US2852011A

US2852011A - Fuel injection system for internal combustion engine

Info

Publication number: US2852011A
Application number: US621693A
Authority: US
Inventors: Henry E J Pringham
Original assignee: Studebaker Packard Corp
Current assignee: Studebaker Packard Corp
Priority date: 1956-11-13
Filing date: 1956-11-13
Publication date: 1958-09-16
Anticipated expiration: 1975-09-16

Description

Sept. 16, 1958 H. E. J. PRINGHAM 2,852,011

FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINE Filed Nov. 13, 1956 2 Sheets-Sheet 1 INVENTOR Sept. 16, 1958 E. J. PRINGHAM I 2,352,011

,FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINE Filed Nov. 13, 1956 I 2 Shets-Sheef. 2

United States l atent i FUEL INJECTION SYSTEM FOR COMBUSTION ENGINE Henry E. J. Pringham, Grosse Pointe, Mich., assignor to Studebaker-Packard Corporation, South Bend, ind, a corporation of Michigan Application November 13, 1956, Serial No. 621,693

6 Claims. (Cl. 123.119)

This invention relates to fuel injection systems for internal combustion engines andparticularly for gasoline .engines.

.Fuel'injection systems of the type to which the present invention pertains essentially include 1) a liquid fuel pump, (2) a liquid fuel distributor adapted to receive liquid fuel under pressure from the pump and effect the delivery of metered charges of the fuel to .the combustion chambers of .the engine, and (3) control means responsive to the pressure and temperature of the mass of air flowing in the intake manifold for controlling the metering of the fuel distributor.

A fuel distributor which may be utilized in connection with the present invention is known as :the shuttle or 'free piston type although broadly the invention may also be utilized with other types of fuel distributors. In the shuttle type of fuel distributor a rotating sleeve is driven at camshaft speed and a shuttle or free piston in the sleeve is forced to reciprocate between a fixed stop and a stop which is axially movable in the sleeve. The distance between the fixed and movable stops determines the travel of the shuttle and concomitantly determines the quantities of the metered charges of liquid fuel delivered by the distributor. The .position .of the axially movable stop is varied continuously by distributor control means which are responsive to engine conditions .including the pressure and temperature of the mass of air flowing in the engine intake manifold.

It is a main object of the invention to provide a fuel injection system having new and improved control means for varying in accordance with engine conditions the quantities of metered fuel charges delivered by the fuel distributor to the combustion chambers of the engine.

Other objects of the invention will become apparent from the following specification, the drawings relating thereto, and the appended claims.

In the drawing:

Fig. 1 shows a diagrammatic, vertical sectional view :of a fuel injection system embodying the invention and a fragmentary sectional view of an internal combustion engine to which it is applied;

:Figs. 2, 3 .and 4 are sectional views :taken respectively on lines 11-11, HI III and IV-IV of Fig. '1'; .and

Fig. 5 is an-enlargedrfragmentary viewofacone type of cam member shown in ,Fig. 1.

.In the drawing there is illustrated a .gasoline .injection system for an automotive type internal combustion engine. In general there is shown one of the engine :air intake conduits which is formed partly by intake :manifold .11 .and engine head 12. A combustion chamber 13 is provided in head 12 and an intake valve 14 is provided to control the admission of air from air intake conduit 10 to combustion chamber 13. A throttle valve 15 is pivotally mounted in manifold 11 for varying the flow of air in the manifold. Throttle valve 15 maybe controlled by an accelerator pedal (not shown) 'to which it maybe attached by suitable linkage.

Metered charges of liquid fuel are supplied to the 2,852,01 l Patented Sept. 16, 1958 combustion chambers of the engine, including combustion chamber 13, by a liquid fuel distributor 20. 'The illustrated section of distributor 20 in Fig. 1 is taken on line I-I of Fig. 2. Distributor 20 receives liquid fuel under pressure from a liquid fuel pump 21 and effects delivery of metered charges of the fuel in timed relation to injection nozzles which service "the respective combustion chambers such as to injection nozzle 22 which services combustion chamber 13. Injection nozzle 22 may be mounted in combustion chamber 13 if desired or on the upstream side of intake valve 14 as illustrated.

