US1272718A - Drifting and relief valve. - Google Patents

Description

H. F. RIPKEN.

DRIFTINGAND RELIEF VALVE.

APPLICATIGN FILED Jun 10. [9!6.

1 ,272,7 1 8. Patented July 16, 191s.

2 SHEETSSHET 2.

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UNITED STATES PATENT OFFICE HUGO F. RIPKEN, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR 01 ONE-HALF TO CHARLES A. MOCULLOCH, 0F MINNEAPOLIS, MINNESOTA.

DRIF'IING AND RELIEF VALVE.

Specification of Letters Patent.

Patented J nly 16, 1918.

Application filed July 10, 1916. Serial No. 108,328.

To all whom it may concern:

Be it known that I, HUGO F. RIPKEN, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Drifting and Relief Valves, of which the following is a specification.

My invention relates to improvements in drifting and relief valves for reciprocating steam engines, and especially for those employed in railway locomotives.

It will be understood that when ,in the ordinary operation of the engine the supply of steam to the cylinder and steam chest is cut off by the closing of the throttle valve, the engine will drift for some time before it actually comes to rest. In thus drifting the piston will continue to move back and forth and as no live steam enters behind the piston a artial vacuum will be formed at that olnt. This wilt cause an inrush of cold all into the cylin der through the cylinder cocks. and also as soon as the valve piston in the steam chest has uncovered, the cylinder port to the exhaust on that side, an inrush of smoke, cinders, and gases of combustion from the smoke box through the exhaust nozzle. This is objectionable because the cold air cools the cylinder walls and steam chest and causes condensation of the steam, and the smoke, cinders, and gases of combustion are destructive of the lubrication of the cylinder.

It is the object of this invention to overcome these objections b providing an improved drifting or relie valve that will antomatically and instantly operate to admit a sufficient amount of boiler steam to the valves and cylinder while the engine is drifting even.at very low speed and with the main throttle'valve closed to revent this partial vacuum being formed m the cylinder, and which will also automatically close and'shut ofi' the steam when the engine comes to rest, so that there will be no escape or waste of steam through the drifting valve when the steam is not needed to prevent a partial vacuum forming in drifting.

With these objects in view I have constructed a valve wherein the cylinder com pression or back pressure upon. the piston, a positive force existing only while the engin is in motion, is utilized to furnish the motive power for operating the valve to open it, and steam entering from the boiler to furnish the power to close it after the back pressure has ceased owing to the stoppage of the engine and wherein the valve is a ported piston valve, so that no boiler pressure will be exerted u on it in opposition to the pressure from t e cylinder until the piston has been moved far enough to uncover the live steam port, so that the valve will be opened whenever the cylinder pressure is sufficient to overcome the weight or inertia of the piston itself, as will always be the case when the engine is drifting, even when it is at the slowest s eed and with the longest cutofl' obtainab e in locomotive service. More particularly the invention consists in the construction, combination, and arrangement of parts hereinafter described and claimed.

In the accompanying drawings showing an embodiment of the invention,

Figure 1 is a vertical longitudinal section through the middle of the cylinder and steam chest of a reciprocating engine with my improved valve in elevation, and v Fig. 2 is a, vertical section through the middle of the valve alone.

In the drawings A represents the cylinder of a reciprocating engine, B the piston working therein, and C the steam chest in which works a. valve piston D, all of usual ty ie.

he drifting valve which is the subject of this invention comprises a cylindrical casing or cage 2, shown in elevation in Fig. 1 and ,in vertical section in Fig; 2, the interior of which is open to communication with one end of the interior of the cylinder throu h the medium of a ipe 3 which leadsfrom t e bottom of the va ve easing into a duct 4 extending around the bushm at one end of the steam chest to the cylinder port 5 on that side of the piston B. The com ressed air or steam in that end of the cylin er can thus ass through the duct 4 and pipe 3 into tlie valve casing below the valve. Another pipe 6 leads from the top of the valve casing and has communication with the steam chamber 7 of the steam chest.

Working within the valve casing 2 is a sliding valve piston 8 closed at the bottom and havin an upwardly projectin sleeve extension 1 The upper portion of t e valve piston is somewhat larger in diameter than a with circumferentia the lower portion and is formed with a shoulder 9 which seats against a cooperating shoulder 10 on the inside of the casing when the valve is not in operation. Just beneath the shoulder the sleeve extension of the valve piston is formed with a circumferential port 11 in position to communicate with a circumferential port 12 in the casing when the valve piston is moved up. The port 12 is in communication with a live steam inlet conduit or pipe 13 which leads from the boiler (not shown) or other source of steam supply. The orts 11 and 12 are guarded from the acci ental passage of steam into the cage by means of packing rings M.

