US2645183A

US2645183A - Starter motor-driven hydraulic pump

Info

Publication number: US2645183A
Application number: US272009A
Authority: US
Inventors: John B Parsons
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-02-18
Filing date: 1952-02-18
Publication date: 1953-07-14
Anticipated expiration: 1970-07-14

Description

Suy 14?, E953 J, E. PARSONS 2345A@ STARTER MOTOR-DRIVEN HYDRAULIC PUMP Filed Fem 1S, 1952 4 sheets-sheet 1 IIH" i INVENTOR. do/m ,0a/"6 ons V *Bx/@ALLA LJ. 62m..

ATTORNEY @My M59 i953 .9. B. PARSONS 296459183 STARTER MoToR-DRrvEN HYDRAULIC PUMP Filed Fem la, 1952 4 amus-snaai 2l 7o unos INVENTOR. JO/1n Parsons BY @www M ATTORNEY July 14, l1953 J. B. PARSONS 2,645,183-

ASTARTER MOTOR-DRIVEN HYDRAULIC-Rum? Filed Feb. 1s, 1952 i 4 'smug-151mm s F154. Fmi. F195.

INVENToR. (7o/1n Pansa/15 ATTO RNEV July 14, 1953 .l. B. PARsoNs 2.645.183

STARTER MOTOR-DRIVEN HYDRAULIC PUMP- Filed Feb. 18, 1952 ,4.;\S hoetse$h1ee-t,4

Full.

INVENTOR. /a/7/7 Parsons Afro/@NE Y Patented July `14, 1953 STARTER MOTOR-DRIVEN HYDRULIC f PUD,y l I John B. Parsons, Maumee, `OhioA Application February 18, 1952, ,SerialNm 272,009

' `14 Claims. 1 l Y This invention relates to fluid pumping systems, but particularly to a hydraulic pump oper-- atively driven by an engine starting motor.

An object is to produce an electric starter motor driven pump, which is so constructed and (o1. s-3s) arranged that when the motor is used for engine starting purposes, the resistance of the pump is reduced to a minimum in a new and improved manner, the same motor being employed also for pump operation so that the motor can serve not only for engine starting purposes but also for pump operation. I v n,

Another object is to produce anV electric motor driven hydraulic pump, means separate from the pump being employed to reduce the resistance of the pump to a minimum whenthe motor lis used for a purpose other than driving the pump.

v A further object is to produce a hydraulic pump and elctricmotor unit in which the pump .is carried by the motor shaft, means being provided for automatically reducing the resistance afforded by the pump to a minimum when the motor is used for a purpose other than for operating apump.

. A still further object'is to produce a hydraulic pump unit operatively connected to an engine starting motor and so interconnected therewith that when the motor is used for engine starting purposes, a control member on the pump is automatically shifted so that although the pump is ldriven by the motor when the latter is used for engine starting purposes, the pump resistance is reduced to a minimum, the arrangement beingy such that the motor can be employed forvpump operation when not used for engine starting'pur-l and for purposes of illustration butnot of limitation, an embodiment of the invention is shown on the accompanying drawings, in which Figure 1 is a diagrammatic View of a hydraulic n window regulator mechanism in which the hydraulic pump is directly connected to the :shaft y of the engine starting motor;

Figure 2 is an enlarged kside elevation of the engine starting motor and hydraulic pump connected thereto, the latter being shown in vertical section:

Figure 3 is a top plan view of the starter motor and pump assembly shown in Figure 2;

2 l f i Figure-i is aside elevation partly'in section of the hydraulic pump and associatedvparts-showing the positionv ofthe control valve and connections when the'starter `motor, vis employed for engine cranking purposes; y

Figure 5 is ay View similar to Figure 4, show.` ing the position the parts assume in the event that a pressure in excess of a predetermined max-` imum is encountered during the pumping'operation causing the valve to be shifted ragainst the pressure of the spring to allow by-passing of ,the

Figure 6 isa viewsimilar to Figures 4 and 5, but showing the valve in the positionr assumed when the pump is used for pumping operations,

vthe valve being shifted sufficiently to enable liquid under pressure to pass to thewindowreguL latoru nit;- v e Figure 7 is a rlongitudinal rsectional view: sub-v adapted to serve as a safetyrelease in the event" becomes stuck or that the main shiftable valve otherwise inoperative Figure A11 is an alternate form of motor'and pump assembly; andV vFigure l2r is a 'fragmentary' sectional view'o'f an alternate vconnection between the motor shaftl and pump rotor. I

