US1026311A - Pressure-retaining valve. - Google Patents

Description

G. O. HAMMOND.

PRESSURE RETAINING VALVE.

APPLICATION FILED MAR.21,1911.

1,026,31 1 Patented May 14, 1912.

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UNITED STATES OFFICE.

GEORGE O. HAMMOND, OF WATER/DOWN, NEW YORK, ASSIGNOR TO THE NEW YORK AIR BRAKE COMPANY, A CORPORATION OF NEW JERSEY.

PRESSURE-RETAINING VALVE.

To all whom it may concern Be it known that I, Gnonon O. HAMMOND, a citizen of the United States, residing in WVatertown, in the county of Jefferson and State of New York, have invented an Improvement in Pressure-Retaining Valves, of which the following description, in connection with the accompanying drawings, is a specification, like numerals on the drawings representing like parts.

The present invention relates to a pressure retaining device of that class which is used in connection with an automatic air brake system in which it is desirable to retain pressure in the brake cylinders in certain cars of the train; and, in cases where a train is made up of empty and loaded cars, to retain a greater pressure in the brake cylinders of the heavier loaded cars than in those of the empty or lighter cars.

The invention is shown as embodied in a valve having a three-way cock provided with an inlet cavity in communication with the triple valve exhaust in all positions, the said cavity being adapted to communicate, respectively, with an open exhaust port and two supplemental exhaust ports controlled respectively by loaded valves to retain different pressures, the movement of the three-Way cock selectively controlling these ports.

The separate pressure retaining valves, in accordance with the invention, are controlled by a weight or equivalent load so arranged that more pressure is required to overcome the load on one valve than is re quired to overcome the load on the other, and the said weight, which acts on both valves, is shown as resting on a yoke 01' lever which is supported at two points directly upon the valves, respectively, while the weight bears on the yoke at a point between the valves. This yoke, when either port is in communication with the exhaust from the triple valve, so that the retaining valve controlling said port is lifted, is capable of operating as a lever having its fulcrum on the other valve, the weight hearing down upon the lever to close the valve when the pressure in the brake cylinder has been reduced to the desired extent.

Figure l is a vertical section, through a pressure retaining valve embodying the invention, the controlling plug valve or three-way cock being shown in elevation Specification of Letters Patent.

Application filed March 21, 1911.

Patented May 1 1, 1912.

Serial No. 615,933.

with the ports in dotted lines; Fig. 2 is a partial view of the cock showing the same in the high pressure retaining position; Fig. 3 is a similar view showing the cock in the low pressure retaining position; and Fig. =1: is an end View of the cock showing the cavity and ports in dotted lines.

In Fig. 1, the pressi'ire-retaining valve is shown as in its normal position, that is to say, the position in which it performs no function in the operation of the brakes, the cock being set so that the cavity 2 receives air from the triple valve exhaust port 3, and permits the air to escape through an open port at in the valve shell or casing If it is desired to retain excess pressure, the cock is turned by means of the handle (3 to one of 'two positions, in both of which positions the open port t is closed, and the exhaust from the brake cylinder delivered to one or the other of the ports 7 and 8. All conmumication with these ports is through a longitudinal pocket or port 9 in the cock 1, the said cock having an inlet passage 10 from the cavity 2 and outlet ports 12 and 13 radial to the axis of the cock, and at an angle to each other, as shown; the outlet 12 opening communication with the high pressure duct 7 when the handle 6 is .in one position, and the outlet 13 opening con'nnunication with the low pressure duct 8 when the handle is in another position. The ducts 7 and 8 are provided with final outlets controlled by valves 14 and 15, which are shown as of different areas, so that more pressure is required to lift one than is required to lift the other, and both of the said valves are loaded by means of a single weight 16, which is supported by said valves at different points. The said weight 16 is contained in the casing 17 intowhich the ports open, and the said casing is provided with an exhaust opening 18. The weight is herein shown as arranged to bear down on an interposed yoke or lever 19 which in turn bears upon both of the valves 14: and 15. The weight is provided with a knife edge or pointed bearing 20 which rests in a depressed portion 21. of the yoke located between the knife edge or pointed bearings 22 and 23 which rest in concave depressions formed in the tops of the valves 14 and 15. WVhen, therefore, either one of the ports 7 or 8 is put into communication with the brake cylinder exhaust, the valve controlling the said port will be lifted, moving the yoke 19 upward with its bearing on the other valve as the fulcrum or pivotal support, the weight-1.6 being lifted, but acting to close whichever port is in communica tion with the exhaust as soon as the pressure exerted by the weight is in excess of the effectual brake cylinder exhaust pressure act-ing on the valve. In the construction shown, the different areas of the valves subjected to the pressure are directly proportional to the pressure to be retained, and the weight is shown as having its center of gravity substantially over a point midway between the valves. It is obvious, however, that this specific arrangement might be modified, and a change in leverage depended upon instead of, or in addition to, the different pressure areas.

To retain the higher pressure, the handle 6 is moved to such a position as to bring the port 12 into communication with the port 7, so that the brake cylinder exhaust will be cont-rolled by the valve 14 of smaller area, and for the low pressure retaining position, the handle 6 is moved to such a position that the exhaust from the brake cylinder through the port 13 and the port 8 will be controlled by the valve 15 of larger area. The three positions of the handle are indicated by lines in Fig. 4, the high pressure retaining position being indicated by the letters HP, the

- low pressure retaining position being indicated by the letters LP, and the normal or free exhaust position being indicated by the letter N. The yoke 19 is loosely hung upon the valves 14 and 15, and is prevented from jarring out of position by means of guide pins 2 1. and 25 which are secured in the upper part of the main valve casing 5 and extend through openings in the ends of the yoke.

The construction is extremely simple, and both the high and low pressure retaining ports are direct, so that there is very little opportunity for leakage of any kind, and the means for supporting the weight are such that substantially no friction is encountered in the operation of the valves, the amount of pressure retained, therefore, being directly in proportion to the weight and its actual effect on the valve controlling the ort.

What I claim is:

1. In a pressure retaining valve, a brake cylinder exhaust port; automatic valves controlling communication with said exhaust port, said valves having different areas subjected to the pressure of the escaping air; means for causing the escaping air to act on said valves selectively; a weight adapted to act on both the said valves; and a support for said weight interposed between the weight and the valves, and resting directly on the said valves.

2. In a pressure retaining valve, a con trolling member consisting of a three-way cock interposed between the brake cylinder exhaust and the pressure retaining valve; a direct outlet adapted to be opened when the said three-Way cock is in one position; ducts controlled by said three-Way cock in addition to said direct outlet; supplemental valves controlling said ducts and having different areas subjected to pressure; a weight arranged to act on both the said valves; and a yoke supported at one end on one of said valves, and at the other end on the other of said valves, the weight resting on the yoke at a point between the'valves.

3. In a pressure retaining valve, the combination with a cock adapted to control selectively a plurality of ports; of valves controlling two of said ports; a yoke or lever engaging said valves and tending to hold them seated; and a weight bearing on said yoke at a point between the parts which engage the valves.

4:. A pressure retaining device comprising automatic valves controlling separate ports leading from a source of pressure, said valves differlng 1n the area exposed to the pressure; a load common to both valves and.

adapted to act on either valve which is subjected to pressure; and means for causing the pressure to act on said valves selectively. In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

' GEORGE O. HAMMOND. Vitnesses JNo. F. MALONEY, WV. F. NIooL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G.

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