US415385A - Steam-engine valve - Google Patents

Description

(No Model.)

W. D. HAVEN.

STEAM ENGINE VALVE.

No. 415,385. Patented Nov. 19. 1889.

$117 .GQZW W f i liu @03566: J www UNITED STATES PATENT OFFICE.

VILSON D. HAVEN, OF TRENTON, NEIV JERSEY.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters Patent No. 415,385, dated November 19, 1889.

Application filed October 29, 1888. Serial No. 289,426. (No model.)

To all whom, it may concern.:

Be it known that I, WILSON D. HAVEN, a citizen of the United States, residing at Trenton, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in Steam-En gine Valves; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appert-ains to make and use the same.

My invention is directed to securing a greater accuracy of travel and greater durability in steam-engine valves; and to this end it consists in certain parts and combinations of parts hereinafter more particularly set forth.

My invention relates to a construction of supporting and guiding devices of the valvestem by which the valve is more accurately balanced, its bearing equalized, and vibration of the valve-stem and valve prevented.

My invention also relates to aconstruction of the valve-ports by which the weight of the valve is carried by the steam-pressure and relieved from the lower part of the valve-seat, thereby rendering the wear upon all parts of the circumference of the valve and case equal.

In order to make my invention more clearly understood, I have shown in the accompany-` ing drawings means for carrying the same into effect.

In said drawings, Figure l is a side view, partly in section, of so much of a steam-engine as is necessary to illustrate my'invention. Fig. 2 is a longitudinal section on a larger scale of a simple form of the outboardbearing for the valve stem. Fig. 3 is a crosssection on line 3 3 of Eig. 2. Fig. 4 is a crosssection on line 4 Je of Fig. l.

Referring to the drawings, A indicates the steam-engine cylinder; B, the valve-gear; C, the valve-stem; l), the valve-case or steamchest into which the live steam enters, asindicated by the arrows, and E the valve or valves mounted therein and secured to and actuated by the valve-stem C.

In the construction illustrated the valves are both oscillating and reciprocating; but such combined movements are not essential to obtaining all of the advantages of my '1nvention. The reciprocation of the valve regulates the exhaust by way of passages e, while the oscillation of the valve admits and cuts otf the steam in a well-known manner. Where the steam-admission ports of the valve are in the form of long slits or openings, I have found that an unequal wear and chattering of the valve in its seat takes place, due to the slight expansion of the hollow shell of the valve and the forcing out of the edges of the ports so made. I have obviated this diiiiculty to a considerable extent by forming the ports, as shown at a, with one or more cross-bridges a', adapted to maintain the proper cylindrical shape of the valve, prevent the forcing outward of the edges of the port, aud unequal wear and chattering in the valve-seat, resulting finally in a materially greater durability of these part-s.

At the end of the valve-case next to the valve-gear there is formed the usual stuiiingbox d for the passage of the valve-stem from the interior of said case to the valve-gear, which box forms a guide and support for one end of the stem and valve.

I have discovered by practical experiment that the peculiar movements of the valve and stem incident to the use of the special valvegear shown have a very objectionable and serious effect in cutting away the valve, steun and casing. I have, however, been able to obviate these serious results by combining with said valve-gearing what may be termed an outboard-bearing, which I will now describe, lirst referring, however, more partielllarly to the valve-gear above mentioned. This gear was rst described in Letters Patent No. 339,814, granted April I3, 1886, to F. Schumann and myself. It comprises, essentially, a rock-lever or equivalent moving part E, connected with the valve-stem for reciprocating it, a bell-crank lever G4, mounted upon a pivot g, carried by said part E4, a means-such as a governor-rod IIL-for oscillating the bellcrank lever relative to part E, and connections-such as the rod J4 and arm D4-between the other end of the bell-crank lever andthe valve-stem for oscillating the latter and the valve. 'lhis mechanism causes a screw-like movement of the valve, which is, however, unequal, being rapid or accelerated IOO at one point, resulting in a serious deterioration of the valve and case. This I have obviated, as above stated, by combining with said valve-gear and valve the following guiding and supporting means.4

Referring more particularly to Figs. 2 and 3, G indicates the head of the valve-case, de-

tachably secured in any suitable manner, as by the hooked bolts g. This head is provided with a cylindrical sleeve G', extending in a direction or directions parallel with the valvestem. g g' indicate a two-part bushing mounted in the sleeve G', and of such interior diameter as to properly tit the exterior Vof the valve-stem. The lateral edges of the two parts of the bushing do not touch, but are arranged to leave spaces, as shown in Fig. 3, to perinitot the lower halt' of the bushing-being from time to time adjusted upward to compensate for the wear which takes place between said lower half and the stem. This adjustment is provided for by the screws g2, which are tapped into the under side of the sleeve G' and bear against the lower half of the bushing g. g3 is a ring fitting in the inner end of thesleeve G', and having between it and said bushing a space g4 for the reception of a suitable packing. The sleeve and bushing above described are of such length as to permit the necessary reciprocation of the valve-stem, and as a finish and to shut out from view the moving end of said stem I provide the outer end of the bearing with a cap G2, which is adapted to be secured upon the sleeve G.

The bearing above described serves to balance the valve-stem by exposing to the outer air at this end of the valve-case an area equal to that of the cross-section of the valve-stem at the end next the valve-gear. To this end the cap G2 is provided with an opening g4, through which atmospheric pressure acts upon the end of the stem.

In order to further take off wear from the under side of the valve and stem, I have constructed the upper port or ports of the oscillating valve-shell of a slightly less area than that of the lower port or ports. Referring to Fig. 4, it will be seen that of the four steamports d shown in the construction there illus trated those at the upper side ofthe valve are the smaller. As this difference is in practice of small account, I have indicated the larger ports by the letters 'y y and the smaller ports by the letters 5c. The difference in area will be proportionate to the weight of thevalve and to the steam-pressure under which the engine is constructed and adjusted to run, and will of course vary in different engines. The result of this construction is that the weight of the valve and stem may be entirely sustained by the live-steam pressure and the friction and wear between the moving and stationary parts much diminished.

I-laving thus described my invention, what I claim is '1. In an engine, the combination, with the valve, valve-stem, and casing, of a moving partsuch as lever Ei-for reciprocating the valve, a bell-crank lever mounted upon a pivot carried by said part, means for oscillating the bell-crank lever relative to said moving part, connections between the bell-crank lever and the valve for oscillating thelatter, and an outboard-bearing situated at the end of the valve opposite said valve-gearing and supporting t-he valve-stem, substantially as set forth.

2. The combination, with the valve, the valve-stem, and the valvecasing provided with the stuffing-box and bearing d, of the outboard-bearing provided with the bushing g', divided horizontally, as described, and adjusting devices for raising the lower half of said bushing, substantially as set forth.-

3. The combination,` with the valve, the valvestem, and the valve-casing having the bearing d, of the outboard-bearing at the opposite end ot' said casing, consisting of a sleeve G', lianged and divided bushing g', and the cap G2, fitting and secured to the end of said sleeve and securing the flanges of said bushing between itself and Vsaid sleeve, substantially as set forth.

4. The combination, with the valve-casing having ports on its upper and under sides, of the hollow valve provided with corresponding ports adapted to simultaneously open and *admit steam tothe cylinder through both the upper and under ports, the upper of said valveports being of smaller area than the lower, substantially as set forth.

In testimony whereof I aflix my signature in the presence of two witnesses.

WILSON D. HAVEN. NVitnesseszl C. L. HARDING,

DAVIDT. IvINs'.

Ico

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