A control mechanism 23 is provided for controlling fuel distributor 20. Control mechanism 23 functions to effect varying of the quantities of the metered charges delivered by distributor 20 in accordance with certain engine conditions.

Fuel pump 21 is an engine or electric motor driven, conventional gear type pump which draws liquid fuel through an inlet pipe 28 from a source which is not shown and delivers liquid fuel under pressure to fuel distributor 20 through a pipe 29. The pressure of the fuel received by distributor 20 may been the order of 100 p. s. i. for example.

Fuel distributor 20 comprises a stationary casing 33 having a longitudinally extending bore in which a stationary :sleeve 34 is disposed. A rotatable sleeve member 35 is rotatably disposed in the longitudinal bore of stationary sleeve 34. Slidably disposed in the longitudinal bore of rotatable sleeve 35 is a reciprocatable shuttle or free :piston 36. A stop member 37 has a cylindrically shaped portion thereof disposed in the longitudinal bore of rotatable sleeve 35 on one side of shut itle36 and in axially fixed relation to sleeve 35. A re- .ciprocatablestop member-38 having a cylindric'ally shaped portion disposed in the longitudinal bore of rotatable sleeve 35 .in slidable relation thereto is disposed on the other side of shuttle 36. The axial position of recipro- -catable stop member 38 relative to rotatable sleeve '35 .is controlled by control mechanism 23 and stop member 38 .functions as metering adjusting means for vary ing the quantities .of the metered charges delivered by distributor 20 to the combustion chambers of the engine.

Stop members 3.7 and 38 are provided with cylindrically shaped abutments 39 and 40 which are smaller in diameter thanthe longitudinal bore of rotatable sleeve 35. It is the abutments 39 and 40 of the stop members that shuttle 36 contacts at each end of its stroke.

Rotatable sleeve 35 is driven by the engine at onehalf crankshaft speedfor a 4-stroke engine and at crankshaft speed for .a one stroke engine through two skew gears 42 :and 43.

Distributor casing 33 is provided with a radial port 46 through which fuel under pressure is delivered to the distributor 20 from fuel pump .21. Eight radial delivery ports 47 to '54 are formed jointly in casing '33 and stationary sleeve 34, as indicated in Figs. 2 and 4, to which pipes such as pipes 55 and 56 are connected for delivering metered fuel respectively to the eight combustion chambers of an eight cylinder engine. -A set of four of the radial delivery ports 47 to 54 are on each side of radial inlet port 46 in the planes of section lines II-II and IV--IV with the four ports in each set being spaced apart Each of the four ports in one set is in circumferential alignment with a port in the other set such as port 47 being circumferentially aligned 'with port 51.

.Eight radial feeder ports 63 to 70 are formed in stationary sleeve 34 with a set offour feeder ports 63 to 66 being in the plane of section line 11-11 and a set of four feeder ports 67 to 70 being in the plane of section line IV-lV. Feeder ports 63 to 66 are spaced 90 sleeve 34 in the plane of section line Ill--1II. Stationary sleeve 34 is provided with four flat surface portions on the. periphery thereof which extend axially in opposite directions from annular groove 72. of the flat surface portions extend axially between two circumferentially aligned feeder ports 63 to 70 to form chambers 73 to 76. Each of the chambers 73 to 76 has communication with two circumferential feeder ports which the chamber services such as the servicing of

feeder ports

64 and 68 by chamber 74. v

Rotatable sleeve 35 is provided with two radial ports 77 and 78 which are circumferentially displaced 45 from each other with port 77 being axially aligned with feeder ports 63 to 66 and delivery ports 47 to 50 in the plane of section line Illl and port 78 being axially aligned with feeder ports 67 to 70 and delivery ports 51 to 54 in the plane of section line IV-IV.

