US2635925A - Manual release valve for railway air brake systems - Google Patents

Description

April 21, 1953 J WADE 2,635,925

MANUAL RELEASE VALVE FOR RAILWAY AIR BRAKE SYSTEMS Filed Dec. 15, 1949 2 SHEETS--SHEET 1 Zhwentor:

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April 21, 1953 T, WADE 2,635,925

MANUAL RELEASE VALVE FOR RAILWAY AIR BRAKE SYSTEMS Filed Dec. 15, 1949 2 SHEETS--SHEET 2 I I50 1 J% I I 700 la I 0 Zinnentor:

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Patented Apr. 21, 195 3 RELEASE VALVE FOR RAILWAY AIR BRAKE SYSTEMS James T. Wade, Ogden, Utah Application December 13, 1949, Serial No. 132,691

'7 Claims.

This invention relatesto railway air brake systems, and particularly to manual release valves as employed in such systems.

Railway air brake systems utilizing currently standard equipment embody manually-operable valves for enabling an airman at an'inspection point, or a member of the train crewduring a run, to-exhaust air fromthe auxiliary reservoir without regard to provisions for automatic exhaust of air during normal operation of the system. Manual discharge or bleeding of air from the auxiliary reservoir becomes important when a train has pulled into a terminal and awaits inspection, with theengine disconnected from the rest of-the train, as well as later, when the train has pulled away from the terminal and it is found that one or'more of the cars still have the brakes set. In addition, there are various times during a run when the brakes on one or more of the cars may, for one reason or another, remain set, and must be released manually; for example, when a train is pulling back into the main track from a pass siding.

As presently constructed, the manual release valve of a railway air brake system requires an attendant to stand and hold the release valve handle until the requiredamount of air is exhausted from the auxiliary reservoir.

In instances of inspection, an airman must stand and hold such handle until all the air is exhausted, and repeat this, in turn, for each car of the train, which, obviously, involvesa considerable Waste of time, especially where there are two reservoirs to'be emptied, auxiliary and emergency, as in the case of the Westinghouse AB freight brake equipment.

In instances where the train is moving, and it is found that the brakes on one or more of the cars are set, it is necessary for a trainman to run alongside the train, manipulating the release valve handle, until a suflicient amount of .air is bled from .the auxiliary reservoir to initiate brake cylinder exhaust. This is a dangerous proposition. Often, impediments alongside the track force the trainman -to .let v go the handle and clamber aboard the .rearmost .car, where he can apply the air to stopthe train. During the interim, of course, thesetbrakes onthe particular car or cars cause the wheels to slide, resulting in flattening thereof.

I eliminate these objectionable features of existing equipment by interposing. a delayed-return mechanism between the usual handle of .a-conventional manual release valve and the valveactuatingmechanism thereof. By means of the resulting novel structural combination in. railway air brake equipment, an attendant need merely with-the manual release of anybrakes which may remain set at the commencement ofa run.

To greatly reducethe occurrence of flat wheels in railway operation.

'Inaccomplishin these objects -I combine with the customary manual release valve a suitable delayed-return mechanism.

A further object of the invention is to provide a simple and positive delayed-return mechanism admirably adaptedfor the purpose.

Additional objects and features of-the invention will become apparent fromthe following detailed clescriptionof the-presently preferred embodiment thereof illustrated in the accompanying drawings.

In the drawings:

Fig. 1 represents an elevation of a typical installation embodying my invention;

Fig. '2, a horizontal section taken on the line 22-of'Fig. 1;

Fig. 3, a vertical section through the structure of Fig. 1, taken with reference to theline 3-3 of Fig. 2 and drawn to an enlarged scale; and

Fig. 4, a view corresponding to that of Fig. 3, but illustrating the release valve tripped to the extent of opening the port controllingexhaust of the auxiliary reservoir.

Referring to the drawings, in which the invention is illustrated as part of the modern. AB freight car brake equipment of a standard Westinghouse air brake system, the duplex release valve customarily provided in the service portion of such equipment comprises a valve housing Ill having operably positioned therein release checks II and I2 controlling exhaust passages I3 and I l, respectively, leading from the auxiliary and emergencyreservoirs (not shown), respectively, of the equipment.

