US1765578A - Angle-cock device - Google Patents

Description

June 24, 1930. FARMER 1,765,578

ANGLE COCK DEVICE Filed Nov. 24, 1928 INVENTOR CLYDE C. FARMER ATTORNEY Patented June 24, 1930 UNITED STATES PATENT OFFICE CLYDE C. FARMER, OF PITTSBURGH, PENNSYLVANIA, ASSI-G-NOR TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA ANGLE-COCK DEVICE Application filed November 24, 1928. Serial No. 321,546.

This invention relates to fluid pressure brakes and more particularly to an angle cock device for opening communication through the brake pipe when two train sections are connected together.

One object of the invention is to provide an angle cock device having a by-pass valve controlled by means which are automatically actuated when the plug valve of the angle cock is opened slightly to permit the fluid from a charged train section to flow into an uncharged train section without causing a too rapid rate of decrease in brake pipe pressure on the charged portion of the brake pipe.

Another object of the invention is to provide an angle cock device of the type specified with means for measuring the time between the cracking of the angle cock plug valve and the Wide opening thereof to pre vent a sudden drop in the fluid pressure of a charged brake pipe when an uncharged train section is coupled to a charged section.

Another object of the invention is to provide an angle cock device of the character mentioned which is simple in construction and reliable and exact in function under all conditions of service. 1

The invention also comprises certain me and useful improvements in the construc tion, arrangement and combination of the several parts of which it is composed, as will be hereinafter more fully described and claimed.

In the accompanying drawing, the single figure is a diagrammatic sectional View of an angle cock device embodying my invention.

In cutting an uncharged section of a train into a charged section, it is customary to crack open the angle cock plug valve to permit the uncharged section of the train to charge, the opening through the angle cock being such as to prevent a too rapid rate of decrease in brake pipe pressure on the charged portion of the brake pipe. A sudden drop in brake pipe pressure would cause undesired emergency in the charged section of the train.

Some train men are capable of so opening the angle cock as to cause the brake pipe pres sure to drop in the charged portion of the train at such a rate as to cause a service re duction, even though the feed valve tends to maintain the brake pipe pressure against such flow. When a brake pipe reduction of possibly eight pounds is thus obtained on three or four cars adjacent the uncharged section of the train, then the angle cock can be opened wide without causing undesired quick action. This is due to the triple valves having moved to service position against the graduating spring, in which position an increased ditferential over the triple valve piston is required to move the triple valve piston to emergency position. This increased differential is hard to obtain, especially on-account of the wide opening of the service port which permits a rapid rate of drop in the auxiliary reservoir pressure. Also the brake cylinder pressure obtained in service acts on the quick action piston of the triple valve in such a manner as to tend to prevent such piston from acting even if the triple valve did go to emergency.

By my present invention, an angle cock device having a by-pass that is normally closed by a valve piston is provided with pneumatic means which are operated by the variation of the fluid pressure on one side of the valve to open and close the bypass valve of the angle cock, so that a time period, proportional to the pressure in the charged section of a train, is required between the cracking of the angle cock plug valve and the wide opening thereof to prevent a sudden rate of drop of the brake pipe pressure in the charged train section until the fluid pressure in the uncharged section coupled thereto has been built up a predetermined amount.

As shown in the drawing, the angle cock device may comprise a casing 1 containing the usual plug valve or key 2 adapted to be operated by the usual handle (not shown). The valve 2' is provided with a passage 8 adapted in the open position of the valve to connect the conduit 4 at the brake pipe end of the angle cock with the conduit 5 at the flexible hose end. The valve 2 has a side port 6 0 en to conduit 5 when the valve is closed.

ssociated with the casing 1 is a cylinder 7 containing a valve piston 8 adapted to control a by-pass 9 through an opening 10 having a seat rib 11. At one side, the valve piston 8 is subject to the pressure of a coil spring 12. At the end of a train, the valve piston 8 is held seated against the seat rib 11 by the spring 12 and intermediate the ends of a train the valve piston is opened by the pressure of the brake pipe fluid acting over its entire area.

