US447490A - Valve for steam-engines - Google Patents

Description

(No Model.) 2 sheets-Sheet 1.

A. L. IDB. VALVE EOE STEAM ENGINES. No. 447,490. Patented Mar. 3, 1891.

(No Model.)

2 Sheets-Sheet 2. A. L. IDE. VALVE EOE STEAM ENGINES.

Patented Mar. 3,1891.

16p@ www A UNITED STATES ATENT Fries.

ALBERT L. IDE, OF SPRINGFIELD, ILLINOIS.

VALVE FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 447,490, dated March 3, 1891.

Application filed September 5 1890. Serial No. 364,046. (No model.)

.To all whom zr may concern:

Be it known that I, ALBERT L. IDE, a resident of Springfield, in the county oi' Sangamon and State of Illinois, have invented certain new and useful Improvements in Valves for Steam-Engines; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

' This invention relates to improvements in valves for steam-engines; and it consists in the matters hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l is a horizontal longitudinal section of a steamchest provided with a slide-Valve embodying` my invention. Fig. 2 is a cross-section of the same on line 2 2, Fig. l. Fig. 3 is a vertical section on line 3 3 of Fig. 2. Fig. 4 is a detail side elevation of the slide-valve. Fig. 5 is an enlarged detail section showing the valve in a changed position from that shown in Fig. l. Fig. G is a similar section showing still another position of the valve. Fig. 7 is a similar view illustrating a modified form of valve.

In said drawings, A indicates the enginecylinder, B the steam-chest, and B the steamsupply pipe.

-C indicates the valve-seat, provided with steam-ports c c', communicating with the 0pposite ends of the cylinder A and provided with a central exhaust-port c2.

D indicates the slide-valve, D the valvestem connected therewith, and E a valve-plate arranged upon the side of said valve D opposite to the valve-seat C and parallel therewith.

As shown in said drawings, the slide-valve D is generally of flat or gridiron form, as shown more particularly in Figs. 3 and et, and consists of two parallel side pieces d d, two end cross-bars d d2, and two intermediate cross-bars d3 di. As a detail of construction in the particular valve show-n, said valve is provided with a central tubular part D2, through which passes the valve-stem D', said tubular part affording a brace to connect the crossbars of the valve, and thereby give strength and rigidityto the same.

The valve D, made as above described, is located in contact with the valve-seat C, and operates in connection therewith and also with the stationary valve-plate E, which is sustained within the steam-chest opposite to the valve-seat C, and is provided with a flat bearing-surface E', which is in contact with the outer side of the valve D. 'lhe valveplate E is conveniently held in position by means of inwardly-p ro j ectin g dan ges ee,which rest at their inner edges against the valveseat C at opposite sides or edges of the valve D, as shown more' particularly in Fig. 2, said Valve-plate E being arranged to bear at its side edges against the side walls of the steamchest, whereby the said valve-plate is held from shifting sidewise, as clearly shown in the drawings. A pin or stud e, Fig. 2, is inserted in the valve-seat C, and enters a recess in the flange e of the valve-plate, to hold the latter from shifting endwise or longitudinally.

E? is a lspring interposed between the outer wall or cover of the steam chest and the valve-plate E, to hold the latter in operative position. The spring E2 does'not act against steam-pressure in holding the valve-plate against the valve-seat C, inasmuch as the steam-pressu re comes outside ot said valvepla'te and tends to press the same against the valve-seat. Said spring E2 enables the valveplate to yield outwardly, so as to relieve the parts from strain in case of an accumulation of water in the cylinder, thereby avoiding danger of breakage of the parts by the compression of the water in either end of thecylinder at such time. The valve-plate E is made shorter than the length of the steamchest, and the end or outer cross-bars d cl2 of the valve E are arranged at such distance apart, and the valve is moved through such distance that said cross-bars are carried alternately past the ends ot the valve-plate or outwardly from beneath the same, so as t0 admit steam from the steam-chest between the valve-plate and the valve-seat to the steam-ports c c. The inner or intermediate cross-bars cl3 d* of the valve are arranged at such distance apart that they are moved alternately away from the surface of the valveseat to a point opposite the exhaust-port c2, thereby leaving open the space between the IOO valveseat and the valve-plate for the passage ol' steam from one of the steam-ports c c to the exhaust-port c2.

In order that steam may enter at both sides or edges of the end cross-bars ot' the valve when the latter are moved outwardly past the end of the valve-plate, as above described, the valve-seat C is made of the same length as the valve-plate, so that spaces are lett between the ends of the valvc-seat and the ends of the steam-chest, and the parts of the wall of the steam-chest adjacent to the ends of the valve-seat are recessed, or, in other words, the valve-seat is elevated above the adjacent parts of the wall of the steanrchest. This construction enables the steam to pass around the said end crossbars, thereby affording a steampassage of twice the area, with the Sallie movement of the valve as is afforded in case the steam enters at 011e side only of said cross-bar. For a s imilar purpose the valve-plate E is provided with a central recess e2 ot' the same length and width as the exhaust-port c2 and arranged opposite the latter. Said recess allows the exhaust-steam to pass around on both sides of the inner crossbars di d4 in its passage from the ports c c to the exhaust-port c2, thereby affording a large area for the exit of steam with a small movement of the valve.

