Untitled record

BACKGROUND OF THE INVENTION

In operating freight trains over long descending grades it is common practice to retain a light brake application at all times. It is also desirable however that the train braking system be kept completely charged during this cycling of the brakes. To provide these features retainer valves are provided on each railroad car which function when set, to retain a chosen air pressure within the brake cylinder at all times. This air charge is retained even though the AB control valves are in the release position. These retainer valves are usually located on the end wall of a freight car adjacent the hand brake.

DESCRIPTION OF THE PRIOR ART

Retainer valves as formerly constructed had irregular shaped bodies and several spring pressed valves controlling various size air ports, together with an operating handle having a valve member with different ports adapted to be placed in communication with the several valves. This construction was difficult to service and maintain, was costly to produce and often unreliable in operation. This construction also was conducive to leakage through the various valve seats since no reliable air seals were employed to compensate for wear iand vibration during train movements.

The principal object of the invention is, therefore, to design an improved retainer valve that is much simpler in construction, is less costly to manufacture, requires considerably less servicing and maintenance, is reliable and positive in operation, and is leakproof.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of the retainer valve of the invention shown in large scale;

FIG. 2 is a full-size top view of the valve;

FIG. 3 is a cross-sectional side view of the two-section tubular bushing and sealing ring;

FIG. 4 is a top view of one of the tubular bushings;

FIG. 5 is a side view of one of the tubular bushings;

FIG. 6 is a top view of the sleeve valve;

FIG. 7 is a cross-sectional side view of the sleeve valve taken along the line 7—7 Of FIG. 8;

FIG. 8 is a bottom view of FIG. 7;

FIG. 9 is a cross-sectional side view of the sleeve valve 5 taken along the line 9—9 of FIG. 8;

FIG. 10 is a top view of the retainer valve with its cover and operating handle removed; while

FIG. 11 is a diagrammatic representation of the sequence of operation of the retainer valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, FIGS. 1 and 2, the re_ tainer valve comprises a hollow cylindrical-shaped body 5 ^lo of brass having supporting flanges 6 and 7 on the bottom end for suitably mounting the device, as by bolts, upon a retaining valve mounting bracket on the end wall of a freight car or other type of railroad car. On the side wall of the body 5, there is an air exhaust opening 8 provided, which air opening is protected from entry of insects and dirt by a rubber disc 9, centrally slitted so. that internal air pressure will force open the slits to permit air to exhaust from the opening. The rubber disc 9 is held in place 25 in the opening 8 by a snap ring 10.

The top end of the body 5 is enclosed by a rotatable cover plate 11, having a manually operable depending handle 12 formed integral therewith, so that the cover plate 11 is rotated whenever the handle 12 is actuated in a clockwise 3θ direction. The rotation of the handle 11 is limited for movement in one direction by a lug 13 formed on the bottom of the handle engaging a similar lug .14 formed on the bottom of the body 5. Another lug 15 formed on the top side of the body limits movement of the ₃₅ handle in the other direction. The handle 12 is adapted to be rotated and frictionally locked into each of three different positions. A third lug 16, formed on the top of the body 5, serves as an indicia for the different handle positions, designated as EX, HP and SD, 40 on the cover, the purpose of which will be hereinafter explained.

Within the hollow body 5, there is arranged a two-part tubular bushing generally designated at 20 and preferably made of a plastic material such as polycarbonate and trade 45 marked Noryl. The bushing 20 is molded of two identical parts, one of which 21, is inserted from the top end of the hollow body 5, and the other 22, from the bottom end. At the outer ends of each bushing part, a series of one or more spaced lugs are formed, such as 23 on bushing 21, and lugs 50 24 on bushing 22. These lugs are set in recesses such as 25 and 26, formed on each end of the body 5, and are for the purpose of preventing rotation of the tubular bushing 20 within the body. The lugs and recesses are spaced unequally around the edge of the bushings 21 and 22, so that 55 the bushings can only be inserted into the body in one positive position. The inner edges 30 and 31 of busings 21 and 22, as seen in FIG. 3, are formed at a diagonal angle as shown, and between these edges 30 and 31, a sealing ring such as O-ring 32 is placed conf orming to the general con60 tour of the two diagonal or oblique edges of the two tubular bushings. The O-ring 32 fits between the two diagonal surfaces 30 and 31 when the two busings 21 and 22 are assembled together in position in the body 5. The sealing ring 32 has interference or close fit between the body 5 and 65 the sleeve 33, thus preventing leakage past the sealing ring. In FIG. 3 these parts are all shown slightly spaced apart for the sake of clarity.

