US502874A - Joseph eli bertrand - Google Patents

Description

UNITED STATES i PATENT OFFICE.

JOSEPH ELI BERTRAND, OF BOSTON, ASSIGNOR OF ONE-HALF TO MELLEN BRAY, OF NEVTON, MASSACHUSETTS.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 502,874, 'dated August 8, 1893.

Application iiled March 15, 1893. Serial N0.466,127. (No model.)

-Which the following, taken in connection with the accompanying drawings, is a specification.

My invention relates to sewing machines and particularly to that class of such machines as is used for sewing leather and to the devices for drawing out the loop of .thread above the work and tightening the stitch, is an improvement upon the machine described in the Letters Patent No. 432,011, granted to me July 15, 1890, and it consists in certai-n novel features of construction, arrangement and'combi'nation of 'parts which will be readily understood by reference to the description of the accompanying drawings and toV the claim hereinafter contained, and in which my invention is clearly pointed out.

Figure l of the drawings is a vertical transverse section of a sewing machine, in general substantially like that described in said prior patent, the cutting plane being on an irregular line and showing the parts morepnearly relating to my presentinvention in elevation. Fig. 2 is a front elevation of the loop uneasuring and stitch tightening finger and its cari rier. Fig. 3 is a plan of said loop measuring and stitch tightening finger. Fig. 4 is a side elevation of the same. Fig. 5 is a diagram illustrating the position of the loop measuring and stitch tightening fingerwhen the loop of thread has been drawn out above the work and the needle is` in position to seize the upper thread, and Fig. 6 is a similar view showing the same parts when the stitch has been tightened and the lock of the stitch drawn into the work.

In the drawings A is the bed plate of the' head of the machine, B is one of the end frames, C the upper tie girt, D the cam or main operating shaft mounted in suitable bearings in ksaid frames B, and E is the cam for operating the loop measuring and stitch tightening finger.

F is one of the two stands secured to the front of the bed A, in bearings in the upper shuttle carrier.

I is the work support, cis the needle guide, d is the loop opener, e the presser-foot, J the presser-foot-har,f the thread tension wheel, g the ratchet wheel connected to said tension Wheel, h the pawl and K the paWl lever for locking said tension wheel, L the thread carrier for throwing the thread into engagement with the barb of the needle a', and M the take up lever. Y

So far 'the several parts except the cam E and the needle and awl are constructed and arranged substantially as shown and described in said prior patent before cited. In said prior patent the loop measuring finger was pivoted to a reciprocating cross-h ead fitted to and movable in a grooveformed in the bed and arranged to vibrate about its pivotal connection 'as it was moved toward and from the front of the machine, said looper nger serving only one purpose, that of measuring the length of loop of thread required for the needle to draw'throughY the work to form the loop below the work through which the shut- -tle was to pass, the stitch being drawn tight by the take-up lever. This arrangement Worked fairly Well but I have found by actual test, that, in order to .properly tighten the stitch and draw the lock of the stitch into the work so as to show a fair stitch on both sides of the work,.it is better to apply the power, to do this, to the thread at a point much nearer thew work than the end of the take up lever. To eect this desirable object is the aim of my present invention and to this end I construct, arrange, and operate the looper finger as Yshown in the accompanying drawings, in which N is the looper finger made in the form shown inFigs. 2, 3, and 4 and having mounted in its hook end the small grooved wheeler sheave vl thefgrooved 95 periphery of which engages the threadA to pull out the loop of thread above the work asl shown in Fig. 5.

The looper linger N is mounted in a socket in the cross-head O tted to and movable endwise in a dovetailed groove formed in the under side of the stand P bolted to, and pendent from, the tie girt C with its lower or grooved side oblique to a horizontal plane so that the finger N has a slight upward movement as it 1s moved toward the rear as shown in Fig. 1.

B is a stand bolted to the rear edge of the bed A and having pivoted to its upper end the lever Q to the slotted lower end of which is adjustably pivoted one end of the link R, the opposite end of which is pivoted to the cross-head as shown in Fig. 1.

The lever Q has mounted on a stud set therein a truck j, shown only in dotted lines in Fig. 1, which fits into, and is acted upon by, the path 7c of the cam E to move said crosshead and the looper-finger toward and from the rear of the machine.

The cam E is dilferent from the cam for operating the looper finger in my said prior patent in that besides the throw 7n for measuring the loop it is provided with the short outward and inward throws n and n between the lines 1 and 2 and 2 and 3 respectively the throw n serving to move the finger N backward a short distance, after the take-up lever has drawn up the slack of the lower loop, so as to tighten the stitch and draw up the lock of the stitch into the work, the sheave or truck z engaging the thread between the work and the thread carrier L and drawing it into the position shown in Fig. 6, this being done while the tension wheel f is locked by the pawl h and the take up lever M is held firmly,in the position shown in Fig. 1, by the cam for operating it, not shown in the drawings.

For information regarding parts of the machine not shown in the accompanying drawings reference may be had to the before cited prior patent.

The needle a and awl a2 are mounted in separate radius arms with their points in opposite directions as shown and described in another application of mine, filed September 17, 1892, Serial No. 446,207.

The operation of my invention will be readily understood from the foregoing without further description here.

A great advantage is obtained by imparting the additional short throw to the looper finger for drawing the lock of the threads into the work and tightening the stitch, and also by the employment of the sheave i on the hook end of the looper finger, by very much lessening the chang of the thread.

Vhat I claim as new, and desire to secure by Letters Patent of the United States, is-

In a sewing machine the combination with a work su pport and presser foot, a needle and awl constructed and arranged to be recipro cated about a common axis and a rotary shuttle, of a loop measuring and stitch tightening linger mounted in a reciprocating cross-head, a pivoted lever, a link connecting said crosshead to the movable end of said pivoted lever, and a cam provided with a path having two outward and two inward throws adapted to impart to said looper finger a long and short rearward and forward reciprocation.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 10th day of March, A. D. 1893.

JOSEPH ELI BERTRAND.

Witnesses:

N. C. LOMBARD, H. T. CROSBY.

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