US 3753446 A
A fluid pressure regulator having a preliminary chamber provided with a biased preliminary inlet valve so that pressure of the fluid in such chamber is substantially reduced from the supply pressure. The preliminary chamber leads a main inlet valve into a main chamber having a discharge pipe. A pressure responsive diaphragm is located in an auxiliary chamber and has a discharge pipe opening into the discharge pipe from the main chamber so that the passage of any fluid along the discharge pipe out of the main chamber causes a suction in the auxiliary chamber which causes the diaphragm to move. The diaphragm carries an operating rod which moves pivotally mounted biased lever to open the main inlet valve and allow more fluid to enter the main chamber from the preliminary chamber.
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Description (OCR text may contain errors)
United States Patent [1 1 Hoogeboom FLUID PRESSURE REGULATOR  Inventor: Adrianus Johannes Theodorus Hoogeboom, l-larmelen, Netherlands [73 Assigneez wilfia ni l tirner Brut Tot, London,
England  Filed: Jan. 11, 1971  Appl. No.: 105,623
Related U.S. Application Data  Continuation of Ser. No. 800,629, Feb. 19, 1969,
 Foreign Application Priority Data June 14, 1968 Great Britain 28,385/68  U.S. Cl. 137/484.8  Int. Cl. F16k 21/00  Field of Search 123/120; 137/484.8, 137/505.12, 505.18, 505.47, 484.2, 484.4, 483, 340; 251/282  References Cited UNITED STATES PATENTS 2,587,375 2/1952 Paulsen 137/484.8 2,933,076 4/1960 Spencer 123/120 847,944 3/1907 Hubner et al.. 137/4848 2,946,344 7/1960 Mott l37/484.8 3,189,043 6/1965 Stadler 137/4848 X 3,086,548 4/1963 Galiger et al. 137/4848 2,352,003 6/1944 Poinsignon 123/120 X 2,563,228 8/1951 Ensign 123/120 X 2,752,758 7/1956 Tann 123/120 X Aug. 21, 1973 3,357,687 12/1967 Vanderpoel 123/120 X FOREIGN PATENTS OR APPLICATIONS 424,790 2/1935 Great Britain 123/120 1,120,808 12/1961 Germany 123/120 534,013 9/1931 Germany 137/4848 1,037,521 5/1951 France 137/4842 615,520 2/1961 Canada... 137/63 R 16,816 l/l956 Germany l37/S05.12
Primary Examiner-Henry T. Klinsiek Assistant Examiner-Robert J. Miller Attorney-Holman & Stern 5 7 ABSTRACT A fluid pressure regulator having a preliminary chamber provided with a biased preliminary inlet valve so that pressure of the fluid in such chamber is substantially reduced from the supply pressure. The preliminary chamber leads a main inlet valve into a main chamber having a discharge pipe. A pressure responsive diaphragm is located in an auxiliary chamber and 5 Claims, 2 Drawing Figures H\ W T l l FLUID PRESSURE REGULATOR BACKGROUND OF THE INVENTION This application is a continuation of application Ser. No. 800,629 filed Feb. 19, 1969 and now abandoned.
This invention relates to a fluid pressure regulator particularly but not exclusively for liquified petroleum gas (l.p.g).
It is often economically desirable for an internal combustion or diesel vehicle to be supplied by liquified petroleum gas (l.p.g.) which is a mixture of light hydrocarbon gases such as propane and butane and is usually a by-product of the oil refining process but is also found in refining a high condensate of natural gas oil.
In the l.p.g. apparatus for supplying l.p.g. as an optional alternative fuel for a motor vehicle, the l.p.g. is fed under pressure from a storage tank through a control valve to the evaporator/pressure regulator which regulates the pressure of the l.p.g. to accord with the requirements of the engine. One disadvantage of these pressure regulators has been that too much l.p.g. is supplied at part load and too little l.p.g. at full load whereas to obtain the best fuel consumption, the engine needs relatively little l.p.g. ,at part load but a substantial increase in the feeding rate of l.p.g. for maximum power at full load.
An object of this invention is to provide an improved fluid pressure regulator in which this disadvantage is reduced.
SUMMARY OF THE INVENTION This invention consists in a fluid pressure regulator including a chamber, an inlet port to supply fluid to the chamber, an inlet valve to control the supply of fluid into the chamber, an auxiliary chamber containing pressure responsive means adapted to open the inlet valve when a sufficient suction is produced in the auxiliary chamber, discharge means for discharging the fluid from the chamber and auxiliary discharge means connecting the auxiliary chamber with the discharge means so that as the fluids contained in the chamber are drawn by suction along the discharge means, suction is produced in the auxiliary chamber to move the pressure responsive means to assist in opening the inlet valve to allow more fluid to enter the chamber. I Preferably, the discharge means is a discharge pipe and the auxiliary discharge means opens into a part of the discharge pipe where there is an increase in the cross-sectional area of the discharge pipe available for the discharge flow of fluid from the chamber in the downstream direction.