A hollow sleeve valve member 33, preferably made of brass, is inserted and arranged within the tubular sleeve 20 70 for rotary movement therein. The top end 34 of the sleeve valve 33 is attached to the cover plate 11 by a pair of recessed bolts 35 located and threaded off-center into the top

27.514 of the sleeve valve 33 in tapped holes 36 and 37, as best seen in FIGS. 6 and 9. It will therefore be apparent from the above that whenever the handle 12 is actuated clockwise, the cover plate 11, as well as the sleeve valve 33, will be rotated as a unit. The operating handle 12 is adapted to control the rotation of the sleeve valve 33 into three separate positions. In the first and normal position with the handle hanging downward as shown in FIG. 2, a direct exhaust (EX) is provided through the valve; in the second position a high pressure air retaining (HP) condition is provided; and in the third position a slow direct exhaust (SD) is provided. The exhaust opening 8 is positioned downward to help prevent entrance of dirt outside the flexible disc 9.

In order to insure that the handle 12 and sleeve valve 33 remain in their set positions and are not dislodged during movements and vibrations of the railroad car, the handle 12 is frictionally locked in each of the adjusted positions. This locking means consists preferably of a pair of locking pins 40 and 41, slidably arranged in bores 42 and 43 at the top end 34 of the sleeve valve 33. Between the pins 40 and 41, there is a spring 44, normally urging the pins apart, as best seen in FIG. 10. The outward ends of pins 40 and 41 are slightly tapered and are adapted to snap into and engage oppositely arranged recesses 45, formed in the inner edges of a ring 46, thereby preventing unintentional dislodgement of the retainer valve handle from its selected setting. The ring 46 has a series of lugs 48 formed around its periphery which fit into the slots 25 in the top of the body to prevent turning of the ring 46. A situable sealing gasket 47 is arranged on a ledge formed around the top end of the tubular bushing 20 and against which the cover plate 11 is pressed to seal off the top end of the body 5 for protection against weather and dirt.

In order to securely clamp the tubular bushing 20 and the sleeve valve 33 in the body 5, a snap ring 50 is arranged on the bottom end of these parts and rests in an annular groove 51 formed in sleeve valve 33. The snap ring 50 also presses up against a ring 52 recessed in the bottom end of the body 5, and this ring 52 in turn is clamped against the bottom end of tubular bushing 20, thereby holding all these elements in assembled relationship within the valve body. A circular gasket 53 on the bottom end of the retainer valve body provides an air seal against a suitable supporting bracket, not shown, to which the inlet air brake connection is made. The retainer valve is bolted to such bracket by the bolts in the holes in flanges 6 and 7. A dirt screen 54 is press-fitted across the air inlet at the bottom of the sleeve valve 33.

Axially slidable within the sleeve valve 33, is a hollow piston 60, having a spring 61 within it extending between the closed bottom end 62 of the piston and the top end of the sleeve valve 33. The bottom end 62 of the piston bears against a stop pin 63, extending through holes 64, on opposite sides of the sleeve valve 33. A sealing ring such as O-ring 65, recessed in a groove in sleeve valve 33, provides the air seal between the sides of the piston 60 and the sleeve valve 33.

Both the sleeve valve 33 and the tubular bushing 20, each have ports or air passages of different diameters and capacity extending through their sides, which are adapted to be placed in communication with the main air exhaust opening 70 in the side of the valve body 5. The sleeve valve member 33 has three such ports, the exact locations of which are best seen in FIGS. 7, 8 and 9. The port 75 in sleeve valve 33 having the largest diameter, is located approximately midway of the length of the sleeve valve 33. Port 76 of a smaller diameter is located almost directly opposite the port 75, while port 77 of slightly greater diameter than port 76, is located to one side of and above the port 75. The specific location of the ports radially around the sleeve valve 33 is best seen in FIG. 8.

Referring now to the ports in the tubular bushing 21, as best seen in FIG. 5, the largest port 80 is located directly in alignment with the air exhaust opening 70 in the valve body. A second port 81 in bushing 21 of smaller diameter is located in the same horizontal plane as port 80 and connected to it by a shallow slot 82 cut in the outside surface of the bushing 21. The third port 83, can be of the 5 same size as port 81, and is located slightly above and to one side of the port 80. A shallow slot 84 connects port 83 with port 80. The other lower tubular bushing 22 of the two-part bushing 20 is made exactly the same as bushing 21 and has the identical ports and slots formed therein. 10 The purpose of providing two identically formed tubular bushings 21 and 22, is so that these parts are interchangeable and in the assembly of the retainer valve it is immaterial whether the bushing 21 is placed on top or on the bottom side of the sealing O-ring 32, as is evident in FIG. 15 3. The ports in the bushing 22 located on the bottom for example, will be ineffective or substantially blocked out by the sealing 0-ring 32 from communication with any of the ports in the sleeve valve 33 above the O-ring and out through the exhaust port 70, in each of the three handle 2q portions, and are therefore ineffective. This is so because while it appears that leakage could occur between the relative contiguous surfaces between the sleeve valve 33 relative tubular bushing 20 below the O-ring 32 from the sleeve valve ports, the fact is that this apparent leakage 25 takes place on the inlet side and is balanced and cannot take place on the downstream side and above the O-ring to the outlet 70.

