US1954812A - Drifting valve - Google Patents

Description

Apr-i1 1934. J. H. HANLON ETAL 1,954,812

DRIFTING VALVE Filed Jan. 9, 1930 2 Sheets-sheaf 1 April 17, 1934. I J. H. HANLON m DRIFTING VALVE Filed Jan. 9. 1930 2 Sheets-Sheet 2 Patented Apr. 17, 1934 UNITED STATES PATENT OFFICE DRIFTING VALVE Application January 9, 1930, Serial No. 419,554

3 Claims.

The invention relates to drifting valves for locomotives, i. e. valves for controlling and furnishing a supply of saturated steam to the working cylinders of a locomotive, for purposes of lubricating the cylinder walls when the locomotive is moving or drifting with the throttle closed.

The drifting valve forming the subject matter of this invention is an improvement of the drifting valves shown and described in the United States patents to John H. Hanlon Nos. 1,378,786 and 1,423,797 of May 17, 1921 and July 25, 1922 respectively.

The drifting valves shown in said patents are entirely automatic in their operation of supplying saturated steam to the cylinders when the throttle is closed and also in cutting off the supply when the locomotive comes to a stop. The former operation is governed by the closing movement of the throttle mechanism while the latter operation is controlled by the action of back pressure from the cylinders after the locomotive has come to a stop, which pressure is directed to a trip cylinder causing certain parts of the mechanism to be tripped and the drifting valve to be closed.

It has been found in practice that the automatic control for cutting off the supply of steam through the drifting valve to the cylinders after the locomotive had come to a stop was unreliable as it depended for its success on the adjustment of travel of the slide valves for the cylinders. If the slide valves were adjusted for long travel the building of pressure in the trip cylinder to close the drifting valve was prevented, when the locomotive was running with closed throttle, by suction in the working cylinders. But if the slide valves were adjusted for short travel and the locomotive was drifting at high speed, pressure would build up in the trip cylinder and close the drifting valve too soon.

Furthermore, it has been found that certain parts of drifting valves which are entirely automatic in their control have a tendency to stick after continued operation and keep the valve open, which is dangerous, because it is absolutely essential that the drifting valve be closed when the locomotive comes to a stop, to prevent pressure building up in the working cylinders and starting the locomotive unintentionally. A further fault of previous construction has been the slow closing of the drifting valve due to the fact that the pressure tending to prevent the closing is notproperly released. This pressure has usually been released through bleeder ports which are open at all times but are limited as to size so as not to lower too much the effectiveness of the pressure tending to open the valve.

One object of the present invention is to control the closing movement of the drifting valve by manually operated means when the locomotive comes to a stop, to prevent the building of pressure in the working cylinders and the unintentional starting of the locomotive caused thereby. With such means provided the drifting valve may be permitted to operate when the throttle is closed until the locomotive comes to a stop at which time the drifting valve is closed by manual operation. Another object is to provide a quick release of the pressure tending to keep the drifting valve open to permit the instantaneous closing of the same.

These and other objects of the invention together with means whereby the latter may be carried into effect will best be understood from the following description when taken in connection with the accompanying drawings and the novel features thereof pointed out and clearly defined in the claims at the close of this specification.

In the drawings:

Fig. 1 is a side elevation of a locomotive to which is applied a drifting valve and its operating mechanism embodying the invention.

Fig. 2 is an enlarged end elevation, partly in section, of the operating mechanism as viewed from the left of Fig. 1.

Fig. 3 is a sectional view taken upon the line 3-3 of Fig. 2, showing the parts of the control valve in their normal inoperative positions.

Fig. 4 is a sectional view taken upon the line 4-4 of Fig. 2.

Fig. 5 is an enlarged section taken on the line 5-5 of Fig. 3.

Fig. 6 is a vertical section of the drifting valve and its closely associated parts.

Fig. '7 is a sectional view similar to that of Fig. 3, showing the parts of the control valve in their open positions. 7

Fig. 8 is a similar sectional view showing the relation of the control valve to the throttle valve operating means when the latter is closed and disconnected from the control valve.

Fig. 9 is a sectional view taken upon the line 9-9 of Fig. 8.

