US2402332A - Fuel supply system - Google Patents

Description

June 18, 1946. l.. LEE, 2D

FUEL SUPPLY SYSTEM Filed May 4, 1944 2 Sheets-Sheet 1 mvENToR v. Y l) AGENT E E N m H J x25. AND... 26mm June 18, 1946. L, LEE, 2D 2,402,332-

FUEL SUPPLY sYsTEM Filed May-4, 1944 2 sheets-sheet 2 FIG. 2

TO CLOSE 'THROTTLE iol |20 22 To l f INCREASE |02 |04 PUMP l |74 oAPAclTY INVENTOR 5575712172717 [EEZ] AGENT application.

Patented June 18, 1946 UNITED STATE s Pil'rEixVrv4 OFFICE y FUEL SUPPLY SYSTEM Leighton Lee, II, Middletown, Conn., assigner to Chandler-Evans Corporation, South Meriden, Conn., a corporation of Delaware Application May 4, 1944, Serial N0. 534,043

air. The invention is especially adapted for use with engines of the spark ignition type, although its utility is not limited to such engines.

Such systems commonly usea set of injector pumps, one foi-.each cylinder of the engine, and

means are provided to control simultaneously the capacity per stroke of all the pumps so as to regulate the quantity of fuel delivered to the 'combustion chamber at each stroke of the engine. An injector pump mechanism of that type is shown in the copending application of AMilton E. Chandler, Serial No. 451,874, filed July 22, 1942, and assigned to theA assignee of the present It has been proposed to operate the pump capacity control mechanism in accordance with the flow of air thru the air induction system of the engine, in such a manner as to maintain the fuel-to-air ratio within suitable limits. In such fuel supply systems, difiiculty has been encountered in controlling the pumpcapacity when the rate of flow of air thru the induction system is relates to fuel supplyl 2o claims. (ci. 12a-14o) relatively low. Under such conditions, the force produced by the device which meters the air ow is rather small, andthe control of the pump capacity by this small force tends lto be erratic. Other diiculties have been encountered in such systems with respect to the control of the pump capacity when it is desired4 to shut down the engine. Under such conditions, the air flow responsive means-tends to maintain the pump at a substantial capacity as long as the engine operates, while the best method of stopping the engine is to cut olf the ow of fuel thru the pump before the engine comes to rest, so that no unburned fuel remains in the cylinders of the engine.

It is therefore an object of my invention to provide improved means for controlling the capacity of an injector pump mechanism for supplying fuel' to an internal combustion engine.l

Another object is to provide, in a fuel supply system including an injector pump mechanism normally controlled by the rate of ow of combustion air to the engine, improved means for controlling the pump capacity under conditions of low air now.

Another object is to provide improved mechanism of the type described wherein the pump capacity is controlled by the throttle position i 2 when the throttle is in a range of positions adjacent its closed position.

A further object is to provide, in a fuel supply system of the type-described, mechanism operable by a manual lever independent of the throttle for operating the pump capacity control. A

still further object is to provide such an arrange-l ment which may be used to cut olf the fuel flowthru the pumps completely, regardless of any other factors which might control the pump capacity under usual operating conditions.

Other objects and advantages of the present invention will become apparent from a consideration of the appended specification, claims and drawings, in which Figure l represents, somewhat diagrammatically, a fuel supply system lfor an internal combustion engine, of the type to which my invention is applicable,

Figure 2 illustrates, partially in perspective and partially in section, an idle and cut off control adapted for use with the system of Figure 1, and

Figure 3 illustrates a modified form of idle control which may be applied to the servo motor of' Figure 1.

Figure 1 There is shown in Figure 1 a passage I0 for air iiowing to an internal combustion engine. This passage Ill includes a venturi portion l2 which produces a differential pressure varying withthe square of the velocity of the air flowing thru the passage. The fiow of air thru the passage ill is controlled by a throttle I4 xed on a shaft IB for rotation therewith.

The pressure dierential set upby the venturi l2 produces a flow of air thru a secondary air passage extending from an impact tube I8 thru a conduit 2li, a restriction 22, a conduit 24, past conduit 30 to the throat of venturi I2.

The pressure differential between the ends of; the secondary air passage may be divided into f two component drops, one appearing across the restriction 22 and the other across the valve 26. The valve 26 is operated by a bellows 32 located in the chamber 28. The bellows 32 is preferably filled with a iiuid having a suitable coeficient of thermal expansion, so that the valve 26 is moved in accordance with changes in the pressure and temperature of the air in the chamber28. The pressure diierential appearing across restriction 22 is thereby controlled both as a function of the velocity and the density of the owing air so that that pressure differential is' a measure of a. valve 26 into a chamber 28 and thence thru a.

the mass of air owing unit time.

