US530400A

US530400A - Main slide-valve and throttle-valve for steam-engines

Info

Publication number: US530400A
Authority: US
Publication date: 1894-12-04
Anticipated expiration: 1911-12-04

Description

(No Model.) 2 Sheets-Sheet 1 J. P. DEVOISSAUD. vMAIN SLIDE VALVE AND THROTTLE VALVEI'OR STEAM ENGINES.

Patented Deer; 4, 1894;

/A/A/A/A////A// 342% NVENTOH A7TOBNEYS.

WITNESSES:

(No Model.) 2 Shets -Sheet,2.=

. JJP. DEVOISSAUD.

MAIN SLIDE VALVE AND THROTTLE-VALVE FOR STEAM ENGINES.

N0.530,400. "Patented 9904,1894? ATTORNEYS.

1 UMTED STATES JOHN P. DEVOISSAUD,

or SHERMAN, TEXAS.

MAIN SLIDE-VALVE AND THROTTLE-VALVE FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters PatentNo. 530,400, dated December 4, 1894.

Application filed June 26,1894.

To all whom it may concern.-

Be it known that I, JOHN P. DEVOISSAUD; of Sherman, in the county of Greyson and State of Texas, have invented a new and useful Improved Main Slide-Valve and Throttle-' Valve for Steam-Engines, of which the following is a full, clean-and exact description.

.gine cylinders, which are horizontally disposed in the same vertical plane, said throttle valve being directly actuated by a suitable governor devicethat receives motion from the main shaft of the engine, whereby the throttle valve is adapted to control the transmission of steam that passes from the steam chest through the main valve and thence through the throttle valve into each, of the two cylinders, as the latter is con trolled by the governor device.

A further object is to provide a co-acting, peculiarly constructed mainslide valve that, in conjunction with the novel throttle valve, afiords a complete and superior valve mechanism for a quick speed steam engineof the type indicated, or any other style forwhich said valves may beap'plicable.

To these ends, my invention consists in the construction and combination of parts, as is hereinafter described and claimed.

Reference is to be had to the accompanying drawings, forming a part of this specification,

in which similar figures of reference indicate corresponding parts in all the views shown.

Figure 1 is a sectional side view of the steam engine shown to illustrate theapplication of the improvements, and said valves in positionthereon, the section being taken on the line'l-l in Fig. 2. Fig. 2 is a partly sectional front view of the engine, with the improved throttle valve shown in position on it, by dotted lines, the section being on the line 22 in Fig. 1. Fig. 3 is'a sectional plan view of parts of the engine, the steam chest, main valve, its seat, and the improved throttle valve, on the line 3+3 in' Fig. 1; and Fig.

serial No. 515,749. on, model.)

4 is a side view of detached. A brief description of the steam engine on which the improved valves are especially well adapted for service, will begiven to render clear their application and operation.

There is an elongated bed plate 10, provided, of a rectangular form, arranged in its details of construction to receive and support the twin cylinders 11, in parallel horizontal planes at the front end'of said bed plate whereon the lower cylinder is aflixed. The cylinders 11 are integrally constructed, and have a rearwardly closed exhaust passage 11, ,formed in the wall that separates their bores, which similar cylindrical bores are forwardly :closed by the single head plate 11", and a lateral outlet 11 is formed in the cylinders "for the exhaust passage 11 The piston .heads 12, are of approved construction not internally shown, of the bucket type, having a pivoted connection with the pair of connecting rods 13, Which pass through vertically elongated slots 14 that are formed in the headvlt, which head is attached tothe the improved throttlo'valve *rear ends of the'cylinders.