The auxiliary discharge means may be a pipe having a part extending into the discharge pipe to form a restriction in the discharge pipe and this part of the auxiliary discharge pipe has an exit part for the suction into the discharge pipe of the atmosphere contained within the auxiliary chamber to reduce the pressure therein.
The pressure responsive means may be a diaphragm and there is a connecting member secured to the diaphragm and arranged to open the inlet valve when the diaphragm is displaced by a predetermined amount, the inlet valve also having a bias so that the inlet valve will also open when the suction in the first mentioned chamber reaches a predetermined amount.
The preliminary chamber may have a preliminary inlet valve to allow fluid into the preliminary chamber until a predetermined preliminary pressure is reached, with the preliminary chamber having an outlet part arranged to supply fluid to the inlet valve of the first mentioned chamber.
An example is shown in the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view and FIG. 2 is a diagrammatic view illustrating the working of the main chamber.
DETAILED DESCRIPTION OF THE INVENTION In the drawings there is a first stage casing or prechamber 1 for receiving l.p.g. under a pressure of about 6 atmospheres through pipe 2. The casing 1 contains a labyrinth 3 for supplying warm water from the vehicle water-cooling system and a preliminary diaphragm 4 is secured to the casing 1 around its edges but has a central movable portion spring biased downwardly by spring 5 against a protecting plate 6 resting against an absorption plate 7 so that the l.p.g. cannot penetrate and warm the diaphragm 4. A preliminary inlet valve has a pivotally mounted rocker arm 8 for opening pipe 2 to admit l.p.g. from the tank when the pressure in the preliminary chamber in casing 1 drops below a predetermined level, for example 0.7 atmospheres, when the diaphragm 4 is moved downwardly by the spring sufficiently for a central downwardly extending pin 9 of pressure plate 10 which is pressed against the diaphragm by spring 5 to push downwardly the inner end of lever 8 to lift the outer end away from the supply port of pipe 2 for more l.p.g. to enter the preliminary chamber and push pack the diaphragm 4. This mechanism achieves the rough adjustment of the pressure regulation of the l.p.g. since, when the supply l.p.g. enters the preliminary chamber, it expands because of the pressure drop and this causes a temperature drop so that the l.p.g. also tends to condense again into liquid form so the labyrinth 3 warms the l.p.g. vapor. A casing 11 has a port 12 for leading l.p.g. from the prelimary chamber into the main chamber defined by the casing 11. The casing 11 is recessed along a back wall 17 and a back cover 13 and auxiliary diaphragm 14 are secured to the back wall 17 at the edge of the recess to form an auxiliary chamber containing the auxiliary diaphragm 14. This second chamber has an inlet supply valve in the form of a second pivot lever 15 spring biased into the closed position and having a head adapted to close port 12. The inner end of the lever 15 lies in alignment with a pin 16 standing upwardly from the diaphragm and extending through a hole in the back wall so as to make contact with and be in connection with lever 15. The back wall 17 has an upstanding tube or auxiliary discharge pipe 18 arranged to extend some distance up a narrow part 19 of a discharge pipe 20 which leads to the air intake manifold. Thus it will be seen that the pipe 18 is located within the pipe 20 and so forms a restriction in the discharge flow of the fluid and causing a corresponding increase in the crosssectional area of pipe 20 available to the flow of fluid where pipe 18 terminates and by this arrangement, pipe 18 opens into pipe 20 where the cross-sectional area of the discharge flow is increasing in the downstream direction, i.e., the direction in which the fluid discharges along the pipe 20.
There is a separate idling device for allowing a small flow of l.p.g. through the device even when there is no suction exerted backwardly into the discharge pipe from the air intake manifold but this invention is not concerned with those features.
In operation, the inlet port 12 is closed by lever until, as the pressure in the main chamber drops as the suction along pipe towards the air intake manifold is increased, suction passes up pipe 18 into the auxiliary chamber and the second diaphragm 14 moves towards the back wall 17 and pin 16 contacts lever 15 and pivots it to open port 12. The l.p.g. from the preliminary chamber is then sucked into the main chamber and escapes along past the restriction in the part 19 of the discharge pipe 20. The slight increase in pressure in the second chamber due to the entry of l.p.g. from the first chamber would normally speedily pushed back the diaphragm l4 and then pin 16 would leave lever 15 which would immediately close port 12. The air intake manifold will suck out some of the air and any l.p.g. contained in the main chamber.
