US122544A - Improvement in exhaust-valves for steam and air cylinders - Google Patents

Description

52 GEORGE wEsTINGHoUsE, 1r.

Vhnproyement' in Exhaust Valves for Steam anall Air Engines. y I

NG. 122,544. Patentedlan.9,1872.

STATES IMPROVEMENT IN EXHAUST-VALVES `FOR STEAM AND AIR CYLINDERS.

Specification forming part of Letters Patent No. 122,544, dated January 9, 1872.

SPECIFICATION. To all whom it may concern:

Be it known that I, GnoRGE 'WEsTINGHoUsn, Jr., of Pittsburg, in the county of Allegheny and State lof Pennsylvania, have invented a new and useful Improvement in Exhaust- Valves and Ports for Steam and Air Cylinders; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing making part of this specification, in which- Figures l and 2 are sectional views of my improvement in one form of its application, and showing the double-ended receiving and exhaust valve in each of its two positions; and Fig. 3 is a detached perspective View of such valve. I

Like letters of reference indicate like parts in each.

My improved exhaust is more particularly designed for use in connection with the brakecylinders of steam-power air-brakes; and I will Iirst describe its construction and operation in sucli use, so as to distinguish the same from other known means of like character, and also enable others skilled in the art to make and use the same.

In such brakes air is compressed into, or when compressed is admitted into, a brakecylinder, A, at such point with reference to a piston therein that, by the movement of the piston, the brake-shoes will be applied to the wheels. To relieve or let off77 the brakes it has been common to turn a cock at the engine and let the compressed air escape at that point. This, in a long train, requires an appreciable interval of time, which it is desirable to avoid. I hence have devised arelief or exhaust valve of such construction that when the air is discharged from the brake-pipes the valve will, by the pressure of the air in the cylinder, be opened at the cylinder and the compressed air be allowed to escape directly from each cylinder, instead of having Iirst to pass the entire length of the train, as heretofore. From the compressed air pipe, which extends back through the train under the cars, a branch pipe, B1, leads to the valve-case B. This valveca-se is open at both ends, and has an enlarged valve-chamber, B2, from which an air-pipe or port, A', leads to the brake-cylinder A. The outer ends of the valve-case B are closed by screw-nuts C C', the nut C being at the airentrance end, and the other, C', at the exhaust end. rIhe valve-chamber B2 is made of a little shorter diameter at the exhaust end than at the other. Under the nut C is a packingring, c, of India rubber or other suitable material, and under the other nut, Cf, is a like ring, c, both resting on shoulders in the valvecase, and held in place by their respective nuts, as shown, and both having' central openings, through which air can enter and leave chamber B2. In this chamber I arrange a double-ended piston-valve, more fully shown in Fig. 3. 0n the opposite ends of a stem, I), I attach the piston-valves D1 D2, the valve l)1 at the air-entrance end being a little larger than the other, and the entire length from outside to outside being a little less than the length of the chamber B2 between the packing-rings c c. rIhe valve D1 has a series of holes, d d, through which the air can pass in entering the chamber B2, and these holes or air-ports are opened or closed by means of a valve-plate, e, which is loosely arranged on the stem D, and is pressed against or toward the piston D1 by means of a spring, e. The other valve has a similar series of air-exhaust holes, or, as shown, its periphery is notched or serrated, as at b, for the egress of air, the projections b between the notches acting as guides in the chamber B2 to keep the valve in line. Its lower face has an annular ring a, V- shaped in cross-section the better to enable it to make an air-tight joint when seated on its gasket c.

The operation is as follows: When it is desired to apply the brakes the compressed air is admitted, as illustrated by arrows in Fig. l, by the pipe B1 through the gasketc and airports d against the face of the valve-plate c, which valve-plate is raised or forced back by the pressure, so that the air passes on into the chamber B2 and by the port Al into the brakecylinder A, where it does its work. The other valve, D l, is at the same time, by the pressure ofthe air, seated on its gasket c'. When the brakes are to be released and the train started, connection with the air-reservoir is cut off and the air allowed to escape from the pipes which extend through the train. The eiect then is that the spring c forces the valve-plate c against the valve D1 and closes the ports al. Also the compressed air in the chamber B2, exercising a greater force against the larger valve D1, causes it to be seated on its gasket c, whereby the other valve D2 is raised clear of its gasket c', when the devices are in the position shown in Fig. 2. The air then passes out freely, as indicated by arrows, from the cylinder A, chamber B2, through the notches b, gasket c', and nut C', and so escapes almost instantly. The opening and closing of the inlet and exhaust ports are thus automatically effected. The valve D1 acts in part as a checkvalve and in part as a lifting device to the It it is desired to let oft' the brakes only in part, it may be done by letting out of the brake-pipes only a portion of the compressed air contained in them and then closing the cock. The air will in such case pass out from the cylinder through the exhaust until the pressure in the cylinder falls a little below the reduced pressure in the pipes, and then the exhaust-valve D2 will be and remainseated. In this Way the force with Which the brake-shoes are applied to the Wheels may be graduated at pleasure. The valve-plate e and spring e may be dispensed With, and the ports d be closed by the valve C coming against the gasket c; but this construction renders it necessary to make the ports d smaller than would otherwise be necessary; and in applying the brakes large air-entrance ports are desirable. The saine devices are applicable in use as an exhaust for air, gas, steam, and water cylinders generally, with only such variations in their arrangement with reference to the cylinders aswill readily suggest themselves to the skilled mechanic, and such uses I include among other purposes of my invention.

What I claim as niy invention, and desire to secure by Letters Patent, is

1. A double-ended piston-valve having ends of different areas exposed to an inside pressure, provided With,-I inlet-ports at one end and exhaust-ports at the other alternating in use, substantially as and for the purposes set forth.

2. The doubleended piston-valve of the preceding claim in combination with a cylinder from which the power is to be applied, substantially as described.

3. An exhaust-valve, D2, lifted from its seat by the pressure and against'the pressure of the duid to be exhausted, substantially as described.

4. The valves D1 D2 arranged on a single stem, in combination with the valve-platee and spring e, substantially as set forth.

In testimony whereof I, the said GEORGE WEs'rINGHoUsE, Jr., have hereunto set my hand.

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