The illustrated embodiment comprises a window panel I0 for any automobile or other vehicle, to the lowered-ge ofwhich isv xed a channel II from which depends ra pair, of retainers I2 havinglongitudinally extending guidewaysy I3 in which studs I4 are slidable hori-` zontally. The studs I4 are fixed respectively to the free ends ofswinging arms I5 and I6, which are pivotally connected respectively to upright stanchions I1 andr I8. The arms I5 and I6 are pivotally connected intermediate their ends vso that Vby swinging movement of the arms in one direction, the windowpanel I0 is lowered intoI the door wellr(not shown) and by swinging movef ment in the opposite direction, the window panel is raised to close the conventional window opening, as will be. readily understood. l n

The lower ends of the stanchions are connected I to a horizontally disposed cross bar I9, which ofv the invention' 3 but the lower end of the stanchion I8 is pivotally connected by a single rivet 2|, so that the latter can rock toward and away from the stanchion |1 during the swinging movement of the cross arms.

Connected to the cross arm I at one side of the pivotal connection between the cross arms is a piston rod 22, which has a piston 23 at its lower end vertically slidable within a cylinder 24. Closing the lower end of the cylinder 24 is a fitting 25 which in turn is connected to a compensating arm 26, one end of which is pivotally connected to the lower end portion of the stanchion 1, a rivet 21 providing a stop for the upward movement of the free end of the arm 26. Hooked against the compensating arm 26 are helically coiled springs 28, the upperfends 'of which are hooked over the cross arm |6 between the pivotal connection of the arms and the stanchions I8.

Within the lower portion of the cylinder 24 is a solenoid controlled valve 29, which is springseated and is adapted to be unseated upon en- 'ergizing of the associated solenoid, thereby to admit liquid under pressure thereto through a tube 30, thus to force the piston 23 upwardly and swing the cross arm regulator in such manner as to raise the window panel I0. By energizing the solenoid without energizing the hydraulic pump or source of liquid pressure, the window is lowered by the coil springs 28, causing the liquid in the cylinder 24 to be forced therefrom through the tube 30 to the reservoir as will hereinafter appear. The solenoid is grounded at 3| and extending from the solenoid is a lead c extending to a control switch as will be hereinafter described.

The tube 30 extends to the high pressure side of a pump P, a tube 3| extending from the lov.l

pressure side of the pump to a liquid reservoir f1 32. As will hereinafter more fully appear', the pump P is driven by an electric motor M, which constitutes the starting motor for an automobile engine, for example, for cranking the internal combustion engine.

Fixed to the housing of the starting motor M is a starting solenoid S, which when energized through a link 33 (Figure 2), rocks an operating arm 34 in a counterclockwise direction thereby to effect an operative driving connection between the motor M and the internal combustion engine. This mechanism forms no part of the present invention and is well known to those skilled in this art, so that further description and illustration are not deemed necessary.

As shown, the actuating arm 34 and link 33 are connected by a pin 35 and mounted thereon is a yoke arm 36, the free ends of which are pivoted on the pin 35 and the opposite end of which is connected to a rod 31, which is threaded at one end to project through an aperture in the end of the arm 36 where it is adjustably held in place by a pair of lock nuts 38. If desired, coil spring means may be interposed between the arm 36 and the rod 31 to afford a resilient lost motion connection therebetween. The outer end of the rod 31 is riveted to a depending arm 38, the lower end of which is apertured to ride freely over a cylindrical extension of the control valve. An intermediate portion of the arm 39 is apertured to receive a stationary cylindrical pin 38 over which the arm slides. The outer end of the extension 40 is formed with an annular groove to receive the forked upper end of a leaf spring 4|, the lower end of which is apertured 46 to receive steel balls 41.

4to receive an adjustable anchor screw 42a. As

will hereinafter more fully appear, when the starting solenoid S is energized, the link 33 is forced inwardly or to the left of Figure l, and, through the arm 36 and rod 31, the arm 39 is moved to the left or away from the pump P thereby sliding the cylindrical extension 40 of the control valve outwardly against the tension of the spring 4|. In the latter position of the valve extension, the pump merely circulates liquid without performing work, thereby enabling the starting motor M to be used for engine cranking purposes with a minimum amount of resistance. When the cylindrical valve extension 40 is in its inward position, the pump can be operated to generate liquid pressure for window regulator i operation.

