US3675417A

US3675417A - Engine starting system with combination air relay and check valve

Info

Publication number: US3675417A
Application number: US134286A
Authority: US
Inventors: John Shum Jr
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 1971-04-15
Filing date: 1971-04-15
Publication date: 1972-07-11
Anticipated expiration: 1989-07-11

Abstract

A valve assembly for use preferably with an engine starting system, the valve assembly including a housing providing a fluid flow path therethrough. A valve seat astride the flow path is disposed in the housing, and a valve head is mounted on a piston reciprocally mounted in the housing. The piston defines, with the housing, a control chamber and a reaction chamber, the latter of which communicates with the flow path downstream of the valve seat. Spring means biases the piston and valve head toward the valve seat so that the flow path is normally closed to fluid flowage therealong. Increased fluid pressure in the control chamber acts on the piston to open valve and thus the flow path, and comparatively high pressure downstream of the valve seat raises the pressure in the reaction chamber to force the valve head against the valve seat to prevent upstream flowage of the gases creating the high downstream pressure.

Description

United States Patent [l5] 3,675,417 [45]- July 11, 1972 Shum, Jr.

[54] ENGINE STARTING SYSTEM WITH COMBINATION AIR RELAY AND CHECK VALVE [72] Inventor John ShurnJn, Valley Station, Ky.

[73] Assignee: Olin Corporation [22] Filed April 15,1971

[2!] Appl. No.: 134,286

[52] US. Cl. ..60/39.l4,60/26.l, l23/l83 [$1] Fine 7/26 [56] Reference Cited UNITED STATES PATENTS 3,459J65 8/[969 Bender et al ..60/26.l

3.633360 l/l972 Kelley ..60/39. l4

2.559.006 7/195l Clapham... .....60/39.l4

2,154,572 4/1939 Lansing ..60/39. 14

3,087,305 4/l963 Hertz ....60l39.l4

3,l33,4l5 5ll964 Deverell et al ..60/39.l4

f @III. J

Primary xandnerCarlton R. Croyle Assistant Examiner-Warren Olsen Attorney-Donald R. Motslto, H. Samuel Kieser and William W. Jones [57] ABSTRACT downstreamofthevalveaeatraisesthepreesure in Lhereac tion chamber to force the valve head against the valve seat to prevent upstream flowage of the gases creating the high downstream pressure.

PATENTEflJuL 1 1 m2 SHEET 2 OF 2 JOHN SHUM JR.

I NV E NTO R ENGINE STARTING SYSTEM WITH COMBINATION All! RELAY AND CHECK VALVE This invention relates to a combination relay and check valve for use with a fluid actuated system, in particular an engine starting system.

The valve of this invention is more particularly adapted for use with a fluid actuated engine starting system which includes a vane motor. The vane motor is preferably of the type having a plurality of vanes mounted on a rotor, the vanes being exposed to a stream of pressurized fluid so as to cause the rotor to rotate. The vane motor is operably connected to the engine in such a way that rotation of the vane rotor causes the latter to engage the engine and crank it until the engine becomes self-sustaining.

The eng'ne starting systems with which the valve of this invention is particularly useful generally include a tank which contains a supply of pressurized operating fluid which is used to rotate the vane motor or starting unit. For purposes of economy and adaptability, the connections between the pressurized fluid tank and the starting unit may be flexible plastic or rubber tubing. Systems of this type commonly use a relay valve interposed between the pressurized tank and the starting unit, which valve is normally closed and can be selectively opened to feed pressurized fluid to the starting unit to actuate the latter. The system may also include a device which can be operated to fire a propellant charge to produce a volume of high pressure, high temperature combustion gases which are utilized instead of the pressurized fluid to actuate the starting unit. Metal tubing which is corrosion and heat resistant must be used to feed the combustion gases into the vane motor, and a separate check valve must be interposed between the propellant firing device and the relay valve to protect the flexible conduits and the pressurized tank from being exposed to the hot, corrosive combustion gases.

The prior art systems for actuating the vane motor with either pressurized operating fluid from a tank, or hot, pressurized combustion gases are undesirably complex in construction and require a number of separate valves and subcomponents which must be packaged in a limited space. Such systems have proven rather complicated to install and maintain, and service in the field, rather bulky, and difl'icult to completely seal from the elements of weather.