Although distributor 20 as described above is adapted for use with an eight cylinder engine, it'will be understood that only routine design changes would be required to adapt the distributor for use with engines having more or less cylinders.

In the operation of distributor 20 liquid fuel under pressure is received through fuel inlet port 46 from fuel pump 21. Fuel from inlet port 46 flows through annular groove 72 of stationary sleeve 34 to chambers 73 to 76, which cross groove 72 at four circumferentially spaced points, to the eight feeder ports 63 to 70 in stationary sleeve 34 Where the fuel is maintained under pressure. When the port 78 in rotatable sleeve 35 registers with one of the feeder ports such as port 70, the other port 77 in sleeve 35 registers with one of the delivery ports such as port 47 which has direct communication through conduit 55 with an injection nozzle 22 associated with one of the cylinders of the engine. Assuming that the shuttle 36 is abutting adjustable stop member 38 and that delivery port 47 and conduit 55 are filled with liquid fuel, the pressurized fuel in chamber 76 Will force shuttle 36 against stationary stop 37 and force a metered quantity of fuel to be displaced and flow through delivery port 47 and conduit 55 and through injection nozzle 22 connected to conduit 55. The metered quantity of fuel is determined by the axial position of the reciprocatable adjusting stop member 38 which determines the stroke of shuttle 36.

In the next phase of the operation of distributor 20 the rotatable sleeve 35 rotates 45 from the position shown in the drawing to a position where the port 78 in rotating sleeve 35 registers with delivery port 51 and port 77 in sleeve 35 registers with inlet port 63. When sleeve 35 is in this position the pressurized fuel in chamber 74 flows through port 63 and forces shuttle 36 against adjustable stop 3% so as to displace and cause a metered quantity of fuel to flow through delivery port 51 and conduit 56 to an injection nozzle connected to conduit. in the further operation of distributor 20 shuttle 36 is caused to move back and forth between stops 37 and 38 as the ports 7'7 and 78 in rotatable sleeve 35 alter nately become registered with feeder ports 47 to 54 and delivery ports 63 to 75) during the rotation of rotatable sleeve 35.

The adjusting means of distributor 20 for varying the quantities of the metered charges delivered through conduits such as 55 and 56 to injection nozzles connected thereto includes the reciprocatable stop member 38 which is axially movable in rotatable sleeve 35. A spring 82 is provided for biasing stop 38 to the left in a direction which reduces the quantities of the metered charges. Stop 38 is provided with a rod extension 83 which. is used for.con-

trolling the position of stop 38 as will appear further on. The injection nozzles, one of which is shown, may be of any suitable type. Injection nozzle 22 illustrated herein is shown on the upstream side of air intake valve but may be positioned to discharge directly into the combustion chamber 13 if desired. Nozzle 22 comprises a valve 86 which is biased to a closed position by a spring 87. When the spring loaded valve 86 is subjected to pressure by pressurized fuel in conduit 55, the valve opens to permit a metered quantity of fuel to be injected into combustion chamber 13.

Control mechanism 23 functions to control the output of fuel distributor 20 by actuating fuel distributor adjusting means which is illustrated herein as the linearly movable, piston shaped stop member 38. Control mechanism 2-3 has an elongated casing 90 which is attached to and positioned normal to fuel distributor 20. Mounted in casing 99 for movement longitudinally of casing 90 and normal to the longitudinal axis of distributor 20 is a linearly movable cone type of cam member 91 having a generally conical portion which forms a camming profile. The camming profile of the conical portion of cam member 91 engages rod 83 of adjustable stop member 38 for limiting the movement of stop member 38 in accordance with engine conditions. The cumming profile is illustrated by way of example as having sections 93, 94-, 95 and 96 which are formed to correspond to coasting, idling, part throttle and full throttle conditions of the engine.