A chamber 13 formed in the casing contiguous to the cylinder 7 is connected to the plug valve 2 by a passage 14 and to the outer end oi the cylinder 7 by a passage 15.

The cylinder 7, at the spring side of the valve piston 8, is connected to another cylinder 16 by a passage 17 having a vent 18 therein open to the atmosphere. The flow area of the passage 14 is greater than that of the vent 18 so that a pressure can be built up in chamber 13 for a purpose to be described.

The outer edge of the valve piston 8 is formed with a seat rib 19 adapted to engage a gasket 20 in the head of the cylinder and close the passage 15 when the valve piston is unseated from the seat rib 11.

Mounted in the chamber 21 of cylinder 16 is a hollow piston 22 which terminates at its rear end in anenlarged piston 23 that is disposed in the chamber 24 of a cylinder 25 of greater diameter thanthe cylinder 16.

At. one side, the piston 22 is subject to the pressure of a coil spring 26 which encircles a stem 27 carried by the head 28 of cylinder 25.

The piston 23 is provided with a cup packing 29 adapted to seal the head of the piston with the, wall of the cylinder 25 when the piston 22 is forced outwardly, so that the fluid will be retained in chamber 24 for the purpose or" retarding or cushioning the action of piston 22. It will thus be noted that the cylinder 25 and piston 23.constitute a dash pot which functions in a manner to be described to prevent a too rapid rate of decrease in brake pipe pressure in the charged portion of the brake pipe when two train sections are being connected together.

Near one end, the wall of the cylinder 16 is provided with a plurality of ports 30 which vent to the atmosphere through a pas sage 31 formed in the wall ofthe cylinder,

29, the ports 30 and vent 31 communicating with a chamber 32 on the side of the piston 23 opposite to the chamber 24. ;Agroove 33 is formed in the wall of the chamber 24 near the head 28 of the cylinder 25. The ports 30 and the groove 33 are so disposed that when the pistons 22 and 23 are at the outer end of their stroke the head of the piston 22 will expose the ports 30 to permit In connecting a charged section of train to an uncharged section, the plug valve 2 is turned from closed toward open position an amount suflicient to only permit a slow drop in pressure in the conduit 4. Fluid pressure from the conduit 4 flows through the passage 3 and conduit 14 to chamber '13.

Since the valve piston 8 is seated on the seat rib 11, fluid from the chamber 13 flows through passage 15 into the chamber 34 and thence through passage 17 to the atmosphere by wayof the vent 18 and also into the cham ber 21 and thereby acts on piston 22.

The flow area of conduit 14 is greater than that ofthe vent 18, so'that pressure can be built up in chambers 13 and 34 to retain the valve piston 8 seated on the seat rib 11 to close the opening 10.

As the fluid pressure in the chamber 13 builds up, the pressure ofthe fluid in chamber 21 will also buildup to a point suflicient to cause pistons 22 and 23 to gradually move outwardly. This action compresses the fluid in chamber 24, which normally is at atmospheric pressure, so as to increase the resistance to the piston movement. However, the pressure of the fluid in chamber 21 gradually increases, so that piston 22 will be moved an amount suflicient to uncover the ports 30.

The capacity of the ports 30 is greater than 2.".

the capacity of the'conduit 14, so that the pressure is suddenly vented from the chamber 34, thereby permitting the fluid under full pressure in the train pipe to force the valve piston 8 from the seat rib 11.

After the valve piston 8 is unseated from the seat rib 11, the plug valve 2 can be opened wide, to the position shown in the drawing, without causing any undesired eflect.

When the pistons 22 and 23 reach their extreme outward positions, the pressures are suddenly balanced on the opposite sides thereof through the groove 33, so that after the plug valve 2 is opened and the passage 17 thus lapped, the pistons 22 and 23 are gradually returned to normal position by spring 26. In this way the return of these pistons is retarded more than would be the case if the pressure built up by the outward movement of piston remained effective in chamber 24. Furthermore, it would be undesirable to have the pistons 22 and 23 suddenly returned to their normal position as would occur if the built up pressure in chamber 4 was not vented, because a sudden return movement of pistons 22 and 23 would tend to increase the pressure of fluid in the chamber 34, thereby causing the valve piston 8 to return to the seat rib 11. The value of spring 26 is such as is necessary to move the pistons 22 and 23 against the resistance of friction, and therefore in the outward movement of these pistons has no. appreciable eflect thereon.

