US2549552A - Means for controlling the supply of liquid fuel to internal-combustion prime movers - Google Patents

Description

April 17, 1951 E. A. WATSON A MEANS FOR CONTROLLING THE SUPPLY OF LIQUID FUEL 'ro INTERNAL-COMBUSTION PRIME MOVERS 2 Sheets-Sheet 1 Filed Feb. 6, 1946 Apnl 17, 1951 E. A. WATSON 59,

mums FOR CONTROLLING THE SUPPLY OF LIQUID FUEL T0 INTERNAL-COMBUSTION PRIME uovsas Filed Feb. 6, 1946 2 Sheets-Sheet Patented Apr. 17, 1951 MEANS FOR CONTROLLING THE SUPPLY OF LIQUID FUEL TO IN TERNAL-COMBUSTION PRIME I MOVERS r Ernest Ansley Watson, Birmingham, England,- assignor to Joseph Lucas Limited, Birmingham, England Application February 6, 1946, Serial No. 645,742 In Great Britain January 1, 1946 Section 1, Public Law 690, August 8, 1946 Patent expires January 1, 1966 6 Claims. (01. 103-11) This invention relates to systems in which liquid fuel is supplied to an internal combustion prime mover by a variable-delivery pump, the means which control the output of the pump end of the lever in the direction for closing the w which is adapted to act on the lever q in oppo sition to the spring 22, the plunger being respon sive to fluid pressure in a sub-chamber a: on the being responsive at least in part to fluid pressure chamber 1. Moreover, the compartment is condependent on the speed of the prime mover. nected by pipes y, z to the tank 0 at the supply The object of the invention is to enable any side of the pump a. The other compartment u desired part of the available fluid pressure to be is provided with an opening 2 leading to the used for actuating the output controlling means 10 atmosphere, and contains an evacuated capsule of th pump -3 adapted to act on the lever q in opposition to r In the accompanying sheets of explanatory the spring 0. drawings: V Adjustment of the swash plate b of the pump a' Figure 1 is a diagrammatic part sectional side to vary the'pump output is efiected automatically view illustrating one form of the invention ap-' by the piston 71. in response to movement of the plied to a variable delivery pump, and Figure-2 lever q. r 1 is a section on the line 22 of Figure 1. In carrying the invention into effect as shown Figure 3 is a sectional side view illustrating a n gures 1 and 2, I provide a by-pass device modified feature, having a hollow body part 4 adapted to form a Figures 4 and 5 are similar sectional views shallow cylindrical chamber in which is mounted illustrating respectively two modified forms of a rotatable di 5 h ng a p ai Outer perip y, t invention, 7 the latter and the inner periphery of the cham- Figure 6 is a similar view to Figure 1 illustratb for ing a narrow annular space 6 through ing another modified form of the invention. which liquid fuel can flow. At diametrically D-. e In Figure 1 it indicates a variable-delivery posite positions the body part 4 is formed with a pump of t swash plate t whi i adapted pair of ports 7, 8 which communicate with the to be driven in any convenient manner by the annular pace 6. The port 1 serves as a connecinternal combustion prime mover (not shown) to tion for One end of a p 9 Which at ts Ot er be supplied with liquid fuel by the pump, the outn i connected t the p mp d liv ry pip iput of the pump being controlled in known man- The other port 8 serves as a connection for one her by an angularly adjustable swash plate b. end of the P pe 2! Which t its other end is con- Liquid fuel is supplied from a tank 0 to the pump nected to the compartment t of the cha er a by a pipe d, and is delivered by the pump to the and which at an intermediate position is conjets e of the prime mover through another pipe f. nected by the pip 2 t0 the tank 0 at the Supply The swash plate b is connected by a rod-g to a d O t e pump a. When the pu ll is in piston h which is slidable in a cylindrical chem: action the annular space 6 in the body part 4 her 2' formed in the stationary part of the pump a, forms a by-pass by which some of the liquid in the piston being loaded by a spring 7. The end the deliverypipefcan constantly be returned to of the chamber 2 towards which the piston h is the supply side of the pump a, and the dimen-j movable by the spring :1 is connected by a pipe is sions of the annular'sp-ace are made such as wil to the delivery pipe I of the pump a, and this end 40 set up a convenient pressure gradient between of the chamber also communicates with the other the two ports 1, 8. end of the chamber through arestricted passage The rotatable disc 5 is formed with a radial m. The latter end of the chamberi is connected passage Ill leading from, t periphery of t by a pipe n to a vent 0 which at its outer end disc to an axial passage H in the disc. The axial, forms a seating for a closure member p on one passage ll communicates with a third port l2-in end of a lever q in a chamber 1'. 5 one end of the hollow body part 4, this port serv- The leverqis secured ata position intermediate ing as a connection for one end of a pipe I3 its ends to a diaphragm swhich serves as a fulwhich. at its other end is connected to the sub-' crum for the lever, and divides the chamber r chamber a: on the chamber 1'. Consequently presinto two o partments t, u. The vent o is sure fluid can flow vfromrthe annular space 6 in adapted to communicate with the compartment t the body part 4 .to the sub-chamber :r'where it under the control of the closure member 10 on the acts on the adjacent end of the plunger 10 which lever q, and this compartment contains a comforms a part of the mechanism for controlling pression spring 0 adapted'to act on the adjacent the pump output. Also the disc 5 is rotatable manually or under ,inanual control (through the 1 medium of an axial stem is on the disc and a lever l on the stem) to move the outer end of the radial passage H) to any desired position between the ports 1, 8 and so vary the fluid pressure acting on the plunger 10. I

