US42245A - Improvement in piston-packings - Google Patents

Description

UNITED STATES ATENT OFFICE.

IMPROVEMENT IN PISTON-PACKINGS.

Sperification forming part of Letters Patent No. 2,211 5, dated April 5, 1864.

To all lwhom -it may concern Beit known that I, JEROME 'WIIEELocK, ot' Worcester, in the county of Worcester, in the State of Massachusetts, have invented a new and useful Improvement in Steam-Pis t ms; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation ot' the same, r ference being had to the accompanying drawings, which make a part of this specilication, in which- Figure l is a longitudinal elevation showing the edge of the packing-rings. Fig. 2 is an end view showing a part of one ring. Fig. 3 is aeentral axial section of the same. Fig. 4 is an elevation ot' one ring separately, showing the inner surface of said ring.

Similar letters of reference indicate corresponding parts in the several figures.

My invention consistsin making a segmental packing ring of cast-iron, brass, or other metal, the segments being cast or made sepa rately, the ends so arranged and fitted as to break joints, for the purpose hereinafter more fully explained.

To enable others skilled in the art to make aid use lny invention, will proceed to describe its use and operation.

A represents a common pistonllead. B is a solid T-shaped ring fitting on the head A. C is a follower screwed onto A, which, together with the ring B and flange on piston-head A, form two separate annular grooves, a a. D E are segmental metallic packing-rings fitting loosely in the annular grooves a a. Each of these segments are formed separately with an -shaped cavity, c o', at one end, and correspondngtongue e c at the opposite end, which lit into each other for the purpose hereinafter more fully explained. g g are apertures through which the steam passes into the grooves ce a to the under side of the packingrings D E, causing them to expand, and by their expansion to make a steam-tight joint. Between the inner surface of the engine cylinder and the piston F is a hole through which the piston rod passes, and is attached to the pistonvhead in the usual manner.

The operation is as follows: The piston being made as described, the ring B :and segmental rings D E are turned to lit the enginecylinder. When steam is admitted. against the follower O, it also passes through the apertures g, causing' the ring E to expand, and, making a steam-tight joint, prevents the steam from escaping to the opposite side of the piston. The pistonv having completed its stroke, steam is admitted against the piston--head A, and passing through the apertures g', causing the ring D to expand, and alternately each ring is expanded and relieved according as steam is admitted and discharged. The iiange on the piston-head A and follower G are turned smaller than the rings, to allow steam to press against a portion of the outer surface of said rings, (see Fig. 2,) causing theirinner surface to t closely against the sides of thel ring B, thereby preventing the escape of steam from the under side ot' said rings. As the segmental rin gs wear, the inner circle is constantly becoming larger, thereby causing the segments to separate by causing the tongues e c to slide in the cavities c c, (see Fig. 4,) and thus breakingjoints and ettectuallypreventing all escape ot' steam.

The principal advantages of the ring herein described over those now in use are, first, a much stronger ring is obtained lthan when two rings are used for the same purpose second, the ring being cast in segments, much labor and material aresaved, it being neces-l sary to finish only the inner surface and outer edge.

Having thus described my invention, what l claim as new and of my invention herein, and desire to secure by Letters-Patent, is-

The segmental packingrings D E, constructed in the manner and for the purpose set forth and described.

Witnesses: JEROME WHEELOCK.

H. W. FENNER, WM. ADAMS.

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