US3354876A

US3354876A - Fuel injection system

Info

Publication number: US3354876A
Application number: US499451A
Authority: US
Inventors: Roger O Durham
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-21
Filing date: 1965-10-21
Publication date: 1967-11-28
Anticipated expiration: 1984-11-28

Description

Nov. 28, 1967 R. o. DURHAM 3,354,876

FUEL INJECTION SYSTEM Filed oct. 2l' 1965 3 Sheets-Sheet 1 r /6 T Mwd 34- vili-IMLQS J BMM@ NOV. 28, 1967 R, Q DURHAM FUEL INJECTION SYSTEM 3 Sheets-Sheet 2 Filed OCL. 2l. 1965 1 f m 5 3 1 w u M f 2 w il .2o J 5 I. 2 1| P. .2 M 4 /ow a Z fw ,a 9 53 6 .5 Z 5 5 M lh l 09 M Ww q, 5 .I i M0 --7 4. 7g o mw 5 rmeuegl.

Nov. 28, 1967 R. o. DURHAM 3,354,876

FUEL INJECTION SYSTEM Filed oct. 21, 1965 z sheets-sheet z Ivrea/rb? $05599 0. ,yam/,444,

United States Patent() 3,354,876 FUEL INJECTION SYSTEM Roger @.Durharn, 3966 Marathon St., Los Angeles, Calif. 90029 Filed Oct. 21, 1965, Ser. No. 499,451 7 Claims. (Cl. 123-140) ABSTRACT F THE DISCLOSURE A fuel injection system for internal combustion engines having a diaphragm type pump the pumping action of which is made dependent on the operating speed of the internal combustion engine and the air pressure in the air intake manifold of the engine. A lever type transmissionl or linkage operates the pump diaphragm in response to rotary motion of the engine crankshaft. A pressure sensitive unit is connected'between the air intake manifold and lever type linkage and causesthe linkage action, and thereby the diaphragm pumping action, to be dependent on air intake manifold pressure.

The present invention relates to a fuel pumping system. Morev particularly, the present invention relates to a fuel injection system for internal combustion engines in which the quantity of fuel pumped to the engine is made dependent on engine speed and on the air pressure within the intake manifold of the engine.

While the use of intake manifold pressure to control the quantity of fuel pumped to the engine is not unique, those fuel injection systems previously designedV to 'operate on this principle have generally been quite complex and costly. As a consequence, very little use is made of such fuel injection today, in spite of its well known advantages over the more commonly used carburetion approach to precombustion mixing of fuel and air. Y f d Therefore, one of the primary objects of the present invention is to provide a simple and inexpensive fuel injection system. Other and more specic objectives will become apparent from the description of the structure of the 'invention and its operation. v

Referring now to the drawings, FIGURE 1 thereof is a plan view of a preferred embodiment of the apparatus, using the device ofcross-sectioning to disclose the interior portions of the structure. Briefly, FIGURE 1 shows the apparatus to lbe comprised of a transmission housing containing a linkage mechanism, a pump housing 11 containing a diaphragm type fuel pump, and a sensor housing 12 containing a device sensitive vto pressure in the engine intake manifold. Y Y

FIGURE 2 is also a cross-sectioned plan View, showing an alternate configuration of the present invention wherein the sensor housing 12 ycontains a bellows device instead of a diaphragm as shown rinV FIGURE 1. FIGURE 3 is merely a plan view showing an alternate configuration for the linkage mechanism contained within the transmission housing 10. And FIGURE 4 is a plan View in crosssection showing an alternate configuration inwhich the transmission housing ltl'isV secured directly vto the crankcase of the engine, and wherein a portion of the linkage mechanism extends into the crankcase, all as will be more fully described herein.y

Turning vnow to the preferred embodiment of the present invention disclosed in FIGURE l, it is to be understood that this invention is intended for use vwith the typical internal combustion engine having an air intake manifold, fuel pump, pistons, crankshaft and so forth. The internal combustion engine of the class described is well known, so no effort has been madeto illustrate the same in any detail.

