US696208A

US696208A - Piston-valve.

Info

Publication number: US696208A
Application number: US3968000A
Authority: US
Inventors: Alexander Spencer
Original assignee: Individual
Current assignee: Individual
Priority date: 1900-12-13
Filing date: 1900-12-13
Publication date: 1902-03-25
Anticipated expiration: 1919-03-25

Description

No. 696,208. Patented Man 25, I902.

' A. srzucsn.

PISTON VALVE.

(Application filed Dec. 13, 1900.)

(No Model.) 4 Sheets-Sheet 2.

THE Ncnms Prrzns c0.. PHOTO-LITHQ, WASHINGTON n. c.

'No. 696,208. Patentd Mar. 25, I902.

' A. SPENCER.

PISTDN VALVE.

(Application filed Dec. 13, 1900.

' 4 Sheets-Sheet a.

(No Model.

THE NORRIS PETERS co.. PuuTo-umm wAsnlNTuN. n. c.

No. 696,208. Patented Mar. 25, I902.

A. SPENCER.

PISTON VALVE.

(Application filed Dec. 13, 1900.

(No Model.) 4 Sheets$heet 4.

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UNITED STATES PATENT CEFICE.

ALEXANDER SPENCER, OF LONDON, ENGLAND.

PISTON-VALVE.

SPECIFICATION forming part of Letters Patent No. 696,208, dated March 25, 1902.

Application filed December 13, 1900. Serial No. 39,680. Y (No model.)

To (ZZZ whom it may concern:

Be it known that I, ALEXANDER SPENCER, a subject of the Queen of Great Britain and Ireland, residing at London, England, have invented Improvements in and in Connection with Pistons Suitable for Use as Piston- Valves and as Engine, Pump, and Like Pistons, of which the following is a specification.

This invention has reference to an improved and simple construction of piston suitable for use as a piston-valve or as an ordinary engine, pump, or like piston whereby a practically fluid-tight joint can be maintained between the spaces at the respective sides of the piston without the necessity of using tongues or equivalent auxiliary jointing means such as have heretofore usually been employed for preventing the passage of steam or other fluid from one side of the piston to the other side thereof through the space or spaces ordinarily left between the ends of the split packing-ring or between the several parts of a segmental packing-ring on such piston.

The accompanying drawings illustrate, by way of examples, piston-valves suitable. for use in the valve-chest of a locomotive-engine.

Figure 1 is a longitudinal section; 'Fig. 2, a transverse section on the line a, a, Fig. 1; and Figs. 3 and 4 are detail views hereinafter referred to. Figs. 5 and 6 are corresponding views to Figs. 1 and 2, respectively, of a modified construction. Figs. 1 and 5 are drawn to a smaller scale than the other figures.

In each of the piston-valves illlustrated there are two compound piston-valves of the kind hereinafter described connected by a common sleeve 1 and fixed upon a valve-spindle 2,

that extends through them and which, though shown arranged eccentrically to the valves, may be arranged concentrically thereto, if desired. The two connected compound valves are arranged to slide in a liner 3, formed with parallel annular rows of ports 4 4 4 4 4 4. The ports in each annular row are separated by straight longitudinally-arranged bridgepieces 5, and the spaces 7 7 at the two ends of the liner at the outer sides of the two compound valves are in communication with the steam-supply pipe or passage 8, and the space 9 within the liner and between the two compound pistonevalves is in comm unication with the exhaust 10.

Each piston-Valve comprises according to when they are pressed together.

an annular groove 12, the opposite annular side surfaces 13 of which are made fiat and smooth, and a series of arc-shaped segmental slide-valves 14, having the same radius as the valve seat or liner 3, in which they are to work. The valves 14 are made with slightly inclined or beveled ends, as shown in Fig. 4, and with side flanges 15, the outer surfaces 16 of which are also made flat and smooth. These slide-valves are fitted in the annular groove 12, so as to bear closely against one or other, or both, of the opposite annular sides 13 of the said groove, and are made of such peripheral length that the adjacent inclined or beveled ends of each adjacent pair fit practicallyclose against one another, the sum of the whole of the spaces between the ends of the several segmental slidevalves l4 amounting to, say, not more than about one one-hundred-and-twenty-eighth of an inch. The annular groove 12 and the side flanges 15 are made of such radial depth that a fluidtight joint will be formed between their ad jacent

flat surfaces

13 and 16, respectively,

The segmental slide valves 14 are pressed outward and into close contact with the valve seat or liner 3 by suitable springs 17, such as coiled springs, interposed between them and the body of the piston, such action being assisted or not, as may be desired, by steam or other fluid under pressure admitted to the inner side of the slide-valves 14. The slide-valves 14 are prevented from turning around the piston-body by suitable means, such as a pin 18, that extends across the groove 12 and passes through radial slots (see Fig. 3) formed in the opposite flanges on two of the adjacent slide-valves 14 by cutting away the inner end portions of the said flanges. The pin 18 is fixed in the opposite side walls of the groove. In this way there is formed a compound piston-valve having an annular seriesof slidevalves that not only make a fluid-tight joint with the piston-body and the Valve seat or liner, in which the compound valve works, but also with themselves without the aid of additional jointing devices.

