US3074433A - Control device - Google Patents

Description

E. H. STARK 3,074,433

CONTROL DEVICE Filed July 10, 1958 Jan. 22, 1963 INVENTOR. ERNEST H STARK BY WW ATTORNEY.

3,974,433 CGNTRUL DEVECE Ernest H. Stark, Michigan City, 3nd,, asstgnor to 303 Manufacturing Company, Pittsburgh, Pin, a corporation of Pennsylvania Filed duly it 1%8, Ser. No. 747,725 7 Claims. (Qi. 137-6275) This invention relates to a control device and more particularly to a new and improved double acting valve for controlling the flow of fluids.

In many compressor installations it is desirable t isolate the compressor from the receiver during the period of little or no demand of compressed medium so that the compressor can run without having to discharge against the pressure or" the receiver. As can readily be appreciated such isolation of the rec iver must be discontinued upon increased demand of the compressed medium and from a practical commercial standpoint such isolation and non-isolation must occur automatically to insure ellicient operation of the compressor and a surlicient supply of compressed medium. Heretoiore with rotary cornpressors driven by a variable speed prime mover, such as a gasoline or diesel engine, it is possible to reduce the energy consumption of the prime mover by merely reducing its speed in some suitable manner such as that shown in the copending application of Willard Green, entitled Control Device, Serial No. 699,838, filed November 2?, 1957, now abandoned, which application has been assigned to the same assignee as the assignee of this invention. in other rotary compressors in which the rotating elem nts are driven by a constant speed prime mover, such as an electric motor, no means heretofore have been provided for reducing the energy requirements of the compressor during its unloaded condition.

Accordingly one object of this invention is to provide a new improved control device for isolating a receiver from a compressor upon suflicient decrease in demand of compressed medium and for discontinuing such isolation upon increased demand of compressed medium.

Another object of this invention is to provide a new and improved control device which is responsive to changes in pressure in an intermediate receiver or" a cornpressor to isolate the compressor from the high pressure receiver.

Still another object of this invention is to provide a new and improved control device which is actuated by positive and negative pressures existing in an intermediate receiver stage of a rotary compressor.

These and other objects of the invention will become more apparent upon consideration of the following detailed description of a preferred embodiment thereof, when taken in conjunction with the following drawing which is a cross sectional view of a control device constructed in accordance with the principles of this invention.

Referring to the drawing a control device constructed in accordance with the principles of this invention comprises a formed multi-part housing which is made in any suitable manner from any suitable material as is well known in the art. The housing 2 is provided with a central elon ated bore having a circular cross section with an elongated portion 4 of a larger diameter located in axial alignment with and connected to another elon gated portion 6. As shown the outer end of the portion '4 is closed by the housing 2 and the outer end of the portion 6 is provided with suitable means whereby it is connected to a suitable fluid transmitting line A. The line A and the means for connecting it to the housing 2 and the various lines and their connecting means hereinafter 'may be or" any suitable structures as are well known in a 9 Patented Jan. 22, lhti the art. The housing 2 is provided with an annular passageway it extending outwardly of the portion 4 outwardly adjacent the inner end of the portion 6 with one portion thereof being suitably connected to an intermediate outwardly extending passageway 12, the outer portion of which is provided with suitable means whereby it is connected to a suitable fluid transmitting line 1-3. The housing 2 is also provided with an annular passageway 14 extending outwardly of the portion 6 outwardly adjacent the inner end of the portion 4- with one portion thereof bein suitably connected to an intermediate outwardly extending passageway to, the outer portion of which is provided with suitable means whereby it is connect d to a suitable fluid transmitting line C.

An elongated open ended formed plunger 2-? is closely reciprocably received within the 0 re of the housing 2 having an elongated cup shaped portion 22 slidably received in the portion 4 and an elongated cup shaped portion 2 2 slidably received in the portion a. The plunger 29 at the juncture of the portions 22 and 24 is provided with an annular inclined seat 26 which engages a cooperable inclined annular seat 23 on the housing 2 at the juncture of the portions 4 and 6 of the bore. The housing 2 is provided with an annular actuating chamber 3b which extends outwardly of and adjacent the intermediate portion of the portion 4 which is of a longer length than and a larger outer diameter than the passageways it} and 14. The plunger 2/6 is provided with an integral annular ring 32 which extends radially outwardly from an intermediate portion of the portion 22 and the outer edge of which is closely received within the chamber 3%. in order to obtain movement of the plunger 2% a portion of the inner portion of the chamber 3% is connected by suitable outwardly extending intermediate passa eway i the outer portion of which is provided with suitable means whereby it is connected to a suitable fluid transrnitting line D. It will also be noted that the outer end or" the chamber 30 is connected by means of an integral passageway 36 extending longitudinally therefrom through the housing 2 to the exterior of the housing 2 which under normal conditions would be atmospheric pressure. Also, the inner end of the portion 24 of the plunger 29; is provided with quadrangularly spaced openlugs 33 extending radially therethrough whereby the interior of the portion 24 is selectably connectible to the passageways it? or 14 as hereinafter described.