Cam member 91 has rod extensions at opposite ends thereof to facilitate actuation thereof. The lower part of casing 90 is formed with a fluid tight chamber 100 in which fluid pressure operable means such as a bellows 101 is disposed. The lower rod of cam member 91 extends into chamber 166 and is attached to the top of bellows 101.

A conduit 132 is provided which extends between fluid tight chamber 100 and air intake manifold 11 on the downstream side thereof from throttle valve 15. Conduit 102 functions to communicate the pressure of the air flowing through the air intake manifold 11 to chamber 180 where the bellows 181 is linearly expanded and compressed in accordance with this pressure.

Bellows 101 is also actuated in accordance with the temperature of the air flowing in intake manifold 11 and for this function temperature responsive means are pro; vided which comprise a bulb 184 exposed to the interior of air intake manifold 11 and a conduit which connects the interior of bulb 104 to the interior of bellows 101. Bellows 101 is provided with a suitable gas and the bellows will tend to expand and contract in accordance with the rise and fall of the temperature of the air flowing in intake manifold 11.

The upper portion of casing 90 houses a spring 107 which is connected to the upper rod extension of cam member 91. Spring 107 functions to bias cam member 91 downwardly in a direction so that spring 187 transmits a compressing force to bellows 181.

In the operation of an engine having the control system, described, the throttle valve 15 controls the air flowing to the engine and no other manual controls are required. When cam member 91 is at a particular position which corresponds to conditions in the air intake manifold 11 the pressurized fuel'admitted alternately to opposite sides of shuttle 36 causes movable stop member 38 to be forced to the right against the biasing force of spring 82 into abutting engagement with cam member 91. The linear position of cam member 91 therefore de termines the distance movable stop member is required to move to contact cam member 91 and concomitantly determines the stroke of shuttle 36 and the quantities of the metered charges of fuel supplied to the engine by distributor 20. I p

The cam member 91 has the profile of the conical portion thereof formed so that at various linear positions of the cam member the distributor 20 will supply the engine with optimum amounts of fuel. The exact configuration for the profile of cam member 91 of course depends upon the particular operating characteristics of an engine with which the control system of the present invention is utilized. In general, however, the conical portion of the cam member 91 may have four sections.

Starting from the apex end of conical portion of cam member 91, section 96 thereof contacts rod 83 of stop member 38 when throttle valve is in a full throttle position and the pressure of the resulting air flow through intake manifold is at a maximum value. The pressure from the intake manifold forces bellows 101 and cam member 91 in a downwardly direction and in this position a maximum amount of fuel is injected into the cylinders of the engine.

Section 95 of cam member 91 is for part throttle operation and gives maximum economy. When throttle valve 15 is partly closed there is less pressure in the air intake manifold 11 than at full throttle. Bellows 101 is caused to expand relative to its full throttle position so that section 95 of the cam member abuts rod 83 movable stop member 38 and functions to control the stroke of shuttle 36.

Section 94 of cam member 91 is for idling operation and the relatively large manifold depression during idling causes bellows 101 to expand further relative to its part throttle position. Section 94 of the cam then abuts rod 83 of movable stop member 38 and only a relatively small amount of fuel is supplied to the cylinders of the engine by distributor 20.

Section 93 of cam member 91 is for coasting operation and functions to cut off entirely the fuel delivered by distributor to the engine. During coasting the throttle valve 15 is closed and there is a relatively high air intake manifold depression. The high vacuum in the air intake manifold causes a maximum amount of expansion of bellows 101 so that section 93 of cam member 91 contacts rod 83 of movable stop member 38. Cam section 93 is sufficiently flared so that it causes movement of movable stop 38 all the way to the left, against the pressure of the fuel supplied to distributor 20, so as to cause shuttle 36 to be trapped between stops 37 and 38. This prevents shuttle 36 from reciprocating and accordingly no fuel is delivered by distributor 20 during the coasting operation.