The valve assembly of this invention solves the above-noted disadvantages found in the prior art by providing a single valve unit which is adapted to perform a multiplicity of functions. The valve is housed in a single housing which is sealed from the surrounding environment to protect the various members in the unit from weather and other external harmful influences. The housing includes an inlet port and an outlet port which combine with a portion of the interior of the housing to define a flow path along which pressurized fluid is fed from a pressure chamber to the starting motor. A valve head and cooperating valve seat are positioned within the housing and are selectively operable to control the flow ot' the pressurized fluid to the starting motor. The valve head is normally biased into engagement with the valve seat so that the valve is normally closed to block the flow of pressurized fluid through the housing. A piston is preferably mounted in the housing and is connected to the valve head and movable therewith. The piston provides with the housing a control chamber into which pressurized control fluid is fed, the pressurized control fluid serving to move the piston within the housing. The piston and valve head are arranged so that an increase in pressure within the control chamber results in movement of the piston operative to move the valve head away from the valve seat to open the flow path for flowage of operating fluid from the pressurized tank to the starting motor.

The piston and housing also cooperate to provide a reaction chamber which is disposed upstream of the valve seat. A conduit, preferably in the form of an aperture drilled through the piston, provides fluid communication between the reaction chamber and the portion of the flow path downstream of the valve seat. A check valve is preferably disposed so as to normally close the conduit to fluid flow, the check valve being ar rangedsoastoopenwhenfluidpressureintheoutletor downstream portion of the flow path substantially exceeds fluid prenure in the inlet or upstream portion of the flow path. The latter condition will typically occur when the propellant firing device is used to actuate the starting motor. When the check valve opens in response to high fluid pressure downstreamofthevalvehesdandseat, the pressurein the reaction chamber increases so as to force the piston and valve head toward the valve seat. Thus the high pressure gases acting on the piston dowmtream of the valve and tending to open the valve, are counteracted and the valve remains closed. In this manner high pressure combustion gases cannot force the valve to open and the combustion gases are thus not free to pass upstream into the flexible conduits and preuurized tank to damage the latter.

It is therefore, an object of this invention to provide a valve assembly for use with a fluid flow system wherein the valve assembly functions both as a fluid relay valve and a reverse flow check valve.

It is yet another object of this invention to provide a valve assembly of the character described wherein actuation thereof as a relay valve is achieved by means of a varying a control fluid pressure.

It is still a further object of this invention to provide a valve of the character described wherein actuation thereof as a check valve is achieved by means of a reaction chamber in fluid communication with the downstream portion of the fluid flow path.

It is an additional object of this invention to provide a valve assembly of the character described which is contained in a single housing for assembly and maintenance.

It is still another object of this invention to provide a fluid actuated engine starting system incorporating a single valve assembly operative to regulate flow of the operating fluid and prevent backward flow of high presure, hot combustion gases.

These and other objects and advantages oi the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention, and the accompanying drawings, in which:

FIG. I is a schematic diagram of an engine starting system incorporating the valve assembly of this invention;

FIG. 2 is a cross-sectional view of the housing of FIG. 1 showing the valve in its closed position with the reaction chamber being closed against fluid communication with the downstream portion of the flow path;

FIG. 3 is a sectional view similar to FIG. 2 but showing the valve in its open position to permit operating fluid flow through the housing; and

FIG. 4 is a sectional view similar to FIG. 2 but showing the reaction chamber open to fluid flowage from the downstream portion of the flow path whereby the valve is closed by high preuure in the reaction chamber.

Referring now to FIG. 1 an engine starting system is shown schematically. The system includes a tank 2 in which is stored pressurized operating fluid which can be used to rotate the vanes in a conventional vane-type starting motor 4. A line 3 is connected to a compressor (not shown) to maintain the fluid pressure in the tank 2. The starting motor 4 includes a gear 6 which is mounted on a roatable shaft (not shown) and which, when actuated, is moved axially into engagement with a complimentary gear 8 which is mounted on a shaft 10. Rotation of the shaft 10 turns the engine 12 over to crank the latter. The starting motor and the manner in which it operates to crank the engine are conventional and form no independent part of this invention. A flexible rubber or plastic conduit 14 is connected to the presurized operating fluid tank 2 and extends therefrom to a valve housing 16.

