US2257289A - Control valve - Google Patents

Description

' Sept. 30, 1941.

E. A. TURNER ET AL CONTROL VALVE Original Filed A"'* 19, 1936 2 Sheets-Sheet 1 INVENTQRS a a 7mm 7 c.

ATTORNFYF p 1941- E. A. TURNER m-A; 2,257,289

' CONTROL VALVE Original Filed Aug. 19, 1956 3 Sheets-Sh et 2 EXHA 1/57- Q Kg:

raw/4R0 FXHAUJT INVENTORS BY (sawmmm A 'ITORNEYS Patented Sept. 30, 1941 CONTROL VALVE Edwin A. Turner and Charles R. Davison, Erie,

Pa., assignors to The Standard Stoker Company, Incorporated, a corporation of Delaware Original application August 19,-1936, Serial No.

96,804, now Patent No. 2,181,840, dated November 28, 1939.

Divided and this application November 3, 1935), Serial No. 382,650

2 Claims.

I This invention relates to a controlvalve for locomotive auxiliary devices, such as stoker drive engines.

The present invention contemplates providing an improved control valve having a positive neutral position whereby any pressure fluid in the intake port that may leak through the movable valve element is vented to atmosphere, thereby preventing passage of pressure fiuid to the driving engine when the control Valve is in such neutral position.

A still further object of the invention resides in the provision of a control valve having a cylindrical bore and a cover over one end of said bore through which cover passes a stem of the movable valve element, the under side of the cover at all times being subjected to exhaust pressure only.

Other objects are to provide an improved control valve of such construction that its installation may easily and conveniently be made in the piping system heretofore provided for control valves of prior construction; to provide a novel arrangement of ports and passages for the admission and exhaust of pressure fluid through the control valve; to provide a novel and efflcient system for draining any condensate in the control valve, and to otherwise improve upon the construction and operation of the control valve as will hereinafter become more apparent from the description when read in connection with accompanying drawings in which the control valve has been embodied for use in connection with a driving engine of a well known locomotive stoker.

Fig. l of the drawings represents a longitudinal section through the rear portion of a locomotive adjacent the flremans side, illustrating the invention in side elevation;

Figures 2, 3 and 4 are central vertical sections through the control valve of the present invention with certain portions shown somewhat diagrammatically, each view showing the control valve in successive operative positions as indicated by the legends; and

Figures 5 and 6 are true sectional views of the control valve taken on the lines 5-5 and 6-6, respectively, of Fig. 3.

On these drawings, the locomotive is indicated by L and comprises a frame I0 above which is supported a boiler backhead II by. means of an expansion plate I2. To the rear of the frame it,

another expansion plate I3 is secured for supporting the cab deck 14. The cab deck I4 may be further supported upon a bracket I 5 carried tened to the locomotive frame II.

flexibly supports the forward end of another conduit I9 leading forwardly from the tender (not shown). A conveyor screw, such as 20, extends through the conduits I6, I 9 and conveys coal therethrough for delivery into a firebox contained within the boiler.

The conveyor screw 20 is operated by means of gearing (not shown) driven by shafting 2| having an operative connection with the stoker drive engine E. The engine E is of the multicylinder, double acting type and utilizes steam or other pressure fluid as an operating medium therefor. This engine is rigidly secured by bolts such as 22 to a bracket 23 which is securely fas- The admission of steam or other pressure fluid to the driving engine E and the exhausting of steam therefrom are controlled by a valve V having an inextensible rod 24 which extends upwardly through the cab deck 34 and terminates in the handle 25 disposedadjacent the firemans seat box 26 for convenience of operation.

Steam from the locomotive boiler is conducted to the valve V by means of an intake pipe 2'! while the steam exhausted by the engine E passes through thevalve V and thence through pipe 28 to the locomotive front end. During normal stoker operation the valve V conducts steam from the intake pipe 2'! to the pipe 29, the latter having a connection with the steam chest 35] of the engine and being also provided with a nipple 3| which is suitably connected with a mechanical I lubricator for the purpose of supplying a small quantity of oil at regular intervals to steam chest 3%] for lubricating the cylinder walls. In the normal operation of the stoker steam exhausted from the engine E passes from the pipe 32 into the valve V and thence to pipe 28. Re- Versal of the stoker engine E is accomplished by movement of the rod 24 as will hereinafter be described, whereby the valve V admits steam from pipe 2'! to pipe 32, the steam exhausting through pipe 29, valve V and thence through pipe 28.

Referring now to Figures 2 to 6, inclusive, illustrating the detailed construction of the control valve V, it will be apparent that this valve consists of an elongated body member 35 having a cylindrical bore 36 therein. Within the cylindrical bore 35 a movable valve element 3! is mounted and it is arranged for movement within the body 35 by means of a stem 38 which has an operative pivotal connection as at 39 with the rod 24. The upper end ofthe valve body 35 is covered by a cap 40 having a stuffing box M through which passes the stem 38. Bolts '22 secure the cap to the body. The movable valve element 37 is in the form of a spool having an upper enlarged end 43 and a lower enlarged end M. In each enlarged end 43, 44 of the movable Valve element 37, rings such as 45 are provided for insuring a pressure-tight seal between the enlarged ends E3, 44 of the valve and the reduced portion 46 thereof.