The fuel owing to the engine comes from a tank (not shown) and passes thru a conduit 84,

a boost pump 36, a conduit 38, a pump 40, a conduit 42, a mixture control 44, avjet system generally indicated at 48, and a conduit 48 to the injector pumps (not shown).

The pump 88 is driven by an electric motor indicated schematically at 50. 'I'he discharge pressure of pump `38 is controlled by a pressure relief valve 82.

Pump 40 is preferably driven by the engine and its discharge pressure is controlled by a pressure relief valve 54. i

The mixture control 44 includes a disc valve 58 xed on a shaft 58. The disc valve 56 controls the ow of fuel thru a pair of conduits 60 and 62 which connect the mixture control 44 to the jet system 46. When the valve 56 is in the position shown in full lines inthe drawings, the mixture control is said to be in its lean position, since the fuel can then flow to the jet system only thru the conduit 80. When the valve 58 is in the position illustrated in dotted lines in the drawings, the mixture control is said to be in its rich position, since the fuel can thenflow thru both conduits 80 land 82 to the jet system 46. It may be seen thatthe valve 56 can be moved to a po Y sition wherein it cuts off the flow of fuel thru both the conduits 60 and 62. The mixture control is then said to be in its cut-oil" position.

When the mixture control is in its lean position, fuel can flow to theiengine only thru a fixed jet or orifice 64 anda parallel jet 86 controlled by a valve 68 biased closed by a spring 10. -When the mixture control is in its rich position, fuel can also flow thru a xed jet 12. The flow thru thejets 88 and 12 also passes thru another fixed Jet 4.

The function of the ,iet system is to control the fuel flow as a function of the pressure differ ential across the jet system. When the mixture control is in its lean position, a given pressure differential indicates a certain rate of fuel flow. When the mixture control is in its rich position,

thru the passage perthe capacity of the .98 to conduits |20 and |22 leading to the opposite ends of cylinder |02 of the servomotor |00. Conduit |24 connects the valve 98 with the conduit 34 in the fuel line at the low presure side of the pumps 36 and 40.

The fuel pressure diiferential across the jet system, which is a measure of the rate of llow of fuel to the engine, is applied to the chambers 88 and 90, with thehigh pressure in the chamber 90, so that this pressure differential acts upwardly on the valve 98. The air pressure differential, which is a measure of the rate of iiow of air to the engine, is applied to the diaphragm 84 so that it acts on' the valve 98 in a downward direction as viewed in the drawings.

When the fuel pressure differential is balanced with the air pressure differential, the valve 88 is at the position shown in the drawing. In this position of valve 88, no fuel flows to either end of the cylinder |02 of servomotor |00.

If the amount of air flowing thru the passage |0 increases, the force acting downwardly on the diaphragm 84 increases, thereby moving the valve 98 downwardly, and opening ports so that fuel under pressure may flow from conduit ||8 into conduit |22 and the right end of vcylinder the cross-sectional area open to the fueliiow -is increased so that the same pressure differential as before produces an increased fuel flow. Since the pressure differential across the jet system is controlled by the air flow, as hereinafter explained, it may be seen that the mixture control may be used to select different fuel to air ratios for different night conditions. The jet 86 and the valve 88 controlling it are provided to increase the fuel flow whenever the pressure differentials across the jets exceeds. a predetermined value, thereby producing an increase in the fuel-to-air ratio at high power outputs.

The pressure differential appearing across the restriction 22 is applied thru a pair of conduits 16 and 18 to chambers 80 and 82, respectively, located on opposite sides of a diaphragm 84 in a pressure meter generally indicated at 88. The pressure meter 88 also includes chambers 88 and 80. Chamber 88 is separated from the chamber 80 by a diaphragm 82 and chamber t0 is separated from the chamber 82 by.a diaphragm 84.

The diaphragms'lz, 84 and 94 are connected to the stem 88 of a valve 88 which controls the flow of fuel to a servo motor |00 which includes a cylinder |82 enclosing a piston |04 which moves a rack |88 cooperating with a gear |08 mounted on a shaft I|0. which is connected to suitable |02. At the same time, the left end of cylinder |02 is connected thru a conduit |20 and valve 88 to the drain conduit |24. A pressure differential is thereby established across the piston 04, causing it to move to the left, land thereby moving rack |08 to the left. This rotates the gear |08 in a clockwise direction. The pump capacity regulating mechanism is so designed that rotation of gear |08 in a clockwise direction increases the pump capacity, as indicated by the legend in the drawings. The increase in the pump capacity causes a corresponding increase in the fuel ow, thereby increasing the pressure differential across the jet system so as to produce a force acting upwardly on the valve 98 to restore it to its neutral position.