The bridge-pieces 5 of the valve seat or liner 3 are equal in number to the inclined or beveled planes of division between the ad jacent ends of segmental slide-valves, the adjacent end portions of the said slide-valves working against the said bridge-pieces when the compound valve is moving over the ports.

The segmental slide-valves 14 may conveniently be made from wide internally-grooved valve-rings,the external peripheries and sides of which are first turned to respectively fit the interior of the cylindrical valve seat or liner 3 and the groove 12. From such valverings segments are then cut of such peripheral length that when a suitable number of them are placed together within and around the groove in the piston-body there will be practically no or very little space between theiradjacentinclinedorbeveledends. Gonveniently there may be six segmental slidevalves of an equal peripheral length of practically sixty degrees each on a grooved piston-body, five of them being cut, as by sawing, from one turned valve-ring of the kind referred to and the remaining one being cut from another similar turned valve-ring.

In the examples illustrated the inn er flanged side of each segmental slide-valve will, owing to there being a greater steam-pressure in the spaces 7 than in the space 9, be pressed close against the adjacent annular surface of the inner wall of the groove 12 containing such slide-valve, so as to form a fluid-tight joint therewith, while the adjacent ends of the slide-valves will be so close together as to effectually prevent the passage of steam be tween them.

Then it is desired that the compound piston-valve shall provide for the ready escape of water of condensation from a cylinder through the cylinder-ports controlled by such valve, the latter may be provided with a relief-valve adapted when subjected to sufficient water-pressure to open and allow 0f the escape of the water from the cylinder through the body of the piston-valve. One arrangement for this purpose is shown in Figs. 5 and 6, wherein two of the segmental slide-valves let of each of the compound piston-valves are each formed at the central portion with a hole 20, that is normally closed by a relief-valve in the form of a hollow cylinder 21, closed at its outer end, which is pressed against the perforated portion of the slide -valve by a coiled spring 22, arranged between the said outer end of the cylinder and the body 11 of the piston-valve. Instead of two of the valves being provided with relief-valves one or more than two maybe so provided. The pistonvalve body is formed on the steam side with one or more relief ports or passages 23, through which water of condensation can escape into the steam-chest when the relief valve or valves is or are forced inward by such water and through which steam can enter the annular space at the inner side of the slidevalves and assist in forcing them outward against the valve-seat against which they work.

A piston having a segmental packing-ring constructed and arranged as described may advantageously be used in the cylinders of engines, pumps, and the like. In this case the pin for preventing rotation of the segmental slide-valves on the piston-body may sometimes be omitted.

What I claim is- 1. A piston-valve comprising a body portion formed with an annular groove, the opposite side walls of which are fiat and smooth, a series of arc-shaped segmental packing-rings having the same radius as the valve seat, liner or cylinder in which the piston is to work and made with slightly inclined or beveled ends and with flanged sides, the outer surfaces of which are also flat and smooth, and springs for pressing the packing-rings outward, the said packin g-rin gs being fitted in the annular groove in the piston-body so as to bear closely against one or both of the opposite annular sides of the said groove, and being made of such peripheral length that the adjacent ends of each adjacent pair fit practically close against one another so that a practically fluidtight joint is produced between the packingrings and the piston-body and between the adjacent packing-rings, substantially as described.

2. In a piston, the combination with the piston-body having a peripheral annular groove, the sides of which are fiat and smooth, of a series of segmental packing-rings having flat and smooth sides and formed by turning undivided rings to a diameter to fit the cylinder or liner in which the piston is to work, and then dividing the said rings by radial inclined cuts into segments and arranging within the said groove a number of these segments of such peripheral length as will cause their adjacent ends to come into close contact with one another and produce practically fluidtight joints between them and form a segmental ring of the same diameter as that of each of the undivided rings from which the segments are cut, as set forth.

3. In a piston-valve, the combination with the piston-body having a peripheral annular groove, the sides of which are flat and smooth, of a series of segmental packing-rings having flat and smooth sides, a water-relief port in one of said segmental packing-rings normally closed by a spring-actuated relief -valve, a drain -passage in the piston-body through which water that enters the piston body through said relief-valve can drain away, so that when the piston is used as a steam-distributing valve in a cylinder it will allow of the escape through itself of condensed water as set forth.

Signed at 77 Cannon street, in the city of London, England, this 28th day of November, 1900.

ALEXANDER SPENCER.

\Vitnesses:

RICHARD THOMSON GLASCODINE, H. BIsnoP.