US138828A - Improvement in rotary valves for steam-engines - Google Patents

Description

G. WESTINGHUUSE, Jr.

Rotary-Valves for Steam-Engines.

NO. 138,828. i Patented Mayl3,l873.

UNITED STATES PATENT EEICE.

GEORGE WESTINGHOUSE, JR., OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT INROTARV VALVES FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. l 38,828, dated May 13, 1873; application filedv February 15, 1873.

To all whom it may concern:

Beit known that I, GEORGE WEsTINeHoUsE, Jr., of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented ay new and useful Improvement in Rotary Valves for Steam-Engines; and I do hereby declare the following to be a full, clear, and exact description thereof.

My present invention relates to improvements in the class of steam-engines described in patents' granted to me August 30, 1870, No. 106,899; June 6, 1871, No. 115,668; and October 8, 187 2, No. 131,985 and more particularly to the devices by means of which the auxiliary or reversing engine therein shown is operated.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and mode of operation, referring for that purpose to the accompanydrawing making a part of this specification, in which- Figure 1 is a vertical sectional view through the axial line of the reversing-cylinder, through the valve-chamber at right angles to the axial line of the valve, and down through the base block, which rests on or constitutes the upper v head of the main cylinder. Fig. 2 is a sectional view through w :v of Fig. 1. Fig. 3 is a detached view of the valve devices of Figs. 1 and 2, but drawn out on the valve-stem so as to give a separate view-of each; `and Figs. 4 and 5 are detached views of parts, hereinafter described.

Like letters of reference indicate like partsk in each.

r[he auxiliary or reversing cylinder B, the valve-box B1, and base block B2 are substantially of the. same construction, relative arrangement, and operation as in the patents above named, as also are the piston l) with its stem and eye D', and the valve-stem f, knob j 2, and shoulder f1. The valve u is also made as in patent No. 131,985, except that the steamport s is made in its periphery, two exhaustrecesses, u c, on opposite sides, with suitable exhaust-ports, take the place of the exhaust` groove there shown, and an oil-groove, s', is made along lengthwise of the lower periphery for convenience in keeping the valve well oiled. rlhe valve-seat m is of the same construction and operation as in the patent last named.

The other steam-ports are also the same, ex-

cept that an exhaust-port, c', leads from one recess t to the opposite exhaust -port w, for reasons which are apparent on examination of the drawing.

In` the present improvement the valve-stem g, on which is arranged the valve u and the rocking block g', has a collar, e, near one end, in such position that the end of the valve a will bear against it; then the steam that leaks past the valve and that end of the stem will so far counterbalance the steam pressure on the other end ofthe valve n that the latter while workin g closely on its seat will not wedge in so tightly as to occasion serious loss by excessive friction. The opposite end of the stem g passes through a stuffing-nut in the valvebox Bl so as to be capable of a free end play, so far as may be necessary to relieve the valve of excessive friction. The rocking block g has a sleeve, t', which passes through the valve u, and dowel-pins t1 t2, by which it is connected with the valve. On one of these pins, il, I slip the slotted eye h, which is made in the upper end of the stem f. This eye .is long enough to allow the pin il to play back and forth so far as may be necessary in. its rotary motion. By means of this stem and crank motion the valve is rotated back and forth so as to bring the steam-port s alternately to the ports c c', which ports communicate by the ports o o with the opposite ends of the cylinder B; also, by the same motion the recesses@ o are alternately brought into communication with the exhaustports u u', and z z', and o t' so as to carry off the exhaust steam to a common exhaust-port, w. Steam is admited into the chamber b by any suitable port, a.

Ihave found in practice that where the steam is allowed to press on the upper end of the enlarged part f1 of the stem f such pressure was sometimes suicient to force the stem down before the main piston in its downward stroke strikes the knob f2. To remedy this defect I make the stem f above the shoulder f1, as at r1, of less size-say, about the size required in the main part f 1 of the stem-and surround this reduced part r1 with a bush, r, which may conveniently be made in two partsand which is supported against the downwardy pressure of the stem by resting on a shoulder, r2, of the base B2. In this way I reduce the area of stem subject to effective downward pressure to suoh extent that the valve a is not liable to be reversed thereby.

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

1. The eonieal valve n subject to steam pressure at its larger end, in combination with the stem g, on which it rotates, and the collar e on said stein with a bea-ring against the smaller end of the valve, the opposite end of the stem g passing through a stuffing-nut so as to have a free end play, substantially as set forth.

2. The stein f having,` a shoulder, f1, and a reduced part, r1, above, in combination with a hand.

GEORGE WESTINGHOUSE, JR.

Witnesses:

A. S. NrouoLsoN, G. H. CHRISTY.

Images