The rods 13, are looselyjoined at their rear ;ends with. the transverse journal pins15 which serve to connect the end portions of 3 two similar upright rocking beams 15, the latiter being mounted an equal distance from their upper ends on the transverse shaft 15 5 said shaft having its ends journaled in boxes onthe bed plate 10, one of said beams and l the connecting pinsand shaft mentioned,be-

\ ing represented in Fig. 1. v

On the bed plate 10, at its rear end, a transverse main shaft 16 is journaled, having a double crank arm 16 formed on or secured to it at a point which will allow the joining cross pin 16 of the arms 16?, to be coupled with the rear end ofth'e pitman 17, that is loosely secured atits forward end on. the cross pin 15, that is secured between the rocking beams 15, at their lower ends, this connection of the cranks on the main shaft adaptingthe alternate equal rearward movement of the piston heads 12, to vibrate the beamsand rotate the main shaft.

channeled on its outer face at the transverse;

. 9 The cylinder head plate 11 is vertically V center, to receive the flat thin throttle valve 18, that will be hereinafter described. The channel mentioned having a suitable width, is rendered exactly level throughout its area on the bottom surface, which is also made parallel with the rear surface of the cylinder head plate that is attached to the forward ends of the cylinders.

On the front side of the head-plate 11 that is true and parallel with its rear surface, except that a central projecting portion is formed on it as will be further explained, a main valve seat 19 is secured, and on said seat the rectangular steam chest 20 is imposed, it being true on front and rear faces, and forming steam tight joints between it and the valve seat it engages, as well as with the chest bonnet 20 that is detachably held with the chest on the seat 19, a steam supply pipe 2O tapping one side of the chest for the introduction of live steam therein. Aslight projection is formed on the inner surface of the bonnet 20 at its transverse center extending vertically and inclined from its upper edge downwardly and toward the valve seat 19, and as shown in Fig. 1, a sufficient space intervenes this true surface to permit a wedge-shaped presser block 21, to be introduced between the bonnet and the adjacent surface of a main valve 22, the presser block havinga tongue 21, on the rear face which has a loose engagement with a corresponding groove produced in the back of the main slide valve, provision being made for the adj ustable attachment of the presser block on the bonnet with the bolts 2l which will adapt the valve 22 to have a proper contact of its working face with the main valve seat 19.

On the main crank shaft 16, at one side of the bed plate 10, an ordinary eccentric 23 is secured, which has its strap connected to the eccentric rod 24 that extends forwardly to have its front end pivoted to the upper end of a rock arm 25, which is secured on the transverse rock shaft 26, that is journaled on the bed plate below the cylinders. At a suitable point from the rock arm 25, another rock arm 27 is affixed on the shaft 26, and forwardly extends in a horizontal plane, its front end being connected by the pair of links 27 with the lower end of the depending valve rod 22, that is projected steam tight through the steam chest on its lower side, and has its upper end attached to the main valve 22.

The cylinder head plate 11 and main valve seat 19, are oppositely and transversely slotted at two points near each end, thus affording two pairs of suitable spaced live steam ports 19, two of said ports intersecting each cylinder bore at points nearly equidistance from its longitudinal axis, each live steam port being bisected by central bar as shown in Fig. 2.

At two points equally distance from the live steam ports that are nearest to the exhaust passage 11 two similar exhaust ports 19 are produced in the cylinder head plate 11 and main valve seat 19, which ports extend from points near the side walls of the cylinders forwardly, and are preferably slightly converged toward their front ends, they being equally distance from a main exhaust port 19, that is formed in the cylinder head and main valve seat opposite the exhaust passage 11, that said exhaust port intersects and thus establishes a continuous exhaust passage from the steam chest to the outer air at the side of the cylinders.

The main valve 22, has a cavity 22 formed in it at its longitudinal center of a width equal with the transverse dimensions of the main exhaust port 19 and of such a length as will adapt it to connect said main exhaust port with either of the other exhaust ports 19 that tap the cylinders so that when the main valve is correctly adjusted and other moving parts that actuate are properly arranged, the rotation of the main shaft 16 will cause the exhaust ports 19 to be alternately brought into direct connection with the main exhaust passage 11 for the discharge of exhaust steam from the cylinders.

To adapt the main valve 22 to permit the passage of live steam from the chest 20, into the cylinders 11 it has two transverse steam ducts 22 formed in it at a correct distance from its ends, and also from the central exmain valve 22, it is essential that its travelbe arranged, so that one of the steam ports 19 in one cylinder willlbe uncovered at the adjacent end of the valve by said valve end, and the parallel and nearest port 19 be brought opposite the steam duct 22 at that end of the main valve, so'as to pass steam through the two steam ports 19 of the cylinder that is to receive live steam, while the similar ports for the other cylinder are covered by the main valve, a free passage for exhaust steam from the exhaust port in the last mentioned cylinder, being simultaneously produced by a proper connection of the exhaust cavity of the valve 22 with the main exhaust passage 19, and exhaust port 19 of said cylinder, so that a sufficient pressure of steam in the chest will afford power to continuously and rapidly actuate the main shaft of the engine.

