US1879696A

US1879696A - Pressure retaining valve

Info

Publication number: US1879696A
Application number: US508399A
Authority: US
Inventors: Fremont P Livingston
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1931-01-13
Filing date: 1931-01-13
Publication date: 1932-09-27
Anticipated expiration: 1949-09-27

Description

Se t. 27, 1932. F. P. LIVINGSTON PRESSURE RETAINING VALVE Filed Jan. 13, 1931 IN VEN TOR.

FREMONT P. LlVlNG$TON BY %zfl/% umm 2 5 m0 5 9 4 2 m T 2 86 457 5 4 o 6 I 36H ffim fi w I (Z 8 67 .2 I .l I mummll/ MN L ll 6 8 7 O6 8 3 i O 3 5 22E 4 A TTORNEY.

Patented Sept. 27, 1932 UNETE stares FREMDNT r. LIVINGSTON, or DENVER, COLORADO, ASSIGNOR TO THE WESTINGHOUSE AIR BRAKE COMPANY, QFWILMERDING, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA PRESSURE RnrAiNING VALVE Application filed January 13, 1931. Serial No. 508,389.

This invention relates to fluid pressure brakes and more particularly to a brake cylinder pressure retaining valve device by means of which different pressures may be retained in the brake cylinder according to traffic conditions.

One of the objects of my inventionis to provide a pressure retaining valve device, of the character described, in which the valve spring is permanently confined under the deslred COIHPIBSSlOHGIltlIGlY within the valve.

casing when the device is initially assembled so as to permit the casing and spring to be thereafter removed as a unit, in order to regrind the valve if necessary, without in any way disturbing the adjustment of. the spring.

Another object of my invention is to provide a device of the type described, in which the valve members are so arranged as to seat upwardly in order to lessen the possibility of foreign matter collecting on the valve, and in which the lower portions of the valve casings communicate directly with atmosphere, when the device occupies its exhaust position, so as to prevent moisture of condensation from accumulating and freezing in the casing and thus impair if not prevent the free operation of the valves.

In the accompanying drawing; Fig. 1 is a central vertical sectional view of a pressure retaining valve device of the high and low pressure type embodying my invention; Fig. 2 is a fragmentary vertical sectional view taken on line 22 of Fig. 1; Fig. 3 is a central vertical sectional view of a pressure retaining valve device illustrating a modified form. of my invention; and Fig. 4 is a fragmentary vertical sectional vlew taken on line 4% of Fig.3.

As. shown in the drawing, the retaining valve device comprises a body portion 1, having an inlet chamber 2 formed in the lower portion thereof which is adapted to be connected by means of a pipe 3 with the triple valve exhaust, in a well known manner. Also formed in the body 1 is an exhaust passage 4, a high pressure passage 5 and a low pressure passage 6. Communication between the inlet chamber and the

passages

4, 5 and 6 is selectively controlled by means of the,usual plug valve 7 having a duct 8 formed therein which communicates with the chamber 2 in all positions of the valve 7, The valve 7 is provided with a handle 9 by means of which the valve may be rotated to positions in which the duct 8 therein selectively registers with any one of the

passages

4, 5 and 6. r

The casing 1 is formed in its upper portion with two

chambers

10 and 11 which are-internally screw-threaded to receive a low pressure valve casing 12 and a high pressure valve casing 13' respectively. The upper portion of the casing 12 is provided with a valve seat 14 having an orifice 15 formed therein through which communication isat times established between the interior of the casing 12 and a passage 16 formed in the wall of the casing. The passage 16 extends downwardly and communicates at its lower endwith an annular cavity 17 formed in the lower face of the casing which, in turn, communicates with the low pressure passage 6 in the body 1. In a like manner, the upper portion of the easing 13 of the high pressure valve is provided with a valve seat 18 having an orifice 19 formed therein through which communication is at times established between the interior of the casing 13 and a passage 20 formed in the'wall of this casing. The passage 20 also extends downwardly and, communicates at its lower end with an annular cavity 21 formed in the lower face of the casing which, in turn, -com'municates with the high pressure passage-5 in the body 1.