In the illustrated embodiment of this invention the plunger 26 is located in its normal operating condition which is obtained by admitting a suitable fiuid under pressure through line D to the inner surface of the ring 32 whereby the plunger 2b is biased outwardly for its full travel towards the closed end of the bore of the housing 2. Such outward movement of the plunger 2%} is lllllited by means of an annular stop .9 formed integrally with the housing 2 and which extends inwardly of the outer end of the chamber 3% around its upper outer edge. When the plunger 29 is in such outermost position the line B is connected to line A by means of the circuit comprising passageways i2 and it openings 38, the interior of the portion 24 or" the plunger 2%, and the outer end of the portion 5 of the bore. Fluid flow from line E to line C is prevented by the outer portion 24 of the plunger it} which extends circumferentially around and across the inner edge of the passageway 14.

in order to permit the plunger to be sensitive only to pressure changes in the chamber 3% the outer and of the portion 22 of the plunger 21% is spaced from the outer end of the portion of the bore and is connected to the line B by means of quadrilaterally spaced laterally entending through openings 4-2 in the lower end of the portion 22 of the plunger so. The openings 42 are contively. through the openings 66 and 68, respectively, with their nected to an annular chamber 44 which extends longitudinally from the outer ends of the openings 42 to the passageway lit. The chamber 44 may readily be provided by undercutting the inner portion 22 of the plunger 2% from the openings 42 to the seat 26. By such structure the fluid medium flowing from line B to line A will also how through the passageways 12 and lil, into the chamber 4 2-, through openings 42 into the inner portion of the portion 22 of the plunger 2% to the outer end of the plunger 29 between the outer end of the plunger 2i) and the housing 2. In order to insure full pressure being applied against the outer end of the plunger 2% the bore of the housing 2 may be outwardly grooved at the outer end thereof. Accordingly, the pressure of the medium flowing from line B to line A will be exerted in opposite directions against the entire cross sectional area of the plunger 2% so that such pressure will not effeet the operation of the plunger 29.

The stop 4t) also prevents the ring 32 from engaging the outer portion of the chamber 3% which outer portion is connected to atmospheric pressure by means of the passageway 35 and the pressure effect of the fluid flowing'from line B to line A is neutralized, it will be realized that the pressure in the chamber 39, which is connected to the line D, must be greater than atmospheric pressure (neglecting friction losses) to obtain such out ward movement of the plunger 29. In actual practice suitable packing glands or O-rings 46 are provided, as desired to prevent leakage between various portions of the valve on the outer circumference of the plunger 29 so that the friction eifect of such O-rings must also be overcome to obtain movement of the plunger 29 in either direction. By reducing the pressure on the inner surface of the ring 32 in chamber 36 below atmospheric the plunger 2% will move in the opposite direction (shown in dotted outline) until the seat 26 engages its cooperable seat 28. Upon such opposite movement of the plunger 2% the line B is disconnected from the line A and is connected to the chamber 44 and the openings 42 now in alignment therewith. At the same time the line C is connected to the line A by means of the openings 38 then aligned with the passageway 14 and the ring 32 is located outwardly from the inner end of the chamber 30'.

Although the control device 'as heretofore described is of a novel structure in the preferred application of this invention with a rotary compressor it is desirable to control additional fluid transmitting lines upon each position of the plunger 2t). Accordingly the valve shown is provided with a pair of elongated valves Stl and 52 which are connected to the housing 2 and extend axially outwardly in opposite dh ections therefrom. Each of the valves 59 and 52- comprise an elongated housing 54- having an elongated passageway 56 extending axially there through. The central portion of each passageway 56 is provided with suitable means to form a restricted opening 58 therein the outer end of which is normally closed by means of a ball 64? which is normally biased into engagement therewith by means of a spring 62 in a manner as is well known in the art. The portion of the passageway 56 between the housing 2 and the opening 58 is provided with a laterally outwardly extending annular groove portion 64 having suitable means for securing a suitable fluid transmitting line E thereto. The outer end of the passageway 55 in the valve 5G is provided with suitable means for securing a suitable fluid transmitting line F thereto. Lines G and H are secured to the valve 52 in the same manner as lines E and F, respectively, are

