US510665A - Reversing-valve for compound engines - Google Patents

Description

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G. E. WRGHT.

REV'ERSING VALVE EOE GOMPOUND ENGINES. N0. 510,665.

- Patented Deo. 12,;1893.

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G. E. WRIGHT.l V EEVEESING VALVE EOE GOMPOENE ENGINES.

' 110.510,665. P Etenwd 1190.112, 1893.

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G. E.- WRIGHT.- l REVERSING VALVE FOR GOMPOUND ENGINES. No. 510,665. l Patented Deo. 12, 1893.

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UNITED STATES PATENT Gwinn.

GEORGE E. WRIGHT, O'F NEWARK, NEW JERSEY.

REVERSlNG-VALVE FOR COMPOUND ENGINES..

SPECIFICATION forming part of Letters Patent N0. 510,665, dated December 12, 1893.

Application tiled October 29, 18,92. Serial No. 450,338. (No model.)

To all whom it may concern:

Be it known that I, GEORGE E. WRIGHT, a citizen of the United States, residing at Newark, Essex county, New Jersey, have invented certain new and useful Improvements in Reversing-Valves for Compound Engines, fully described and represented in the following specification andthe accompanying drawings, forming a part of the same.

This invention relates especially to valves for small compound engines; and its 'object is to provide a single valve to govern both the quantity and direction of the steam. admitted to the cylinders, and to conduct live steam directly to the low pressure cylinder from theI boiler, when desired.

The invention consists essentially in the combination, with a suitable casing provided with a supply aperture at one end and an exhaust aperture at the other end, and con-` a third passage to direct the exhaust steamk from the low pressure valve chest to the 'exhaust aperture in the casing.

The invention also consists in additional: l means for conducting live steam fromthe;

boiler directly to the low pressure valve chest, when desired; i

The invention will be more fully understood by reference to the annexed drawings, in which-- U Figure 1 is a central vertical section of my improved valve interposed between the valve chests of a compound engine, only that portion of each cylinder containing the steam ports being shown. Fig. 2 is a horizontal section of the same on line in Fig. l, with the portions of the cylinders omitted. Fig. 8 is a plan of the parts shown in Fig. 2; and Fig. 4 is a vertical transverse section of the valve on line y y in Fig. 1. Figs. 5, 6, 7 and 8 are diagrams indicating the operation ofthe valve under the various conditions for which it is designed.

The valve casing a is shown of cylindrical form with the cap a constructed with a boss a2 having the supply aperture into which is screwed the steam pipe s (shown only in dotted lines in Fig. 4) which supplies all the steam for both cylinders of the engine. The casing is provided with four diametricallyopposed lateral openings b, c, d and e, the opposite openings being connected respectively with |the induction port of one ot' the valve chests and the eduction port of the other.

The casing is provided at its lower end with openings in the casing; the passage g leading to the upper face of the plug, the passage h terminating at bothextremities in the periphery, and the passage i leading to the lower face of the` plug. The casing is made a little longei than the valve plug, which latter is suspended therein by its'stem, thereby affording a connectionin all positions of the valve between the supply and exhaust pipes Aand the passages in the plug o.

The en trance and exit of the steam through the ports A and B of the high pressure cylinder and the ports A andB of the low pressure cylinder is eected by means of the ordinary piston-valves p and 19', respectively, in the valve chests C and C', which are provided with the induction ports m and m and the eduction ports n and n. The piston valves are reciprocatedin the ordinary manner by means of the valve stems q and q. A pipe j is applied to the valve chest() and the casing a to connect the induction port m with the opening b,- and a similarpipe connection 7o is provided to connect the eduction port m with the opening c in the casing. The casing being interposed betweenthe two valvechests, the opening c'communicate's directly with the IOC eduction port n of the'highf pressure valve V The position of the valve plug shown in Figs. l to 4E inclusive directs the steam to the two valve chests as follows as indicated diagrammatically in Fig. 5 by the arrows:-Upon the entrance of the live steam through the supply aperture in the cap a', the same passes through the passage g and the pipe] to the induction port m, whence it is directed by the piston valve p to the high pressure cylinder. On the return stroke of the piston it passes through the eduction port n and the passage hin the plug t to the induction port m', whence it passes to the low pressure cylinder. On its return to the valve chest C as exhaust steam, it passes through the eduction port n, through the pipe 7c and downward through the passage t' in the plug i: to the exhaust pipe.

The diagram in Fig. 6 indicates the effect of turning the lever Zthrough an angle of fortytive degrees, whereby the supply of steam is wholly cut oif from the valve chests, as the passages in the valve plug cease to register with anyin its casing. By turning the lever through another angle of forty-five degrees, as indicated in dotted lines in Fig. 3, and in the diagram in Fig. 7, the supply passage g in the plug c is made to register with the port fn. of the high pressure valve chest; the passage h connects the port m with the port a',- and the exhaust port t' registers with the port m; whereby the direction of the steam is reversed from that given by the valve in its normal position, as indicated by the arrows in the diagram.

It will be observed that the induction and eduction ports of the two valve chests are referred to in connection with the main valve in it normal position in the description of Figs. l to 4c inclusive; but that the reversal of the engine, as indicated in Fig. 7, necessitates the reversal of the operation of these ports,the normal induction port becoming the eduction port of the valve chest when the engine is reversed, and the normal eduction portbeco1n ing the induction port.

