US359420A - Tension device for sewing-machines - Google Patents

Description

(No Model.) B. O. BEDELL.

TENS ION DEVICE FOR SEWING MACHINES- 7 No. 359,420. I Patented Mar. 15, 1887.

N. pnzns, Photo-Lithographer, wmin m n a UNIT D STATES PA'rnNr UFFICE.

BYRON G. BEDELL, OF PORT HURON, MICHIGAN.

TENSION DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No.359,420, dated March 15, 1887.

Application filed July 1, 1886. Serial No. 206,788. (No model.)

To all whom it may concern:

Be it known that I, BYRON O. BEDELL, of Port Huron, in the county of St. Clair and State of Michigan, have invented new and useful Improvements in Attachments to Sewing-llIachines; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to certain new and useful improvements in attachments to sewing-maehines.

As my invention is especially applicable to that class of machines wherein the tension of the upper thread is controlled and regulated by the compression of the thread between two disks upon the machine-head, I show and describe my improvement in connection therewith.

It is a well-known fact that after having run up a seam and it is desired to remove the work the presser-foot has to be raised and a slack given to the thread by pulling upon it before removing the work; otherwise in pulling the work out with the tension on the thread the needle is often bent and has its point hooked by striking against the presser-foot.

The object of my invention is to construct a device that will, immediately upon raising the presser-foot, release the tension upon the thread, so that the work can readily be removed without bringing any strain upon the needle. v

To this end my invention consists in the peculiar construction and arrangement of the tension device, adapted to be operated by the lever of the presser-foot, all as more fully hereinafter described.

Figure l is a perspective view of the head of a sewing-machine provided with my improved tension device. Fig. 2 is a cross-section on the line 00 ac, Fig. 1. Fig. 3 is avertical section through a portion of the head, showing the lever of presser-footin two posi-- tions. Fig. 4: is a detail perspective of the tension device.

In the'accompanying drawings, which form a part of this specification, A represents a sewing-machinehead, B its presser-foot, and O the needle'bar. The resser-foot is raised by means of the cam-lever D, these parts being arranged substantially alike in the various classes of machines now manufactured.

E is a stud tapped into the bottom of an enlarged recess, a, in the head, and around the stud within the recessis placed a coil-spring, F. size, as shown, and threaded for a portion of its length. Over this end of the stud are slipped the two tension-disksG G, then a washer, H, and coil-spring I, the whole being retained in place by the nut J. Thus far I have described one of the tension devices now in use, and the action or operation of which is well known.

My particular improvement consists in boring a hole through the longitudinal center of the stud E, which communicates with the slot bin the outer end of the stud. Across the central opening gin the washer H, I form a bridge, K, which latter, when the washer is in place, slips into the slot 2) and moves freely under the action of the tension-springs.

L is a headed pin, which I insert through the central bore of the stud, its inner end coming in contact with the bridge of the washer, while its headed end projects into the line of travel of the leverD when such lever is raised or depressed to operate the prcsser-bar.

Referring to Fig. 2, it will be observed that the inner end of the lever D is upon one face beveled off, as at c, and the lever is shown in place as in the position in dotted lines, Fig. 3, after having raised the presser-foot. In this The outer end of this stud is decreased in position the lever D, coming in contact with the I head of the pin L, pushes the latter forward, and it in turn, pushing the washer away from the disk G, necessarily releases such disk from the action of the spring I, and hence the frictional tension on the thread between the disks is destroyed, and the thread is free to be drawn through between them and through the needle without exerting any strain upon the latter. When the lever D is thrown down so as to lower the presser-bar, the head of the pin L slides down the beveled face of such lever, thus leaving-the spring I free to perform its functions in re-establishing the tension upon the thread.

What I claim as my invention is slot, 1), spring F around said stud within said recess, disks G G on said stud, the washer H, provided with bridge K, rcmovably engaging the slot 1) of the stud, spring I and nut J on said stud, and the headed pin L, passed through said stud and engaging said bridge, substantially as described, andfor the purposes specificd.

BY ON C. BEDELL. \Vitnesses:

H. S. SPRAGUE, CHAS. 'lnUmuN,

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