secured to the valve 54 In order to actuate the valves 5! and 52, elongated clearance openings 66 and '68 are provided in the housing 2 which extend axially from the inner and outer ends of the chamber 36 to the inner ends of the passa eways 56 in the valves 50 and 52, respec- Suitable elongated push rods It? and 72 extend outer ends being suitably slidably supported within the passageways 56 of the valves and 52, respectively. As shown, the outer ends of the push rods 66 and 68 are normally located within the openings 53, respectively, and their inner ends extend into the chamber 30 from opposite ends thereof. In the position of the plunger 20 shown the movement of the ring 32 towards the closed end of the bore of the housing 2 engages the rod 72 so that the bias of the spring 62 on the ball of the valve 52 is overcome and the line H is connected to the line G. At the same time the spring 62 biases the ball 60 of the valve 5% into the outer edge of the opening 58 therein whereby the line F is disconnected from the line E. Upon reverse movement of the plunger 20 as heretofore indicated the reverse operation of the valves 5% and 52 will occur with the line H being disconnected from'the line G and the line F being connected to the line E.

As heretofore indicated the valve of this invention is primarily adapted for use with rotary compressors and accordingly for a more complete understanding of the forces available to obtain actuation of the plungerZt) reference is made herein to the copending application entitled Control Circuit, Serial No. 747,784, now Patent No. 2,977,039 filed concurrently herewith by Ernest H. Stark and Willard E. Green which application has been assigned to the same assignee as the assignee of this invention.

In order that a ready comparison can be made the fluid transmission lines connected to the valve of this invention have been identified by the same letter designations in the latter mentioned copending application. In addition the latter mentioned copending application clearly describes how the pressure conditions existing in the various fluid transmission lines are obtained so that actuation of the valve of this invention is obtained. Thus, with the plunger 2% of the valve in the position as shown, the line D is connected to a fluid existing at a pressure above the atmospheric pressure and less than the high discharge pressure of the compressor. As heretofore indicated the pressure of the fluid medium flowing from the line B to the line A is balanced so as not to eifect the operation of the plunger 29. Under certain operating conditions of the compressor the fluid medium to which the line D is connected changes from a positive pressure to a negative pressure, that is a vacuum, and since the plunger 20 is balanced the evacuation of the chamber 30 causes atmospheric pressure to be exerted through passageway 36 against the outer surface of the ring 32 so that the seat 26 of the plunger Ztlis moved into engagement with the seat 28 of the housing 2. Upon such movement of the plunger 20 the bias of the spring 62 of the valve 52 causes the opening 58 therein to be closed whereby the line H is closed from the line G. At the same time the ring 32 engages the outer end of the push rod to cause outward movement thereof whereby the ball 60 of the valve 58 is moved out of engagement with the opening 58 therein and the line F is connected to the line B. At the same time upon such movement of the plunger 20 the line C is connected :to the line A and the pressure of the fluid medium flowing therethrough is exerted upon the plunger 20 over an area equal to the cross sectional area of the portion 6 of the bore which force is exerted on the plunger 20 to urge the plunger 2% out of engagement with the seat 28. Since the line B is connected to the high receiver pressure and with the plunger 20 engaging the seat 28 the receiver pressure is transmitted through the passageway 19 and openings 42 into the portion 4 of the bore so as to bias the plunger 20 into engagement with the seat 23. Since the highest pressure of the medium flowing from the line C to line A is the receiver pressure, which is the pressure of the medium flowing through the line B, the greater cross sectional area of the portion 22 of the plunger 20 over the portion 24 thereof biases the plunger 20 into engagement with the seat 28 whenever the line D is at a negative pressure.

Thereafter as the pressure flowing from'the line C to the line A decreases and as the receiver pressure remains substantially constant the plunger 24} is locked into engagement with the seat 28 by the pressure of the medium flowing through the line B.

In operation the pressure of the medium flowing from the line C to the line A will again increase to the receiver pressure and at the same time the pressure of the medium flowing through line D changes from a vacuum to a posi- :tive pressure greater than atmospheric pressure but less than the receiver pressure. This pressure from the line 'D is exerted on the ring 32 so that the force thereof in conjunction with the pressure of the medium flowing from the line C to the line A causes the seat 25 of the plunger so to move out of engagement with the seat 28 and return to its illustrated position. Upon such movement the line P will be disconnected from the line E and the line H will be connected to the line G in the reverse manner as heretofore indicated.

