US1169304A - Electric pump-governor. - Google Patents

Description

w. v. TURNER.

ELECTRIC PUMP GOVERNOR.

APPLICATION FILED nov= 25. |914.

1,169,304# Patented Jan.25,19 16.

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/ l i 2 w WITNESSES INVENTQR 155 tion through a passage UNITED sms PATENT caricia y WALTER V. TURNER, 0F EDGEWOOD, PENNSYLVANIA, ASSIGNOR T0 THE WESTING- HOUSE AIR BRAKE COMPANY, 0F WILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

lEl'nlilCTRI() PUMP-GOVERNOR.

Specification of Letters Patent. v Patented Jan. 25, 1916.

Application led November 25, 1914. Serial No.y 873,891.

27, 1912. While governors of the above type operate satisfactorily in ordinary service, where the operating conditions are severe, the valve pistons sometimes become worn to such an extent as to permit excessive leakage, and as heretofore constructed, the governor is then apt to cut in with too short a range 'between the cutting in and, cutting out pressures.

The principal'object of my invention is to provide an improved electric pump governor of the puppet valve type in which the effect of leakage is reduced to a minimum, so that the pump governor may be kept in service eventhough the parts have become worn to a considerable extent.

In the accompanying drawing, the single figure is a central vertical section of an electric pump governor of the puppet valve type embodying my improvement.

According to the construction shown in the drawing, the pumpgovernor may comprise a casingl having a main piston chamber 2 containing piston 3 for actuating the of an adjustable spring 10, so that only av small area of the valve piston is then subject to pump pressure. Fluid at pump pressure is also supplied through passagel 11 to one face of a cut-out valve piston 12 which is normally held to its seat 13 by an adjustable spring 14.

The respective spring chambers 15 and 16 of the springs 10 and 14 are in communica- 17. and the spring chamber 10 .is provided with an atmospheric exhaust portv 18.

A passage 19 controlled by the movement yof the cut-out valve piston 12 leads to the piston chamber 2 anda passage 2Q opening into the chamber back of the cut-in valve plston 8 1s controlled by a seat 21 on the piston 3, so that outward movement of the piston opens communication from passage 20 to the plston chamber 2.

In operation, the switch 4 being closed,

the pump operates to compress fluid andthe seated areas vof the valve pistons 8 and 12 are subjected to the rising pump pressure. The relative tensions of the ,springs 10 and 14 are so adjusted that the cut-in valve piston 8 is first operated by pump pressure, so that when the pump pressure rises to the predetermined degree for which the spring 1.0-is adjusted, the valve piston 8 is lifted from its seat 9, instantly exposing the full area of the valve piston to pump pressure. This causes the quick movement of the valve piston 8 to its rear seat 22, closing communication between spring chamber 15 and passage 20. Fluid compressed by the pump can now tlow from passage 7 through chamber 23, and groove 24 to passage 20. Fluid at pump pressure now acts against the eX- posed area of the seat 21 on switch piston 3, but this area is so small that the pressure of fluid thereon is insufficient to `overcome the resistance of the spring 5. Upon a further rise in pump pressure, the cut-out valve piston 12 is lifted from its seat 13,l exposing the full area' to pump pressure, so that a quick movement of the cut-out valve piston to its rear seat 25 is eHected. Fluid under pressure can now flow directly to the piston chamber 2 through passage 11, chamber 26, and passage 19, so that the piston 3 operates to quickly shift the switch 4 to its cutout position. The cut-in valve piston 8 is held to its seat 22, since the seated area is subject to the atmospheric pressure spring chamber 16 is also open to exhaust port 18 by way of passage 17, the cut-out- -valve piston 12 is likewise held to its seat'f2`5,

in?. spring chamber 15, which is open tov the 'atm .mosphere through eXhaustport 18 andlas Both the cut-in and cut-out valve pistons will now remain in the cut-out position,"

until the pump pressure has been reduced to the predetermined cutting-in point, as determinedby the spring 10 and the area enposed to the atmospheric pressure at the seat 22 and since this area is less than the exposed area at seat 25, the cut-in valve piston will be operated first. When the valve piston 8 lifts from the seat 22, fluid under pressure from piston chamber 2 can floW through passage 20 to spring chamber 15, and since this How is at a greater rate than the rate of escape through the exhaust port 18, the fluid pressures on opposite sides of the valve piston 8 tend to equalize and thus permit `the spring 10 to quickly yshift the valve piston to its seat 9. Fluid under pressure also flows from spring chamber 15 through passage 17 to springchamber 16 Where the pressure acts on the exposed area at seat so as to lift the cut-out valve piston 12 from its seat '25.. The full area of the valve piston being now exposed to the fluid pressure in spring chamber 16, the valve piston 12 is quickly shifted to its seat 13. The admission of fluid under pressure same,

to the switch piston 3 is thus cut off While the venting of fluid from the piston chamber 2 through passage 20 and spring chamber 15 to exhaust port 18, permits the spring 5 to shift the piston to its inner position, closing the switch 4.

