US2345380A - Drain valve mechanism - Google Patents

Description

March 28, 1944. w. B. KIRK DRAIN VALVE MECHANISM Filed July 30, 1942 ATTORNEY Patented Mar. 28, 1944 DRAIN VALVE MECHANISM Walter B. Kirk, East McKeesport, Pa., assigner to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application July 30, 1942, Serial N0. 452,882

Claims.

This invention relates to drain valve mechanism for discharging condensate from uid pressure storage reservoirs, and more particularly to an automatically timed drain valve apparatus operative at predetermined intervals.

In order to insure proper drainage of condensed lmoisture from the receiving reservoirs of a, compressed air system, such as the main reservoirs and aftercoolers associated with an air lbrake system on a locomotive, it has been-proposed to equip such a reservoir with a fluid pressure actuated drain valve device, together with means for effecting intermittent operation of the drain valve device in accordance with variations in :pressure in a brake cylinder, or in response to operation of a compressor governor. While such means for controlling a drain valve mechanism have been employed with success in certain classes of railway service, there is nevertheless a need for means effecting periodic operation of a drain valve at predetermined intervals of time, regardless of the operationr of the associated brake system or pump governor device.

'I'he principal object of my invention is to provide an improved drain valve equipment including means for effecting periodic discharge ofA condensate from a reservoir at regular intervals.

Other objects and advantages of the invention will appear in the following more detailed description thereof, taken in connection with the accompanying drawing, in which the single gure represents in diagrammatic form the several elements, shown partly in section, of an automatic drain valve mechanism constructed in accordance with the invention.

The equipment illustrated in schematic form in the drawing comprises a main'reservoir I, which is adapted to be charged with compressed air by means of a suitable compressor, not shown, and which has associated therewith a fluid pressure actuated drain valve device 2, a timing reservoir 3 and a timing valve device 4. It will be understood that in actual practice the drain valve device and timing valve device may be associated with more than one main reservoir, or with an aftercooler or the like, depending upon the equipment carried by the locomotive.

The drain valve device 2 comprises a casing y tube I0. Formed in the casing section 5 is a con.- densate collecting chamber I2 which communicates by way of a passage I3 with the interior of the main reservoir I. A bore I4 connects the chamber I 2 with a valve chamber I5, also formed in the casing section and communicating by way of a bore I6 with the chamber 9. A double valve element I8 disposed within the valve chamber I5 is engageable with a seat I9 for controlling communication between the chambers I2 and I5, or alternatively with a valve seat for controlling communication between chambers I5 and I 9. The double valve element I8 is supported through the medium of the fluted stem 23 slidably tting the bore I4, and a similar stem 24 slidably mounted in the other bore I 6, it being noted that the valve element and stems are inclined in alignment with the axis of the canted diaphragm 1. The uted stem 24 operatively engages a follower member 25 which is attached to the diaphragm 1, 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 1 downwardly and into engagement with a stop portion 21 of the casing. A coil spring 28 is interposed between the uted stem 23 and an upper wall of the chamber I2 for urging the double valve element I8 downwardly vinto engagement with the seat 20, as shown in the drawing, in which position of the valve element communication is maintained between the chamber I5 and chamber I2.

The timing valve device 4 comprises a cylindrical lcasing 30 having an end wall 3|, a closure member 32 having screw-threaded connection with the open end of the casing, and a piston valve element 34 which is slidably mounted in a bore 35 formed in the cylindrical casing. A lchamber 36 is formed between the valve piston 34 and the end wall 3 I which chamber communicates by Way of passages 31 and a pipe 38 with .the lowermost portion of the timing reservoir 3. The valve piston 34 carries a sealing gasket 39 which is adapted to engage an annular seat rib 40 formed on the wall 3I for cutting oi communication between the timing reservoir 3 and the chamber 36. A coil spring 43 is interposed between the valve piston 34 and the closure member 32 for urging the valve piston into seated position as shown in the drawing. The reference character 45 designates the chamber within which the spring 43 is disposed, vwhich chamber communicates with the atmosphere through a passage 46 in the closuremember, and is also normally in communication lby way of a port 41,

passage 49 and pipe 48 with the chamber 8 of the drain valve device 2. A sealing rib 50 carried on the end of the valve piston 34 is adapted to engage a gasket 5I, carried in the closure member,vupon movement of the valve piston 34 away from the seat rib 40, as hereinafter explained.

The valve piston 34 is also constructed and arranged to control communication between the chamber 36 and pipe 48 by Way of a port 53, which is formed in the casing 30 and is adapted to be uncovered by the valve piston upon movementto its right-hand position. The apparatus is arranged to permit drainage of any condensate deposited in the timing reservoir 3, from which the iluid can flow downwardly by way of the pipe 38, chamber 36, port 53 and pipe 48 to a' discharge pipe 55, which communicates with the atmosphere by way of a restricted opening 56.