In'a similar manner, if the air flow decreases, the valve 88 is moved upwardly to admit pressure to the left hand side of cylinder |02 thru conduits I8 and |20, and to connect the right end of cylinder |02 to the drain conduit |24 thru conduit |22. I'his produces a rotation of the injector pump capacity control shaft in the opposite, or capacity decreasing direction. A spring |28 acts upwardly on the lower end of the valve 88, biasing it in a pump capacity decreasing direction. This spring is provided so 05 that when no air or fuel is flowing to the engine.

the pump capacity control will be operated to its minimum capacity or cut-off position.

Figure 2 nasse t edectively control the valve @e and hence the.

injector pun-ip capacity. There is shown in Fieure 2 a mechanism by which the injector pump capacity is controlled directly by the throttle' when the throttle reaches a predetermined re of positions near its closed position.

The shaft I6 oi Figure 2 is there identied as the throttle shaft. but it may be any shaft suite1 ably connected to the throttle shaft so as to rotate concurrently with it. The left end o shaft i i 6 from the pcsitionin which it appears in Figure 1. Therefore movement of the piston IM in the idle range in the construction illustrated causes i5! to the right is terminated by the shoulder it. v

The sleeve ld has e. groove |58 cut in its sur@ face. For the greater portion of its length the groove los is parallel to the ends oi' the sleeve ld and 56, but near its upper end, es viewed in the drawings, the groove it curves towerd the left end of the sleeve 56.

The throttle shaft it rotates counterclockwise, as viewed from its right-hand end in Figure 2, to close the throttle.

A 'nell crsnklever E52 is xed on a shaft ist to rotatetherewith. One armit@ oi' the lever it estends'upwardly therefrom and carries near its upper end a. pin l, one end of which is adapted to ride in the groove |58. y

The other arm il@ of the lever it? extends to the right from shaft |64 and carries a pin il@ which cooperates with a slot ilo in en elonseted arcuate memberv ilo. The member llt is pivotelly supported by a shaft llt, shown near-the center of the member |16.

The lower end oi member ile is'pivotally e. tsched to a linkv il@ whose opposite end is piv- -otelly attached to a rod it@ connected to piston valve it .is closed, but when the sheft los is moved from its normal position in either direction, then valve |82 is opened to provide duid communication between the opposite ends of the cylinder M2.

As long as the throttle is opened by :zu more'than a predetermined amount, the pin it@ rides in the portion of the groove` its which isY parallel to the ends of sleeve ldend the wel@ tion of lever it? .does not change. At such' times, the piston mt may reciprocate in the-cylinder lo?, causing the element Bld to pivot about its supporting shari-. ile, without causing move= ment or pin ill and lever |62.

As the throttle is moved toward closed position, the pin it encounters the curved portion of groove loe, which 'causes the bell crank lever it and shalt tot to he turned counter-clockwise. This opens vslve i s2; so that the opposite ends of cylinder its are connected end the pressure an operation of the pump capacity control in a capacity decreasing direction.v y

It will be readily apparent to those skilled in the art that other contours of the groove |58 may be use d if other relationships between the throttle position end the pump capacity setting are desired. The contour illustrated was chosen because it has been found that with a xed pump capacity setting, the actual ow thru the pump per revolution of the engine tends to increase with decreased speed. Therefore, in order to prevent thernixture from becoming too rich at low speeds, the groove |58 is contoured to-decreese` the pump capacity setting. If, with e. particular type of pump or engine an increased pump capeclty setting is required, the groove |58 would be contoured so that its upper end curved to the right, es it appears in Figure 2.

There is also provided in Figure 2 means whereby manipulation of the mixture control shaft de toits cut on position causesoperetion of dii uid supplied to the cylinder under control of the piston ld end-pump capacity control mechanism to its minimum capacity position.

For this purpose, there is xed on the mixture control shaft d@ a disc |83 having a. groove |788 cutin one of its lateral surfeces A lever leo is pivotelly mounted on e. shaft |92 and carries vet its upper end a pin its which rides in the groove `Hill. The lower end of lever |86 is adapted to cooperate either vvith ange |56 of the sleeve |54 with the vertical arm 68 o2 bell crank lever Groove ld hes a portion ot constant radius extending about the\sheft 5% as a center. The pin lo@ rides in this portion of the groove whenever the mixture c trol shaft is in its lean or rich positions. lindel these conditions, .the lever it@ engages flange |68 and holds the sleeve ldd against the shoulder l5@ on the shaft i8.