The most essential feature provided in this invention, is the peculiar throttle valve 18, before mentioned, which consists of a fiat rectangular plate, having such proportionate dimensions, as will adapt it to fit steam tight in the channel formed to receive it inthe cylinder head plate 11 and yet be permitted to freely slide in said channel endwise.

There are live steam ports transversely cut in the plate like throttle valve 18, at such points as will allow them to coincide with the similar live steam ports in the cylinder head plate and main valve seat that have been already described. I

The center of the throttle valve 18 is rectangularly apertured of a sufficient size to produce a large aperture 18 that loosely receives the central forward projection of the cylinder head plate 11 which latter is thereon formed to allow the ports.l9 .to be rendered continuous with their extensions in the valve seat 19. The aperture 18 in the throttle valve is of a sufficient length to afford space of ample dimensions above and below the head plate projection mentioned, to permit the free reciprocation of the throttle valve, the expelled exhaust steam being allowed to pass unrestrained through the exhaust ports 19 in the head plate 11 and the valve seat 19 without regard to the reciprocal adjustment of the said throttle valve.-

A flat stem 18 is projected from the upper end of the vertically located throttle valve 18 which stem is at its upper terminal detach ably connected with the governor device 28 that is saddled on and secured to the upper side of the top cylinder 11 atits forward end.

The governor preferably employed, is of an improved construction for which a patent has been allowed to me, and as it is not a part of the present invention a detailed description is not necessary.

Briefly considered the governor 28 consists of two flat disks centrally pivoted between laterally projectedarms of a yoke frame that is centrally and loosely mounted on the bracket frame 28 each disk having a loose connection produced by a link between its edge that is nearest to the vertical spindle 28 and said spindle, whereby the rocking movement of the disks on their pivot centers, will longitudinally move the spindle in accord with the degree of oscillation given to the disks.

Bevel gearing is arranged to rotate the yoke frame that supports the disks and their Weights, one of said bevel wheels being secured on theinner end of the horizontal shaft 28 that is rotatably supported on the bracket frame 28, a pulley 28 that is affixed on the outer end of this shaft having a belted connection with a pulley 29 on the main shaft of the engine.

The operation of the throttle valve is as follows: It is so adjusted that for a maximum load on the engine which requires full pressure of steam from the main valve 22, the ports in the throttle valve will be aligned with the live steam ports 19, so that the latter will be full open while the engine is thus working.

Should speed increase on account of increased steam pressure from the boiler, or a reductionof load on the engine, the more rapid rotation of the governor will depress the latter, and correspondingly actuate the throttle, so as to diminish the openings in the live steam ports, which will thus control the working of the engine to secure a uniform speed, any increased load on the engine causing an opening of the steam ports in an obvious manner.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent 1. In valves for a steam engine, the combination of a throttle valve in plate form hetweeng a main slide valve and two engine cyl inders, said valve being provided with a contral aperture and with live steam ports, and v a governor connected with said valve, substantially as described.

2. In valves for a steam engine, the combination with two cylinders provided with a head having a projection thereon, said head having live steam and exhaust ports therein,

a steam chest on the head anda slide valve in said steam chest, of a throttle valve in plate form, said valve being arranged in the head and provided with acentral aperture to receive the projection of the said head, and with live steam ports registering with the live steam ports of the head, substantially as described.

3. In valves for a steam engine, the combination with two cylinders provided with a head having a projection and provided with exhaust steam ports in said projection and with two live steam ports at each side of the exhaust ports, of a valve casing in the head, a valve in the casing and provided with live steam and exhaust ports, and a throttle valve in said head and having a central aperture to receive the said projection and With two live steam ports ateach end, substantially as herein shown and described.

JOHN P. DEVOISSAUD.

Witnesses:

GEORGE OorTs, JOHN DOYLE.