' In FIGURE 1, the air intake manifold of theengine is ICC illustrated schematically by a body designated by numeral 6. The fuel intake portion yof the engine is similarly illustrated by body 7 in FIGURE 1, shown positioned to receive fuel as it is pumped from housing 11.

The fuel injection pump itself, as shown in FIGURE l, .is comprised of a housing .11 having a fuel inlet port 13, a fuel outlet port 14, and a pumping port 16. These three ports all enter onto a pumping chamber 15. The housing 11 is secured to transmission housing 10 by bolts 17. The fuel inlet port 13 is threaded and has disposed therein a standard inlet check valve 18 and O ring seal 19. The fuel outlet port 14 is also threaded and has disposed therein a standard outlet check valve 20 and O ring seal 21.

Therpumping mechanism of the fuel pump, or fuel injection pump, is comprised of a diaphragm 22 positioned in the pumping port, a diaphragm clamp ring 23 against which the diaphragm 22 can seat atits periphery to be sealed between the clamp ring and the housing 11, by securing action of bolts 17. The clamp ring is vwasher shaped and in its center a retainer screw 24 is secured by washer 26 and nut 27 to the diaphragm so that a force applied to the head of retainer screw will move the diaphragm inwardly into the pumping chamber, decreasing Vthe volume of the pumping chamber, and a force applied to the washer will move the diaphragm outward, increasing the volume of the pumping chamber. A spring 28 is vcompressively positioned in the pumping chamber to act upon washer 26 as shown. The head of retainer screw 24 is of such dimensions that, when diaphragm 22 has moved outwardly as far as clamp ring 23 permits, a small air space 29 exists between the transmission housing 10 and the head of retainer screw 24. This air space is intersected by an air passage 30 leading to the exterior of the housings. The purpose of air space 29 and air passage 30 is to prevent the alternate compression and rarefaction of air between retainer screw 24 and transmission housing ttl during pumping operations. y

The pump housing 11 also contains an air bleed passage 31, with screw type plug 32, the purpose of which is to bleed off air from the pumping chamber so that it can be completely filled with fuel at the onset of fuel injection system operation.

The apparatus used to detect and respond to air pressure in the air intake manifold of the engine is contained in the sensor housing 12, which housing, like the pump housing 11, is secured to the transmission housing 10 by bolts (not shown). The sensor housing 12 contains a substantially cylindrical chamber 33 having an inlet port 34 and an exit port 36. The inlet port 34 is threaded to re ceive a conduit connected between the engine intake manifold and chamber 33 whereby -air pressure, or lack thereof, in the intake manifold is communicated to chamber 33. A A pressure sensitive rolling type diaphragm 37 is clamped at its periphery between two portions of housing 12 so as to be responsive to pressure changes in chamber 33. A threaded rod 40 extends from the transmission housing, through the exit port 36, and through the diaphragm 37, being connected to the diaphragm by

washers

41, 42, spring centering washer 43, and

nuts

44 and 46. In this preferred embodiment rod 40 is threaded its entire length and is made of a flexible material such as nylon or Teflon. A spring 47 is compressively disposed in chamber 33 to act against diaphragm 37 and urge it against the exit port 36 of the chamber. Consequently, if the intake manifold pressure, transmitted to chamber 33, is the same as the air pressure admitted by the exit port 36, then the diaphragm will be positioned as shown in PIG- URE l by the action of the spring 47.

The ytransmission housing 10 has an opening 4S over which the sensor housing 12 is secured. The transmission housing contains a rotatably mounted shaft 49 (supported by bearings not shown) which carries a cam 50 as shown.

The shaft 49 in this preferred embodiment piotrudes outside of the transmission housing at one end and has a pulley xed thereon (not shown). This pulley can then be connected to the crankshaft or pulley or iiywheel thereof by means of the usual V belt, just as other engine equipment is operated off the crankshaft, such as the typical electricity generator.

