US2347939A - Governor and drain valve control apparatus - Google Patents

Description

May 2, 1944. a G, N 2,347,939

GOVERNOR AND DRAIN VALVE CONTROL APPARATUS Filed Aug. 28, 1942 INVENTOR I S1, dmey GDQw'n,

ATTORN EY Patented May 2, 1944 UNITED STATES PATENT OFFICE GOVERNOR AND DRAIN VALVE CONTROL APPARATUS Application August 28, 1942, Serial No. 456,462

3 Claims. (Cl. 303-458) This invention relates to automatic drain valve devices for fluid pressure systems, and more particularly to a combination drain valve control and compressor governor apparatus operative according to variations in pressure of air in a receiving reservoir to efiect discharge of condensate accumulating therein while controlling the associated compressor.

Various types of automatic drain valve devices have been proposed to efiect intermittent discharge of condensed moisture from the receiving reservoir of a compressed air system, such as the main reservoirs and aftercoolers associated with an air brake system upon a locomotive. In the case of a compressor equipment of the class including a fluid pressure responsive govern-or which is controlled in accordance with the receiving reservoir pressure for starting and stopping the compressor, the desired operation of a drain valve device may be effected through the medium of the governor device. It is a principal object of my invention to provide an improved drain valve control apparatus constructed and operative in combination with a compressor governor means to insure proper drainage of condensate from the associated compressed air system.

A further object of the invention is to provide a combination governor and drain valve control apparatus comprising a drain valve device, a fluid pressure responsive control device, such as a steam valve or electric switch for controlling the operation of the compressor, and a cornmon governor-relay valve device adapted to control both the drain valve and the control device? in accordance with variations in pressure of air in the receiving reservoir.

Still another object of the invention is to provide an equipment of the above type includin a fluid pressure operated drain valve device for the reservoir, a fluid pressure operated control device for the compressor, and a common governor device therefor having a rela valve portion of a suflicient capacity to supply both said fluid pressure operated devices with compressed air from the reservoir, regardless of the remote positions in which the devices may be placed.

Other objects and advantages of the invention will appear in the following more detailed description thereof, taken in connection with the accompanying drawing, wherein the single figure is a diagrammatic sectional view of a combination governor and drain valve control apparatus embodying the invention.

As illustrated in schematic form in the draw- 'ing ll.

ing, there may be provided a steam driven compressor l operative to supply compressed air to a main reservoir 2, an automatic drain valve device 3 associated with the reservoir, a steam supply valve device 4, and a governor-relay valve device 5. The compressor i may be of any suitable construction, and is adapted for operation to supply compressed air to the reservoir 2 through suitable pipes, which are not shown in the drawing. The equipment illustrated is particularly adapted for use on a locomotive, but it will be understood that the principal features of the invention may be employed in connection with other types of fluid pressure systems.

main reservoir 2, a casing section 1 bolted to the casing section '6, and a flexible diaphragm 8 which is clamped between the two casing sections in a canted position, forming on one side thereof a pressure chamber 9 and on the opposite side a chamber Ill having a drainage open- Formed in the casing section 6 is a condensate collecting chamber 12, which communicates by way of a passage l3 with the interior of the main reservoir 2. A bore 14 connects the chamber l2 with a valve chamber l5, also formed in the casing section and communicating by way of a bore l6 with the chamber 9. A double valve element [8 disposed within the valve chamber I5 is engageable with a seat 19 for controlling communication between the chambers l2 and [5, or alternatively with a valve seat 20 for controlling communication between chambers l5 and It]. The double valve element I8 is supported through the medium of a fluted stem 23 slidably fitting the bore [4, and a similar stem 24 slidably mounted in the other bore 16, the valve element and stems being in alignment with the axis of the canted diaphragm 8. The fluted stem 24 operatively engages a follower member 25 which is attached to the diaphragm 8, and which is subject to the force exerted by a coil spring 26 interposed between the follower element and an upper Wall of the chamber 9. The spring 26 normally urges diaphragm 8 downwardly and into engagement with a stop portion 21 of the casing. A coil spring 28 is interposed between the fluted stem 23 and an upper wall'of chamber [2 for urging the double valve element [8 downwardly into engagement with the seat 20, when fluid under pressure is released from the chamber 9 during operation of the device, as hereinafter explained.

The steam valve device 4 comprises a casing ment of the valve element into and out of engagement with a seat 39 formed on a wall of the casing structure separating chambers and 32.