A plunger it having two upstanding stems its and I 5b is providedfor opening eithercne or both of the release checks 1H and ltdepending uponhow far the plungerispushed upwardly on 3 any given actuation of the valve, it being noted that the check H, which controls the auxiliary reservoir exhaust passage I3, is positioned at a lower level than check l2, and is opened by the stem |5a prior to the opening of check l2 by stem |5b on the upward travel of plunger l5.

As normally constructed, the duplex release valve possesses a handle arranged for manual actuation in directly raising the plunger |5 the desired distance to open either one or both of the release checks II and I2. In operation, an airman or trainman must hold the handle in its actuated position until the requisite quantity of air is exhausted.

In accordance with my invention, I interpose a delayed-return mechanism between the said handle and the plunger l5, whereby the handle need merely be given a flip to insure exhaust of air for a given period of time. By pre-establishing to the time required for releasing the brakes, the period involved in return of the said mechanism to its original position (and, therewith, the plunger l5 and the actuating handle to their respective original positions) from the position concerned in opening the release check II, a trainman who finds brakes remaining set when the train starts up need merely give the handle a quick flip to insure complete release of the brakes. An airman has the time he must spend in completely discharging the auxiliary and emergency reservoirs for inspection purposes greatly shortened.

While a variety of well-known delayed-return mechanisms may be easily adapted for the purpose by those skilled in the art, the particular mechanism which I here illustrate is especially advantageous for reasons hereinafter set forth.

As illustrated, see especially Figs. 3 and 4, the manually-actuated handle, indicated |6, depends from the lower open end of a cylindrical casing H, which is rigidly but removably attached, as by threading, to the lower open end of an intermediate cylindrical casing [8 containing the delayed-return mechanism. Such intermediate casing I8 is rigidly but removably attached, also preferably by threading, to the customary depending annular portion llia of valve housing It.

Within intermediate casing I8 is defined a chamber IQ for a plunger 29, which is fixed intermediate the length of a push-rod 2|. As shown, the upper end of the chamber I9 is closed by an end wall |8a of the casing l8, such end wall being integral with the casing proper. A central opening 22 is provided through such end wall i801. for passage of the upper portion of the push-rod 2|. The lower end of the chamber I9 is closed by a plug made up of two annular pieces 23 and 24, between which is interposed an annular packing gland 25. The pieces 23 and 24 are threaded into the open upper end of easing H, and serve to compress the packing gland 25 into sealing contact with the lower portion of push-rod 2|.

Th closed upper end of casing I8 is advantageously recessed to receive depending annular portion lila of the valve housing It as a pressure agency for bearing tightly against washer 26 and compressing packing gland 21 into sealing contact with the upper portion of push-rod 2|.

The chamber I9 is adapted to be filled with a hydraulic medium, as shown. A light grade of lubricating oil is preferred, the same being convenlently introduced through an opening which is normally closed by plug 28.

In permitting proper movement of the pushrod 2| when pushed upwardly by handle I5, adequate passage for rapid flow of the hydraulic 4 medium from the upper portion of chamber l9, above plunger 20, to the lower-portion thereof, below plunger 20, is provided. As illustrated, a plurality of flow passages 29 extend vertically through plunger 20, the same being normally closed at their upper ends by balls 3|] seating up wardly against annular lips 3| under the urge of springs 32 held in place by annular inserts 33. Thus, the balls 30 function as check valves, permitting flow downwardly through the passages 29, but preventing flow upwardly therethrough.

For delaying the return of push-rod 2| to its original position after being pushed upwardly by handle l5, restricted passage for relatively slow flow from the lower portion of chamber H] to the upper portion thereof is provided. As illustrated, a predetermined limited degree of clearance 34 between plunger 20 and the walls of chamber l9 within which it operates, provides such restricted passage. j

The upper end of push-rod 2| is positioned in abutting relationship with depending boss |5c of the valve-actuating plunger l5, while the lower end thereof is positioned in abutting relationship with the concave crown member lea of handle l6. Such handle it is operably suspended from the lower open end of easing ll by means of an annular insert member 35, which furnishes support for the crown member Via. Such insert member 35 has a passage 36 therethrough sufficiently large in diameter to accommodate the required sideward movement of handle stem |6b when the handle member idc is manually flipped to open either the release check alone, or both the release checks H and |2, together.