The pump P comprises a pair oi'

similar gears

42 and 43, which are in mesh with each other, the gear 42 being secured to the armature shaft 44 of the starting motor M For conveniently securing the gear 42 to the shaft 44, the outer end of the shaft is formed with a socket 45. Extending radially from the socket 45 are openings The outer end portion of the socket 45 is counterbored and tapped to receive a screw 48 which has a cylindrical extension terminating in a tapered end portion 48. The screw 48 is preferably magnetized to retain the balls in position for facilitating assembly. The parts are so proportioned that when the screw 48 is tightened in the socket, the tapered end portion 49 and cylindrical extension force the balls outwardlyrmly embedding them in the metal of the gear 42 thus to effect a simple, efficient and easily effected driving connection between the armature 44 and the pump gear 42. The pump gear 43 rotates freely upon a post or axle 50, the outer end of which is tapped to receive the anchor screw 42a.

The pump housing is formed of an intermediate plate section 5| which, as shown on Figure 8, has cavities to receive the pump rotors 4Z and 43, there being

arcuate cavities

52 and 53 on opposite sides of the meshing portions of the pump rotors. A groove 54 communicates with the cavity 52 on one side of the housing section 5| and a groove 55 on the opposite side of the housing section 5| communicates with the upper portion of the cavity 53.

Fastened to the outer side of the housing section 5| is an end plate 56, which has a centrally disposed aperture for the reception of the armature shaft 44 and a substantially inverted L-shaped countersunk groove or cavity 5T. In the upper portion of this cavity is an aperture 58 for the cylindrical extension 40 of the control valve and at the lower portion is a tapped hole 59 to which is connected the tube 3|. In the lower portion of the end plate 56 is an aperture 6D to receive the rotor supporting post 50. This section is formed with a continuous groove 6| to receive a sealing ring or packing 62.

Closing the inner side of the central SectOn 5| of the pump housing is an end plate 63, which is formed with a countersunk groove or cavity 64 which is generally of inverted L-shape. A continuous boundary groove 65 receives a packing ring 66 and formed centrally is an opening 61 through which the armature shaft 44 extends. At the lower end is an annular cavity 68 into which projects the inner end portion of the axle 50. Manifestly, by placing the

end plates

56 and 63 on opposite sides of the intermediate or body portion 5|, the cavities in the taking yinliquid through` the opening r59 and 4,delivering liquid under pressure to the ,

cavities

64 and 54. Both of the cavities org1`00ve-s-lllr and 51 u communicate withthe valve `rece1vmg lopening 69 formed inla bossg'll) on theintepmediatev or body section of the pump housing.

n the outer side of the boss 10 is a centrally apertured part 1I, which has; a presst withln vthis section with the aperture thereof aligned with the aperture 69. When the parts are assembled, the control valve is slidablethrough these registering apertures, this valve having a cylindrical extension 40, an intermediatespool portion 'l2 and a radially bladed or uted end portion 13 affording a seriesfof fluid passages in a predetermined position of the valve. i

The position shown in Figure 4is.thefpos1 tion in which the valve member is moved substantially to the left so thatvthe fluted or bladed end portion 13 enables the liquid to circulatey within the pump housing as shown :by the varrows. In this position .of the parts, it willbe observed that the arm 39 has been moved `to the left positively to move ,the valve to this'posi-` tion, this being the position the parts assume when the starting motor is used for enginestarting or cranking purposes. In Figureg, the-valve is in the same position show in Figures; but the vertical arm 39 is in its normal position against the outer wall of the pump housing. This is the position the valve assumes for regulating the maximum pressure. In other words, the pressure exerted by the spring 4I is predetermined and when that pressure is exceeded, the valve automatically moves klto the lefto.ve1"c01iy ing the tension of the spring 4 l and allowing the liquid to recirculate, thereby. inilitatin'g against damage to the parts operated by hydraulic tiressure. In this connection, it may be jmentioned that the anchor screw 42a can be adjusted to regulate the pressure exerted by the spring 4|`y the spring having a portion bearing' against the pump housing so that the more the screw 42a is tightened, the greater pressure will be: exerted by the spring 4l.