Referring to the drawings and particularly to Fig. 1 there is shown a locomotive having a boiler A provided with a steam dome 13, working cylinders C (only one of which is shown) and a throttle valve D which is operated by the hand lever E and connecting rod F to supply steam to said cylinders. At G is indicated a drifting valve illustrative of and embodying the invention which as the drifting shown is mounted on the side of the locomotive at a convenient point between the steam dome B and the working cylinders C thereof. This valve comprises a body or casing 10 (see Fig. 6) which houses a valve 11 normally held closed by a spring 12 against a cooperating valve seat 13 to separate, saidcasing into two'chambers. One of these chambers isconnected .by..a,.pipe14 with the steam dome B while the other chamber is connected by a pipe 16 and branch pipes 17-17 with the working cylinders C. The passage .of steam through the pipe 14 may be regulated by a valve 18 manually operated by a hand-wheel 1'9 and rod 20 convenientlyaccessibleto the engineer.

The valve 11 is provided with a stem 21 which projects through the casing .10 anclis adaptedto be engaged and operated by a piston'22 working in a cylinder 23 depending from said casing. The piston 22 is provided with a series of grooves 24 for the reception of packing. It has been found in actual use thatmetallic packing rings fail to prevent leakage and also have a ten'dency .to score the cylinder walls and that *leather packingis impractical due toits-lackbf resistance to the eifects of high temperatures. 'In-accordance with one feature of-the present-invention the packing comprises rings 25 of asbestos preferably in the form of rope and saturated with some self-lubricating substance such -as graphite or-plumbago. Such a packing is heat resisting and'requires no lubricationafterithas been installed. It 'is also flexible and will not score the cylinderwalls. Eachgroove 24 is-shaped in cross section to provide adepth varying;progressively from its outer edges-to anintermediate point. This cross-sectionalcontour of the groove is'preferably'in the shape of an arctoconform'to the cross-sectionalshape of the packing Ting to permit engagement between these parts throughout the entire area of said groove. When-compressed air is admitted tothe-cylinder 23 it tends to pass between the piston 22 and the cylinder walls thus forcing thevpacking rings upwardly. Due'to the cross sectional shape ofthe-grooves 24 and the flexibility of the packing rings this upward pressure forces said-ringsoutwardly against the cylinderwalls thus making atight jointan'd sealing said cylinder and piston.

The operating cylinder 23 is connected by a pipe26 with a control valve I-Iwhich is-bolted or otherwise secured to a plate 27 secured "by a bracket 28-to=therearface of the locomotive. The valve H controls a flow of air under pressure to the cylinder 23-and comprises a cylindrical body or casing 29 formed with a lateral partition 30 preferably located at'a point midway between its ends. The partition 30 divides the casing into two chambers 31 and 32 (see Fig. 3),"the chamber 31 being connected by the pipe 26 previously referred to with the-operating cylinder 23 of valve G, while the chamber 32 is connected by a pipe 33 with a reservoir 34 containing compressed air preferably at a pressure of about 130 lbs. to the square inch. Extending outwardly to the'end of the casing 29-through the chamber 32 and concentric therewith is acylindrical projection 35 which as shown forms an integral part of the partition 30. A cylindrical passage 36 extends through the partition 30 and its projecting portion 35 and terminates ina valve seat 37 at its outer end. An inlet-valve 38 cooperating with the seat '37 is normally held in engagement therewith by-a coiled spring 39 interposed between said valve and a removable cap 40 ".properseating of said valve. It will be seen from the construction shown in Fig. 3, that compressed air entering the chamber 32 through the pipe 33 .must take a right-angle turn to pass through said chamber and a similar turn before reaching the valve 38 and any dirt or grit that cannot pass 'throughthe screen41-falls back into the chamber .32 which forms-a pocket or trap for its reception. :Anyaccumulation of dirt in the chamber 32 may .be quickly blown .out by removing the cap 40 and permitting the pressure to escape to the atmosphere. at this point.