In operation, handle i6 acts directly upon push-rod 21, which, in turn, acts upon the valveactuating plunger I5. Upward travel of the pushrod is facilitated by downfiow of the hydraulic medium through passages 29 of the delayed-return plunger 20, while the return of push-rod 2| to its original position is delayed by the necessity of the hydraulic medium below plunger 20 to return to the upper portion of chamber It by way of restricted passage 34.

The simple construction of the illustrated delayed-return mechanism, and the ease with which it may be disassembled and reassembled are distinct advantages. It is absolutely positive in operation, and requires little attention to maintain.

Furthermore, it is relatively inexpensive to manufacture and install.

Whereas this invention is here illustrated and described with respect to a certain presently preferred specific embodiment thereof, it should be understood that various changes may be made therein and various other forms may be constructed on the basis of the teachings hereof, by those skilled in the art, without departing from the protective scope of the following claims.

I claim:

1. In a railway air brake system, a manual release valve, comprising check valve means normally closing exhaust of reservoir air from said system; trip means for said check valve means; handle means arranged for manual actuation; and a delayed return mechanism interposed between and operably interconnecting said handle means and said trip means, said delayed return mechanism comprising a housing having a fluidsealed section; a rigid actuating rod extending longitudinally through said housing and beyond said fluid-sealed section at opposite ends thereof, said rod interconnecting the handle means and the trip means; a plunger fixed to said actuating rod and slidable within said fluid-sealed section thereof as a, cylinder; a hydraulic fluid within said fiuidsealed section of the housing; free flow passage means extending from one end to the opposite end of said plunger for accommodating passage of hydraulic fluid during movement of the plunger, check means associated with said passage means for permitting fluid flow in only one direction; and restricted passage means also extending from one end to the opposite end of said plunger, for accommodating a considerably lesser flow of hydraulic fluid during movement of the plunger.

2. The combination recited in claim 1, wherein the housing is made up of two tubular sections removably fastened together endto-end; wherein a cylinder for the plunger is defined by one of said sections, and a mounting for the handle means by the other; and wherein cylinder-sealing means are interposed between the interiors of the two sections, dividing one from the other.

3. The combination recitedin claim 2, wherein the check valve means controlling exhaust of reservoir air from the system are disposed in a housing having an annular projection extending opposite the trip means; wherein the free end of the cylinder section of the delayed-return mechanism is removably attached to said annular projection; wherein cylinder-sealing means are interposed between said end of the cylinder section and said annular projection; and wherein the actuating rod extends slidably through the sealing means at opposite ends of said cylinder, into connection with said trip means at one of its ends, and into connections with said handle means at its opposite end. i

4. The combination recited in claim 3, wherein the free flow passage means are relatively large bore passages extending through the body of the plunger; and wherein relatively slight clearance between the plunger and the walls of the cylinder in which it slides provides said restricted passage means.

5. The combination recited in claim 4, where-- in the handle means comprises a stem having a disk crown, and wherein the actuating rod is arranged as a push-rod, with its one end abutting against the trip means, and its opposite end abutting against the superficial surface of the disk crown of said handle means.

6. The combination recited in claim 5, wherein an annular insert is positioned at the free end of the handle-mounting housing section for retaining the handle means in operative position, the disk crown of said handle means being disposed within said housing section, and the stem thereof extending from said housing section through said annular insert.

7. Delayed-return, valve-actuating mechanism, comprising a, cylindrical housing having a portion of its length fluid-sealed as a hydraulic cylinder, one end portion formed as a housing for actuating handle means, and the opposite end portion formed for connection to valve structure; a push-rod extending longitudinally through said fluid-sealed portion of the housing and beyond, into said end portions of the housing, for longitudinal sliding movement; a hydraulic fluid within said cylinder; a plunger fixed to said pushrod within said cylinder; free flow passage means extending from one end to the opposite end of said plunger for accommodating passage of hydraulic fluid during movement of the plunger; check means associated with said passage means, said check means being arranged to permit fluid flow only toward said one end portion of the housing; restricted passage means also extending from one end to the opposite end of said plunger, for accommodating a considerably lesser flow of hydraulic fluid during movement of the plunger; and actuating handle means operably mounted within and extending from the free end of said one end portion of the housing.

JAMES F. WADE.

References Cited in the file of this patent FOREIGN PATENTS Number

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