An always open communication is provided for connecting the main reservoir I and the timing reservoir 3, comprising a pipe 58 having interposed therein an air strainer device 59 of suitable construction, and a choke fitting having a restricted passaged 60 for limiting the rate of flow of compressed air to the timing reservoir. In operation, air supplied under pressure to the main reservoir I flows therefrom by way of the pipe 58 to the timing reservoir 3 at a rate.

the entire pressure area of the piston valve ele- 1 ment, which thereupon forced to its right-hand position, with the rib 58 in engagement with the gasket 5I. In so moving, the piston valve element 34 uncovers the port 53, through which compressed air flows from the chamber 35 to the pipe 48 and thence to the chamber 8 of the drain valve device 2. It will be understood that although air under pressure meanwhile is gradually vented from the pipe 48 to atmosphere by way of the restricted passage 56, the rate of such venting is so controlled as to permit the initial increase in fluid pressure in the chamber 8 necessary to effect operation of the drain valve device. y A

The pressure of air thus supplied to the pressure chamber 8 operates the diaphragm 1, Vfollower member 25, and stem 24 to shift the dou-'- ble valve element I8 away from the lower seat 20 and into'engagement with the upper seat I9, in opposition to the combined forces of the springs 26 and 28. As the double valve element I8 traverses the distance between the two seats, the pressure of air contained in the main reservoir I acts' againstthe water which has accumulated inthe chambers I2 and I5 to effect quick discharge thereof, the condensate being driven out past the seat 20 and through the chamber 9 and drainage tube I0. It will be understood that movement of the double valve element I8 into engagement with the upper seat I9 is accomplished quickly, so that the amount of compressed air required for this operation is limited. Y y

When the escapeof air from the pipe 48 by way of the restricted passage 56 has eifected a predetermined reductionin the fluid pressure in the chamber 36 and the timing reservoir 3, the spring 43 becomes effective to return the valve piston element 34 to its seated position as shown in the drawing, wherein the gasket 39 is held in engagement with the seat rib 4I) for outing off communication between the timing reservoir 3 and the pipe 48, While the pipe is connected to atmosphere by way of the passage 49, port 41, chamber 45 and passage 46.

As the pressure of air in the diaphragm chamber 8 of the drain valve device 2 is thus nally reduced to that of the atmosphere, the springs 2B and 26 again become effective to shift the valve I8-and vassociated elements downwardly toward the position in which they are shown in the drawing. While the double valve element I8 is thus moved from the seat I9 to the seat 28, it effects another discharge of accumulated water from the chamber I2 as hereinbefore explained. The Various elements of the drain valve apparatusv are thus vreturned to the initial position, ready for the next cycle of operation. It will be understood that after the valve piston element 34 has been moved to the seat rib 40 by the spring 43, the pressure of air in timing reservoir 3 will again be gradually built up by ilow of air from the reservoir l, as hereinbefore explained. After a predetermined interval, the air pressure acting on the valve piston element overcomes the spring 43, whereupon the equipment once more becomes effective to actuate the drain valve device 2 through the same operative cycle. The drain valve device thus continues to cycle regularly as long as sufficient air under pressure is available in the main res ervoir I.

From the foregoing'description it will be seen that the elements required for construction of an automatic drain valve apparatus in accordance with my invention are simple in design and relatively inexpensive, and may be expected t0 operate through a long service life without appreciable wear.

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

1. In a drain valve equipment for discharging condensate accumulating in a receptacle for compressed air, the combination therewith of ran automatic drain valve device having valve means responsive to variations in fluid pressure in a chamber for ejecting water deposited in said receptacle, a timing reservoir having an always open but restricted communication with said receptacle, and reciprocating valve means operative upon a predetermined increase in the pressure of air in said timing reservoir for establishing communication therefrom to said chamber. 2. In a drain valve equipment for discharging condensate accumulating in a receptacle for compressed air, the combination therewith of an automatic drain valve device having valve means responsive to variations in iluid pressure in a chamber for ejecting water deposited in said-receptacle, a timing reservoir having an always open but restricted communication with said receptacle, a spring, and fluid pressure operated compressed air, the combination therewith of an automatic drain valve device having valve means responsive to variations in fluid pressure in a chamber for ejecting water deposited in said receptacle, a timing reservoir having an always open but restricted communication with said receptacle, a pipe connected to said chamber, said pipe having a restricted atmospheric communication, and normally closed timing Valve means controlling communication between said timing reservoir and said pipe, said timing valve means being subject to the pressure of air in said timing reservoir and to a yieldable opposing force.

4. In a drain valve equipment for discharging condensate accumulating in a receptacle for compressed air, the combination therewith of an automatic drain valve device having valve means responsive to variations in fluid pressure in a chamber for ejecting water deposited in said receptacle, means providing a communication from said chamber to the atmosphere, a timing reservoir always having restricted communication with said receptacle, and control means including a spring and a timing valve element biased thereby toward seated position, said element bey ing operable upon each predetermined increase in pressure of air in said timing reservoir to establish communication therefrom to said chamber until timing reservoir pressure is reduced to a predetermined value.

5. In a drain valve equipment for discharging condensate accumulating in a receptacle for compressed air, the combination therewith of an automatic drain valve device having valve means responsive to variations in Iiuid pressure in a chamber for ejecting water deposited in said receptacle, a timing reservoir having a restricted inlet communication with said receptacle and a gravity ow drainage outlet, a pipe disposed below said timing reservoir and connected to said chamber in the drain valve device, said pipe having a restricted atmospheric discharge communication, and a valve device operative alternately to establish and cut off communication from said timing reservoir inlet to said pipe.

WALTER B. KIRK.

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