US1093660A - Pressure-governor for pumps. - Google Patents

Description

W. V. TURNER.

PRESSURE GOVERNOR IOR PUMPS.

APPLICATION FILED SEPT. 16, 1907.

1,093,660. Patented Apr. 21, 1

WITNESSES INVENTOR ml M UNITED STATES PATENT OFFICE.

WALTER V. TURNER, OF EDGEWOOD, PENNSYLVANIA, ASSIGNO'R TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF PITTSIPURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

PRESSURE-GOVERNOR FOR PUMPS.

Specification of Letters Patent.

Patented Apr. 21, 1914.

To all whom it may concern:

Be it known that I, \VALTER V. TURNER, a citizen of the United States, residing at Edgewood, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Pressure-Grovernors for Pumps, of which the following is a specification. i

This invention relates to pressure governors for pumps, and particularly to electric pump governors.

In a prior construction of this character, the action of the controlling device or switch isgoverned by a high pressure regulating mechanism, the movable abutment of which is subject to pump pressure and causes the pump-to be cut out when a predetermined pump pressure is attained, and a low pressure regulating mechanism, the movable abutment of which is subject to pump pressure and causes the pump to be cut in, upon a predeterminedreduction in pump pressure.

One object of my invention is to provide an improved device of this character, wherein the high and low tension regulating mechanisms are actuated by a single movable abutment. .As at starting, the pump piston is subject to the fluid pressure of the system, the pump motor is obliged tostart under a heavy load, thereby consuming an excessive current, Wlnch 1s very liable to burn out or damage the motor armature. For this reason, a resistance has sometimes been interposed in the motor tircuit, which is adapted to be gradually and automatically cut out, asthe motor armature picks up speed. In such constructions, as the resistance is cut in or cutout the contacts are more or less liable to burn, by reason of the formation of arcs, and therefore another object of my-invcntion is to obviate this difli-.

culty, by providing qulck acting switches for controlling the resistances in the motor circuit.

Another object of my invention is to provide means for adjusting the range between the high and low tension operating pressures of the governor.

Still another object is to provide an improved governing device, generally, adapted to secure a more accurate and positive action of the operating parts.

In the accompanying drawings Figure 1 is a central sectional view of a governor device embodying my improvements; Fig. 2 a similar view of the main supply valve, showing the same in its position to cause the pump to be cut out; Fig. 3 a face View of the main supply valve, showing the arrangement of ports and cavities; Fig. 4 a plan View of the main slide valveseat, showing the arrangement of ports and Fig. 5 a face view of the auxiliary valve of said main slide valve. According to a preferred construction, the improved governor device may comprise a casing 1, as shown in Fig. 1 of the drawing, having avalve chamber 2 containing main slide valve 3, and an auxiliary valve 4, havmg a movement relative to said main slide valve. The valves are operated by 'an abutment having two piston heads 5 and 6, contained respectively in piston chambers 7 and 8. The main slide valve 3 controls the fluid pressure on an actuating piston 9 for an electric switch or other controlling device 10, through a port 11 leading from said piston 9 to the seat of the main slide valve.

The piston heads 5 and Gare provided with small ports 12 and 13, or other means, to permit leakage of fluid from valve chamher 2 to the chambers 7 and 8, and the abutment is actuated by releasing fluid under pressure from the piston chambers 7 and 8 by means of the respective high and low tension release valves 14 and 15, controlled by a diaphragm or movable abutment 16, which is governed by the opposing pressures of an adjust-able spring 17, and the pump or reservoir pressure. The spring 17 is adjusted to open the release valve 15, when the pump pressure in diaphragm chamber 24 has reduced tothe desired cutting in degree.

The main slide valve chamber 2 is in open communication with reservoir 18 and pump 19 through pipe 20 and-port 21.