Another position of the valve. isv illustrated kill- Figure 6 which is the operating position when liquid under pressure is forced past thev bladed or fluted end`of the valve to the tube 3D', .the

latter being connected to the intermediate heus;-i

ing section I' at the upper portion`thereof,"' ail channel 14 extending to the space between the ends of the apertures member 1| andI the'bess 10. In this position, the valve is moved tofthe left of Figure 6 by hydraulic pressure which j1s sufcient to overcome the tension exerted by the spring 4I.

The other position of the lValve member is the extreme right-hand position, which is shown 0n portion 12 uncovers an outletpassage 14, there# by enabling liquid from the tube 30 to pass'aboutr the spool portion and through the cavities 51 and 55 to the outlety port 59 andthence to the Thisk latter. vIDO-' reservoir through the tube 3|. sition of the valve is the normal position assumed by the valve when the pump is idle.

A series of bolt and nut assembliesy "l5 securel together the parts of the pump housing "whichil as shown, is essentially supported by the end 0f the motor shaft 44. To hold the housing from:

turning, a bracket'l `is secured tothe lower end of the pump housing and 6 to theend wall oi"` the electric motor;M,v an aperture'l'l. in av flange of the bracket fitting over oneof theheads 18" of the vmotor securing bolts. Thus it will-befunderstood that the bracket 16 is not a supportingbracket but merely to cof operate-with amotorbolt to hold the pump from turningmovements. f Y l Figure 10 shows a pressure relief valve in which a spring-tensioned ball valve 19 is disposed betweena pressure passage 54a rand an intake pas'- sage 55d.; The, tension exertedA by the spring which normally seats the ball 19 is suchtl'iat'the ball valve 19is normally seated. However, when a pressure is generated on the pressure' side of the pump in excess ofa predetermined maximum, such that the iluted end 13 of the slidable valve shouldvmove to the position indicatedinFigure 5, to serve as -a relief, the ball check valve 19 may besubstantially at this time unseated to afford an additional precautionary or safetyfeature. The pressure relief valve 19 ordinarily willfunction only inthe event -that the main slide valve be.- comes stuck for one reason or'another. Under ordinary circumstances, it is not contemplated that the pressure relief Valve 19 will function. .f The pump housing is maintained in spaced relation lfrom the end wall of the starter motor M byya sleeve 80, a felt packing 8| being interposed between the end of thesleeve and an end plate 82 of relatively thin sheet metal which abuts against the inner wall of the pump housing. 'A plate r83 abuts against the front or outer wall of the pump housing,- andassistsfin retaining the usual packingsurrounding the rotary-or shiftable-parts in place, the plates 82 and 83y being retained in posi'- tion by the bolt and'nut assemblies 15.

AAs shown in Figure l, a switch 84 is for' the pose of energizing the starter motor VM for engine cranking purposes, a lead d extending fromithe switch 84 to the starting solenoid Sy forming a part'of the starter motor assembly. From the otherterminal of thegswitchr extends va lead'd whichvjoins a lead fkwhich ,connects with a storage vlbattery gandalso extends to a binding post on the, startergsolenoidfS. A branch h from the valve of lthe pump moves tothe position shown'in Figurefl', allowing the motor M to operatewith a; minimum of resistance afforded by the operation of thehydraulic pump. I 1

Foroperating the rwindow regulator `mecha-- nism, a switch 86 is employed, this switch ,having three poles from one kof which extends. a leadb.- to the motor relay 85.-r From another pole ofthe switch 86 extends a leadl a whichy joins the lead f1 'extending to the battery g, relay 85 and starter.-

motor solenoid S, as above described.. .A third lead c extends from the remaining pole ofthe switch 86 to the solenoid of the solenoid valve as-` From the above, itfwill` be understood rthat byy actuation of the switch 86 in `one direction, the

leads c and )i are electrically connected, there.` s concomitantly,toenergize the starter motor M as; this bracket extends Well as ,the solenoid` associated `with the.solenoid..l