Thus it will be noted that this invention comprises a valve which is automatically operable between two different positions upon change or" pressure in a compressor from a pressure above to a pressure below atmospheric pressure. In addition pressure of the fluid medium flowing through the valve is employed to bias the plunger 20 into engagement with the seat 28. Having described a preferred form of this invention in accordance with the patent statutes, it is to be realized that modifications thereof may be made without departing from the broad spirit and scope of the invention. Accordingly it is requested that the invention be interpreted as broadly as possible and be limited only by t.e prior art.

What I claim is:

1. A control valve comprising, a housing having an elongated bore therein with a portion extending axially from one end thereof being of a larger cross section than the remaining axial portion, said housing having a chamber therein extending laterally outwardly from said axial portion of the larger cross section, an elongated plunger reciprocably received within said bore having portions closely received laterally within said axial portions respectively, said plunger having an integral outwardly extending portion closely received within said chamber, passageways in said housing connected to axially opposed portions of said chamber whereby said plunger is movable into one of two axially spaced operating positions, an opening in one of said portions of said plunger conecting a first passageway in said housing to an exit passageway in said housing when said plunger is in one operating position, said opening connecting another passageway in said housing to said exit passageway when said plunger is in the other of said operating positions, the other portion of said plunger engaging said housing to seal said first passageway from said one portion of said plunger when said plunger is in said other position, and a passageway in said other portion of said plunger extending from said first passageway to the outer end of said other portion of said plunger for each operating position of said plunger.

2. A control valve comprising, a housing having an elongated bore therein with a portion extending axially from one end there-of being of a larger cross section than the remaining axial portion, said housing having a chamber therein extending laterally outwardly from the larger cross sectional portion of said bore, an elongated plunger reciprocably received within said bore having portions closely received laterally within said axial portions respectively, said plunger having an integral outwardly extending portion closely received within said chamber, said plunger portion received in the bore of the small diameter portion being the one portion of the plunger and that opening in said one portion of said plunger connecting a first passageway in said housing to an exit passageway in said housing when said plunger is in one operating position, said opening connecting another passageway in said housing to said exit passageway when said plunger is in the other of said operating positions, the other portion of said plunger engaging said housing to seal said rst passageway from said one portion of said plunger when said plunger is in said other position, a passageway in said other portion of said plunger extending from said first passageway to the outer end of said other portion of said plunger for each operating position of said plunger whereby said other portion is biasable towards said one portion of said plunger by a fluid medium flowing through said first passageway.

3. A control valve comprising, a housing having an elongated bore therein with a portion extending axially from one end thereof being of a larger cross section than the remaining axial portion, said housing having a chamsaid axial portions respectively, said plunger having an integral outwardly extending portion closely received within said chamber, passageways in said housing connected to axially opposed portions of said chamber whereby said plan er is movable into one of two axially spaced operating positions, an opening in one of said portions of said plunger connecting a first passageway in said housing to an exit passageway in said housing when said plunger is in one operating position, said opening connecting another passageway in said housing to said exit passageway when said plunger is in the other of said operating positions, the other portion of said plunger engaging said housing to seal said first passageway from said one portion of said plunger when said plunger is in said other position, control means extending inwardly of said chamber to be engageable witn said extending portion of said plunger operative in response to movement of said plunger, and passageway means in said other portion of said plunger connecting said first passageway with the outer end portion of said other portion of said plunger for each operating position of said plunger.

4. A control valve comprising, a housing having an elongated axially extending bore therein with one portion of the bore being of a larger cross section than the other axial portion of the bore, said housing having a chamber therein extending laterally outwardly of said a ;ial Portion having the larger cross section, an elongated plunger reciprocably received Within said bore having portions closely received laterally within said axial portions, respectively, and an integral outwardly extending portion closely received within said chamber, passageways in sa1d housing connected to axially opposed portions of said chamber to move said plunger into one of two axially spaced operating positions upon a pressure differential in said passageways, one of said passageways being connected to atmosphere, a pair of passageways extending through said housing one of which extends laterally outwardly from one portion of said bore and the other of which extends laterally outwardly from said bore at the juncture of said portions thereof, and said plunger having a bore at the respective ends interconnected by passageway means when said plunger is in one of its operating positions.