The switch 10 being closed, the pump 19 compresses air into the reservoir 18 and through pipe 20 and passage 21 into the valve chamber 2, whence it leaks past the piston heads 5 and 6 into the piston chambers 7 and 8. If the main slide valve 3 is not in its cut in position at this time, it will the diaphragm 16. The chamber 8 is there fore open to the atmosphere through passage 22, passage 23, opening into the diaphragm chamber 24, around the open release valve 15, throughpassage 25, passage 26' leading to the main slide valve seat, cavity 27, in the main slide valve, which registers with the passage 26, and also with an exhaust port 28, so that fluid in chamber 8 is vented, and the pressure in chamber 7 moves the abutment and main slide valve to the position shown in Fig. 1.

It will be noted that in the cut in position of the parts, as shown in Fig. 1, the passage 32 leading to piston chamber 7, registers with cavity 33 in the main valve 3 which cavity also registers with passage 34 leading to the regulating valve 14, but as the valve 14 is now closed, the fluid under pressure which leaks past the piston head 5 to piston chamber 7 is prevented from escapmg.

As the pump continues to compress air, the pressure rises in the reservoir 18 and is communicated to the valve chamber 2 and the fluid'leaking through the port 13 in piston head 6, passages 22 and 23 into chamber 24, acts on diaphragm 16. In this position, it will be noted that the passage 26 is cut off from the exhaust port 28, consequently the pressure rises on the diaphragm 16, until sufficient to overcome the pressure of the spring 17 whereupon the diaphragm moves away from the valve 15 and permits the same to close. Upon further movement the release valve 14 is opened. The degree of fluid pressure at which the valve 14 is opened, may be adjusted by varying the distance through which the diaphragm'16 and its stem29 moves to engage the release valve 14, the pressure required to compress the spring increasing as it is further compressed. For this purpose, the-stem- 29 is provided with an adjustable rod 30, which may have a screw threaded engagement with the stem 29, so that, by turning the rod 30,

. the-same may be lengthened or shortened.

.A look nut 31' may be provided, having screw threaded engagement with the rod 30,

so thatthe rod and stem can be securely locked in their adjusted position.

Upon opening the high tension release valve 14, fluid is first vented from the piston chamber 7, through passage 32, cavity 33 in the main slide valve, and port 34, which leads to the release valve 14. The abutment thereupon moves, and, on its preliminary movement, shifts the auxiliary valve 4-, which then connects, through its cavity 35, the ports 36 and 37,'so that an additional exhaust port is open to the chamber 7 from passage 32, cavity 33 in the main slide valve, port'36, cavity 35, in the auxiliary valve, and port 37, opening to the large cavity 27, which is in communication with the exhaust port 28. In this manner, the quick release of fluid under pressure from the piston chamber 7 is assured, even though the vrelease valve 14 should not fully open. The movement of the auxiliary valve, also slightly uncovers the port 38, which registers in this position with passage 22, leading to piston chamber 8, so that a large bypass, for the flow of air from the valve chamber to said chamber 8 is provided, thus insuring the maintenance of fluid pressure on said piston head, regardless of any leakage which may occur, and the consequent positive and quick movement of the abutment and main valve 3. The main valve is then shifted to the position shown in Fig. 2, in which the passage 11, leading to the actuating piston 9, is uncovered, so that there is a large flow of air to said piston, rapidly shifting the same and thereby opening th switch 10, cutting out the pump.

Communication from the piston chamber 7 to the passage 34 and the release valve 14 is cut off by the main slide valve. Leakage of air past the valve 14 is thus prevented, which would otherwise occur, by reason of the vent valve 14 being open, and the leakage of fluid through the port 12 in the piston head 5.

