US1423797A - Drifting valve - Google Patents

Description

J. H. HANLON,

DRIFTING VALVE.

APPL'ICATIQN FILED OCT. 24. 1917.

PatentedJuly 25, 1922.

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F B INVENTUVI Patented July 25, 1922.

2 SH EETSSHEET 2.

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JOHN H. HANLON, OF SOMERVILLE, MASSACHUSETTS.

DRIFTING- VALVE.

Application filed October 24, 1917. Serial No. 198,217.

To all whom it may concern:

Be it known that 1, JOHN H. TIANLON, a citizen of the United States, residing at Somerville, countyot' Middlesex, State of Massachusetts, have invented a certain new I and useful Improvement in Drifting Valves,

of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has for its object a new and improved drifting valve "for use on steam locomotives by which a supply of wet or saturated steam will be furnished to the working cylinders during the time when the locomotive is in motion but is not being supplied with steam through the dry pipe. As is well understood by those skilled in the art,'the use of superheaters on steam locomotives has resulted in certain difiiculties which it is the purpose of so-called drifting valves to overcome. For instance, the temperature of the; cylinder walls as a result of the use of superheated steam is so high that when the throttle is closed, the cylinder and piston are practically without lubrication so that p the packing is quickly destroyed or the cylindone to the parts.

ders scored. The air drawn into the cylin ders by the suction or" the pistons contains dust which together with the oil burns or carbonizes as it is termed and injury is The carbonization which takes place builds up a layer on the piston head and walls of the valve chamber reducing the clearance and causing the engine to knock, interfering with its proper operation and with the removal of the parts. Accordingly it is desirable to supply saturated steam to the cylinders in sufiicient quantities to lubricate the walls of the cylinders at such times as the locomotive is moving and the supply of superheated steam is shut oft. The drifting valve embodying my invention is so constructed that saturated steam is sent to the cylinders whenever the engineer closes the throttle valve and the flow continues as long as the locomotive is in motion and stops automatically when the locomotive stops. Provision is made so that there is no possibility of steam pressure building up in the cylinders of the locomotive and moving the locomotive in case the engineer fails to give the apparatus its proper attention. The apparatus is wholly automatic and requires no attention whatever aside from oiling.

The invention will be fully understood when taken in connection with the following description and accompanying drawings and the novel features thereof will be 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 embodying my invention.

Fig. 2 is a vertical section on line 22 or Fig. 1 on an enlarged scale. I

F g. 3 is a section on line 3-3 of Fig. 2.

F 1g. at is a view similar to that shown in F 1g. 2but with the parts in a different p01 sitlon.

Fig. 5is a View showing the position of the parts after the trip cylinder has operated.

b Fig. 6 is a detail of the main valve mem- Fig. '7 is a section on line 77 of Fig. 6. I

pipe leading to the interior of the locomotive boiler as for instance through a steam dome 12. At 13,13 are shown two branch pipes leading to'the' locomotive cylinders. The three pipes are connected by a valve casing 14: within which is located a balanced main valve 15 (see particularly Fig. 6.) This balanced valve 15 has a valve member a which engages a seat Z). The valve is also provided with a stem 0 and piston d adapted to oper ate in a cylindrical bore formed at c in the lower part of the casing 14. It will'be seen that when the valve member a is oil its seat 6, as shown in Fig. 4:, the pipe 11 is connected with the two pipes 13, 18 so that saturated steam can flow through them to the cylinders oi the locomotive. The valve member 15 is bored longitudinally to receive an auxiliary valve 16 the stem of which is of substantially triangular cross section as shown in Fig. 7. The stem 16 protrudes below the lower end of the main valve 15 and terminates in a head 17. The upper end is provided with a conical valve member 18 engaging a seat f which is formed in the main valve member. At 20 is shown a small port through the piston a to prevent steam from accumulating under the piston 65 or" the main valve 15. It will be seen that the construction is such that when the auxiliary valve 16 is lifted steam can pass through the bore ofthe main valve and under its lower end thereby largely counterbalancing the pressure on the upper side of the main valve and making it possible to lift the main valve with a minimum effort.