5. A control valve comprised of a housing with two concentric bores communicating therethrough, one of said bores being or" a large diameter and the other bore being of small diameter, a plate closing the end of said larger diameter bore, an exhaust conduit connected axially to the end of said small diameter bore, a first annular groove in said housing at the junction of said large and small diameter bores, a first conduit connected to said first annular groove, a second annular groove in said housing located between said first annular groove and said exhaust conduit communicating with the small diameter bore, a

second conduit connected to said second annular groove, an annular groove in said large diameter bore defining a chamber having one end spaced from said first annular groove and the other end spaced from said plate, a third conduit connected to said chamber at said one end, a

fourth conduit connected from a reference pressure source to said other end of said chamber, a reciprocable plunger 'a wall separating the sleeve portion of the plunger from the piston bore, and openings in the sleeve portion adjacent said wall for selectively connecting the first or second conduit to the exhaust conduit as fluid medium adapted to flow in said conduits is varied in said third conduit.

6. A control valve comprising a housing with two concentric bores communicating therethrough, one of said bores being larger in diameter than the other of said bores, said one bore being closed at its end, said other bore being connected to a first conduit, a second conduit connected to said one bore immediately adjacent said other bore, an annular groove in said housing intermediately of the length of said one bore communicating therewith to define a chamber, a hollow reciprocable plunger having one end portion received by said one bore and anotherend portion received by said other bore, said plunger having an outwardly extending portion closely received in said chamber, a closure member located in said hollow plunger intermediately thereof to define two cup shaped members one of said cup shaped members facing said closed end and the other of said cup shaped members facing said first conduit, a plurality of openings in said plunger intermediate the ends thereof operatively connecting said second conduit to the inner portion of said one cup shaped member, a third conduit operatively connected to one end of said chamber for supplying pressurized medium thereto for moving said plunger toward the closed end of said one bore.

7; A control valve as set forth in claim 6 wherein a fourth conduit is operatively connected to said other bore intermediately of the connection to said first and second conduits, and a, passageway operatively connecting the other end of said chamber to atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 823,086 Bowers Aug. 7, 1906 844,828 Oehlke Feb. 19, 1907 1,354,311 Landrum Sept. 28, 1920 1,855,696 Stover Apr. 26, 1932 2,187,811 Smith Jan. 23, 1940 2,587,375 Paulsen Feb. 26, 1952 2,621,885 Schmitt Dec. 16, 1952 2,651,491 Ashton et al. Sept. 8, 1953 2,684,838 Rush July 27, 1954 2,897,836 Peters Aug. 4, 1959 2,940,070 1960 Sanders 2. June 7,

Claims (1)

1. A CONTROL VALVE COMPRISING, A HOUSING HAVING AN ELONGATED BORE THEREIN WITH A PORTION EXTENDING AXIALLY FROM ONE END THEREOF BEING OF A LARGER CROSS SECTION THAN THE REMAINING AXIAL PORTION, SAID HOUSING HAVING A CHAMBER THEREIN EXTENDING LATERALLY OUTWARDLY FROM SAID AXIAL PORTION OF THE LARGER CROSS SECTION, AN ELONGATED PLUNGER RECIPROCABLY RECEIVED WITHIN SAID BORE HAVING PORTIONS CLOSELY RECEIVED LATERALLY WITHIN SAID AXIAL PORTIONS RESPECTIVELY, SAID PLUNGER HAVING AN INTEGRAL OUTWARDLY EXTENDING PORTION CLOSELY RECEIVED WITHIN SAID CHAMBER, PASSAGEWAYS IN SAID HOUSING CONNECTED TO AXIALLY OPPOSED PORTIONS OF SAID CHAMBER WHEREBY SAID PLUNGER IS MOVABLE INTO ONE OF TWO AXIALLY SPACED OPERATING POSITIONS, AN OPENING IN ONE OF SAID PORTIONS OF SAID PLUNGER CONNECTING A FIRST PASSAGEWAY IN SAID HOUSING TO AN EXIT PASSAGEWAY IN SAID HOUSING WHEN SAID PLUNGER IS IN ONE OPERATING POSITION, SAID OPENING CONNECTING ANOTHER PASSAGEWAY IN SAID HOUSING TO SAID EXIT PASSAGEWAY WHEN SAID PLUNGER IS IN THE OTHER OF SAID OPERATING POSITIONS, THE OTHER PORTION OF SAID PLUNGER ENGAGING SAID HOUSING TO SEAL SAID FIRST PASSAGEWAY FROM SAID ONE PORTION OF SAID PLUNGER WHEN SAID PLUNGER IS IN SAID OTHER POSITION, AND A PASSAGEWAY IN SAID OTHER PORTION OF SAID PLUNGER EXTENDING FROM SAID FIRST PASSAGEWAY TO THE OUTER END OF SAID OTHER PORTION OF SAID PLUNGER FOR EACH OPERATING POSITION OF SAID PLUNGER.

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