At the opposite ends of the arcuate portion of groove SSB, the groove extends Vsubstantiollv of the disc itt. -When the shaft Se is rotated counter-clockwise to move the valve 5S to its cut=o position, the pin 85 -rides along this redisl portion of the groove |88, and thereby' causes the lever its to rotate in a clockwise direction about its pivot 92. The lower end of lever it@ thereby moves to the left, engaging the upperV end of arm ld and rotating the hell crank lever to2 in e counter-clockwise direction.

The rotation, of shaft |54 opens the valve 82 to tolse the sirow responsive mechanism out oi control ci the servomotor i i. At the seme time, the pin ill moves upwardly in the slot |16 rotatthe element llt counter-clockwise and movthe piston. It to the right. or in a pump capocity decreasing direction. A The proportions of the various levers should be such thatwhen the mixture control shalt reaches its cut-of position, the piston Its is positively set at its minimum ce pscty position.

when the piston its is being positioned by the mixture control shaft, the throttle has no control over the piston, since the sleeve lithen slides on the splines |52 sions the she-ft i6, and the position ci? pin its in groove |58 has no effect on the i position of the piston lcd.

While l lieve illustrated the disc |88 es being xed onl the v.` e control shaft, it should be apparent that it may with equal facility lne-placed on e, seperate t which may be manually operuted to set pump amassa 7 Figure 3 There is shown in Figure 3 an alternative arrangement by which the throttle position may be used to control the injector pump capacity in the idle range.

In Figure 3, the throttle shaft I6 carries a drum 200 having a cam groove 202 cut in its surface. A follower 204 rides in this groove and is attached to a rod 206. The rod 206 has a portion 200 of relatively small diameter. 'I'his portion 208 serves as a valve to control the flow of fuel from the conduit |20, which may be the same as conduit |20 of Figure 1, 'to a conduit 2I0 connected to the right end of a cylinder 2 I2. The cylinder 2I2 is a part of a servo-motor mechanism generally indicated at 2 I4, which includes a hollow piston 2I6 connected thru a suitable rod 2 I8 to the injector pump capacity control (not shown).

The fuel supply conduit |22 is connected to the left end of cylinder 2I2. The rod 206 extends into thecylinder 2 I2 and thru one end of the hollow piston 2I6. At the end of rod 206 inside the piston 2 I 6 there is mounted a spring retainer 2 I8, and a spring 220 is held in compression between the retainer 2 I8 and the inside of piston 2| 6.

Just outside the piston 2I6, the rod 206 carries a pair of spring retainers 222, between which is compressed a spring 224. The retainers 222 are on a portion of the rod 206 of relatively narrow cross-section so that the separation of the retainers 222 is limited by the shoulders at the ends of that portion. The spring 224 has a spring rate twice as great as that of the spring 220, so that when no fluid pressures are acting on the piston 2I6, the 'retainers222 are held against the shoulders on the rod 206 by spring 224. The spring 220 holds the piston 2I6 against the right-hand retainer 222. The springs 220 and 224 therefore tend to maintain the left end surface of piston 2I6 aligned with the shoulder at the right end of the narrow portion of rod 206.

When a. pressure differential is applied to the ends of cylinder 2I2 which tends to move the piston 2I6 from its normal position with respect to rod 206, it may be seen that'that spring force which the pressure differential must overcome is the same regardless of the direction in which the piston is to be moved. If the piston is to be moved to the left, for example, the motion is opposed by the spring 224 and aided by spring 220. As previously stated, the force of spring 220 is one half that of spring 224 so that the force required to be overcome is `1ust equal to one half that of spring 224. If the piston is to move t the right, on the other hand, the spring force to be overcome is only that of spring 220, which as previously stated is equal to one half that of spring 224.

A by-pass conduit 226 connects the opposite ends of the cylinder 2I2, and is opened by the piston 2I6 when it reaches a predetermined position in its travel. When this by-pass is open. the valve portion 208 of the rod 206 shuts olf the supply of fuel thru the conduit |20. The air flow responsive mechanism cannot control the piston 2 I6 when the by-pass 226 is open.

