US240201A - Charles h - Google Patents

Description

(NoModeL) C. H. THURSTON.

Sewing Machine. No. 240,20; Patented April 12,1881.

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NJEI'ERS. PNDTO-LITHOGRAPNER, WASHINGTON. lLC.

UNITED STATES ArENr FFICE.

CHARLES H. THURSTON, OF MARLBOROUGH, NEW HAMPSHIRE, ASSIGNOR TO THURSTON MANUFACTURING COMPANY.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 240,201, dated April 12, 1881. Application filed September 13,1880. (No model.)

To all whom it may concern Be it known that I, CHARLES H. THURs- TON, of Marlborough, county of Cheshire, State of New Hampshire, have invented an 5 Improvement in Sewing-Machines, of which the following description, in connection with the accompanying drawings, is a specification.

This invention in sewing-machines relates, chiefly, to improvements in mechanism foriml parting a variable motion to the shuttle.

In my improved machine the under thread is supplied from a shuttle held in a vibrating carrier connected with ahorizontal rocker shaft extended from end to to end of the machine under the cloth-plate, such devices being common. To this rocker-shaft I have added an arm, made as an open loop, and denominated by me as the looped arm. opening ofthis looped arm receives a stud provided with a loose block, the stud being connected with the lower end ofa link actuated by a crank on the upper rotating or needle-bar-operating shaft, the said link being joined with a radius-bar, so that the said link, as it is 2 5 raised and lowered by the crank, is moved laterally, to thereby cause the said stud and block at the lowerend of the link to approach toward and recede from the axis of the said rocker-shaft, it moving the said rocker-shaft c the fastest as it approaches its center in traveling within the looped arm, and vice versa. The feeding-bar, moved forward positively by an arm of a rocker-shaft, rests upon a lifting bar, which is raised positively by a roll on an 5 arm of the' shuttle-operating rock-shaft, the said roll elevating the lifting-bar and raising the toothed surface of the feeding-bar against the fabric or material being sewed, when it is to be engaged and fed forward. A suitable 4.0 spring retracts and lowers the feeding-bar at the proper time.

Figure 1 represents an under-side View of a sewing-machine containing my improvements; Fig. 2, a front view of the machine, the bear- 4 5 ing for the front end of the under rocker-shaft beingbroken away to show the feeding devices; Fig. 3, a Vertical section, taken at the rear of the machine, to illustrate clearly the upper rotating mainshaft and the intermediate conneotions between it and the shuttle and feedactuating rockershafts; Figs. 4, 5, 6, details of the shuttle-carrier, and spring-finger to retain the shuttle in place in the carrier, or permit it to be easily removed; Fig. 7, a detail of the looped arm; and Fig. 8 a detail of the feed-bar.

The cloth-plate A and the head B and frame 0, constituting part of the usual standard and overhanging arm, are and may be of usual construction, as may be the needlebar, D, needle 1), and 'presser-bar E and its foot.

The main or driven shaft (1, located in the usual overhanging arm, and rotated positively to actuate the needle-bar by a heart-cam, or

otherwise, not of my invention, has upon it a crank,b, and an eccentric, 0. (See Fig. 3.) The crank b is embraced by an ordinary two-part collar at the upper end of the link F, the latter having at its lower end a stud, d. The block and stud enter within the elongated slot e of the looped arm G, connected with the shuttle-carrier-operating rocker-shaft G by a screw, 6. This looped arm will preferably be composed of a piece of metal bent or forged into the form shown in Fig. 7, and screwed to the said shaft. The link F, between its ends, is loosely connected at c with one end of a radius-bar, H, pivoted at 0 upon a lag at the under side of the cloth-plate. This rockershaft G near its front end, has secured upon it the shuttle-carrying arm I, having at its upper end a surface, 2, upon which the shut-' tle rests as it is carried forward through the loop of needle-thread by the horns of the carrier in the usual manner. 8 Rotation of the crank b actuates the link f and causes its lower end to rise and fall, and the radius-bar, during such time, causes the crank-pin to be moved out away from and in toward the center of the said rocker-shaft G As the crank reaches its lowest position the shuttle reaches its backward position and almost stops, while the crank moves a little and turns the link F on the pivot 0 causing the block and stud to move toward the shaft G 5 along within the looped arm G, into the position shown in Fig. 3. Further rotation of the crank lifts the link F, and as the block and stud are then held nearest the center of the shaft G the shuttle-carrier will be moved to cause the shuttle (not shown) to quickly enter and pass through the loop of needle-thread. Just as the heel of the shuttle passes through the loop of needle-thread the block and stud commence to travel outward along the space in the looped arm, and the shuttle and shuttle-carrier remain at rest, while the needle clears the upper side of the fabric being sewed, and the feed takes place. The block and stud reach the outer end of the space in the said looped arm a little before the needle reaches its highest position. The block and stud, in their descent, commence to act within the looped arm next its outer end and start the shuttle-carrier backward slowly while the needle completes its upward motion, and as the crank b descends from near its highest to its lowest point the block and stud again gradually approach the center of the shaft G and the needle-bar and needle descend quickly, the needle reaching its lowest position just as the shuttle reaches its most backward position, and then the needle-bar rises slowly, while the shuttle is again moved forward rapidly, as before described.