When the pump pressure reduces to the degree of pressure for which the spring 17 is adjusted, the diaphragm shifts and permits the release valve 14 to close. ()11 further movement the release valve 15 is opened, and fluid is thereupon vented fromchamber 8, through the passage 22, passage 23, diaphragm chamber 24, past the valve 15, through passage 25, passage 26 to the cavity 27 in the main slide valve, which is open to the exhaust port 28 in this position. It will be noted that the diaphragm cham ber 24 is open to the atmosphere, also, and consequently the slight preliminary opening of the valve 15 at the beginning of the movement of the diaphragm 16 in this direction releases the fluid in chamber 24 and thus accelerates the movement, insuring the full opening of said release valve. The abutment is then shifted by the pressure in chamber 7 and moves the auxiliary valve to close the ports 36 and 38 in the main slide valve. Further movement of. the abutment shifts the main slide valve to the position shown in Fig. 1, in which the cavity 27 connects the passage 11, to the actuating piston 9, with the exhaust port 28, thus venting the fluid at the face of said piston, causing the same to be quickly shifted by its spring to close the switch 10 and start the pump. The movement of the mainvalve 3, to this position, closes the communication from the passage 26 and the release valve 15, to the exhaust port 28, so that further release of fluid from the chamber 8 is prevented.

My invention further consists in means governed by the pump pressure for varying the resistance of the pump motor circuit, thereby regulating the motor current, to prevent excessive current at starting. For this purpose, my invention comprises in a preferred form, as illustrated in Fig. I, one or more electric switches as the switches 40 and. 41, adapted to cut in or cut out resistances 42 and 43, located in the pump motor circuit. The switches 40 and 41 are controlled by pistons 44 and 45 contained in piston chambers 46 and 47 In the inner position of. the pistons 44 and 45, only a restricted area is preferably exposed to fluid pressure, so that the pump pressure, which acts thereon, must overcome the pressure of the piston spring; then, as the piston is slightly lifted from its seat, the full area of the piston is subjected to fluid under pressure, which causes the piston to assume its .outer position with a quick and positive movement.

The main switch 10 being cut in and the pump in action, fluid is compressed into the reservoir and the valve chamber 2 and flows thence through a preferably restricted port 49 and a port 48 in the main slide valve 3, to a port 50, leading to the piston 44. As the pump pressure rises to a point sufficient to overcome the tension of thepiston spring, the piston is unseated, and suddenly shifted to its outer position, closing the switch 40, and cutting out the resistance 42, correspondinglyi increasing the current to the motor.

A port 51, which is uncovered by the outward movement of the piston 44, permits the flow of air to a chamber 52 and the piston 45. When the pump pressure acting on the reduced area of piston 45 attains a certain degree according to the tension of the spring of piston 45, said piston is rapidly shifted to its outer position, closing switch 41 and cutting out resistance 43.

It is preferable to provide enlarged chambers open to the pistons 44 and 45, in order to secure ample volume to insure the rapid movement of the pistons throughout their stroke.

Upon the pump pressure rising to the degree at which the regulating mechanism is adjusted the piston 9 is shifted outwardly and opens the switch 10, causing the pump to stop, as before described. The main valve then connects the port 50 with cavity 27 and exhaust port 28, so that fluid is vented from the pistons 44 and 45 and the piston springs thereupon return the pistons to their inner position, cutting'the- resistances 42 and 43 into circuit, ready to repeat the foregoing operation.

It will thus be seen that with my improvemcnts, one or more resistances may be serially cut out of the pump circuit according to the definite increases in pump pressure corresponding with the pump load, 'thereby obtaining a positive and accurate regulation of the resistance.

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

1. A pressure governor comprising a controlling device, an actuating piston, a main valve and abutment for controlling the pres- ..sure on said actuating piston, a low tension regulating valve and a high tension regulating valve for governing the actlon of said main abutment, and a movable abutment for actuating said regulating valves.

2. A pressure governor comprising a controlling device, a high tension regulating valve and a low tension regulating valve for governing the operation of said controlling device, and a single diaphragm for actuating said valves.