In designing the contour of the cam groove 202, many factors must be considered. In the idle rangeVwhen by-pass 226 is open, the cam positively determines the relationship between throttle position and injection pump capacity. In this range, it is usually best to determine empirically the proper cam contour for a given pump and engine. When the throttle is opened 8 beyond the idle range, the valve portion 200 of rod 206 opens the passage |20 and the piston 2I6 closes the by-pass 226. The piston 2I6. is then controlled chiey by the valve 08 (Figure 1). The only influence of cam 202 at such times is to determine the biasing force due to springs 220 and 224 which must be overcome by the pressure .differential acting on the opposite ends of the piston -in order to set the rate of fuel flow at any particular value. In order to minimize the effect of this biasing force, the cam 202 should be designed to set the pump capacity control at an optimum position for a given throttle position. I prefer to base the design for the cam on the assumption that the propeller governor controls the relationship between propeller speed and horsepower output to maintain maximum propeller efficiency. If that is assumed, then for a given throttle position, definite values of speed and power are determined, and the cam may be designed to give the best fuel to air ratio for those conditions.

Of course, the engine is seldom controlled in practice so that the speed and power output vary in accordance with the ideal conditions assumed. The variation from those ideal conditions is relatively small under normal operating conditions, however- If the cam is so designed, then the throttle does most of the work ot moving the piston 2I6 and the injector pump capacity control mechanism, and the fluid pressure differential acting on the piston serves merely as a ilne adjustment. The operation of the piston by the throttle aids in securing a rapid increase of the fuel supply upon acceleration of the engine, since a force is effective on the piston as soon as the throttle is moved. Also, in case of failure of the hydraulic control system, the injector pump capacity control mechanism is manually positioned in accordance with the throttle position, so that the engine receives a workable mixture, even though it may not be the most desirable mixture.

While I have shown and described certain preferred embodiments of my invention, other modications thereof will readily occur to those skilled in the art, and I therefore intend my invention be limited only bythe appended claims.

I claim as my invention:

1. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, uid motor means for operating said capacity control means including a pair of expansible chambers separated by a movable wall and a connection between said wall and said control means, means for selectively supplying motive fluid to said chambers to cause operation of said control means, a passage for air flowing to said engine for combustion purposes, throttle means for controlling the flow of air thru said passage. a by--pass connection between the opposite ends of said cylinder, and means effective upon movement of said throttle means to a range of positions adjacent its closed position to open said by-pass connection and to cause said wall to move concurrently with said throttle means.

2. A fuel supply system for an internal combustion engine, comprising injector pump mechanism forsupplying fuel to said engine, uid motor means for controlling the delivery of said pump mechanism including a piston moving in a cylinder, means for selectively supplying motive uid to the opposite ends of said cylinder to cause operation of said control means, a passage 9 for air iiowing to said engine for combustion purposes, throttle eens for controlling the flow of air thru said pasxskge, a by-pass connection between the opposite ends of said cylinder, valve means controlling said connection, and means eective upon movement of said throttle means to a range of positions adjacent its closed posiescasas tion to open said valve means and to operatively connect said throttle means to said piston.

3. A fuel supply system for an internal combustion engine, comprising a conduit for supplying Iuel to said engine, means for controlling the iiow oi fuel thru said conduit, :duid motor means for operating said now controlling means including a pair of expansible chambers separated by a movable wall and a connection between said wall and said control means, means for selectively supplying motivevfuel to said chambers, a passage for air flowing to said engine for combustion purposes, throttle means for controlling the flow of air thru said passage, means responsive to the rate of flow of air thru said passage for controlling said motive fuel supply means, and

means effective upon movement of said throttle means to a range of positions adjacent its closed position to open a duid connection between said chambers and to operatively connect said i'uel iiow controlling' means to said throttle for concurrent operation therewith.

4. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying iuel to said engine, means for controlling the delivery of said pump mechanism, fluid motor means for operating said capacity control means including a piston moving in a cylinder and a connenotion between said piston and said delivery control means, a passage for air owing to said engine for combustion pur.- poses, throttle means for controlling the flow oi air thru said passage, a by-pass connection betweenithe opposite ends of said cylinder, said bypass connection being closed during normal engine power output conditions, cam means connected to said throttle for movement therewith, follower means associated with saidcam means, a connection between said follower means and said piston so as to cause said piston to move con'- currently with said follower means, and means in said connection for permitting movement of said piston independently of said follower means, said cam means and follower means cooperating when said throttle means is in a range of positions adjacent its closed position to cause opening of said by-pass and concurrent movement of said throttle means and said piston.