The lower end of the body member 35 is provided with a seat 41 upon which the lower enlarged end 44 of the valve element 31 is adapted to rest, as shown in Fig. 2. Adjacent the lower end M of the valve 31 the stem is provided with a shoulder 48 seating against a central boss 49 which is formed with the valve element 31 and connected to the cylindrical walls thereof by ribs 50 (as clearly Shown in Fig. 6). The stem 38 passes through the central boss 49 and its lower end is engaged by a nut 9 drawn tightly against the under side of the central boss 49 to form a secure connection between the stem 38 and the movable valve element 31.

By connecting the stem 38 to the valve 'ele ment 3?, it will be noted that the length of the control valve is maintained as small as possible without reducing the cross sectionalarea interiorly of the valve element 3'3 through which the exhausted steam must pass.

Below the seat 47 the valve body 35 is threaded as at to receive the exhaust pipe 28. Elbow 52 in the exhaust pipe 23 is provided with a drainage tube 53 through which condensate is conducted to a suitable point of discharge. Immediately above its threaded portion ill and beneat-h the seat t7 the valve body 35 is provided with another drain passage 54 which establishes communication between the exhaust pipe or passage 28 and the lowermost point of a port 55 extending vertically along a side of the valve body 35. Adjacent the lower portion of the port 55 the valve body is threaded to receive pipe 32 -which, during normal stoker operation, conducts exhaust steam from the engine E to the pipe 28.

At the upper portion of the valve body the passage 55 opens inwardly, as at 56, into the cylindrical bore 36 for conducting the exhaust steam through the valve element t'l during normal stoker operation. Since, as will be hereinafter more fully described, the upper end d3 of the movable valve element 3? must at times pass across the inward opening 56 of the passage 55 and since the passage must be of substantial cross-sectional area, a series of bridge walls 51 is provided, as best shown in Fig 5, for the purpose of maintaining the rings it within their respective grooves in the upper end 43 of movable valve element 31.

The steam intake pipe 27 is threaded into a boss 69 and admits steam between the enlarged position it will be apparent that steam passing from the intake 2i will be confined between the enlarged ends 43, it of the valve 31 and thence will pass through port 64 into the pipe29 for' admission to the steam chest (it.

In order to prevent building up of back pressure in the passagetit and pipe 32 when the valve is in its forward position, as shown in Fig. 2, the passage through the valve element 3"! has a crosssectional area at least as great as the crosssectional area of the opening or port 56 so that v cross sectional areas of the openings or ports 56 and 6| are substantially equal so that either may constitute an exhaust port while the other constitutes the live steam port without building up of back pressure on the exhaust side of the engine E. g

As shown in Figs. 2, 3 and 4, in order to reduce the overall length of the valve body 35 to a minimum, the cap ill and seat 41 are disposed a distance apart so that the travel of the valve member 31 is limited in each direction to just uncover the ports 56 and 6f.

At a suitable distance below the lowermost point of the port 6! a drain valve 62 is connected to the valve body 35 by means of a coupling 63. element fi i which, in the absence of any substantial pressure in port 5i, is maintained in an open position by means of a spring 65. Thus any accumulated condensate in pipes 21, 29 will flow out through the drain valve 62 before operation of the stoker engine is started. As soon as steam is admitted to the intake 2? and port 6|, the pressure of steam will cause the valve element 65 to close, thereby preventing leakage of steam through the drain valve 62 during normal stoker operation. I

It will be apparent from Fig. 1, wherein the control valve V is in a position to cause forward operation of the engine E, that the rod 24 is free of any positive connections with the cab deck i l but merely protrudes freely therethrough. Thus, as relative movement between the frame it and the deck it occurs, the rod M is free to move With respect to the deck Id and therefore will not transmit any stresses to the valve stem 38 which might cause breakage thereof. It will be further observed from Fig. 2 that when the control valve of the described construction is utilized, breakage of the valve stem 38 or the rod 24 for any reason will not result in a stoker failure because the movable valve element 37 is pressure-balanced on all sides and will normally come to rest in the position illustrated in Fig. 2, thereby insuring admission of steam to the engine E for operating the latter normally.v

Occasionally it is desirable to reverse the direction of rotation of the conveyor screw 20 in order to release extraneous matter lodged between the flight of the screw and the stoker conduit walls. In order to accomplish this reversal, the fireman grasps the handle 25 and pulls the rod 24 upwardly until the movable valve element 31 is in the position illustrated in Fig. 4, whereuponsteam from the intake pipe 21 will pass around the reduced portion 56 of the valve element and through the openings 56 into the port 55. The live steam then enters the steam chest 39 through pipe 32 and is admitted, through suitable valves in the engine E in a manner well known, to cause the crank shaft 8 to be rotated in reverse direction. During reverse operation of a 'As in the forward running position of the engine, the operating rod 2 iis not in any Way posi: tively connected to the cab deck during reversal The drain valve 62 comprises a valve of the stoker engine, it being necessary for the fireman to retain the handle 25 in its uppermost position in order that reversed operation of the engine be continued. As soon as the handle 25 is released, the valve element 31 will of itself move downwardly and cause the stoker engine to operate normally. This feature is of particular advantage in locomotive stoker operation where it has been found in past practice that when a positive lock is used to retain the valve in a reversing position, the fireman frequently fails to return the valve to its normal position until lowering of steam pressure caused by poor fire conditions brings to his attention the reverse operation of the stoker.

