US1754227A - Feed-valve device - Google Patents

Description

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April 15, 1930. c. c. FARMER FEED VALVE DEVICE Filed Dec. 1o, 192e Patented Apr. 15, 1930 l UNITED STATES PATENT OFFICE CIIYDE C'. FARMER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 THE 'WESTING- HOUSE AIR BRAKE COMPANY, OF WILIVIERDING, PENNSYLVANIA, A CORPORATION F PENNSYLVANIA FEED-VALVE DEVICE Application tiled. December 10, 1926. Serial No. 153,824.

This invention relates to fluid pressure feed or reducing valve devices, and more particularly to a feed valve device of the type employed on railway trains to maintain the fluid pressure in the brake pipe.

The principal object of my invention is to provide an improved feed valve device of the above type.

In the accompanying drawing, the single ,j 10 figure is a sectional view of a feed valve del 9 and on the opposite side to fluid under pressure supplied from the brake pipe 10 of the fluid pressure brake system. The diaphragm 8 controls the operation of a regulating valve 11 and said valve controls communication from piston chamber 4 through passage 12 to the chamber 13 of the diaphragm 8, which is open to the brake pipe 10.

The piston 5 is subject to the pressure of a coilspring 14 and upon a predetermined movement of piston 5, said piston is adapted to en gage a spring stop 15, which is Subj ect to the pressure of a second coil spring 16, the stop member 15 having sliding engagement with a guide stem 17.

The outer end of the piston stem 18 of the piston 5 is provided with a cylindrical portion 19 having a neat sliding lit in the bushing 3 and a chamber 20, at the outer end of bushing 3 is connected to a main reservoir 21. The

bushing 3 is provided with a plurality of ports 22 which connect chamber 20 with valve chamber `6. An annular chamber 23 surrounds a portion of the bushing 3, above the seat 24 and is connected to the brake pipe 10 and also, through passage 25, with diaphragm chamber 13. j The slide valve 7 is provided with a through port `26, adapted upon outward movement of the slide valve to register with a port 27 which opens into chamber 23.

The piston 5 is provided with a packing ring 28 and disposed axially in the piston is a choke plug 29 having screw-threaded engagement in the piston. A. chamber 30 is provided in the piston 5 below the plug 29 and passages 31 lead from said chamber to a chamber 32 which is formed between the piston 5 and a loose fitting piston 33.

The plug 29 is provided with an axially disposed restricted port 34 and a plurality of downwardly inclined radially extending ports 35, which connect the port 34 with chamber 36. The piston head 33 is so positioned that it remains in engagement with the valve chamber bore of the bushing 3 even when the piston 5 has moved to its extreme outer position, so that chamber 32 at all times only communicates with valve chamber 6 by way of the space between the piston head 33 and the inner face of the valve chamber bore.

In operation, the chamber 20 is charged with fluid at main reservoir pressure and y from chamber 2O fluid at main reservoir pressure flows through ports 22 and charges the valve chamber 6. Fluid equalizes from valve chamber 6 around piston head 33 into chamber 32 and also through the restricted port 34 in choke plug 29 to Lpiston chamber 4.

Fluid from the brake pipe 10 flows into chamber 23 and thence through passage 25 t0 diaphragm chamber 13, and if the pressure in the brake pipe slightly exceeds the pressure at which the spring 9 may be adjusted,

then the diaphragm 8 will be held downwardly, permitting the valve 11 to be seated by the spring 36. The valve 11 being seated, the fluid pressure in piston chamber 4 is permitted to build up by flow through the restricted port 34, to equalization with the pressure in valve chamber 6, and the spring 14 then hlds the piston 5 in its normal position, as shown in the drawing.

lf the brake pipe pressure should fall below the degree of pressure at which the spring 9 is adjusted, the diaphragm 8 will be moved upwardly by the spring and the valve 11 will then be unseated, so that fluid in piston chamber 4 will be vented through passage l2 to diaphragm chamber 13 and thence to the brake pipe 10. The higher pressure in valve chamber 6 and chamber 32 then operates to shift piston 5 outwardly, so that slide valve 7 is moved to cause the port 26 to register with port 27. Fluid under pressure is then supplied from valve chamber 6 and the main reservoir 21 to chamber 23 and the brake pipe 10.

When the brake pipe pressure has thus been increased to a degree slightly exceeding the pressure of spring 9, the diaphragm ismoved downwardly, permitting the valve 11 to seat. The fluid pressure in piston chamber 4 is then built up by flow through the restricted port 34 ofthe choke plug 29, permitting the spring 14 to return the piston 5 andfslide valve 7 to their normal position, as shown in the drawing.