' Communication between the interior of the low pressure valve casing 12 and the passage 16 through theorifice 15is controlled by means of a verticallyextending low pressure valve member 22 which is mounted for vertical sliding movement within the casing 12. This valve member is maintained in axial alinement with the orifice 15 by means of a collar 23 secured to the valve member 22 adjacent to the upper end thereof. and having a diameter only communication between the interior of the casing 12 and the chamber 10. The low pressure valve member 22 is yieldably urged into engagement with its seat 14 soas to close the orifice 15, by means of a coiled spring 29 which surrounds the valve member 22 between the collar 23 carried thereby and the base plug 27. Constant communication is established between the chamber and the outer atmosphere through a suitable choke plug 30. This choke plug is preferably located in the bottom wall of the chamber 10 so as to provide a drain for any moisturethat may enter this portion of the device or which may form therein through condensation.

Communication between the interior of the high pressure casing 13 and the passage through the orifice 19 is also controlled by means of a vertically extending high pressure valve member 31' which is mounted for vertical sliding movement within the high pressure valve casing 13. This valve member is also maintained in axial alinement with the orifice 19 by means of a collar 32 secured'to the valve member adjacent to the upper end thereof and having a sliding fit with the inner surface of the casing 13. This collar is provided with a plurality of spaced perforations 33 so as not to obstruct the free flow or" air through the casing when the valve 31 is opened. The lower end of the valve member 31 is also formed with a reduced portion 34 which extends through and is slidably mounted in a central bore 35 formed in a base plug 36. This plug is forced into the lower end of the high pressure valve casing 13'wi'th a pressed fit and is provided with a plurality of p assages 37 which establish communicationbetween the interior of the casing 13 and the chamber 11. The high pressure valve memher 31 is yieldably urged into seating engagement with its seat 18 so as to close the orifice 19 at reduced'pressures by means of a coiled spring 38 which surrounds the valve member 31 between the collar 32 carried thereby and the base plug 36. Constant communication is established between the cham ber 11 and the passage 6 in the body 1 through a choke plug 39. Moisture forming in the high pressure valve mechanism may drain through a vertical passage 40 (Fig. 2), the lower end of which communicates with a cavity 41 in the plug valve 7 leading to the outer atmosphere when the valve operating handle 9 occupies its vertical or exhaust pos1- tion.

In Figs. 3 and 4 I have shown 'a modified form of pressure retaining valve device em-' bodying my invention. The construction and operation of the device shown in these figures are substantially indentical with that hereinbefore described in connection with the device shown in Figures 1 and 2, except that moisture is drained from the chamber 10 of the low pressure valve 22 through a passage 42 which connects the bottom of this chamher with a second cavity 43 in the plug valve 7, and that achokeplug-44 is provided in the side of the casing 12 of the low pressure valve instead of in the bottom of the chamber 10, as shown in Figure 1.

The lower extremities of the

valve members

22 and 31 are slotted, as indicated at 45, to permit them to be engaged by a suitable tool and rotated on-their seats in regrinding these valves. This may be-done without disturb ing the adjustment of the

springs

24 and 38 by merely unscrewing the

valve casings

12 and 13 from their

respective chambers

10 and 11 so as to expose the slotted ends of thevalve stems. j

The operation of my improved'retaining valve device is substantially the same as that of prior devices of this type in that the lowpressure spring is adjusted to maintaintlie low pressure valve 22 closed under a certain desired pressure, whereas the high pressure spring 38 is adjustedtohold the high pressure valve 31 closed under a pressure of predetermined greater'value. When the valve operating handle'9 occupies its vertical po sition, shown in the drawing, the exhaust of the triple valve escapes directly to atmosphere through the chamber 2 of the pressure retaining valve device, duct 8 in the valve plug 7 and'exhaustpassage 4. If the valve op erating handle 9 is moved to a position at a 45 degree angle with respect to the vertical, the duct 8 in the valve plug 7 will register with the high pressure passage 5. In this case the air exhausted from the triple valve will escape through the chamber 2, duct 8 in the valve plug 7, passage 5, duct 21, passage 20, orifice 19 of the high pressure valve31, interior of casing 13, passages 37 in base plug 36, chamber 11, choke plug 39, passage 6, cavity 17, passage 16, orifice 15 of the low pressure valve 22, interior of easing 12,'passages 28in the base plug 27 of this casing,

chamber 10 and thence through the choke plug 30 to atmosphere. A relatively high pressure will consequently be retained inv the brake cylinder after the brakes are released, which is desirable in certain cases where traffic en 8 in the-valve plug 7 directly into the passage '6, and thence through cavity 17, pas

sage 16, orifice 15, interior of low pressure valve casing 12, passages 28 in the base plug 27 of this casing, chamber 10, and through the choke plug 30 to atmosphere. A relatively low air pressure will consequently be retain-ed in the brake cylinder after the brakes have been released which is sometimes desir able under certain traific conditions.