Guided in the stuffing box 21 secured to the casing 14 is plunger 22 adapted to be moved vertically and to engage the lower end of the auxiliary valve 16 and the main valve 15. The upper face of the plunger is grooved as shown at 19 (see Figs. 2 and 8) to permit steam to flow beneath the main valve 15 when the plunger and main valve are in contact. This plunger is moved verti- Cally byacam 23 which is rotatable on a rod. 24, said rod being slidable in a bracket 30 by which the trip cylinder 31 and main valve casing 14 are supported. The lower end of the cam is provided with atail g located in the path of the throttle lever B. For convenience of: adjustment the contact between the throttle lever B and the tail of-the cam 23 may be regulated by means of a screw pin 25 and check nut 26. Surrounding the rod 24 is anopen spiral spring 27 one end of which contacts with the pi-n28 on the bracket 30 and the other end ofwhich enters a hole 29 in the cam 23. The spring .27 performs two functions, first that of rotating thecam 23 on the rod 24 in a direction oppositeto that which the throttle lever rotates the cam 23, and second, to push the cam 23 and attached parts as far to the left as shown in Fig. 2 as possible. i

Secured to the bracket. 30 which supports the device is a tripcylinder 31 containing the piston 32 secured to a stem 33 which acts on the cam 23 to slide it with the rod 24. One end of the tripcylinder is connected by a pipe 34 to a. port 35 which intercepts the main port of the main valve. The amount of opening of said port 35 maybe adjusted by means of a needle valve 36 enclosed within the cap 37. This needle valve 36 regulates the amount of steam which can flow from the main valve to the trip cylinder 31 and therefore the length of time which will elapse before the trip cylinder will act to move the cam 23 to the right. At 38 is shown a bleed port through which the steam in the trip cylinder is exhausted after the trip cylinder has been actuated.

At 39 and 40 is shown a bypass around the main valve seat and this by-pass is opened or closed by the valve 41 operated by the handle 42. An alarm port 43 leads out through the stem of this valve and gives warning by the emission of steam whenever the valve is left open. By opening this valve the engineer can'permit a small quantity of steam to pass to the cylinders of the locomotive when the locomotive is standing still. even though the drifting valve is closed.

This is advantageous because it makes it possib le to admit live steam to the cylinders to warm them up or to blow out any accumulation of condensation.

The operation of the drifting valve embodying my invention is as follows: Under normal conditions when the locomoti've is standing still or is running with the throttle open, the drifting valve is closed. When the engineer closes the throttle, the throttle lever engages the pin 25 on the tail 9 of the cam 23 and swings the cam about its centre moving up the plunger 22 and first lifting the auxiliary valve 16 and then the main valve 15. When the main valve is lifted, the steam flows from the pipe 11 to each of the cylinder pipes 13. At the same time, steam is free to flow through the port 35 and pipe 34 to the trip cylinder 31 but no pressure accumulates in the trip cylinder because the suction produced by the locomotive cylinders when the locomotive is running with closed throttle isso great that the man supply of steam entering through the pipe 11" does not produce any appreciable pres sure. If the engineer opens the "throttle again before the locomotive comes to a stop, the operation of the drifting valve ceasesbecausethe movement of the throttle lever perm'its'the pressure on the main steam valve to push'the main steam valve down causing the cam 23 to swing on its axis and to return to its former position. The movement of the cam 20 to its original position is caused in part by the curvature of the cam, and in part by the spring 27 which is constructed to retate the cam about its axis as well as to move it axially. If, however, the 1000'- motive comes to a stop so that the suct-icnin the cylinders ceases, pressure is immediately communicated through the port. 35 and pipe 34 to the trip cylinder 31 and this forces the piston 32 to the right from the position shown in Fig. 2. The movement of the piston 32 to the rightmoves the cam 23 out from under the plunger 22 as shown in Fig. 5 compressing the spring 27. As soon as the cam 23 is moved out from under the plunger 22 the main valve closes shutting off the sup ply of saturated steam to the locomotive cylinders. There is, therefore. no possibility of pressure building up while the locomotive is standing. The pressure in the trip cylin der immediately leaks out through the bleed port 38 and the spring 27 pushes the cam 23 and piston 32 back to the left until the cam 23 strikes the side of the plunger 22 shown in F ig. 5. The parts remain in this position until the engineer begins to open the throttle. The spring 27 causes the cam to rotate and follow the throttle lever until the cam has moved far enough so that'the spring can push it under the end of the plunger. The parts are then set ready a repeat the operation.

steam connections from the main valve to the trip cylinder and throttle. operated means for opening the main valve by the closing movement of the throttle.

2. In a device of the character described, a main valve controlling a steam passage leading from the boiler to the cylinders of the locomotive, throttle actuated mechanism to open said main valve by the movement which closes the throttle, "a trip cylinder operatively connected with the main valve and connections from said steam passage to said trip cylinder whereby an accumulation of pressure in the cylinders of the locomo-' tive will produce pressure in the trip cylinder and actuate it to permit the closing of the main valve.

3. In a device of the character described, and in combination with a boiler throttle and working cylinders of a locomotive, a steam passage leading from the boiler to the cylinders, a main steam valve control ling said steam passage, mechanism actuated by the throttle valve to open said main valve, a trip cylinder and piston acting on said mechanism to permit the closing of said main valve and connections from the main valve to the trip cylinder so that pressure will accumulate in said trip cylinder whenever the main valve is open and the suction produced by the locomotive cylinders is not sufiicient to relieve the pressure produced by the flow of steam through the main valve.