The governor-relay valve device 5 comprises a casing section 42 and a casing section 43, between which is clamped a flexible diaphragm 44 having formed on the lower side thereof a chamber 45 and on the upper side a chamber 46. The casing section 43 has mounted therein a pair of pilot valve assemblies, which may be designated as a low pressure top 41 and a high pressure top 48, the construction of both tops being similar. The valve assemblies contained in the low and high pressure tops are designed for operation at different times to control operation of the com-- pressor for maintaining a low fluid pressure in the main reservoir 2 at one time and a high fluid pressure therein at another time. For example, if the apparatus illustrated is part of the equipment of a railway locomotive, the low pressure top 4! may be arranged to control operation of the air compressor when the associated brake valve, not shown, is in brake release position, but is cut out of operation while the high pressure top 48 i rendered operative to control the compressor when an application of the brakes is effected.

For the purpose of the present disclosure, only the elements of the high pressure top 48 need described. The valve assembly of the high pressure top 48 comprises a valve element 55 vwhich is engageable with a seat 5| provided on the casing structure for controlling communication between the diaphragm chamber 46 and a valve chamber 52, which communicates by way of a pipe 53 with the reservoir 2. The valve elemerit 55 is subject to the opposing pressures of a light spring 54, which urges the valve element away from its seat, and a metering spring 55, which acts downwardly through the medium of a follower element 56 and a flexible diaphragm 51, which is in turn subject to the pressure of air in the valve chamber 52. The force exerted by the spring 55 may be varied in accordance with the adjustment of a set screw 59.

The chamber 45 within the casing section 42 is connected with an atmospheric exhaust port 50 formed in the casing section, and contains a slide valve 6! that is constructed and arranged for operation through the medium of a follower member 52. A disc portion 53 of the follower member operatively engages the flexible dia phragm 44, and is subject to the force exerted by a coil spring 65 which is interposed between the disc portion and a recessed Wall 85 of chamber 45. The slide valve BI is urged against seat surface 58, formed on the casing section, through the medium of a loading stem 55, which is connected to a flexible diaphragm 19 that is subject to the force of a spring 'H and of compressed air in a chamber 72 communicating by way of a passage and pipe 13 with the reservoir 2. As hereinafter explained, the slide valve ii! i constructed and arranged to control the .supply of air under pressure from the res rvoir to a pipe 15, which has a branch leading to the piston chamber 35 cf the steam valve device 4 and another branch connected to the diaphragm chamber 9 of the drain valve device 3.

Since the drain valve device 3 is constructed and arranged to respond to the same variations in fluid pressure that are transmitted to the steam valve device 4 for controlling the compressor I, it will be evident that the frequency of, operation of the drain valve device will be dependent upon the rate of withdrawal of compressed air from the reservoir 2 for use in the associated air brake system or other fluid pressure system, as measured by operation of the governor-relay valve device 5 in response to changes in reservoir pressure. In the drawing, the various elements of the governor and drain valve control apparatu are illustrated in the positions assumed following operation of the compressor I to build up the pressure of air in the main reservoir 2 to a maximum value, as determined by functioning of the high pressure top 48 of the governor-relay valve device 5, it being assumed that the other or low pressure top 41 is not conditioned for operation.

With the air in the reservoir 2 and the con nected valve chamber 52 thus maintained at the maximum pressure, the diaphragm 51 is held in its uppermost position against the force exerted by the metering spring 55, so that the spring 54 is permitted to hold the valve element 55 away from the seat 5| for supplying compressed air from the chamber 52 to the diaphragm chamber 46. The pressure of air thus admitted to the diaphragm chamber 46 acts through the medium of the diaphragm 44 to hold the follower member 62 and slide valve 5| in the position shown in the drawing, wherein a shoulder on the follower member engages a stop portion SI of the casing section 42. With the slide valve Bl in this position, a cavity 83 formed therein establishes communication between a pair of ports 73a and 15a. Compressed air is thereby sup plied from the reservoir 2 by way of pipe and passage 13, port 13a, cavity 83, port 15a and pipe 15 to the piston chamber 35 of the steam valve device 4, and to the diaphragm chamber 9 of the drain valve device 3.

The pressure of air in the piston chamber 35 acts against the piston 38 to hold the valve member 36 in engagement with the seat 39, thus cutting off flow of steam to the compressor I. At the same time, the pressure of air supplied to the diaphragm chamber 9 of the drain valve device 3 acts through the medium of the flexible diaphragm 8 to maintain the valve element 18 in engagement with the seat I9. Water condensed in the reservoir 2 meanwhile is free to flow therefrom through the passage i3 to the chamber l2 0! the drain valve device.

