US359707A - William beowist - Google Patents

Description

(No Model.)

W. BROWN.

VALVE EOE STEAM ENGINES.

Paten ed Mar. 22, 1887.

Unire B'rnfrns Parent @lirica WILLIAM BROlV-N, F JERSEY CITY, NEV JERSEY, AND JHN MCVILLIAMS, OF SAME ASSIGNOR TO HIMSELF PLACE.

VALVE FOR STEAM-aucunes.

SPECIFICATION forming part of Letters Patent No. 359,707, dated IJarch 22, 1887.

(No model.)

To @ZZ whom it may concern:

Beit known that I, WILLIAM BROWN, of Jersey City, in the county of Hudson and State of New Jersey, have invented a. new and useful Improvement in `Valves for Steam-Engines, ot' which the following isaspecification.

My invention relates to engines having piston-valves which are hollow, or have extending` from end to end a straight eylindric bore,

io in which operates a reciprocating cut-oft valve composed of two piston-heads adjustable toward and from each other bya rod having reversed serew-threads; and the invention consists in novel combinations of parts, hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l is a sectional elevation of the cylinders, valvechests, and valves of a compound engine einbodying iny invention, and in which the two 2o cylinders are arranged in line with the highpressure or sinallcr cylinder above the lowpressure or larger cylinder. Fig. 2 is a vertical section, upon a larger scale, of the main piston-valve and cut-ofi' valve for the highpressure cylinder; and Fig. 3 is a horizontal section upon the plane oi' the dotted line a: x,

Fig. 1.

Similar letters of reference designate corresponding parts in the several figures. l A B designate the high and low pressure cylindcrs,which are here represented as arranged one above another, and supported one from the other by a support, C, suoli as is shown and described in my United States Letters Patent No. StL-54:9, dated May 11, i886. To the two cylinders A B are fitted pistons D E, which are secured upon a coniinon pistonrod, D.

A B designate the two valvechests of the 4o engine, one for each cylinder A B, and which, as here represented, are formed in the saine integral castings with the cylinders, and are arranged with their axes approximately parallel with or extending in the saine direction as the axes of the cylinders. The valvechests A B are cylindric in their horizontal section, and steam may be supplied to the valve-chest A of the high-pressure cylinder through a pipe or opening, A2, communicating with the sido thereof, and the steam exhausted from the high-pressure cylinder may pass by a pipe, B2, to the side of the valvechest B ot' thc low-pressure cylinder.

The high-pressure cylinder is provided with ports c, which serve alternately for the passage of steam from the valve-chest A to the cylin der A and the exhaust of steain from the cylinder A and through the exhaust-port c to the main exhaust-cavity A5. Frein this niain exhaust-cavity leads the pipe Bf, whereby steani exhausted from the high-pressure cylinder is delivered to the valve-chest B of the low-pressure cylinder.

F designates the main piston-valve, which is fitted to the cylindric valve-chest A', and controls the admission of steam to the main cylinder A.- It may be provided with suitable ring-packing, f, at opposite ends, vwhich packing may be held in place by ring-shaped followers F, and in these followers are formed cut-olf ports or passages f The main valve F also has an annular groove or portion of rcduced diaineteiyj, which, when the valve is working in the valve chest, forms an annular belt or passage around it, and this annular belt or passage f serves to control the coniinunicatiou of the ports c alternately with the exhaust-ports c'.

The low-pressure cylinder is provided with ports or passages b, which serve alternately ,for the passage of steam from the valve-chest B to the cylinder B and the exhaust of steam from said cylinder to the niain exhaust port or cavity b, from which thesteam passes to the condenser. In the valve-chest B is arranged a hollow piston-valve, H, substantially like the valve F, before described, which may be provided with suitable ring-packing, 7L, held in position. by follower-rings H. This valve H also has a portion of reduced diameter, h', forming an annular belt or passage surrounding the valve and serving to control the alternate communication of the supply-ports b with the exhaust-port b. A

I designates the main-valve rod, which works through suitable stuffing-boxes in the heads of the two valve-chests A B', and which is centrally connected with both the main valves F and H. As here represented, the niain valve H has bridges extending across it,

IOO

in which the valve-rod I has a bearing, and is secured in proper position on the rod by nuts t', applied to' the rod above and below said valve I-I. The upper end of the stem I is connected by nuts i with a bridge or yoke formed upon the ring-shaped follower F' at the lower end of the main valve F, as best shown in Fig. 2. rIhe portions of the rod which are connected respectively with the valves II and F are preferably connected by a screw-threaded coupling-nut, I', arranged between the valve-chests A B', and whereby provision is afforded for properly fixing the length of rod between the two valves F and II.