A propellant charge firing device 18 of conventional construction is positioned downstream of the operating fluid tank 2 and is connected to a metal conduit 20 adapted to conduct high pressure, high temperature combustion gases generated when a charge of propellant is fired in the device 18. The conduit is connected to s similar metal conduit 22 which extends between the housing 16 and the starting motor 4. It is thus apparent that either the pressurized operating fluid from the tank 2 or combustion gases from the device 18 may be used to actuate the starting motor 4. A tank 24 containing a supply of pressurized operating fluid is connected to a flexible conduit 26 which leads to the housing 16. A valve 28 regulates flow of the control fluid from the tank 24 through the line 26. A remote actuator 30 is connected to the valve 28 so that the latter can be operated from some remote point, such as in the cab of the piece of apparatus which the engine 12 runs.

Referring now to FIG. 2, the housing 16 is shown in crosssection. The housing 16 includes an inlet port 32, to which is connected the flexible conduit 14, and an outlet port 34, to which is connected the metal conduit 22. A valve seat 36 is disposed in the housing between the inlet 32 and outlet 34. the valve seat 36 defining an orifice which interconnects the inlet 32 and outlet 34 to permit fluid flow between the two. A piston indicated generally by the numeral 38 is reciprocally mounted in the housing 16. The piston 38 includes a first enlarged head portion 40 having an exterior groove 42 in which is mounted a resilient ring 44 which engages the side wall 46 of a portion of the housing and which forms a fluid-tight seal therewith. The piston head 40 and the housing wall portion 46 combine to form a chamber 48. A port 50 opens into the chamber 38, the port 50 being connected to the flexible conduit 26 which extends from the control fluid tank 24. Thus the chamber 48 will be referred to as the control chamber since the pressurized control fluid is directed thereinto.

The piston 38 also includes a second enlarged head portion 52 having an external groove 54 in which is seated a resilient ring 56. A plug member 58 is screwed into the housing 16, the plug member 58 having an internal cylindrical bore 60 in which the piston head 52 is disposed. The resilient ring 56 forms a fluid-tight seal with the wall of the bore 60 and the piston head 52 defines a second chamber 62 with the wall of the bore 60. The chamber 62 is termed the reaction chamber for reasons set forth more explicit hereinafter.

A flange 64 is formed on the piston 38, the flange 64 having a groove 66 in which is seated a resilient valve head member 68. A spring 70 is mounted in the reaction chamber 62 the spring 70 engaging the piston 38 to bias the latter so that the valve head 68 is urged into sealing engagement with the valve seat 36. Thus the valve is normally closed to prevent fluid flow from the inlet 32 to the outlet 34. A hole 72 is drilled through the piston 38 downstream from the valve seat 36, the hole 72 providing fluid communication between the outlet port 34 and the reaction chamber 62. A valve head 74 of nylon or other suitable material is movably mounted in the reaction chamber. A spring 76 is mounted in the reaction chamber 62 in engagement with the valve head 74 to bias the latter into sealing engagement with an annular valve seat 78 interposed between the hole 72 and the reaction chamber 62. Thus a check valve arrangement is provided to normally close the reaction chamber 62 from the outlet port 34.

The valve assembly operates in the following manner. When the operator desires to actuate the starting motor 4 by means of operating fluid from the tank 2, he uses the actuator 30 to open the valve 28 to permit pressurized control fluid to flow from the tank 24 into the control chamber 48. Thus the fluid pressure in the control chamber 48 is increased to cause the piston 38 to move against the bias of the spring 70 to compress the latter. The valve head 68 is thereby moved away from the valve seat 36 to open the valve thus permitting operating fluid to flow from the tank 2 through the inlet port 32 and to the outlet port 34 along a path indicated generally by the arrows 80 in FIG. 3. It is noted that the check valve in the reaction chamber 62 remains closed when the main valve is thus opened.

ll the operator desires to actuate the starter motor 4 by firing a propellant charge with the device 18, the latter is loaded with the charge and fired to create a volume of high pressure, high temperature combustion gases. The gases travel through so that the high pressure gases thus flow into the reaction chamber 62 to act upon the rear face of the piston head 52. Thus the action of the cornbustion gases on the downstream side of the flange 64 is countered by the opposite reaction of the combustion gases on the piston head 52 so that the spring is able to keep the valve head 68 seated against the valve seat 36. Therefore, the valve will not open when the pressure in the outlet port 34 is substantially greater than pressure in the inlet port 32 so that the combustion gases are prevented from flowing upstream past the housing 16 and into the operating fluid tank 2.