The inlet valve 38 of the control valve H is provided with a stem 42 of triangular cross-section (seeI-Figfi 5) which extends-through the passage 36 andterminates in an exhaust valve 7 which cooperates with a'valve seat 8 formed on the inner end of a-plunger 43 slidably mounted in a :bushing 44in threadedengagement with the end of the casing 29. The plunger 43 is coaxially alined with the stem 42 of the inlet valve 38, and

.the exhaust valve 7 isnormally open as shown in Fig.3. Theplunger 43 isprovided with a head15 .on its inner end to limit its outward movement relative to the casing 29. The plunger extends outwardly through the bushing=44 and a removrablecap-9 thereon and is provided with an exhaust port 145:1eading outfrom the valve seat 8. A port b-connectsthe-chamber 31 with a port 0 in a re- -movab1e .plug 46 in threaded engagement with the casing29. 'Theseports are of relatively small .size and open the -chamber 31 totheatmosphere Ltoindicate'byJthe emission of airthat the system .isworking and also-give warning when the valve isileft 'open' unnecessarily. A wire (1 having a'finger .portion iby which it may be manipulatedextends looselyiithrough theiport c in the plug 46 to whichit is secured and servesasameans to keep .said port from getting plugged with dirt.

The-plunger 430i thecontrol valve H is moved to engagezand-operate theinlet valve 33 thereof .bymechanism that will now be described. A shaft 149 iss'lidablyand rotatably mounted in spaced.

ibearings47and 48 '(Figs.2 and 3) carried by the .plate227. :AdogL50 securedto the shaft 49 by a -set-screw:51:projects outwardly in opposite directionsfrom said:shaft betweenthe bearings 4'7 and under side of the -plate27. The piston 56 actuates the dog 50 to .move the end e thereof out of the path of movement of the plunger 43. A spring 58 confined in the arm e of the dog 50 and engaging a plunger '59 slidably mounted in said arm .and -bearing against the upper side of the plate 27 (see Fig. 4), tends to move the arm 2 of the dog into the path of movement of the plunger.

One end of the shaft 49 terminates in a cylinder 52 formed as an extension of the bearing 47. A member 53 extends into the cylinder 52 through 48. One endeof thedog 50 extends into the path.

a hole 2 in the outer end wall thereof and is provided with an enlargement f at one end positioned within the cylinder 52 and adapted to engage the end of the shaft 49. The member 53 is loosely carried by the cylinder 52 and is retained therein by engagement of the enlargement with the portion of the end wall of the cylinder surrounding the hole 2'. The other end of the member 53 extends over the rod F which connects the hand lever E to the throttle valve D of the locomotive and is arranged to be engaged by a pin 54 on the rod F.

A removable head 60 in threaded engagement with the outer end of the cylinder 57 limits the outward movement of the piston 56. The head 60 is provided with a chamber 61 which is connected by a port m with the cylinder 57 and by a pipe 62 with the air reservoir 34. A removable plug 63 opposed to the pipe connection 62 in the head 60 permits the chamber 61 in said head to be cleaned out periodically by air pressure from the reservoir 34. A manually operated valve K is installed in the pipe line 62 at a place conveniently accessible to the engineer to admit pressure to the trip cylinder. The piston 56 is provided with a bleeder port n as shown in Fig. 2 to release the pressure under said piston to permit the dog 50 to return to its normal position, shown in Fig. 4, by the action of the spring 58, and also to prevent injury to the piston and trip cylinder due to a sudden heavy pressure when the valve K is opened.

The operation of the drifting valve above described is as follows:

When the locomotive is running with the throttle open the parts of the control valve are all in their normal inoperative positions as shown in Fig. 3 of the drawings. When the engineer closes the throttle while the engine is moving the pin 54 engages the member 53 to turn it about a fulcrum point g from the position shown in Fig. 3 to that shown in Fig. '7, thus causing the shaft 49 to be moved to the right in the bearings 4'7 and 48 against the action of the spring 55 as viewed in Figs. 3 and 7. During this movement of the shaft 49 the dog 50 thereon engages the plunger 43 to move it in the same direction to bring it into engagement with the valve stem 42 and move the same to open the inlet valve 38 against the action of the spring 39. When the inlet valve 38 is thus opened fluid under pressure is supplied from the tank 34 through the pipe 33 to the chamber 32 and thence through the passage 36 opened by the valve 38 into the chamber 31 from which chamber it is supplied through the pipe 26 to the cylinder 23 to raise the piston 22 and open the drifting valve G against the action of the spring 12 and permitting steam to be supplied from the dome B to the engine cylinders for the purpose of lubrication.