The valve-plate E is herein shown as provided on its inner or bearing surface near its ends with two transversely-arranged recesses cis e4, made of the same length and width as the steam-ports c c and located opposite the latter. Bythe presence of said recesses in the bearing-surface of the valve-plate the lat ter is made to correspond exactly with the bearing-surface of the valveseat, thus insuring an equal steam-pressure on opposite sides of the valve and the perfect balancing ot the latter. l

As a separate and further improvement, the valve-plate E is provided with a steampassage E3, extendinglongitudinally through the body of said plate and opening at its ends through the inner or bearing surface of the plate near the ends of the latter. The said passage E3 is designed to aitord an additional area ot' passage tor the inflow of steam to the cylinder-ports, and for this purpose its ends are so located with reference to the ends of the valve-plate that when the cross-barat one end of slide-valve begins to leave the edge of said plate the cross-bar at the opposite end of the valve will begin to pass from over the end of said passage, thereby admitting steam through said passage to the ports c c at the same time that steam is admitted to said' steam-port around the edges ofthe outwardlymoving cross-bar of the valve.

The operation of the valve will be more clearly understood by reference to Figs. l, 5, and 6.

As illustrated in Fig. 1, the valve D is in position for the passage of live steam through the port c to the cylinder A. At this time the cross-bar di? of the valve l) stands outside of and free from the valve-scat C and the valveplate E, so that steam is l'ree to pass from the steam-chest around both sides ot' said bar (l2 to the space between said valveplate E andthe valve-seat C and into the port C', as before described. At this time the intermediate cross-bar d* nearest the cross-bar d2 stands between the steam-port c and the exhaustport c2, thus closing Vthe space between said ports, while the external cross-bar d at the opposite end of the valve stands between the port c and the end oi' the valve-seat, thus closing the space between the said valveseat and the valve-plate E at this point. Ex hauststeam is at this time free to pass from the said port c to the exhaust-port c2 through the space between the valve-plate and the valve-seat, the cross-bar d3 at. this time being located opposite the exhaust-port and in position to allow the free passage of steam around both sides of said bar into said port.

Fig. 5 shows the valve at the limit of its stroke opposite to that shown in Fig. l, live steam at this time passing through the port c to the cylinder, the exhaust passing through portc to the exhaust-port crz in the manner illustrated. v

Fig. 6 illustrates an intermediate position ot the parts when the valve is being shifted from the position shown in Fig. 5 to that shown in Fig. l. This figure shows the exhaust-port as already partially opened to allow the passage of exhaust-steam from the port c to the exhaust-port c2 by the movement of the intermediate cross-bard3 from contact with the valveseat C and the bearing-surface E in that part of the same between the steamport c and the exhaust-port c2, thereby allowing steam to pass around both sides of the bar d3 to the exhaust-port. Admission ot' steam will begin as soon as the cross-bar d2 passes from between the surfaces of the valveseat and the valve-plate.

'lhe passage E3 in the valve-plate E affords an additional or increased area for the passage of live steam to the cylinder during the opening ot the steam-ports, the ports or openings in the face of the valve-plate E at the ends of said passage being so arranged that one of the end cross-bars, as d', will begin to uncover said passage at one end of the valve at the same timethat the cross-bar (Z2 at the opposite end of the valve begins to leave the edges of the valve-seat and the valve-plate. This is shown in Fig. 6 of the drawings, from which it will be clearly seen that a slight further movement of the valve D toward the right hand will lbring the crossbar d past the edge of the opening of the passage E3 at the same time that the inner margins of the cross-bar d2 pass beyond the edges of the valve-plate and the valve-seat. It will of course be seen that one end of the passage E3 is always in communication with the steam-port into which live steam is about to be admitted when the other end of said IOO IIO

IIS

passage is being opened for the admission of steam from the steam-chest. This passage beingI of considerably less width than the openin g afforded by thecross-bar d or d when the valve is at either limit of its throw, said passage will commonly be of use only when the engine is working at short stroke, it being obvious that when the valve is moved throughout the full length of its stroke, or nearly so, the steam-inlet space afforded between each cross-bar rl or (Z2 and the adjacent ends of the valve-plate and the valve-seat will be as great or greater than required to admit all the steam that can pass through the steamports.

It will of course be understood that the desired area for the admission of steam to the cylinder may be provided without employing the passage E3 by making the valve D of sufficient width forthe purpose; but for compactness of construction and to avoid the objectionable features which would be connected with a very broad valve said passage is employed.