5. A fuel .supply system'for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, uid motor means for controlling the delivery oi said pump mechanism including a piston moving in a cylinder, a passage for air owing to said engine for combustion purposes, means responsive to the rate of iiow oi' air thru said passage for controlling the flow ci motive fluid to the opposite ends of said cylinder, throttle means ior controlling the flow of air thru said passage, a bypassv connection between the opposite ends or said cylinder, valve means controlling said connection. cam means movable with said throttlemeans, a nbell-crank lever having a normal position and movable therefrom, a follower for said cam means carried by one arm of said bell-crank lever, means'associated with said lever for operating said valve means, said valve means being 10 closed when said lever is in its normal position and being opened when said lever is moved from its normal position, a. pin carried by the other arm of said lever, an elongated member having a longitudinal slot for receiving said pin, a pivotal mounting for said member at an intermediate point thereof, said mounting being aligned with said pin when said lever is in its normal position, and a link connecting one end of said member to said piston, said member permitting movement of said piston independently oi' said follower when said pin is aligned with said pivotal mounting, and transmitting motion from said follower to said piston when said pin is out of alignment with said pivotal mounting, said cam means belng contoured to maintain said lever in its normal position when said throttle is opened by more than a predetermined amount and to move said lever so as to open said valve means and to cause concurrent movement Iof said; throttle Y means land said piston as said throttle means approaches its closed position.

6. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine', uid motor means for controlling the delivery oi said pump mechanism including a piston moving in a cylinder, a passage for air flowing to said engine for combustion purposes, means responsive to the rate oi flow oi air thru said passage for controlling the now of motive duid to the oppo-H site ends of said cylinder, a by-pass connection between the opposite ends oi said cylinder, bypass valve means controlling said connection a conduit for delivering fuel to said pump mechanism, cut-oit valve means in said conduit, a manual operator for moving said cut-oli valve means to closed position and means effective upon closure of said cut-od valve means by said operator to open said by-pass valve means and to ,cause concurrent movement of said operator and said piston. Y

7. A iuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, uid motor means for controlling the delivery oi said pump mechanism including a piston moving in a cylinder, a passage for air flowing to said engine for combustion purposes, means responsive to the rate of now oi' air thru said passage for 'controlling the flow of motive fluid to the opposite ends of said cylinder, throttle means for controlling the ow of air thru said passage, a by-pass connection between the opposite ends of said cylinder, lay-pass valve means controlling said connection, means effective upon movement of said throttle means to a range of positions adjacent its closed position to open said by-pass valve means and to cause concurrent movement of said throttle means and said piston, a conduit for delivering fuel to said pump mechanism, cut-o -valve means in said conduit, a manual operator 11 sive to the rate of flow of air thru said passage for controlling said motor means, a' conduit for delivering fuel to said pump mechanism, cut-off valve means in said conduit, a manual operator for moving said cut-off valve means to closed position and means operable to cause concurrent movement of said operator and said delivery control means regardless of the rate of flow of air thru said passage.

9. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, fluid motor means for controlling the delivery of said pump mechanism including a piston moving in a cylinder, a by-pass connection between the opposite ends of said cylinder, valve means controlling said connection, a lever having a. normal position and movable therefrom, means associated with said lever for operating said valve means, said valve means being closed when said lever is in said normal position and being moved to open position when said lever is moved from its normal position, a pin carried by an arm of said lever. an elongated member having ailongitudinal slot for receiving said pin, la pivotal mounting for said member at an intermediate point thereof, said pin being aligned with said mounting when said lever is in its normal position, a link `connectingone end of said member to said piston, said member permitting movement of said piston independently of said lever when said pin is aligned with said pivotal mounting, and transmitting motion from said lever to said piston when said pin is out of alignment with said pivotal mounting' manually operable control means for cutting off the supply of fuel to said pump mechanism, and a connection between said manual control means and said lever, said connection being eective upon operation of said manual control means to cut oil the fuel supply to operate said lever in a pump delivery decreasins direction.

10. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, uid motor means for operating said delivery control means including a pair of expansible chambers separated by a movable wall, a connection between said wall and said delivery control means, a passage for air flowing to said engine for combustion purposes, means responsive to the rate of ow of air thru said passage for controlling the ow of motive fluid to said chambers, throttle means for controlling the flow of air thru said passage, a by-pass connection between said chambers, by-pass valve means controlling said connection. said valve means being closed under normal engine power output conditions, means eiective upon movement of said throttle means to a range of positions adjacent its closed position to open said by-pass valve means and to cause movement of said delivery control means concurrently with movement of said throttle means toward closed position, a. conduit for delivering fuel to said pump mechanism, valve means in said conduit. a manual operator for moving said conduit valve mans, and means effective upon closure of said'conduit valve means by said operator to open said by-pass valve means and to cause concurrent movement of said capacity control means in a delivery decreasing direction regardless of the .position of said throttle means.