The control mechanism 23 is described above only with regard to its operation in accordance .with pressure variations in the air intake manifold 11. The optimum fuel requirements of an engine also depend on the temperature of the intake air. At a particular air intake manifold depression more fuel will be required for cold air flowing in the intake manifold than for warm air to maintain optimum air-fuel ratios. The temperature responsive means associated with bellows 101, which includes bulb 104 and conduit 105, functions to compensate for variations of the air intake temperatures. Temperatures increases and decreases of air flowing in air inlet manifold 11 tends to respectively expand and contract the gas in bellows 101 and consequently tend to expand and contract the bellows. Expansion of bellows 101 in the illustrated control system effects a decrease in the fuel delivered by distributor 20 and contraction of the bellows effects an increase in the fuel delivered.

The illustrated control mechanism 23 includes means for controlling cam member 91 thereof which is operative to air starting of an engine when it is cold. "In'referring to a cold engine it is meant that the internal temperature of the engine is below the normal operating temperature. One way in which the internal temperature of an engine may be obtained-or indicated is by placing temperature responsive means in the exhaust manifold of the engine. The temperature of exhaust gases flowing through the exhaust manifold of an engine is a reliable indication of the internal temperature of theengine and, as illustrated herein, a bimetallic temperature responsive element 110. is mounted in an exhaust manifold 111 of the engine;

Suitable means are provided which allows "bimetallic element to dominate the control of cam member 91 during the time an engine is being warmed from a'cold condition to a predetermined temperature and then "completely relinquishes control of cam member 91. This mechanism includes a camf112fpivotally mounted in the upper portion of casing '90 whichis connected to bimetallic element 110 by a link 113 which causes cam .112 to pivot in response to expanding and contracting movements of element 110. Cam112 has a follower 114 which has a flange in abutting engagement with spring 107. Cam 112 moves adjustable upper spring abutment 114 downward compressing spring 107 when bimetallic element 110 is contracted due to the engine being'col'd. The additional compression of spring 107 opposes the upward force exerted by bellows 101 beyond "its normal value, causing an enrichment of "the fuel-air mixture as required by a cold engine. As the engine war-ms up, 'bimetallic element 110 expands and causes cam 1'12 to gradually rotate until the pressure of "spring 107 returns to its normal value as set by the adjustment screw of upper spring abutment 114 with a warm engine. Control of cam member '91 is then taken over by bellows .101'as described above.

The invention may be embodied in other specific form-s without departing from the spirit or essential character istics thereof. The present embodiment of the invention is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claimsrather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced ztherein.

It is claimed and desired to secure by Letters Patent:

1. A fuel control system for an internal combustion engine having an air intake manifold, an exhaust manifold, and throttle means for varying'the flow of air through the air intake manifold, .said system comprising liquid fuel pumping means, an engine driven liquid fuel distributor adapted to receive liquid fuel under pressure from said pumping means and effect the delivery of metered charges of the fuel to the combustion cham'bers of the engine, said distributor including metering ad'- justing means for varying the quantities of the metered charges, cam means mounted for linear movement to efliect positioning of said metering adjusting means corresponding to linear positions of the cam means, means responsive to engine conditions including the internal temperature of the engine and the temperature and pressure of air .flowing in said engine intake manifold on the downstream side of said throttle to effect linear movement of said cam means, said cam means having .a profile forrned to effect movement of said metering adjusting means to positions corresponding to engine conditions upon linear movement of the cam means.