It will Vbe noted that fluid -flowing from valve chamber 6 through the restricted port 34 must pass around the piston headV 33 and must then change its direction of flow so as to pass through the passages 31 to chamber 30,

so vthat oil or foreign matter contained in the air flow tends to :be deposited on the surfaces exposed'to the flow, before the fluid reaches the chamber 30.

The port 34 is necessarily of restricted area and might be easily clogged with oil or foreign matter, but by the above construction, the flow of fluid is freed to a large extent of 'its oil and foreign matter before it reaches the chamber 30. In addition, the chamber l30 itself assists in preventing the passage of oil tothe restricted port 34, since oil or foreign materia-l passing through the passages 31'can col-lect at the lbottom of the chamber 30 and is then free to drain back into the valve cham- "ber G by way of-passages 31, if the valve devvice 4is positioned as shown in the drawing,

with the axis of the piston 5 in avertical position. If the feed val-ve device happens to 'be positioned so that :the piston axis is hori- Zontally disposed, then the oil which might collect'in chamber 30 will flow out through one or more of the passages l31, which happens to extend downwardly.

The'radialrestricted passages 35 ensure an `always open passage for the flow of fluid, `since if one or more of the passages 35 be'- come clogged, so longas only one passage remains open, fluid can flow through the port 34.

Having now described my invention, what I claim as new and desire to' secure by Let. ters Patent, is:

1. A feed valve device comprising a fluid pressure supply valve for supplying fluid under pressure to an outlet, apiston foroperating said valve having a piston chamber at one side, a removable choke plug disposed axially in said piston and having a restricted port through which fluid under pressure is supplied to said piston chamber from the chamber at the opposite side of said piston, and

controlling means operated upon a reduction in fluid pressure at the outlet for venting fluid from said piston chamber.

2. A feed valve device comprising a fluid pressure supply valve for supplying fluid under pressure to ,an outlet yand contained in a valve chamber, a piston subj ect to the opposing pressures of said valve chamber and a piston chamber for operating said valve and .having a restricted port for supplying fluid under pressure from said valve'cliainber .to said piston chamber, a piston head movable with said piston and around which fluid under pressure issupplied kfrom said valve chamber through said Q restricted port to said piston chamber, and controlling means operated upon a reduction in fluid pressure Aat the outlet for ven-ting .fluid from said piston chamber. v

3. A feed valve device comprising a fluid Apressure supply -valve for supplying fluid under pressure `to an outlet and contained in a valve chamber, a piston subject tothe opposingl pressures of said valve chamber and a piston Vchamber for operating said valve and having a restricted port for supplying `fluid under pressure Vfrom saidv valve -chamber to said piston chamber, said pistonhavinga chamber open tosaid restricted port and connected by passages to said valve chamber, and eontrolling means operated upon a reduction in fluidl pressure at :the outlet for venting fluid from said piston chamber,

- 4. A feedv'al-ve device comprising .a fluid pressuresupply'valve for supplyingfluid 11nvder pressure to an outlet 4and contained in avalve chamber, `a piston subject to the op posing pressures of said valve chamber and a --piston chamber' for operating .said valve and having a restricted port. for supplying vffl-uid Vunderpressure from said valve .chamber to said piston chamber, a piston head separating said valve chamber fram another chamber adjacent ito v said piston, said vother chamber being opento said restricted port, and controlling means operated uponla .reducber, `and controlling means operated vupon a reduction in fluid pressure atythe outlet for venting jfluidfrom said piston chamber.

6. A feed valve |device comprising a fluid pressure supply valve for supplyingfluid -under pressure'to an outlet and .contained 1in a valve chambena piston subjectto theppposing pressures of said valve chamber and a piston chamber for operating said valve, said piston having a removable choke plug provided with a restricted port connecting said piston chamber with a pocket formed in said piston and said piston having radial passages connecting said pocket with said valve chamber, and controlling means operated upon a reduction in fluid pressure at the outlet for venting fluid from said piston chamber.

7 A feed valve device comprising a fluid pressure supply valve for supplying fluid under pressure to an outlet and contained in a valve chamber, a piston subj ectto the opposing pressures of said valve chamber and a piston chamber for operating said valve, said piston having a removable choke plug provided with a restricted port connecting said piston cham-` ber With a pocket formed in said piston and said piston having radial passages connecting said pocket with said valve chamber, a piston head spaced from said piston and permitting communication from said valve chamber to said radial passages, and means operated upon a reduction in fluid pressure at the outlet for venting fluid from said piston chamber.

In testimony whereof I have hereunto set my hand.

CLYDE C. FARMER.

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