If upon continued reversal of the conveyor screw 20 the extraneous material is not released, it is customary for the fireman to shut off the supply of steam to the intake pipe 21 and then, as a precautionary measure, place the movable valve element 31 in a neutral position. Under these conditions the fireman may then attempt to release the clog manually without any danger. In Fig. 3 the movable valve element 31. is shown in the neutral position and it will be apparent that any steam which may have entered the intake pipe 21 will be confined between the enlarged ends 43, 44 of the movable valve element 31. The arrangement is such that at least one ring 45 provides an effective sealagainst steam leakage. However, should the rings become slightly worn, any leakage of steam past the enlarged ends 43, 44 of the movable valve element 37 will always be vented to atmosphere through the exhaust pipe 28 and the leakage would not, therefore, cause the engine to operate.

Since the fireman must direct his manual efforts to release the clog, means is provided for maintaining the operating rod 24 in the neutral position illustrated in Fig. 3. This means comprises a latch plate 10 which is secured to the cab deck I4 by means of screws H and having therein an opening 12 through which passes the upper end of the rod 24. This rod is provided with a notch 13 which is calibrated to engage the latch plate 10 when the movable valve element 3'! is in the position as shown in Fig. 3. Thenotch 13 and latch plate 10 are maintained in engaging position by a spring 14, one end of which is secured to the rod 24, the other end being fastened to an eye bolt 15 which is threaded into an angle iron 16 on the under side of the cab deck I 4. The spring 14 also serves to stabilize the rod 24 against excessive angular fore and aft movement about pivot 39 when the movable valve element is in the positions shown in Figures 1, 2 and 4.

Because it is essential to maintain the operating rod 24in the position illustrated in Fig. 3 by means of the latch plate 10, it will be apparent that as relative movement between the deck I 4 and frame I occurs, the movable valve element 31 will reciprocate slightly within the valve body 35. This movement is not objectionable, however, because the movable valve element is free to slide a considerable distance to either side of its neutral position Without striking the seat 41 or the cap 40. Furthermore, should the valve element 31 be moved by vibration of the stem 38 a distance sufficient to cause its reduced portion 46 to establish communication with port 6| or port 55, any steam confined between the enlarged ends 43, 44 of the valve element 31 will be vented to the exhaust pipe 28 and will not pass into either of the pipes 29, 32.

Whenever it is desired to move the valve element 3! from its neutral position into either of its other positions, the fireman pushes the rod 24 forwardly, it being clear that the rod 24 is free to move about its pivotal connection 39, to cause disengagement of the latch plate 10 with notch H, whereupon the rod may be pulled upward to place the valve element 3! in a reverse position as shown in Fig. 4, or, if desired, the rod 24 may be pushed downwardly to place the valve element 31 in a forward position as shown in Fig. 2.

Those familiar with the art will readily understand that a control Valve constructed according to this invention will be efiicient in operation; that the construction aifords adequate protection to a stoker operator by reason of its positive neutral position; and that this construction prevents breakage of the valve stem and other failures attendant with control valves of prior construction.

This application is a division of our application Serial No. 96,804, filed August 19, 1936, now Patent No. 2,181,840, granted November 28, 1939.

We claim:

1. A control valve for a pressure fluid engine comprising a body member having a cylindrical bore therein, said body member having an intake passage. an exhaust passage and a pair of pressure fluid ports opening into said cylindrical bore, a movable valve element in said cylindrical bore for selectively establishing communication between said intake passage and either of said ports, said valve element being hollow between the remote ends thereof, forming a passage opening endwise within said bore for establishing a constant communication with said exhaust passage, means formed with said body member providing a duct leading from that pressure fluid port more remote from said exhaust passage, means providing a restricted passage between said exhaust passage and said duct in any position of said valve element, a cover secured to said body member over one end of said cylindrical bore, a stem operatively connected to said valve element and passing freely through said cover, and a stufiing box carried by said cover and cooperating with said stem to form a fluid-tight joint.

2. A control valve including a body member having a cylindrical bore therein, said body member being formed with an inlet port, a pair of longitudinally spaced ports and an exhaust port communicating with said cylindrical bore, a movable valve element in said cylindrical bore for selectively establishing communication between said intake port and either of said longitudinally spaced ports, said valve element being hollow between the remote ends thereof forming a passage for establishing a constant communication with said exhaust port, means formed with said body member providing a passage leading from that one of said longitudinally spaced ports more remote from said exhaust port, and means providing a restricted passage between said exhaust port and said passage in any position of said valve element.

EDWIN A. TURNER, CHARLES R. DAVISON.

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