If the engineer opens the throttle while the 10- comotive is still moving the pin 54 is moved out of engagement with the member 53 permitting the spring 55 to return the shaft 49 and member 53 to their normal inoperative positions shown in Fig. 3. At the same time the spring 39 closes the inlet valve 38 and the fluid pressure in the chamber 31 moves the plunger 43 away from the valve '7 upon the end of the stem 42, thus permitting the spring 12 to close the drifting valve G and at the same time exhaust the fluid under pressure in the cylinder 23 by passing therefrom through the pipe 26, chamber 31 and exhaust port 45.

When the engineer closes the throttle in order to bring the locomotive to a stop the drifting valve is automatically opened as above explained. This, however, would be dangerous inasmuch as it would permit pressure to build up in the locomotive cylinders tending to cause the locomotive to creep. Therefore, when the throttle is closed to bring the locomotive to a stop the engineer opens the valve K to cause fluid under pressure to be supplied from the tank 34 to the trip cylinder 57 to move the piston 56 therein upwardly to rotate the dog 50 and shaft 49 from the position shown in Fig. 4 to that shown in Fig. 9 to bring the dog 50 out of engagement with the plunger 43, thereby permitting the drifting valve to remain closed or to close automatically depending upon whether the valve K is opened before or after the throttle valve is closed. The parts of the control valve and its operating mechanism will assume the positions shown in Fig. 8.

From the foregoing description it will be seen that a drifting valve constructed and operated in accordance with the principles of the invention is automatic in its operation to supply saturated steam to the working cylinders of a locomotive that is moving with the throttle closed, and is under manual control at all times whereby the supply of saturated steam for drifting purposes may be cut off.

What we claim is:

1. In a locomotive having a throttle valve and means for operating the same for supplying steam to the working cylinders thereof, the combination of a drifting valve for supplying steam to the Working cylinders when the throttle valve is closed, means for supplying fluid under pressure to open said drifting valve including a control valve, a plunger operable to open said control valve, a spring tending to close said control valve, operative connections between said plunger and throttle valve operating means including a shaft mounted for rotative and. longitudinal movement 115 and a dog carried by said shaft adapted to engage said plunger to move the same longitudinally to open said control valve when said throttle valve is closed, a trip cylinder and piston adapted to move said dog out of operative engagement with 120 said plunger, a supply of fluid under pressure, a passage connecting said supply with said trip cylinder, a manually operable valve for said passage to supply fluid to said trip cylinder to move said dog out of operative engagement with said plung- 125 er to permit said spring to close said control valve,

a second spring tending to move said shaft to its original longitudinal position, and a third spring tending to rotate said shaft in a direction to move said dog into the path of movement of said 130 plunger.

2. In a locomotive having a throttle valve and means for operating the same for supplying steam to the working cylinders thereof, the combination of a drifting valve for supplying steam to the working cylinders when the throttle valve is closed, a cylinder and piston for opening the drifting valve, a supply of fluid under pressure, a casing, connections from said casing to said fluid supply and to said cylinder respectively, a partition in said casing between said connections, an opening through said partition, an inlet valve controlling said opening, a screen enclosing said inlet valve and through which the fluid must pass from one connection to the other, a dirt pocket in said casing between said screen and said fluid supply, mechanism operatively connecting said throttle valve operating means and said inlet valve adapted to open the latter by closing the throttle valve, manually operable means for disconnecting said mechanism and throttle operating means, and means for closing said. drifting valve when said mechanism and throttle operating means are so disconnected.

3. In a locomotive having a throttle valve and means for operating the same for supplying steam to the working cylinders thereof, the combination of a drifting valve for supplying steam to the working cylinders when the throttle valve is closed, means for supplying fluid under pressure to open said drifting valve including a control valve, a plunger movable to engage and open said control valve, a spring tending to close the control valve, a longitudinally movable shaft, a lever adapted to move the same, mechanism adapted to connect said lever and throttle valve operating means to move the same by closing the throttle valve, a dog carried by said shaft adapted to engage said plunger to move the same to open the control valve, a trip cylinder and piston therein adapted to engage said dog to move it out of engagement with said plunger, a supply of fluid under pressure, a passage connecting said trip cylinder with said fluid supply, and a manually operable valve for controlling the fluid in said passage to move said dog out of operative engagement with said plunger to permit said control valve to be closed by said spring.

JOHN H. HANLON.

JOHN W. HANLON.

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