The inain valve has a cylindric bore open from end to end, and from which the cut-ofi" ports or openingsf' lead to the exterior of the valve, and within such cylindric bore ofthe main valve F is Fitted aout-oft' valve composed of two piston-heads, G, which are secured upon a rod, G', having right and let't hand l screw-threads s, which iit suitable nuts pro vided in the two piston-heads G, constituting the cut-oli' valve. The two piston-heads G may be connected by a rod, G2, as best shown in Fig. 2, so that they are prevented from turning one relatively to the other, and when the valve-rod G' is turned the piston-heads will be advanced toward each other or moved from each other in order to vary the point of cut-off in a well-understood manner. IVhen the stem G' is turned in a direction to move the piston-heads away from each other, the cut-oft' valve will be lengthened, and thesteam will be cut ott from the 'cylinder A earlier in the stroke of the piston D. On the contrary, when the valve-rod G' is turned in the direction to bring the piston-heads nearer together, the cutoff valve will be shortened, and steam will be admitted to the cylinder A during a greater portion of each stroke. The pistonheads constituting the cut-oli' valve are provided with openings s' through them, as best shown in Fig. 2, in order to enable steam to flow freely from one end to the other of the valve-chest A.

For the purpose of turning the valve-rod G to vary the point of cut-oli?. I have represented the upper end of the rod G' as provided with a gear-wheel, j, which is supported in a bearing, J, and through which the upper end portion of the valve-rod G may slide, said rod bcing provided with a grooveaud-feather connection with the gcar-wheelj. W'ith the wheel j engages a wheel, 11", on a crossshaft, J', and

this crossshaft may be turned through bevelwheels j* by means of an upright shaft, J2, which may be provided at the lower end with a hand-wheel, js. turned, motion. is communicated through the gearing described to the valve-rod G', and it may thus be turned in one or other direction, as may be desired.

The valve-rod G is operated from an arm, K, upon an upright bar or rod, K', which may be reciprocated verticall yin suitable bearings, lampen the valve-chests A B. The valverod I and the'rod K', from which the valve-rod G' is operated, may be worked by eccentrics in the usual way common to marine engines, and which I have not shown, as they form no part of my invention. rlhe valve-rod I .may be operated by means o f two eceentrics and the ordinary link-motion for reversing, and the rod K' and valve-rod G may be operated by a single eccentric.

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

1. The combination, with an engine-eylinder and the cylindrie valve-chest A', constructed with supply and exhaust ports, of the main piston-valve F, having a cylindric bore extending from end to end, and in which are cut-off port-s, the cut-off valve composed of the piston-heads G G, having openings in them and fitting the bore ofthe main valve, and the valve-rods I and G', working through opposite ends of the chest and connected one with the main valve F and the other with the piston-heads G G for reciprocating the said valves, substantially as herein described.

2. The combination, with the cylinder and cylindric valve-chest of a steam-engine, of a hollow piston-valve having a cylindric bore extending from end'to end and provided` at the ends with rthe followers F', having formed in them cut-off ports f', audthecut-ott' valve consisting of piston-heads G, working within the bore of the main-valve, substantially as herein described.

3. The combination, with the cylinder and cylindric valve-chest of a steam-engine, of a hollow piston -valve, F, having a cylindric bore, and the rod I, for working it, extending through one end ofthe chest, the cut-oft' valve consisting of piston-heads fitting the bore of the main valve, and the rod G', for operating the cnt-od' valve, provided with right and left hand screw-threads, to which the piston-heads are ttcd, and working through the opposite end of the chest and receiving within it the valve-rod I, substantially as herein described.

W. BROW'N.

IVitnesses:

FREDK. HAYNEs, HENRY J. MCBRIDE.

When the hand-wheel js is IOO IlU

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