US254603A - Daniel w - Google Patents

Description

(No Model.)

I D. W. BROWN.

- TENSION DEVICE EOE SEWING MACHINES. No. 254,603. Patented Mar.-7,1882

WITNESSES. eNvEN TOR.

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DANIEL W. BROWN, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO JOHN B. ANTHONY, OF SAME PLACE.

TENSION DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 254,603, dated March '7, 1882,

l Application filed May 2, 1881. (No model.)

To all whom it may concern Be it known that I, DANIEL W. BROWN, of the city and county of Providence and State of Rhode Island,have invented a new and useful Improvement in Sewing-Machines; and I do hereby declare that the following specification, taken in connection with the accompanyingdrawings, forming a part ofthe same, is a full, clear, and exact description thereof.

My improvement relates to a tension device of novel construction attached to the needlebar, whereby the needle-thread above the eye of the needle is lifted bodily with the needle, thus assuring the formation of a proper loop :for the passage of the shuttle,snbstantially as heretofore,with tension devices variously constructed,but operating upon the same general principle.

My invention consists in a needle-bar tenzo sion device embodied within the head of the needle-clamp bolt, which is vertically recessed for the reception of thread extending downward to the needle, and is laterally recessed for the reception of a lateral tension pin or bar, z 5 which lies across' the vertical recess, so that the thread in line with the needle-eye and the usual thread-eyes above the needle may also pass to the rearof and be frictionally engaged by said bar or pin and by a neighboring surface ofthe bolt-head. With this construction a desirable intermediate-tension device is obtained at low cost, and no portion thereof unduly projects beyond the needle-bar, and it is therefore not liable to strike or cha-fe the hands 3 5 of the operator.

Referring to the drawings, Figures 1, 2, and 3 represent, in perspective, vertical section, and side view,respectively,a portion of a needle-bar, A, a needle, B, and a clamp-bolt, O, 4o the head of which is constructed to produce the desired tension or friction upon the thread. As shown in these views, the bolt-head is provided with a vertical groove, c, a horizontal groove, c', and a pin,d, which extends through the latter groove. The thread passes behind the pin d and in engagement with its rear sur face, then down through the groove cto the needle-eye, as shown in Fig.2. It will be seen that the needle-thread isreadily passed behind the thread-pin from its outer end, and that 5o when in that position, as the needle rises, the usual tension on the thread above the clampbolt causes the thread to be frictionally engaged not only by the rear surface of the pin y d, but also by the bolt-head at the edge presented at the upper end of the vertical recess c, thus making a short turn or angle in the line of the thread, which enables the thread to be lifted bodily with the needle as it rises. The size of the clamp-bolt head need be but 6o little, if any, larger than heretofore to admit of the necessary recessing thereof; and it will be seen that the friction-pin is well housed within the head, and that there is no undue projection from the needle-bar to provide for the attainment of the ends sought. Heretofore intermediate or needle-bar tension devices for the same purpose have sometimes been separately constructed and applied to the needle-bar, and sometimes theclamping-bolthasbeen provided 7o with a spirally-grooved stud or pin projecting outward therefrom, and around which the thread is wrapped, and in other cases a projecting clamping tension device has been separately constructed and applied to the head of 'the needle-clamping screw or bolt.

In Fig. 3 I have shown the usual brd-plate, E e, the fabric F,`and the needle at its lowest position, it being understood that the friction of the thread with the pin and the bolt-head will be sufcient tc cause the thread to be lifted bodily bythe needle,instead of permitting the fabric to hold the thread down when the needle rises.

What I claim as my invention, and desire to secure by Letters Patent, is

'lho intermediate or needle-bar tension device, consisting ot' the needle-clamp bolt, having a head grooved or recessed vertically and laterally,in combination withalateral threadpin occupying said lateral recess in said head, substantially as described.

DANIEL W. BROWN. Witnesses:

W. H. THURs'roN, I. KNIGHT.

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