11. A fuel supply system for an internal cmbustion engine, comprising infector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, fluid motor means including a pair of expansible chambers separated by a. movable wall, a connection between said wall and said capacity control means, a passage for air flowing to said engine for combustion purposes, means responsive to the rate of flow of airthru said passage for controlling the flow of motive fluid to said chambers, throttle means -controlling the flow of air thru said passage, a by-pass connection between said chambers, valve means controlling said by-pass connection, a shaft rotatable with said throttle means, cam means splined on said shaft so as to be slidable along said shaft, a bellcrank lever having a normal position and movable therefrom, a follower for said cam means carried by one arm of said bell-crank lever. means associated with said lever for operating said valve means, said valve means being closed when said lever is in its normal position and being moved to open position when said lever is moved from its normal position, a pin carried by .the other arm of said lever, an elongated member having a longitudinal slot for receiving said pin, a pivotal mounting for said member atan intermediate point thereof, said pin being aligned with said mounting when said lever is in its normal position, a link connecting one end of said member to said piston, said member permitting movement of said piston independently of said lever when said pin is aligned with said pivotal mounting, and transmitting motion from said lever to said piston when said pin is out of alignment with said pivotal mounting, said cam means being contoured to maintain said lever in its nor mal position when said throttle is opened by more than a predetermined amount and to move said lever so as to open said valve means and to cause movement of said capacity control means in a capacity increasing direction concurrently with movement of said throttle means toward closed position, a conduit for delivering fuel to said pump mechanism, normally open valve means in said conduit, a manual operator for moving said conduit valve means and means for transmitting motion from said operator to said lever so as to move said lever from its normal position in a direction to cause movement of said capacity control means in a capacity decreasing sense when said conduit valve means is moved toward closed position, said cam means sliding along said shaft when'said motion transmitting means is active. so that said cam means does not interfere with the operation of said motion transmitting means.

12. Control apparatus for a device to be selectively positioned either manually or by fluid motor means including a pair of expansible chambers separated by a movable wall which is connected to said device, said control apparatus comprising means for supplying said chambers selectively with motive fluid to cause movement of said device in opposite directions, a by-pass conduit connecting said chambers, by-pass valve means in said conduit, s, manually movable control element. a lever having a normal position and movable therefrom, a connection between said element and said lever, means associated with said lever for operating said valve means. said valve means being closed when said lever is in its normal position and being moved to open position when said lever is moved from its normal position, a pin carried by said lever, an elongated member having a longitudinal slot fOr rei3 oeiving said pin, a pivotal mounting for said member at an intermediate point thereof, said mounting being aligned with said pin when said lever is in its normal position. and a link connecting one end of said member to said wail. said member permitting movement oi' said wallinde- Y pendently oi said lever when said pin is aligned with said pivotal mounting, and transmitting motion from said lever .to said wall when said pin is out oi alignment with said pivotal mounting.

i3. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, duid motor means for operating said delivery control means including a pair of espansible chambers separated by a movable wall and4 a connection between said wall and said control means, a passage for air flowing to said engine for combustion purposes, means-responsive to the rate of ow of air thru said passage for selective- 1y supplying said chamberswith motive uid, a by-pass conduit connecting said chambers, said by-pass conduit being closed under normal engine power output conditions, a valve for shutting o the supply of uid to one of said chambers, and means eective upon movement of said throttle means to a range of positions adjacent its closed position to close said shut-od valve and open said by-pass conduit to terminate control of said motor means by said air ilow responsive means.'

ld. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, uid motor means for operating said deiiverycontrol means including a pair of expansible chambers separated by a movable wall. and a connection between said wall and said control means, a passage for air flowing to said engine for combustion purposes, means responsive to the rate of iiow of air thru said passage for selectively supplying said chambers with motive duid to control the delivery oi said pump'mechanism, throttle means for controlling the flow of air thru said passage, a rod extending thru said wall, a pair oi' spring retainers carried by said rod on opposite sides of said wall, a pair of springs each retained between one of said retainers and said wall, said springs biasing said wall to a predetermined position relative to said rod, anda connection between said throttle means and said rod for translating it concurrently with movement of said throttle means.