3. A pressure governor comprising a con trolling device, an actuating piston therefor, means for controlling the pressure on said actuating piston, high and low tension release valves for controlling the pressure on said means, and a single diaphragm, subject to the opposing pressures of an adjustable spring and pump pressure, for actuating said valves.

4. A pressure governor comprising a controlling device, an actuating piston therefor. means for controlling the pressure on said piston, a. release valve governed by pump pressure for releasing fluid from said controlling means to operate the same, the outlet through said release valve being controlled by said means.

5. A pressure governor comprising a con trolling-device, an actuating piston therefor, a main valve and abutment for controlling the pressure on said piston, valve means for controlling the release of fluid from said abutment to operate the same, the outlet valve, and means for admitting fluid to one side of said abutment upon preliminary movement thereof.

8. A pressure governor comprising a controlling device, an actuating piston therefor,

a main valve and abutment for controlling the pressure on said piston, regulating valve mechanism governed by pump pressure for releasing fluid from one side of said abutment to actuate the same, and means in said main valve for admitting fluid to the opposite side of said abutment upon the preliminary movement of said abutment.

9. A pressure governor comprising a controlling device, an actuating piston therefor, a main valve, an auxiliary valve, having a movement relative to said main valve, and an abutment for controllingthe pressure on said piston, regulating .valve means subject to pump pressure for actuating said abutment and valves, and means operated upon the movement of said auxiliary valve,- for opening a by-pass to one side of said abutment.

10. A pressure governor comprising a controlling device, an actuating piston there for, means for controlling the fluid pressure on said piston, a regulating valve mechanism operated by a reduction in pump pressure to actuate said controlling means, and means for accelerating the reduction in pressure on said regulating valve mechanism, upon the preliminary movement thereof.

11. A pressure governor comprising a controlling device, an abutment and main valve for governing the action of said controlling device, a diaphragm subj ect'to pump pressure and a release valve actuated thereby for venting fluid from one side of said abutment to operate the same and adapted to release fluid from said diaphragm to accelerate the movement thereof.

12. A pressure governor comprising a controlling device, means for governing the action of said controlling device, a release valve and an actuating abutment therefor, operated by a reduction in vpump pressure to release fluid from one side of said meansto operate the same, and from said actuating abutment to accelerate its movement.

13. A pump governor comprising a main switch for cont-rolling the pump motor circuit, a plurality of resistances-in said circuit, aquick acting switch device for each resistance, and means operated by fluid pressure produced by the pump for operating each switch to cut out its corresponding resistance at different predetermined degrees of pump pressure.

14:. A pressure governor comprising an electric switch for controlling the pump motor circuit, a plurality of movable abutments governed by pump pressure for controlling resistances in said pump motor circuit, and means controlled by the movement of one abutment to admit pump pressure to another abutment.

15. A pressure governor comprising an electric switch for controlling the pump motor circuit, an actuating piston therefor, a main valve and abutment-for controlling the pressure on said piston, and means, operated by pump pressure, for controlling a resistance in said pump motor circuit, and ports in said main valve for controlling the fluid pressure on said means.

16. A pressure governor comprising a controlling device, a high tension regulating valvemeans and a low tension regulating valve means, for governing the action of said controlling device, a movable abutment, subject to pump pressure for actuating said valve means, and means for adjusting the range of pressure between said high and low tensions.

17. A pressure governor comprising a controlling device, a regulating valve mechanism for governing the action of said controlling device, a movable abutment, subject to pump pressure and an adjustable spring, and operated at a predetermined high and a predetermined low pump pressure to actuate said re 'ulating valve mechanism, and means for adjusting the range between said high and low pressures.

18. A pressure governor comprising a controlling device, an actuating piston therefor, a main valve mechanism for varying the fluid pressure on said piston, and a regulating valve means governed by pump pressure for controlling said main valve mechanism.

In testimony whereof I have hereunto set my hand.

- WALTER V. TURNER.

\Vitnesses:

R. F. EMERY, E. B. MACDONALD.

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