2. A fuel control system for an internal combustion engine having an air intake manifold, an exhaust manifold, and throttle means for varying the flow of tail through the air intake manifold, said system comprising liquid fuel pumping means, an engine .driven liquid fuel distributor adapted to receive liquid fuel under pressure from said pumping means and effect the delivery of metered charges of the fuel to the combustion chambers of the engine, said distributor including reciprocata b'le metering adjusting means .for varying the quantities of the metered charges, cam :means mounted for linear movement to effect positioning :of said metering adjusting means corresponding to linear positions of the cam means, means responsive 'to engine conditions including the internal temperature of the engine and the temperature and pressure of air flowing 'in said engine intake manifold on the downstream side of said throttle to effect linear movement of said cam means, said cam means having'a profile formed to effect movement of said metering adjusting means to positions corresponding to engine conditions upon linear movement 'of the cam means, and means responsive to internal engine temperature operably connected to said cam means for dominating the control of said cam means when the temperature of said engine is below the normal operating temperature, said means responsive to internal engine temperature being effective to move said cam means to a position corresponding to the delivery of maximum quantities of metered fuel charges by said distributor when the temperature of said engine is substantially below normal operating temperature and to gradually relinquish control of said cam means as the normal operating temperature of said engine is approached.

3. A fuel control system for an internal combustion engine having an air intake manifold, an exhaust manifold, and throttle means for varying the flow of air through the air intake manifold, said system comprising liquid fuel pumping means, an engine driven liquid fuel distributor adapted to receive liquid fuel under pressure from said pumping means and effect the delivery of metered charges of the fuel to the combustion chambers of the engine, said distributorincluding metering adjusting means for varying the quantities of the metered charges, cam means mounted for linear movement to effect positioning of said metering adjusting means corresponding to linear position of the cam means, fluid pressure operable means operably connected to said cam means to effect linear movement of said cam means in opposite directions to increase and decrease the quantities of the metered charges when said'fluid pressure operable means is respectively contracted and expanded, conduit means connecting said fluid pressure operable means to the interior of said intake manifold downstream from said throttle means to effect contraction and expansion of said fluid pressure operable means in accordance with pressure variations in said intake manifold, temperature responsive means exposed to the air flowing in said intake manifold operably connected to said fluid pressure operable means to effect expansion and contraction of said fluid pressure operable means in accordance with the temperature of the air flowing in said intake manifold, said cam means having a profile formed to effect movement of said metering adjusting means to optimum positions corresponding to engine conditions upon linear movement of said first cam means.

4. A fuel control system for an internal combustion engine having an air intake manifold, an exhaust manifold, and throttle means for varying the flow of air through the air intake manifold, said system comprising liquid fuel pumping means, an engine driven liquid fuel distributor adapted to receive liquid fuel under pressure from said pumping means and efiect the delivery of metered charges of the fuel to the combustion chambers of the engine, said distributor including metering adjusting means for varying the quantities of the metered charges, cam means mounted for linear movement to effect positioning of said metering adjusting means corresponding to linear positions of the cam means, fluid pressure operable means operably connected to said cam means to effect linear movement of said cam means in opposite directions to increase and decrease the quantities of the metered charges when said fluid pressure operable means is respectively contracted and expanded, conduit means connecting said fluid pressure operable means to the interior of said intake manifold downstream from said throttle means to effect contraction and expansion of said fluid pressure operable means in accordance with pressure variations in said intake manifold, temperature responsive'means exposed to the air flowing in said intake manifold operably connected to said fluid pressure operable means to effect expansion and contraction of said fluid pressure operable means in accordance with the temperature of the air flowing in said intake manifold, means operably connected to said cam means which dominates the control of said cam means when the temperature of said engine is below the normal operating temperature, means responsive to the internal temperature operably connected to said cam means to effect movement of said cam means to a position corresponding to the delivery of maximum quantities of metered fuel charges by said distributor when the temperature of said engine is substantially below normal operating temperature and to gradually relinquish control of said cam means as the normal operating temperature of said engine is approached, said cam means having a profile formed to effect movement of said metering adjusting means to optimum positions corresponding to engine conditions upon linear movement of said-first cam means.