The hollow piston 60 has an air passage 58 leading to a small port 59 in its side, which port is located below the 30 sealing O-ring 65 in the normal position of the piston 60 as illustrated, the piston being normally held down by the restoring spring 61. Whenever the piston 60 is forced upward by the inlet air pressure, the port 59 is shifted above the sealing O-ring 65 opposite the port 77 in sleeve valve 35 33 and in communication therewith and with the port 83, whenever the sleeve valve 33 is rotated to that particular position to shift the port 77 above the sealing O-ring 32. The annular groove or recess 57 around the inner diameter of sleeve valve 33 enables the piston port 59 to be 40 effective to exhaust the air through port 77 regardless of the rotated position in which the piston 60 in the sleeve valve 33 may be placed by the rotation of the sleeve valve.

Referring now to FIG. 11, this diagrammatically indicates the various positions of the ports, both in the sleeve ₄₅ valve and the tubular bushing, in each of the three different positions of the operating handle 12. The tubular bushings 21 and 22 have both been laid out lineally and it will be assumed that the sleeve valve 33, not indicated here, but with its ports shown as dotted circles, is shifted ₅₀ or moved to the left and behind the tubular bushings. The three different positions of port 77 in the sleeve valve are indicated as A—1, A—2 and A—3. Port 75 is indicated at its different positions at B-l, B-2 and B-3 while port 76 is shown at C-l, C-2 and C-3. Whenever any of the ports 55 75, 76 and 77 are moved together by the sleeve valve to the left and behind the lower tubular sleeve 22, and below the sealing Ο-ring 32, they will be blocked or ineffective whereas when they are moved into position behind the ports 80, 81 and 83, they will be in communication 60 with the large port 80 to exhaust position through body opening 70.

DESCRIPTION OF THE OPERATION

Assume now that in the normal operation of a freight 65 car connected in a train on a straight level run and with the brake pipe charged with air pressures of approximately 70 p.s.i., then each retainer valve will be set so that the handle 12 is in the vertical or position EX as shown in FIG. 2. The air brake pipe connection leading from the 70 usual AB control valve to the retainer valve is accordingly provided with a full direct and unrestricted exhaust path through the retainer valve over a flow path including the inlet connection 55, ports 75, 80, and 70, and outward through the expanded dirt guard 9 and the exhaust open75 ing 8. At this time the piston 60 is also forced upward

27,514 so that a slow gradual dissipation of the air pressure takes place. Referring to FIG. 11, in the above described position of the retainer valve, port 76 is shown positioned at C—3 while port 77 is at A—3 and port 75 at B—3; both 5 the latter ports being blocked off by the tubular bushing and below the sealing ring 32. Ports 75 and 77 being on the upstream side are not now effective while port 76 downstream is effective to pass the air at the restricted rate.

In each of the positions in which the handle 12 has been placed it is snap-locked so that vibration and shocks during train movements cannot disturb the handle from its set position.

According to present regulations of the Association of 15 American Railroads, the retainer valve must be calibrated and function to permit a blow down from a 435 cubic inch volume testing reservoir with an initial charge of 80 p.s.i., for each of the three different positions to which the retainer valve is set, and in the time interval specified as 20 follows:

(!) Direct Exhaust (DE) from 70 to 10 p.s.i. in not more than 3 seconds.

(2) High Pressure Retain (HP) from 60 to 40 p.s.i. in 33 to 43 seconds.

(3) Slow Direct Exhaust (SD) from 60 to 40 p.s.i. in to 22 seconds.

In the second (HP) position the air pressure in the brake cylinder shall reduce to and be retained at the piston valve closure point at not less than 16 p.s.i. or more than 30 22 p.s.i.

The ports in the sleeve valve 33 and the tubular sleeve 20 are bored and sized to provide the above conditions and are therefore in accordance with the above AAR standard regulations. As a preferred example the opening 35 in port 75 is .187 inch, in port 76 .032 inch, and in port 77 .062 inch. The size of the opening in port 77 however is not controlling since the port 59 in the piston 60 is .025 inch. In the tubular bushing 21 the size of the ports is of course much larger, port 80 being .312 inch and both ports 40 81 and 83 being .187 inch. The area of the slots 82 and 84 are sufficient so no air restriction takes place in these passages. _

The retainer valve made according to the invention meets all the above AAR specifications and functions in a ._r highly reliable and satisfactory manner in all respects. ⁴⁰ While a particular embodiment has been shown and described, it is not intended to limit the same to details of construction set forth, but, instead, the invention embraces such changes, modifications and equivalents of the ₅₀ various parts and their relationships as come within the purviews of the appended claims.

It will be understood that the location of the parts in relation to the cars can be varied. Whereas, in FIGS. 1,3, 4, 5, 7 and 9, the axis of the structure is indicated as up₅- right, and I have described the structure in terms of top and bottom, it will be understood that, in use, the casing 5 is most commonly applied to a car with its axis horizontally disposed. Therefore, where I have used the term “Top and Bottom” in describing various parts of the ₆θ device, no limitation is intended, and this language is merely for convenience in description.