When the governor is in its cut-in posi-A tion, any leakage past the cut-in valve seat 9 can escape through groove 2.4, chamber 15, and exhaust port 18. Leakage past the cutout valve seat 13 Will escape through 'a groove 27, annular groove 28 in valve piston 12, and passage 29 to the springchamber above the switch piston 3, which chamber is open to the atmosphere, as is usual.

It will also be noted that in case the valve piston 12 becomes Worn, any leakage around the valve piston, when the same lifts from its seat 13 will escape by Way of the passage 29.

By constructing the governor in accordance with the present invention, leakage due to Wear of the valve pistons is prevented from interfering With the normal action of the governor, so that the governor can be kept in service for a longer period of time than heretofore.

. Having now describedmy invention,what I claim as new and desire to secure by Letters Patent, is:

1. A pump governor comprising a, pump controlling device, a piston for actuating a passage through which fluid under pressure is admitted to the control piston, a cut-1n valve piston for controlling a passage through which fluid is released from the control piston, and an exhaust passage communicating with an annular groove in the cut-out valve piston for venting fluid leaking around the cut-out valve piston.

2. A pump governor comprising a pump controlling device, a piston for actuating a cut-out valve piston for controlling.

same, a cut-out valve piston subject to the opposing pressures of the pump and an adjustable spring for controlling a passage through which fluid is supplied to the control piston, and a cut-in valve piston subject to the opposing pressures of the pump and an adjustable spring for controlling a passage through which fluid is released from the control piston, the cut-iii valve piston being adapted to be operated by an increase in pump pressure, before the cut-out valve piston is operated,to rclose communication from the control piston release passage to a restricted exhaust port.

3. A pump governor comprising a pump controlling device, a piston for actuating same,.a. cut-out valve piston subject to the opposing pressures of the pump and an adjust-able spring contained in a chamber, and a cut-in valve piston subject to the opposing'pressures of the pump and an adjustable spring contained in a chamber, both spring chambers being in constant-communication With a. restricted exhaust port.

4. A pump governor comprising a pump controlling device, a piston for actuating same, .a cut-out valve piston subject to the opposing pressures of the pump and an ad-4 justable spring contained in a chamber, a cut-in valve piston subject to the opposing pressures of the pump and an adjustable spring contained in a chamber, both spring chambers being in constant communication with a restricted exhaust port, a passage for releasing fluid from the control piston chamber through said restricted exhaust port, which is closed upon movement of the cut-in valve piston to the cut-out position,

and a passage adapted to be opened upon movement of the cut-out valve piston to cutout position for admitting fluid to the con-` trol piston chamber.

5. A pump governor comprising a pump controlling device, a piston for lactuating same, a cut-out valve piston for controlling a passage through which fluid is admitted to lthe control piston chamber, and a cut-in valve piston for controlling a passage through which fluid is released from the controll piston chamber,-the release passage being controlled by the switch piston.

6. A pump governor comprising a pump controlling device, a piston for actuating same, a cut-out valve piston adapted to seat in the cut-out position and expose a restricted area to atmospheric pressure, and a cutin valve piston adapted to seat in the cutout position and expose a restricted area to atmospheric pressure, the exposed area of the cut-out valve piston being greater than the exposed area of the cut-in valve piston.`

opposing pressures of the pump and an ad 130 justable spring and movable to cut-out. posipiston being greater than the exposed area 10 tion fit one degree of pump pressure, and a of the cut-in valve piston. cut-out vulve piston subject to the opposing In testimony whereof I have hereunto set pressures ot the pump and an adjustable my hand.

5 spring und movable to eutsout position at u higher degree lof pump pressure, both valve WALTER V TURNER' pistons being' provided Wlth seats for eX- Vltnesses: posing restricted areas to atmospheric pres- A. M. CLEMENTS,

sure, the exposed area of the cut-out valve S. W. KEEFER.

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