15. A fuel supply system for an interna-l combustion engine, comprising injector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, uid motor means for operating said delivery control means including a pair of expanslble chambers separated by a movable wall and a connection between said wall and said control means, a passage for air owing to said engine for combustion purposes, means responsive to the rate of ow of all` thru said passage for selectively supplying said chambers with motive fluid to control the delivery of said pump mechanism, throttle means l for controlling thev :dow of air thru said passage, a rod extending thru saidwall, a pair of spring retainers carried by said rod on opposite sides of said wal', a Pair of springs each retained `between one of said retainers and said wall, said springs biasing said wall to a predetermined position relative to said rod, cam means movable with said ducale. and cam follower means attached to said rod for translating it concurrently with movement of said throttle means, saidcam means being contoured to position said capacity controlV means at the position required to produce the desired fuel to air ratio when the relationships oi'V the throttle opening, air ilow. and engine speed are those obtained when the propeller load is controlled with respect to power output to secure maximum propeller eiciency.

16. A fuel-supplv system for an internal combustion engine, comprising injector pump mech'- anism for supplying fuel to said engine, means for controlling the delivery of said pump mechanlsm, iluid` motor means for operating said delivery control means including a piston movable within a cylinder and a connection between said piston and said control means, a passage for air ilowing to said engine for combustion purposes,

means responsive to the rate of ilow of air thru said passage for selectively supplying the ends of said cylinder with motive uid to control the delivery of said pump mechanism, throttle means for controlling the ow of air thru said passage, a rod extending thru said wall, a pair oi' spring retainers carried by said rod on oppositefsides et said wall, a pair of springs each retained between one of said retainers and said wall, .said springs biasing said wall to a predetermined position relative to said rod, a connection between said throttle means and said rod for translating it concurrently with movement of said throttle means, and a by-pass conduit connecting one end ofy said cylinder with a port on the side of said cylinder which is uncovered by said piston at a point. in its travel corresponding to a nearly closed position of said throttle means. said by-pass conduit beingeective when open to prevent control of said piston by said air flow responsive means.

17. A a fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, uid motor means for operating said delivery control means including a pair of expansible chambers separated by s, movable wall and a connection between said wall and vsaid control means, a passage for air iiowing to said engine for combustion purposes, means responsive to the rate ofow of air thru said passage for selectitvely supplying said chambers with motive iiuid to control the delivery of said pump mechanism,

throttle means for controlling the flow of air thru said passage, a rod extending thru said wall, a pair of spring retainers carried by said rod on oppasite sides of said wall, a pair of springs each retained between one of said retainers and said wall and biasing said wall to a, predetermined position relative to said rod, a connection between said throttle means and said rod for translating it concurrently with movement of said throttle means, a by-pass conduit connecting said chambers, and means movable to open said by-pam conduit to place said capacity control means under direct control of said throttle means.

18. A fuel supply system for an internal combustion engine, comprising injector pump mechl A gine, a second control device responsive to the rate of air ow thru said passage, valve means operated by said second control device for regulating the Supply of motive fluid to said chambers to cause operation of said control means, me-

chanical connecting means associated with said 'l manual control device and said movable wall and operable selectively to cause concurrent movement of said manual device and said wall or to permit independent movement of said device and said wall, a by-pass connection between said chambers, a valve in said by-pass, and a common operator for said by-pSs valve and said mechanical connecting means, said operator being movable between a first position wherein said valve is closed and said connecting means permits independent movement of said wall and a second position wherein said valve is open and said wall is movable concurrently with said manual control device.

19. A fuel supply system for an internal combustion engine, comprising injectorpump mechanism for supplying fuel to said engine, means for controlling the delivery of said pump mechanism, motor means for operating said delivery control means, a passage for air ilowing to said engine for combustion purposes, means responsive to the rate of flow of air thru said passage for controlling said motor means, means for interrupting control of said motor means by said air flow responsive means, a manually movable control device, mechanical connecting means associated with said manual control device and said motor means and operable selectively to cause concurrent movement of said manual control device and said motor means or to permit independent movement of said motor means, and a common operator for said interrupting means and said connecting means, said operator being movable between a first position wherein said air movement of said motor means and a second position wherein control of said motor means by said air flow responsive means is interrupted and said motor means moves concurrently with said manual control device.

20. A fuel supply system for an internal combustion engine, comprising injector pump mechanism for supplying iuel to said engine, means for controlling the capacity of said pump mechanism, motor means for operating said capacity control means, a passage for air flowing to said engine for combustion purposes, means responsive to the rate of ow of air thru said passage for controlling said motor means, throttle means for controlling the flow of air thru said passage, means for interrupting control of saidy motor means by said air flow responsive means, mechanical connecting means associated with said throttle and said motor means and loperable selectively to cause concurrent movement of said throttle means and said motor means or to permit independent movement of said throttle means jacent its closed position to cause movement of said operator to said second position.

LEIGHTON LEE, II.

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