As an alternative to the disc 5 shown in Figures 1 and 2 I may employ a peripherally toothed disc as indicated by 5 in Figure 3.

Instead of having the form above described the by-pass device may have any of a variety of forms two of which are illustrated in Figures 4 and 5.

In the example shown in Figure 4 I employ a chambered body part 4 having a pair of cylindrical ports 1 8 at its opposite ends, the outer ends of the ports serving respectively as connections for the pipes 9, y previously described. In each of the ports 1 8 is arranged a slidable flow-controlling plug 5 which may be of tapered form or of cylindrical form with one or more tapered grooves as 6 along its length. The two plugs 5 are interconnected by and may be integral with a part [5 adapted to receive linear movement from a crank or like mechanism ineluding a pin H engaging a slot i8 in the said i part, the said mechanism being operable manually or under manual control. By operating the crank or like mechanism the plugs 5 are moved so as simultaneously to increase the effective area of one of the ports i 8 and decrease the other. Alternatively two separate plugs may be used, these being actuated by a rotatable cam situated between their adjacent ends. In one side the body part 4 is provided with a third port ('2 which serves as a connection for the previously described pipe I3 whereby pressure fluid is conducted to the output controlling mechanism of the pump. By varying the effective areas of the two first mentioned ports 7 8 thepressure of the. liquid in the body part 4 (and consequently the pressure acting on the pump controlling mechanism) is also varied.

In the example illustrated by Figure5 I employ a body part 4 provided with three ports 1 8 and H2 which serve respectively as connections for the pipes 9, y and [3 previously described. The ports '1 12 communicate respectively with passages 59, 26 in the body part 4 and these passages are interconnected by a third passage 2i in the body part. Also the third passage 2! is connected at one end to the port 8 by a fourth passage 22 in the body part 1 Moreover, fluid flow from the passage H) to the passage 2| is restricted by an adjustable member 23, and fluid fiow from the passage 22 to the port 8 is likewise restricted by an adjustable member 25. Further, fluid flow from. the passage 21 to the passageZZis controllable by a flow-restricting member 25, the latter being adjustable by rack-and-pinion mechanism 25 from a lever 2'! which is operable manually or under manual control. By adjusting the flow-restricting member 25, the fluid pressure in the passage 2! (and consequently the pressure acting through the port H on the pump controlling mechanism) is varied. 7