valve assembly z5. This enebiesthe hydraulic gear motor to be operated to force liquid under pressure through the tube 30 past the solenoid valve assembly 25 for driving the piston 23 upwardly with respect to the cylinder 24 and thus actuate the regulator arms for raising or closing the window. Upon release of the switch 86 and its return to normal position, the liquid within the cylinder 24 will retain the piston in the position of adjustment. In the event that the switch is retained in its on position after the window l has been moved to its closed or fully raised position, the pressure built up by the pump will force the fluted end portion 'I3 of the valve to the position shown on Figure 5, so that the liquid can then merely circulate without performing useful work, such movement of the valve occurring after the pressure overcomes the force of the spring 4|. However, in the event that this valve structure becomes stuck for any reason, i

then the pressure release valve 19 will be unseated to relieve the pressure generated by the pump. When the switch 86 is moved in the opposite direction to that above described, the leads c and f alone are electrically connected, thereby to energize the solenoid valve assembly to effect opening of the valve and enable the coil springs 28 to pull the cross arm regulator as well as the piston 23 downwardly, thereby to effect lowering of the window |0. This movement of the piston forces the liquid from the cylinder 24 back to the reservoir through the tube 30, and past the reduced neck 'l2 of the control valve and to the reservoir through the tube 3|. Upon release of the switch 86, it will return to an intermediate or neutral position. A suitable switch for this purpose is shown and described in my United States Patent 2,446,141, dated July 27, 1948.

The form of the invention shown on Figure 11 is similar to that above described except for the connections to the motor shaft and to the solenoid actuated yoke. In this instance, the starter motor shaft 44a does not extend much beyond the end of the motor casing and is formed with a tapered socket 88 terminating in a tapped portion 89. Fitting into the socket 88 is the tapered projecting end portion 90 of a separate pump shaft 9| which terminates in a threaded end to engage the threads of the tapped portion 89. The pump rotor 42a has a keyway 92 to receive a key 93 in the shaft 9|. One advantage of this structure is that it enables the pump to be separate from the starting motor and can be used and mounted else- Where since it is a complete unit in itself and is equipped with its own shaft.

Another feature shown in Figure l1 which differs from the above structure is the adjustable connection between the yoke 36 actuated by the starter solenoid. In this case, the valve operating arm 39a has a vertical portion, upwardly and forwardly inclined, which is integral with a terminal portion having elongate slots for adjustably receiving bolts 94. The bolts 94 extend through apertures in an angle arm 95 which is riveted to the yoke; The bolts 94 engage threaded holes in a nut plate 86. This structure enables adjustment ofthe valve arm 39a relative to the yoke to be conveniently effected.

Figure 12 illustrates an alternate connection between the starter motor shaft 44 shown in Figure 2 and the pump rotor 42. In this instance, the screw 48a has a fiat end 91 to bear against a relatively large ball 41a which in turn bears against the two smaller balls 41h. When the screw is tightened, the ball 41a forces the balls 4`|b outwardly in a radial direction into rm intimate engagement with the pump rotor 42, thereby creating a simple and effective driving connection.

From the above description, it will be apparent that I have produced an exceedingly simple and efficient starter motor driven pump, the entire assembly of which is carried by an extension of the motor shaft, thus dispensing with the necessity of a separate motor for driving the pump. The arrangement is such that when the motor is employed for engine cranking purposes, the pump is automatically rendered ineffective, the pump operating in the usual manner but the liquid merely circulating from the pressure side to the intake side. Thus the resistance afforded by the pump is reduced to a minimum and is such as to cause no appreciable load on the starter motor. It will further be manifest that the operation of the starter motor solenoid by which the starter motor and engine is effected, effects the shifting of the pump control valve in an extremely simple manner, thus positively rendering the pump ineffective at the time the electric motor is employed for engine cranking purposes.

It is to be understood that numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as defined in the appended claims.

What I claim is:

1. A device of the class described, comprising an enginestarting motor, a fluid pump connected to be driven by said motor, a valve in said pump for controlling fluid flow having a portion projecting exteriorly of the pump, said valve having one position enabling fluid under pressure to be forced from the pump and a second position enabling relatively free fluid flow, and an operator engaging said projecting portion of the valve for actuating same to said second position when the motor is used for engine starting purposes thereby to reduce the pump resistance to a minimum.

2. A device of the class described, comprising anv engine starting motor, a fluid pump connected to be driven by said motor, a valve in said pump for controlling fluid flow having a portion projecting exteriorly of the pump, said valve having one position enabling fluid under pressure to be forced from the pump and a second position enabling relatively free fluid flow, an operator engaging said projecting portion of the valve for actuating same to said second position when the motor is used for engine starting purposes thereby to reduce the pump resistance to a minimum, and means for automatically rendering said operator effective.

