuating means against movement at a predetermined period in a stitch-forming cycle. 2. In a sewing machine, in combination, a reciprocating needle, a looper, actuating means for imparting operative movements to said needle and looper, means whereby said looper may be shifted from normal operative position to a position favoring easy threading thereof, means acting to lock said actuating means against movement at a predetermined period in stitching cycle and means permitting the shifting of the looper from its normal path at a plurality of periods in a stitching cycle. v

3. In a sewing machine comprising, in combination, a work-support, a reciprocating needle, a looper, actuating means for imparting cyclical operative movements to sald needle and looper, means for locking said actuating means operative only at a given time during the cycle of operation, and means for shifting said looper to an abnormal position at any time during a cycle of'operation.

4. In a sewing machine, in combination, a main-shaft,a reciprocating needle, a movable looper cooperating with said needle, a looper-support, actuating connections between said main-shaft and said looper-support, means whereby said looper-support may be moved from normal to abnormal position, shiftable means for so moving said looper-support, connections between said shiftable means and said main-shaft for locking the latter against rotation when said looper is in easy threading position and including means actuating the locking connections to prevent operation of the machine when the main-shaft arrives at a predetermined position.

5. In a sewing machine, in combination with stitch-forming mechanism comprising a needle, looper and actuating means therewhen the looper has been moved from its normal path.

6. A sewing machine looper mechanism comprising .a looper, a carrier therefor, a

' supporting fulcrum upon which said carrier is adapted to perform rocking movements, an actuating shaft and a rotary actuating element thereon for said looper, an

operative connection between said element and said earner, and meansoperative independent'ly of said actuating shaft for shifting said supporting fulcrum toward and from said actuating element at any tim during a stitching cycle.

7. A sewing mach'ne looper mechanism comprising a looper, a carrier therefor, a

supporting fulcrum upon which said carrier is adapted to perform rocking movements, a rotary actuating element for said looper,

' said element and the said carrier, shifting means operative during several degrees of a stitching cycle for retracting and returning said supporting fulcrum from and into normal operative relationwith said actuating element,- and means for locking said acplate lever.

an operative connection between tuating element against turning while the fulcrum is out of normal relation therewith.

9. In a sewing machine, in combination with stitch-forming mechanism comprising a needle and looper, actuating means for said looper, means for moving said looper from its normal, path including a lever, a plate mounted movably on said lever, means operated through said plate for locking said actuating means against mo'vement, means for moving said plate upon said lever, and means for limiting the-movement upon the lever of said plate. v In testimony whereof, I' have signed my name tothis specification.

ALBERT H. DE VOE.

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