Instead of employing the pressure of fluid delivered by the pump for actuating the plunger 10 of the pump controlling mechanism shown in Figure 1, I may employ the delivery pressure of a blower driven by the prime mover. An example of this modification is illustrated in Figure 6 in which parts similar or analogous to those shown in Figure 1 are indicated by the same reference characters sufiixed by 4. In the example illustrated in Figure 6 the sub,-

chamber r is divided by a diaphragm 28 into two compartmentsone of which is provided with an air vent 2E and the other of which is connected by the port l2 and a passage 30 to a pair of ports 7 8 The diaphragm 28 serves to actuate the plunger'w The port 7 serves as a connec tion for one end of a pipe 33 which at its other end is connected to the outlet of the compressor lable by a second flow-restricting member 37, the

latter being adjustable manually or under manual control. When the compressor 34 is in action a portion of the air delivered by it is constantly discharged to the atmosphere through the port 1 passage 36, and port 8, and the first mentioned flow-restricting member 36 sets up a convenient pressure drop between the compressor outlet and the passage 39 leading to the diaphragm 28. By adjusting the second flow'restricting member 31, the fluid pressure acting on the diaphragm 28 (and consequently on the plunger w can be varied.

By this invention the control of the liquid fuel supply to an internal combustion prime mover can be efiected in a very satisfactory manner. The invention is not, however, restricted, to the examples described, as its essential features may be embodied in a variety of forms.

Having'thus described my invention what I claim as new and desire to secure by Letters Patent is: 1

1. A liquid fuel supply system comprising a variable delivery pump and a member responsive to fluid pressure for controlling the output of the pump, a by-pass device having in combination a pressure fluid inlet, a pressure fluid outlet, a restricted passageway interconnecting the inlet and outlet, 2. port which communicates with the passageway at a position between the inlet and outlet, and means through which the pump control member is exposed to the fluid pressure at the said position within the passageway, and adjustable means for establishing a variable pressure drop in the passageway to vary the fiuid pressure acting on the said member.

2. A liquid fuel supply'system as claimed in claim I, in which the by-pass device comprises in combination a shallow cylindrical chamber provided at diametrically opposite positions with the inlet and outlet, and at one side with the port, a rotatable disc mounted within the chainberso as to leave a narrow annular space between the outer psriphery of the disc and the inner periphery of the chamber, the disc being formed with a passageway through which the said space communicates with the port, and manually controllable means for imparting rotational adjusting movement to the disc.

3. A liquid fuel supply system as claimed in claim 1, in which the by-pass device comprises in combination a shallow cylindrical chamber provide-cl at diametrically opposite positions with the inlet and outlet, and at one side the port, a rotatable and peripherally toothed disc mounted within the chamber so as to leave a narrow annular space between the periphery of the disc and the inner periphery of the charm, her, the disc being. formed with a passagewaythrough which the said'space communicates with,-

4. A liquid fuel supply system as claimed in claim 1, in which the by-pass device comprises in combination a hollow body part provided at opposite ends with the inlet and outlet, and at one side with the port, a pair of slidable flowcontrolling plugs mounted respectively in the inlet and outlet, and manually controllable means for imparting simultaneous adjusting movements to the plugs.

5. A liquid fuel supply system as claimed in claim 1, in which the by-pass device, comprises in combination a body part provided with passages interconnecting the inlet and outlet and the port, a member for restricting fluid flow from the inlet to the port and the outlet, another member for restricting fluid flow through the outlet; a third member for restricting fluid flow between the port and the outlet, and manually controllable means for varying the position of the third member.

6. A liquid fuel supply system as claimed in claim 1, in which the by-pass device is provided at its inlet with a member for restricting fluid flow between the inlet and outlet and the port, and at its outlet with an adjustable member for restricting fluid flow through the outlet.

ERNEST ANSLEY WATSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES BATENTS

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