5. A fuel control system for an internal combustion engine having an air intake manifold, an exhaust manifold, and throttle means for varying the flow of air through the air intake manifold, said system comprising liquid fuel pumping means, an engine driven liquid fuel distributor adapted to receive liquid fuel under pressure from said pumping means and effect the delivery of metered charges of the fuel to the combustion chambers of the engine, said distributor including reciprocatable metering adjusting means for varying the quantities of the metered charges, first cam means mounted for linear movement to effect positioning of said metering adjusting means corresponding to linear positions of the cam means, a bellows operably connected to said first cam means to effect linear movement of said first cam means in opposite directions to increase and decrease the quantities of the metered charges when said bellows is respectively' contracted and expanded, a fluid tight casing surrounding said bellows, conduit means connecting the interior of said casing to the interior of said intake manifold downstream from said throttle means to vary the external pressure on said bellows to effect contraction and expansion of the bellows in accordance with pressure variations in said intake manifold, temperature responsive means including a hollow bulb having the exterior of the bulb exposed to the air flowing in said intake manifold and the interior of said bulb in communication with the interior of said bulb to effect expansion and contraction of said bellows in accordance with the temper ature of the air flowing in said intake manifold, second cam means operably connected to said first cam means which dominates the control of said first cam means when the temperature of said engine is below the normal operating temperature, resilient means operably disposed between said second cam means and said first cam means, a temperature responsive bimetallic strip disposed in the exhaust manifold of said engine and operably connected to said second cam means to effect movement of said first cam means to a position corresponding to the delivery of maximum quantities of metered fuel charges by said distributor when the temperature of said engine is substantially below normal operating temperature and to gradually relinquish control of said first cam means as the normal operating temperature of said engine is approached, said first cam means having a profile formed to effect movement of said metering adjusting means to optimum positions corresponding to engine conditions of coating, idling, part throttle and full throttle upon linear movement of said first cam means.

6. A fuel control system for an internal combustion engine having an air intake manifold an exhaust manifold, and throttle means for varying the flow of air through the air intake manifold, said system comprising of the engine, said distributor including reciprocatable metering adjusting means for varying the quantities of the metered charges, first resilient means biasing said metering adjusting means towards a closed position, first cam means mounted for linear movement to effect positioning of said metering adjusting means corresponding to linear positions of the cam means, a bellows operably connected to said first cam means to elfect linear movement of said first cam means in opposite directions to increase and decrease the quantities of the metered charges when said bellows is respectively contracted and expanded, second resilient means biasing said first cam means in a direction towards decreasing the quantities of the metered charges, a fluid tight casing surrounding said bellows, conduit means connecting the interior of said casing to the interior-of said intake manifold downstream from said throttle means to vary the external pressure on said bellows to effect contraction and expansion of the bellows in accordance with pressure variations in said intake manifold, temperature responsive means including a hollow bulb having the exterior of the bulb exposed to the air flowing in said intake manifold and the interior of said bulb in communication with the interior of said bulb to efiect expansion and contraction of said bellows in accordance with the temperature of the air flowing in said intake manifold, second cam means operably connected to said first cam means which dominates the control of said first cam means When the temperature of said engine is below the normal operating temperature, said second resilient means being operably disposed between said second cam means and said first cam means, a temperature responsive bimetallic strip disposed in the exhaust manifold of said engine and operably connected to said second cam means to effect move ment of said first cam means to a position corresponding to the delivery of maximum quantities of metered fuel charges by said distributor when the temperature of said engine is substantially below normal operating temperature and to gradually relinquish control of said first cam means as the normal operating temperature of said engine is approached, said first cam means having a profile formed to effect movement of said metering adjusting means to optimum positions corresponding to engine conditions of coasting, idling, part throttle and full throttle upon linear movement of said first cam means.

References Cited in the file of this patent UNITED STATES PATENTS 1,802,848 Summers Apr. 28, 1931 2,136,959 Winfield Nov. 15, 1938 2,341,257 Wunsch Feb. 8, 1944 FOREIGN PATENTS 616,721 Great Britain Jan. 26, 1949 653,030 Great Britain May 9, 1951 256,648 Switzerland Mar. 1, 1949