If two trains, or two sections of a train are brought together, and both sections are charged, the uncharged volume in the connecting hoses is suflicient to cause quick action it the angle cock at either end is suddenly opened. Therefore, the angle cock on one car is operated in the manner described above, to time the opening of the valve piston 8 in that angle cock. Since a build up of approximately five pounds pressure in the hose and on the face of the valve piston 8 outside the seat rib 11 in the angle cock of the other car is suflicient to open the by-pass valve of such car, undesired emergency would thus result in spite of the timed operation of the other by-pass valve.

In order to prevent this action, air flowing into the hose from the first angle cock is per mitted to flow through port 6 in the plug valve 2 of the second angle cock which is in closed position, in which position passage 3 registers with the conduit 14:, and thus equalizes the fluid pressure acting on the valve piston 8 so as to prevent the opening of the valve piston 8 until the piston 22 operates to vent the chamber 34 of the second angle cook.

The hose thus becomes substantially charged before the brake pipe of the two portions of the train become connected.

It will be noted that the outward travel of pistons 22 and 23 depends upon the rate of pressure built up in chamber 21. Since the rate of charging the uncharged section of a train depends upon the pressure head of the fluid pressure supply in the charged portion of the train, it is obvious that the rate of operation of the timing element may vary in proportion to the head of the fluid pressure supply, so that with varying brake pipe pressures the timing element will always operate to open the bypass valve as soon as possible, that is to say, with a high brake pipe pressure head the pistons 22 and 23 will be actuated quickly, and with a lower brake pipe pressure head it will require a longer time to move these pistons to their extreme outward position.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A device of the class described comprising a cock, and having a passage for establishing communication from one side of the cock to the other, valve means for the passage, and pneumatic means for actuating the valve means when the pressure of fluid at one side of the cock increases or decreases a predetermined amount.

2. A device of the class described comprising a cock, and having a passage for establishing communication from one side of the cock to the other, and means actuated automatically by the variation of fluid pressure on one side of the cock for opening and closing the passage.

3. An angle cock comprising a cock, valve means for controlling communication through a passage from one side of the cock to the other, and means for timing the action of the valve means.

4. An angle cock device comprising a cock, and having a passage for establishing communication from one side of the cock to the other, a valve for controlling the flow of fluid through the passage, a chamber communicating with the cock and with the valve, and means actuated by the pressure of fluid in the chamber for timing the operation of the valve.

5. An angle cock device comprising a cock, and having a passage permitting the flow of fluid under pressure from one side of the cock to the other, a cylinder communicating with the passage, a valve piston in the cylinder for closing the passage, a chamber communicating with the cock and also with the cylinder whereby the pressure of fluid at one side of the cock will act on the valve piston to close the passage, and means for reducing the pressure of fluid in the cylinder to release the valve piston when the pressure of fluid in the chamber reaches a predetermined amount.

6. An angle cock device comprising a cock, and having a passage permitting the flow oi fluid under pressure from one side of the cock to the other, a cylinder communicating with the passage, a valve piston in the cylinder for closing the passage, a chamber communicating with the cock and also with the cylinder,

and a dash pot actuated by the fluid pressure in the chamber for varying the amount of fluid pressure in the cylinder.

7. An angle cock device comprising a cock, and having a passage permitting the flow of fluid under pressure from one side of the cock to the other, a cylinder communicating with the passage, a valve piston in the cylinder, a chamber communicating with the cock and also with the cylinder, and means actuated by the amount of pressure in the chamber for actuating the valve whereby the passage is opened to permit the flow of fluid around the cock and the communication between the cylinder and chamber is closed.

In testimony whereof I have hereunto set my hand, this 22nd day of November, 1928.

CLYDE G. FARMER.

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