In order to prevent the hammering of the valve piston 8 in the casing and also to reduce the bottom area of the piston sulficiently to allow the steam pressure from the steam chest entering above it to keep the valve piston on its seat while the main throttle valve is open and the engine is working, the valve is provided with a centrally depending plunger 15 of much less diameter than the diameter of the iston and this plunger works within a das pot 16 carried by the cage 2 a suitable distance below the valve seat 10. The plunger is shown formed grooves to catch drippings of oil and condensed steam for lubrication purposes, but this is no part of my invention. I

The operation of the valve is as follows: When the ressure in the steam chamber of the steam c est falls owing to the closing of the throttle valve, the compression in the forward end of the cylinder, resulting from the continued movement of the piston after the valve in the steam chest has closed the cylinder port to the exhaust outlet, will force the steam in the cylinder out throu h the ducts 4 and 3 into the lower part of t e valve cage 2 below the valve piston 8. This will throw the valve piston up and bring the circumferential valve port 11 in the sleeve 17 into communication with the port 12, so that the live steam in the pipe 13 will pass into the sleeve chamber on the upper side of the valve piston 8. From this chamher it will pass through the pi e 6 to the steam chest and thence throng the usual channels into thecylinder thereby preventin the formation bf a partial vacuum in the c inder when the steam supply is cut off by t e closin of the throttle valve. The valve piston will remain in this position with the ports open to allow the'steam from the pipe 13 to enter the steam chest and cylinder, until the engine comes to rest and the piston no longer causes cylinder compression in the pipe 3 of valve casing 2. When the cylinder compression thus ceases the ressure of steam in the sleeve chamber of t e valve iston will force the valve piston down upon its seat, thereby closing the port .12 and shutbe extremely sensitive to cylinder compression, because the upward travel of the piston will not be opposed by the counter-pressure of live steam from the boiler until the lateral ports in the piston sleeve and steam conduit have come into registration so as to allow the live steam to enter the valve casing. And when the live steam inlet port is constructed so as completely to encircle the piston sleeve as here shown, the pressure. of the live steam against the sleeve will be exerted equally upon all sides thereof, so as to hold it in balance without .crowdin it against the casing, thereby avoiding riction with the casing wall.

\Vhile I prefer to use the particular valve structure shown in the drawings it will be understood that I do not limit myself to this particular form but mean to include all modifications thereof which come within the principle of the invention as defined in the claims. It will also be understood that the duct 3 from the valve casing may be connected with the cylinder directly or indirectly in any convenient way, the only essential being that it be constructed and connected so as to serve as a means of communication between the cylinder and the drifting valve when the cylinder port to exhaust is closed.

It is to be understood that such changes and rearrangements of parts may be resorted to as fall within the scope of the appended claims.

I claim as my invention:

1. In a reciprocating engine, the combination with the cylinder and steam chest, of a drifting valve comprising a valve casing open to communication wlth the cylinder at one end and the steam chest at the other end and having intermediately a lateral inlet port for live steam, and a pressure actuated valve piston having a projecting extension norma ly closi said liver-steam inlet ort but adapted, w on the piston is move by the rewure in the cylinder after themain supp y of steam thereto has been shut oil and the engine is drifting, to slide over and uncover said live steam inlet, said valve having means of communication between the casing inlet and the steam chest when said inlet port is uncovered, whereby to allow live steam to enter the valve casing beyond the piston and pass to the steam chest for the purpose set forth.

2. In a reciprocating en 'ne, the combination with the cylinder an steam chest, of a balanced drifting valve comprising a valve casing open to communication with the cg'linder at one end and the steam chest at engine is drifting, will come into registmt e other end and having intermediately a tion with the live steam inlet port in the eascircumferential inlet port for live steam, ing and allow live steam to enter the portion and a valve piston having-a projectin sleeve of the valve casing beyond the piston and 15 extension normally covering said in et port pass into the steam chest.

so as to prevent the live steamfrom entering In testimony whereof I aflix my signature the valve easing, said sleeve extension bein in presence of two witnesses.

formed with a circun'lferential port, whic HUGO F. RIPKEN. port, when the piston is moved. by. the pres- Witnesses:

sure in the cylinder after the main su ply BEATRICE BROWN,

of steam thereto has been shut ofl and the H. SwANsoN.

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