4. In a device of the character described, and in combination with a boiler throttle and the working cylinders of a locomotive, a steam passage leading from the boiler to the cylinders, a main steam valve controlling said main steam passage, said main steam valvehaving a valve plunger, a cam engaging said valve plunger and actuated by the throttle of the locomotive, a trip cylinder and piston acting on said cam to move it out of operative relation with said plunger and connections from the main valve to the trip cylinder so that pressure will accumulate in said trip cylinder whenever the main valve is open and the suction produced by the locomotive cylinder is not sufiicient to relieve the pressure produced by the flow of steam through the main valve.

5. In a device of the character described, and in combination with a boiler throttle and the working cylinders of a locomotive, a steam passage leading fromthe boiler to the cylinders, a main steam' valve controlling said .main steam passage, sald mam steam valve having a valve plunger, a cam engaging said valve plunger and actuated by the throttle of the locomotive, said cam being mounted to rotate and slide, a trip cylinder and piston acting on said cam to slide it out of operative relation with said plunger, and connections from the main valve to the trip cylinder so that pressure will accumulate in said trip cylinder when-- ever the main valve is open and the suctlon produced by the locomotive cylinders is not suliicient to relievethe pressure pro--- duced by the flow of steam through the main valve.

6. In a device of the character described, a main valve controlling a steam passage leading from the boiler to the cylinders of a locomotive, throttle actuated mechanism to open said main valve by movement which closes the throttle, a trip cylinder and pis ton acting on said mechanism to permit the closing of said main valve, connections from the main valve to the trip cylinder so that pressure will accumulate in said trip cylin der whenever the main valve is open and the suction produced by the locomotive cylinders is not suiiicient to relieve the pressure produced by the flow of steam through the main valve, and a needle valve in said connections between the main valve and the trip cylinder whereby the rate of flow of steam to the trip cylinder may be varied.

7, In a device of the character described, a casing containing a main valve, a main valve, connections from the boiler to the casing and from the casing to the cylinders of the locomotive said connections being controlled by said main valve, a trip cylinder operatively connected with said main valve, steam connections from said main valve to the trip cylinder, throttle operated means for opening the main valve by the 'closing of the throttle, an auxiliary valve in said main valve, said auxiliary valve having a stem for engagement with said throttle operated means so that the auxiliary valve is opened in advance of the opening of the main valve.

8. In a device of the character described, a casing containing a main valve, a main valve. connections from the boiler to the casing and from the casing to the cylinders 01? the locomotive said connections being controlled by said main valve, a trip cylinder operatively connected with said main valve, steam connections from the main valve to the trip cylinder, throttle operated means for opening the main valve by the closing movement of the throttle, and a bypass about said main valve to admit steam directly to the cylinders.

9. In a device of the character described, a casing containing a main valve, a main lve, o nect s from. t eile t e casing and from the casing to the cylinders of the locomotive said connections being controlled by said main valve, a trip cylinder ope 'atively connected with said main valve, steam connections from the main valve to the trip cylinder, throttle operated meens fo opening the main valve by the closing movement of the throttle, and a hand-controlled by-pass about said main valve to admit steam directly to the cylinders.

10. In device of the character described, in combination, a valve for controlling the flow of steam to the cylinders of a locomotive, means for opening said valve, and a trip cylinder and piston controlled by the pressn ge in the locomotive cylinders when said falve is open for acting onsaid open- 111g means to permit said valve to close, said device having'p ovision, controlled by a part oi the locomotive which is moved in Stanting the locomotive, for ien dering said openiii' g means inoper tive to Open said valve until the locomotive is started after having 2 5 stopped;

11. In a device of the character described, in combination, a valve foi c on t toll'ing'the flow of steam to the cylinde 's'of a locomq tive, means for opening said valve, 'a'nda trip cylinde and piston cont 'olled by the pressure in the locomotive cylinders when said valve is open foirendering said ope ing means inoperative and'theiieby' per ting said valve to close vv'hen'the lOCOh iotlve stops, said opening means being controlled y s me P r 't m f i e wh ch i? moved in starting the locomotive bei pre en ed th t 11 R ming 'p' tive position nntil the locomotive is's 12. In a device of the ichai 'ac ter descr b a Steam mi es? lad ns from the boi e the cylinders of the locomotive, a main valv' tr h ie" Sai Passe-s8 hib' l'j'i p d means to cause aniovenient" f the n a e n on rec n, and a r u j c ed t s em Press it ,1 i. ders of the locomotive to cau

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