It will of course be obvious that in the structure shown in Figures 3 and 4, the air after passing through the orifice 15 of the low pressure valve 22 will escape directly to atmosphere through the choke plug 44 in the side of the low pressure casing 12.

From the foregoing it will be apparent that by means of my improved construction, each of the valve springs is at all times protected by the casing in which it is confined under the proper compression when the device is initially assembled and that the valve and its cooperating valve seat may be reground from time to time by removing the casing from the body portion so as to expose the notched extremity 45, without in any way disturbing the adjustment of the associated spring or the position of the valve member relative to its cooperating valve seat. Also it will be apparent that by arranging the parts so that the valve seat and orifice is located in the upper portion of the device and by providing drainage passages in the lower portion thereof, the possibility of dirt collecting on the valve, or from accumulated moisture freezing within the casing is materially decreased.

Athough I have shown only two forms of pressure retaining device embodying my invention, it will be understood that various changes and modificationsmay be made therein without departing from the spirit and scope of my invention as defined inthe appended claims.

lVhile two illustrative embodiments of the invention have been described in detail, it is not my intention to limit its scope to these embodiments or otherwise than by the terms of the appended claims.

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

1. In a pressure retaining valve device, the combination with a body portion having a chamber formed therein, of a casing secured at its lower end in said chamber and having a valve seat located at the upper end thereof communicating with an inlet passage formed in said casing, a plug permanently secured within the lower end of said casing and having an outlet passage formed therein connecting the interior of said casing with said chamber, a valve member disposed within said casing for engagement with said valve seat and accessible for grinding through said plug, and a spring disposed entirely within said casing for urging said valve into engageture from the lower portion 'municating with said outlet ment with said seat to control communication between said inlet passage and the interior of said casing. v 2. In a pressure retaining valve device, the combination with a body'portion having an inlet passage and an outlet chamber formed therein, of a casing securedat its lower end in said outlet chamber and having a verti cally extending passage communicating with said inlet passage, a valve seat located inthe upper end of said casing'communicating with said vertically extending-passage, a valve member disposed within said casing for engagement with said valve seat, a closure for therein, of a casing secured at its lower end in said outlet chamber and having a vertically extending passage formed in the wall thereof communicating with said inlet passage, a valve seat located in the upper end of said casing communicating with said vertically extending passage, a valve member disposed within said casing for engagement with said valve seat, a spring disposed within said casing for urging said valve into seating engagement with said valve seat, and

means for permitting the drainage of moisof said casing.

4. In a pressure retaining valve device, the combinationwith abody portion having an inlet passage and an outlet chamber formed therein, of a casing secured at its lower end in said outlet chamber and having a vertically extending passage formed in the wall there of communicating with said inlet passage, a valve seat located in the upper. end of said casing communicating with said vertically extending passage, a valve member disposed within said casing for engagement with said valve seat, a spring disposed within said casing for urging said valve into seating engagement with said valve seat, and a drainage passage formed in said body portion comchamber.

5; In a pressure retaining valve device, the combination with a body portion having an inlet passage and an outlet chamber formed therein, an inlet valve for controlling the flow of fluid through said inlet passage, of a casim secured at its lower end in said outlet chamber and having a vertically extending passage formed in the wall'thereof communicating with said inlet passage, a valve seat located in the upper end of sald'casing communicating with said vertically extending 0 my hand,

passage, avalve member disposed within said casing for engagement with saidvalve seat, a spring disposed Within said casing for urging said valve into seating engagement With saidvalve seat, and a drainage passage formed in said body and controlled by said inlet valve for establishing communication between said outlet chamber and the outer atmosphere. v V

In testimony whereof I have hereunto set this 5th day of January, 1931. FREMONT P. LIVINGSTON.