When there is a rapid increase in the suction due to full load being asked from the engine, for example during rapid acceleration, then the suction of l.p.g. from the main chamber causes great suction in the pipe 18 due to the venturi effect produced by the restriction pipe 18 in pipe 20 and a sustained pressure drop occurs between the back wall 17 and diaphragm 14 to keep lever 16 in the open position l.p.g. flows out of port 12 and then through the main chamber and out along discharge pipe 19 and 20. On the other hand, if only a little suction is applied at pipe 20, then diaphragm 14 will move towards wall 17 to open lever 15 and admit some l.p.g., the lower flow rate of l.p.g. from the main chamber through narrow part 19 will cause a much smaller suction to be sustained in the cavity between wall 17 and diaphragm 14 so that the diaphragm will more speedily return to its original position than if the diaphragm 14 experienced all of the suction applied to pipe 20.
Clearly the casing 1 enclosing the preliminary chamber need not be necessary in some regulators. The preliminary chamber in casing 1 serves to supply the fluid through the valve 12.
1. A fluid pressure regulator for controlling the flow of l.p.g. to an internal combustion engine having an air intake manifold, including means defining a main chamber, an inlet port for supplying l.p.g. to the main chamber, an inlet valve controlling the supply of l.p.g. into the main chamber, means defining an auxiliary chamber, pressure responsive means within the auxiliary chamber adapted to open the inlet valve when a sufficient suction is produced in the auxiliary chamber, a discharge pipe leading to the air intake manifold for discharging the l.p.g. from the main chamber, and auxiliary discharge means connecting the auxiliary chamber with the discharge pipe so that as the fluids contained in the main chamber are drawn by suction along the discharge pipe, suction is produced in the auxiliary chamber to move the pressure responsive means to assist in opening the inlet valve to allow more l.p.g. to
enter the main chamber, said auxiliary discharge means being defined by a pipe having a part extending axially along the discharge pipe for forming a restriction said sai discharge pipe, and said part of the auxiliary discharge pipe having an exit part for the suction into the discharge pipe of the atmosphere contained within the auxiliary chamber for reducing the pressure therein.
2. The regulator as claimed in claim 1, wherein the auxiliary discharge means opens into a part of the discharge pipe in which there is an increase in the crosssectional area of the discharge pipe available for the discharge flow of l.p.g. from the main chamber in the downstream direction.
3. The regulator as claimed in claim 1 wherein the pressure responsive means is a diaphragm and a connecting member is secured to the diaphragm and arranged to open the inlet valve when the diaphragm is displaced by a predetermined amount, and bias means for the inlet valve so that the inlet valve will also open when the suction in the first mentioned chamber reaches a predetermined amount.
4. The regulator as claimed in claim 1, including a source of l.p.g. under pressure, a preliminary chamber, means for supplying l.p.g. to the preliminary chamber, a preliminary inlet valve for controlling supply into the preliminary chamber, and pressure responsive means operably connected tothe preliminary inlet valve to open the preliminary inlet valve when the pressure in the preliminary chamber drops below a predetermined level, and the preliminary chamber having an outlet part arranged to supply l.p.g. to the inlet valve of the main chamber.
5. A fluid pressure regulator for controlling the flow of l.p.g. to an internal combustion engine having an air intake manifold, including a first casing for receiving l.p.g. under pressure, a second casing, means within the second casing providing a main chamber and an auxiliary chamber, a port providing communication between the first casing and the main chamber, a diaphragm within the auxiliary chamber, a lever pivatally mounted within the main chamber, a valve member on the lever cooperable with the port to open and close the port, spring means biasing the lever so that the valve member closes the port, means operably connecting the lever to the diaphragm, so a discharge pipe communicating with the main chamber and leading to the air intake manifold for discharging the l.p.g. from the main chamber, an auxiliary discharge pipe communicating with the auxiliary chamber and extending axially along the discharge pipe for defining a restriction in the discharge pipe, said auxiliary discharge pipe having an outlet end, and the discharge pipe having a portion of increased cross-sectional area into which the outlet end of the auxiliary pipe for the discharge flow from the auxiliary chamber in the downstream direction so that as the fluids contained in the main chamber are drawn by suction along the discharge pipe, suction is produced in the auxiliary chamber to move the diaphragm and hence the lever against the action of the spring means whereby the valve member opens the port to allow more l.p.g. to enter the main chamber.