Withdrawal of compressed air from the reservoir 2 for use in the associated fluid pressure system, which is not illustrated, finally causes suflicient reduction in the pressure of air acting in the valve chamber 52 of the relay-governor device 5 to permit the spring 55 to move the diaphragm 51 and valve element 54 downwardly until the valve element engages the seat 51. With the supply of air from the chamber 52 thus cut off, the gradual escape of air from the chamber 46 by way of an always open restricted exhaust port decreases the fluid pressure urging the diaphragm 44 downwardly, until the spring 65 becomes effective to raise the follower member 62 and the slide valve 6| to the uppermost position thereoi, this movement being limited upon engagement of the diaphragm 44 with a stop surface 9| on the upper Wall of chamber 46. As the slide valve 6| is thus moved upwardly, the cavity 83 thereof is moved out of communication with the port 15a, which is then connected by way of a passage 93 in the slide valve with the vented chamber 45.

Air under pressure is thereby vented from the piston chamber 35 of the steam valve device 4, and from the diaphragm chamber 9 of the drain valve device 3, through the communication established by the slide valve 6| as just explained. Upon the reduction in the pressure of air in the piston chamber 35 of the steam valve device, steam in the supply chamber 3| forces upwardly the valve element 36, stem 31 and piston 38, and passes through the chamber 32 and the pipe 33 to the steam-driven compressor l, which is thereby set in operation to supply compressed air to the reservoir 2.

Upon reduction in the pressure of air in the diaphragm chamber 9 of the drain valve device 3, the spring 26 is rendered effective to shift the diaphragm 8 and the follower element 25 downwardly, thus permitting the spring 28 to move the double valve element I8 away from the seat [9 and into engagement with the lower seat 20. As double valve element [8 thus traverses the distance between the two seats the relatively high pressure of air contained in the main reservoir 2 acts against any accumulated water, which may have collected in the chamber [2 by flow from the reservoir through the passage l3, and quickly drives out such water by way of the chambers l5 and I and the drainage openin II. This discharge of compressed air from the main reservoir is of course quickly terminated by engagement of the double valve element is with the lower seat 20, so that only a small amount of air is required for the operation. Drainage of water from the chamber [0 is facilitated by reason of the inclined position in which the diaphragm 8 is disposed.

When the maximum pressure of air in the reservoir 2 is restored, the diaphragm 51 and valve element 50 of the governor-relay valve device 5 will again be operated to supply compressed air to the diaphragm chamber 45. Movement of the diaphragm 44, follower member 62 and slide valve 6| to the position in which they are illustrated, in response to the increase in fluid pressure in the chamber 46, will then cause another increase in the pressure of air in the piston chamber 35 of the steam valve device 4 and in the diaphragm chamber 9 of the drain valve device 3, as already explained. The double valve element [8 of the drain valve device is thus returned to its upper seated position as shown, and in so moving again eflects momentary discharge of condensate from the chamber [2 through the communications described.

From the foregoing description it will be a ent, is:

1. In a fluid pressure equipment including a compressor and a reservoir adapted to receive fluid compressed thereby, in combination, fluid pressure operated control means for starting and stopping said compressor, fluid pressure controlled drain valve means operative intermittently to eject from said reservoir any water condensed therein, and a governor-relay valve device comprising valve means controlling communication from said reservoir to both said control means and drain valve means, a spring, a movable abutment subject to the opposed pressures of said spring and of fluid in a chamber for actuating said valve means, and pilot valve means responsive to the pressure of fluid in said reservoir for controlling the fluid pressure in said chamber.

2. In a fluid pressure equipment including a compressor and a reservoir adapted to receive fluid compressed thereby, in combination, fluid pressure operated control means for starting and stopping said compressor, drain valve means responsive to either an increase or a decrease in fluid pressure for ejecting condensate from said reservoir, and a governor-relay valve device comprising a slide valve operative in one position to supply fluid from said reservoir to said control means and said drain valve means and operative in another position to vent fluid under pressure from said two means, movable abutment means operative to shift said slide valve from one position to the other, and pilot valve means responsive to variations in the pressure of fluid in said reservoir for controlling the fluid pressure acting on said movable abutment means.

3. In a fluid pressure equipment including a compressor and a reservoir adapted to receive fluid compressed thereby, in combination, fluid pressure operated control means for starting and stopping said compressor, fluid pressure controlled drain valve means operative intermittently to eject from said reservoir any water condensed therein, and a governor-relay valve device operative to control communication from said reservoir to both said control means and said drain valve means.

SIDNEY G. DOWN.

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