3. The combination of an electric motor, mechanism for operatively connecting said motor to an internal combustion engine for cranking same, a hydraulic pump carried and driven by the shaft of said motor, a control valve for said pump movable to a position enabling free circulation of the liquid handled by the pump, and an operative connection between said control valve and said mechanism for automatically moving the former to said free circulation position when the motor is employed for engine cranking purposes.

4. The combination of an electric motor, mechanism for operatively connecting said motor to an internal combustion engine for cranking same, said mechanism including a solenoid, and an actuating member responsive to said solenoid, a. hydraulic pump carried and driven by the shaft of said motor, a control valve for said pump movable to a position enabling free circulation of the liquid handled by the pump, and an operative connection between said control valve and said sole- 'noid for automatically moving the Vformer to said free circulation position when the motor is employed for engine cranking purposes.

5. The combination of an electric motor, mech# anism for operatively connecting said motor to an internal combustion engine for cranking same, a hydraulic pump carried and driven by the kshaft of said motor, a control valve for said pump movable to a position enabling free circulation of the liquid handled by the pump, an operative connection between said control valve andsaid mech,r` anism for automatically moving the .former to j sure to the intake side of the pump, and an opv erator outside of and separate from the pump for actuating said valve to said latter position.

, '7. A device of the class described, comprising an electric motor for engine cranking purposes, a hydraulic pump connected to be driven by said motor, a rectilinearly shift-able spring-tensioned valve normally disposed in an operative position enabling liquid under pressure to be iorcedfrom the pressure side ofthe pump, said valve being shiftable to a position to enable relatively free circulation of liquid from the pressure to the intake side of the pump, an extension on said valve disposed outside of the pump, and an operator outside of and separate from the pump and engaging said extension for actuating said valve to said latter position.

8. A device of the class described, comprising an electric motor for engine cranking purposes, electrically operated starter mechanism for operatively coupling the motor to the engine and embodying a translatorily movable part, a hydraulic pump connected to be driven by said motor, a rectilinearly shiftable spring-tensioned valve normally disposed in an operative position enabling liquid under pressure to be forced from the pressure side of the pump, said valve being shiftable to a position to enable relatively free circulation of liquid from the pressure to the in-v take side of the pump, an extension on said valve disposed outside of the pump, andan operator responsive to movement of said movable part disposed outside of and separate from the pump and engaging said extension for actuating said valve to said latter position.

9. The organization as claimed in claim 8, in'

which the spring tensioning the Valve assists in returning the translatorily movable partto normal position when the starter mechanism is deenergized.

10. The organization as claimed in claim '7, comprising a lost motionconnection between the valve and the operatorenabling normal operation of the valve-When the pump is operated `for pumping purposes. v

11. The lcombination of an electric engine starting., motor, electrically operated starting mechanism including a solenoid and a rockable arm actuated by the solenoid, a fluid pump suspended on and operatively connected to the motor shaft, a control slide valve for the pump y' movablev in one direction automatically in response to fiuid pressure, an extension on said valve disposed outside of the pump, a spring urging said valve to normal pumping position,

' arm means engaging said valve extension for en- A abling valvemovement freely and independently thereof, said varm means being connected to said valve extension for moving same against the tension of said spring to a position enabling free fluid circulation from one side tothe other, and

vlink means connecting said arm means to said rockable arm.

12. A fluid pump comprising a casing including a flat central plate and side plates on opposite sides of and closing said central plate, rotor apertures in said central plate, interengag- Y ing'pump rotors in said apertures, shaft means for one rotor, an inlet and an outlet for the casing, the inlet communicating with the low pressure side of the pump rotors, cavities in said plates respectively, one cavity establishing communication between .the high pressure side of the from they highl to the low pressure side of the Y pump rotors. Y

A fluid pump `as claimed in claim 12, comprismg an extension on the shiftable valve disposed outside vof the casing, and actuating means valve.

engaging said extension.

14. A fluid pump as claimed in claim 12, comprising an extension on said shiftable valve disposed `outside of the casing, and adjustable spring means engaging said extension for tensioning the JOI-IN B.' PARSONS.

References Cited in the file of this patent Gurewitsch Mar. `16, 1943