I am aware that valve-plates have been heretofore employed, the same being arranged parallel with the surface of the valve-Seat and the valve being arranged to move between the surface of said plate and the seat; butin all these prior forms of construction the valve-plates have been provided with perforations or ports extending' through them from face to face, through which steam passes to the valve when the ports in the valve coincide with those in the valve-plate. It is obvious that in this form of construction the advantage of increased area for the admission of steam such as is provided for in my improved form of construction is entirely absent.

rIhe valve D (shown in the accompanying drawings) is arranged vertically, the steamchest being placed at one side of the cylinder, so that the weight of said valve comes entirely upon the lower edge thereof.

As a further and separateimprovement applicable to valves of this character when arranged in the manner shown, I place between the lower edge of the valve and the supporting-surface ofthe steam-chest adjacent to it one or more anti-friction rollers, which sustain the weight of the valve, and thereby avoid the frictional resistance which would result from the sliding contact of the lower edge of the valve with the surface by which lthe same is sustained. As illustrated in the accompanying drawings, two anti-friction rollers F F are employed, said rollers being located in notches or recesses ff, formed in the lower flange e of the valve E, so that the rollers rest upon the bottom wall of the steamchest. In this construction the rollers are conveniently made of the same diameter as the thickness of the flange e. The rollers F F (shown in the drawings) are of cylindric form and are made of such length that their flatend faces come flush with the side faces ot' the valve D. This particular construction is not, however, essential, and the rollers employed may be of spherical instead of cylindric form, and the bearing-surfaces therefor may be arranged otherwise than in the manner described.

I am aware that rollers have been hereto- 'fore employed in connection with slide-valves,

'said rollers being arranged between the bearing-face of the valve and its seat and adapted to prevent friction between said surfaces vor being arranged upon the surface of the valve opposite or remotefrom the seat and adapted lo take the lift of the steam and prevent the valve from being raised from its seat. By my improved construction, however, the valve is entirely balanced, and there is no necessity for rollers or other anti-friction devicesbetween the bearing-surfaces; but the valve being arranged vertically and its weight belng supported entirely upon its narrow lower edge, I provide the rollers, as shown, to prevent the friction between the support for the valve and the lower edge of the valve, which arises from the use of a relatively large and heavy valve having a narrow bearing-edge.

Some of the features of the valve shown may be used with advantage without other features shown and described, it being obvious that under some circumstances the reduction in first cost of the engine or cheapness of fuel will warrant the omission of some of the novel features herein shown, even at a loss of the advantages gained by the presence ICO of such features--as, for instance, the cond struction of the valve-plate shown in Fig. 7 may be used, in which said valve-plate is formed without the passage Eg.

In the flat valve I) shown in Fig. 7 the advantage of a double admission of steam is obtained-that is to say, a relatively large opening for the passage of the steam is afforded by a short movement of the valve; but this favorable result is obtained to a greater degree when the passage E3 in the valve-plate is employed, such passage obviously affording a triple instead of a double opening for the admission of steam without increasing the stroke of the valve, with obv1- -ous advantages in steam economy and consequent saving of fuel.

The dat gridiron or barred valve,combined with a valve-seat and imperforate valve-plate, as herein described, may obviously be used either in single-acting engines or by being combined with another valve of any desired form of construction may be adapted for use in a compound engine.

The valve construction herein described and shown is the same as that illustrated in another application filed by me on June l0, 1890, Serial No. 3545927, for improvements in compound engines.7`

I claim as my invention- IZO I. The combination, with an engine-cylinder and a stationary chest having a valveseat provided with steam-ports near its ends and a. central exhaust-port, of a flat reciprocating valve provided with four transverse parallel bars and a stationary impertorate valve-plate arranged parallel with the valveseat, said valveseat being made shorter than the steam-ehestand the outer cross-bars of the valve being located at such distance apart that at each limit of the movement of the valve the cross-bar at one end of the valve seat having steam-ports near its ends and a central exhaust-port, of a i'lat valve provided with four transverse parallel bars and animperforate Valve-plate arranged parallel with the valve-seat, said valveplate and the valveseat being made shorter than the interior of the steam-chest, and the valveseat being raised. at its ends above the adjacent wall of the steam-ehest, and the exterior cross-bars ot' the valve being disposed at sueh distauee apart that at each limit of the movement of the valve the cross-bar at one end of the valve will stand outside oi' or beyond the said plate, so as to admit steam from the chest to the adjacent steam-port, while the cross-bar at the opposite end of the valve will stand between the end of the plate and the adjacent steam-port, so as to eut oft the flow ot' steam to the latter, the said valve-plate being provided with a longitudinal passage opening at its ends at the inner or bearing face of the plate adjacent to the ends thereof, substantially as described.

In testimony that I claim the foregoing as my invention I aflix my signature in presence of two witnesses.

AL EERl L. IDE.

lVitnesses:

Il. L. IDE, I). E. BLAKE.

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