In order to temporarily increase the power of the engine, a transverse hole o is formed in the stem t a little above the valve plug/v to intersect a longitudinal hole o extending the whole length of the stem t" and terminating in the passage h. A valve seat o2 is formed in the hole o' below the transverse hole o to which is fitted the conical valve 'r having its stem r threaded at its upper end to fit a similarly threaded portion of the hole o and having a hand wheel for turning the same to move the valve 1' to and from its seat. By opening this auxiliary valve, live steam is supplied through the passage 7L to the ports n and m', and also by means of the passage g to the port m when the valve plug is in its normal position,as indicated by the arrows in Fig. 8; whereby the pressure in the induction and eduction portsof the high pressure valve chest is equalized and the high pressure enginethus becomes of no effect, but the large increase of piston area afforded by the low pressure be admitted to thevalve chest C through the port 'n'. Y

From the foregoing description it will be evident that the essential feature of my invention consists in the construction of the rotary valve plug with three passages each terminatingin its periphery, one passageleading from one end, one leading from the opposite end, and a third terminating at both extremities in the periphery of the valve plug, the same being combined with a suitable casing and passages connected with both ports of the high and low pressure valve chests; but that the precise form of the valve plug (whether cylindrical or conical) and the exact arrangement of the passages therein,as shown in the drawings, are not material to the invention.

By applying the valve plug to the casing between the supply and exhaust apertures, I am enabled to secure certain advantages. First, as none of the passages are required to pass one another through the body of the plug, their form and arrangement may be much more simple and thus eifective than in other constructions; second, only a single passage terminating at both ends in the periphery is required, and consequently the upwardly and downwardly extending passages may be formed in the body of the plug with only one end of each in the periphery, whereby the provision of lateral passages in the periphery may be avoided, the effect of such passages being to diminish the peripheral bearing surface of the plug and thereby diminishing the durability of the valve through rapid wear; third, the live steam being let intothe casing above the plug, the constant downward pressnre produced upon the valve stem operates to force thelowerface of the shoulder formed bythe handle Zwith the stem downward upon the end of the perforated boss (bearing the letter a in Fig. l) through which the stern is inserted, thereby forming a tight joint between such surfaces and avoiding the necessity of a stuffing box for the valve stem.

Vhile the inclosed passages in the ends of the plug are preferable for the reasons set forth above, it is evidently not material to the essential feature of the invention that they should be of the precise form shown and described herein; as mere notches of sutlicient area would operate as equivalent passages for the steam between the ends of the plug and the peripheral apertures in the casing, as before described. "l

I am aware that it has been proposed hereh tofore to construct a valve for a compound IIO ' to stop the engine.

engine for directing the live steam from the boiler at once to the low pressure cylinder when it is desired to temporarily increase the power of the engine, and that a valve has been constructed with three transverse passages to effect this result; butin such case a separate exhaust has been provided for the low pressure cylinder as well as a separate supply pipe for the high pressure cylinder, and a throttle valve in addition has been necessitated to cuto the whole supply of steam In my invention, the single valve serves bot-h to receive and discharge all the steam used in both cylinders, to deliver it in either direction to each cylinder, and to regulate or to wholly cut off the supply of steam when it is desired to stop the engine.

Although the auxiliary valve 0" is preferably applied to the valve plug c to adapt the engine for increased power in emergency, it isevident that it is not a material part of my invention; as such valve could readily be applied to a branch of the supply pipe connected directly with the valve chest of the larger cylinder, or omitted entirely, without affecting the operation of the main valve.

It will further be observed that one of the chief advantages of my invention is that the valve is adapted to be interposed directly be-k tween the high and low pressure valvechests, and that the straight transverse passage hin the plug thus serves, in conjunction with the similar passages c and cl leading from the valve plug to the eduction port of the high pressure valve chest and the induction port of the low pressure valve chest respectively, to form a straight continuous passage to conduct the exhaust from the high pressure valve chest to the low pressure valve chest. a passage of the shortest possible length is provided to lead the steam from one valve chest to the other,and forms the smallest possible space for the expansion of the steam in passing from one` cylinder to the other. It will thus be seen that provision is made for the least possible loss of steam pressure between the high and low pressure cylinders.

Having thus set forth the nature of theinvention, what I claim herein isl. The combination, with a valve casing having asupply and an exhaust aperture at the opposite ends, and four lateral openings, of a rotary valve plug fitted within such casing between its supply and exhaust apertures having three passages terminating in its pe- ThusA leading from one end ofthe plug to its periphery, one leading from the opposite end of the plug to its periphery. and one terminating at both extremities in the periphery of the plug, as and for the purpose set forth.

2. The combination, with the valve chests of a compound engine, of the valve casing a having at one end the cap ct with suppl y aperture a2, the exhaust aperture a3 at the opposite end, and the lateral apertures b, c, CZ and e, the pipe connections j and lo, the valve plug c .having the passages g, h and z' adapted to register with the said lateral openings inthe casing and to connect the same with the supply and exhaust apertures, and means for turning the valve plug, substantially as herein shown and described.

3. The combination, with the valve chests of a compound engine, of the valve casing ct having the cap ct vwith supply aperture @Zat one end, the exhaust aperture a3 at the opposite end, and the lateral apertures b, c', d and e, the pipe connections j and k, the valve plug v having the passages g, h and i arranged as described, the hollow valve stem c having transverse passages o and the valve seat o2, the valve fr with stem r', and means for independently turning the said valve plug 'u and valve r, substantially as herein set forth.

4. The combination, with the valve chests of a compound engine, of a valve casing interposed directly between the same having a supply and an exhaust aperture at opposite ends and connected by lateral apertures with both ports of each of the valve chests, and a valve plug fitted within the casing between its supply and exhaust apertures and provided with a transverse passage adapted to form a straight continuous connection between the eduction port of the high pressure valve chest andthe induction port of the low pressure valve chest and to connect the supply and exhaust apertures of the valve casing with the other ports of the valve chests, respectively, as and for the purpose set forth.

In testimonywhereof I have hereunto set my hand in the presence of two subscribing witnesses.

IOO

GEORGE E. WRIGHT. i

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