It is readily apparent that the valve assembly of this invention is contained in a single housing thus facilitating ease of assembly and field maintenance. The valve provides dual capabilities of operating fluid relay and rearward checking of combustion gases when used in a dual actuated engine starting system.

Since many changes and variations of the disclosed em bodiment of the invention may be made without departing from the inventive concept, it is not intended to limit the invention otherwise than as required by the appended claims.

What is claimed is:

1. An engine starting system comprising:

a. a source of pressurized operating fluid;

b. a source of pressurized control fluid c. a vane motor;

d. a housing having an inlet and an outlet and providing a fluid flow path from said inlet to said outlet;

e. first conduit means connecting said operating fluid source to said housing inlet;

fv second conduit means connecting said vane motor to said housing outlet;

g. a propellant firing device;

h. third conduit means connecting said propellant firing device to said second conduit means;

i. a valve seat in said housing astride said flow path;

j. piston means mounted in said housing, said piston means combining with a first portion of said housing to provide a control chamber, and said piston means combining with a second portion of said housing to provide a reaction chamber whereby predetermined increased fluid pressure in said reaction chamber is operative to move said piston means in a first direction, and predetermined fluid pressure in said control chamber is operative to move said piston means in the opposite direction;

. a valve head mounted on said piston means, said valve head being movable into sealing engagement with said valve seat to close said flow path when said piston means is moved in said first direction, and said valve head being movable away from said valve seat to open said flow path when said piston means is moved in the opposite direction;

I. fourth conduit means interconnecting said pressurized control fluid source with said control chamber; and

m. fifth conduit means interconnecting said reaction chamber with a point on said flow path downstream of said valve seat, whereby increased fluid pressure created downstream of said valve seat by firing said propellant firing device results in increased fluid pressure in said reaction chamber operative to move said valve head against said valve seat to close said flow path against upstream flow of combustion gases.

2. The engine starting system of claim 1, wherein said fifth conduit means extends through said piston means.

3. The engine starting system of claim I, further comprising spring means contacting said piston means to bias the latter in said first direction whereby said flow path is nonnally closed.

4. The engine starting system of claim 1, further oomprining check valve means in said fifth conduit means operative to open only when downstream fluid preaure in said flow path is increased by firing said propellant firing device.

Claims

1. An engine starting system comprising: a. a source of preSsurized operating fluid; b. a source of pressurized control fluid c. a vane motor; d. a housing having an inlet and an outlet and providing a fluid flow path from said inlet to said outlet; e. first conduit means connecting said operating fluid source to said housing inlet; f. second conduit means connecting said vane motor to said housing outlet; g. a propellant firing device; h. third conduit means connecting said propellant firing device to said second conduit means; i. a valve seat in said housing astride said flow path; j. piston means mounted in said housing, said piston means combining with a first portion of said housing to provide a control chamber, and said piston means combining with a second portion of said housing to provide a reaction chamber whereby predetermined increased fluid pressure in said reaction chamber is operative to move said piston means in a first direction, and predetermined fluid pressure in said control chamber is operative to move said piston means in the opposite direction; k. a valve head mounted on said piston means, said valve head being movable into sealing engagement with said valve seat to close said flow path when said piston means is moved in said first direction, and said valve head being movable away from said valve seat to open said flow path when said piston means is moved in the opposite direction; l. fourth conduit means interconnecting said pressurized control fluid source with said control chamber; and m. fifth conduit means interconnecting said reaction chamber with a point on said flow path downstream of said valve seat, whereby increased fluid pressure created downstream of said valve seat by firing said propellant firing device results in increased fluid pressure in said reaction chamber operative to move said valve head against said valve seat to close said flow path against upstream flow of combustion gases.

3. The engine starting system of claim 1, further comprising spring means contacting said piston means to bias the latter in said first direction whereby said flow path is normally closed.

4. The engine starting system of claim 1, further comprising check valve means in said fifth conduit means operative to open only when downstream fluid pressure in said flow path is increased by firing said propellant firing device.