The shuttle-carrier has a spring-finger, f, connected with a rod,f, to retain the finger in the position shown in Fig. 4. Instead of lifting this finger positively, I add to the carrier a cam-ledge, 3, that acts to raise and hold the springf as the latter is pushed aside from over the shuttle in the carrier.

7 The feeding-bar'g (shown separately in Fig. 8)-has a slot, 1 in which is entered the pin or screw g, upon which the feeding-bar slides,-

and by which it is supported at its rear end. This feeding-bar, near its forward end, has a smooth straight foot, 13, that rests upon the smooth straight crown or head 4 (see Fig. 2) of the feed-lifting lever it, having its fulcrum on the stud 9, before described, upon which the feeding-bar slides, and about which it also turns or vibrates as it is raised and lowered. The feed-bar has its slot packed at one end with leather, as at 5, to lessen noise when the feed-bar strikes the ping, and the said bar is also provided with a second piece of leather at 6, to strike against the feed-regulating stop i, which latter is shown as a sliding wedge attached to a rod, i screw-threaded at 7, and provided with a milled nut, W, the periphery of which is extended through a slot, 8, in the cloth-plate A, as seen in Fig. 3. This nut may be operated by the thumb or finger, and as the nut is held against longitudinal movement .the upper end of the feeding-bar.

it follows that the rod and wedge will be moved backward or forward, according to the direction in which the nut is turned. The length of stitch may be readily controlled by this operation. The feed-lifting lever is curved or recessed at its lower side, and bears upon a roller-stud, j, of an arm,j of the rocker-shaft G and as the said shaft is rotated the roller-stud acts to lift or elevate the lifting-lever to raise the feeding-bar, so that its teeth will engage the fabric and retain the said bar lifted while it is being moved forward the length of the stitch,

' when the lifting-bar is permitted to fall, and

with it the feeding-bar,which is quicklythrow down and back by the spring 2'.

The feeding-bar is moved forward positively by the arm 70 at the front end of the feed-operating rock-shaft W, the said arm being provided at its upper end with a stud or roller,- as shown in Fig. 2, located within a notch at This rockshaft 762 has an arm, 10, with which is pivoted the lower end of a link, m, that at its upper end is made to embrace the eccentric c on the main driven shaft of the machine.

The take-up is of usual construction and operation.

The shafts G k are sustained upon pointed screws.

Instead of crank b, I might employ an eccentrie.

I claim- 1. In a sewing-machine, the main rotating shaft at, its crank, the link, its stud, and the radius-bar, combined with the shuttle-carrieroperating rock-shaft, its looped arm, and the shuttle-carrier, the said stud, when operating the said shuttle-carrier, moving away from and in toward the said shaft, substantially as and for the purpose described.

2. The shuttle-carrier provided with a camledge, 3, combined with the shuttle-holding spring-fingerf, adapted to be raised by the said cam as the finger is turned aside from above the shuttle in the carrier, substantially as described.

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

CHARLES H. THURSTON.

Witnesses:

G. W. GREGORY, N. E. O. WHITNEY.

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