In FIGURE 1, the crankshaft is designated by numeral 5, and a pulley shown positioned thereon is designated by the numeral 8. The pulley in turn is connected by belt 9 to the shaft 49 of transmission housing 10.

The transmission housing also contains two

levers

51 and 52 mounted on substantially oppositely disposed

fulcrums

53 and 54. The levers are parallel to each other and remain essentially so during operation. As illustrated, the -rod 40, which is actually a fulcrum rod or member, is positioned between the two levers and carries a fulcrum bearing or element 56 threaded onto the rod. Thus, action of lever 51 is transmitted to lever 52 through fulcrum element 56, and the position of fulcrum element 56 prescribes the movements of lever 52 in response to lever 51.

Lever 51 contains a cam follower 57 that is continually in contact with cam 50. Lever 52 contacts a pump operating element 58 slidably mounted in a bearing 59, which element 58 is in contact with the retainer screw 24 and, thus, diaphragm 22 of the pump housing. The levers and fulcrum element 56 act as the mechanism to convert rotary motion of cam 50 into movement of pump operating element 58.

The lever 52 also has a guide slot 60 to guide fulcrum bearing 56, and two stop members or feet, one of which is shown and designated by numeral 61, which stop members are disposed on opposite sides of guide slot 60. The follower 57 is provided with threads to be adjustable as shown. With the cam 50 at its nadir the cam follower is adjusted to cause levers S1 and 52 to be parallel. The height of stop members or feet 61 is slightly greater than the diameter of fulcrum bearing S6 so that when the two levers are parallel the feet 61 cause the fulcrum bearing S6 to be freed from contact with the levers. In this condition, the fulcrum bearing 56 is easily movable by diaphragm 37 located in the sensor housing. For easy adjustment of the cam follower 57, an adjustment entry 82 in housing 10 is provided, with -a closure plug 83, and an access hole 84 is positioned in lever 52 opposite the cam follower.

FIGURE 2 shows an alternate configuration of the present invention wherein the sensor housing 12 contains an evacuated bellows 62 to be responsive to intake manifold pressure admitted through port 63. The port 64 through which flexible fulcrum rod 40 extends is made air tight by a seal 66. The levers in the transmission housing are shown with their fulcrums reversed from that of FIGURE 1, but this is merely by way of illustrating another alternative.

FIGURE 3 illustrates the

levers

51 and 52 turned 90 degrees to each other. The purpose of this alternative configuration is to provide a more nearly linear relationship between the stroke or position of pump operating element 5S and the position of the fulcrum bearing 56, if such linear relationship is desired.

FIGURE 4 shows still another alternate to the apparatus of FIGURE 1. In FIGURE 4 the transmission housing 10 is secured directly to the crankcase 67 of the engine. The cam 50 is placed directly on the engine crankshaft 68, and the lever 51 extends into the crankcase to ride on the cam. To adjust the

levers

51 and 52 to be parallel when the nadir of the cam is contacting lever 51, the entire transmission housing can be raised or lowered on the side of the crankcase. An obvious way to do this would be to provide housing 10 with slots (not shown) instead of holes, through which the bolts securing housing |10 to the crankcase could be positioned. Of course, another approach would be to have the fulcrums 53 `and 54 (of the levers) adjustable up and down. A variety of standard devices could be used for this purpose.

The structure of the invention having been explained, attention is now directed to its operation.

The preferred embodiment of FIGURE 1, as with most fuel injection systems, is preferably used with a fuel pump which pumps fuel from a source, such as a gas tank, to the inlet check valve on the pump housing 11. When the engine is started and the crankshaft begins to rotate, the shaft 49 in the transmission housing 10 also rotates, being connected thereto by the usual pulley and V belt, as previously described. As the cam 50 rotates with shaft 49, the lever 51 is caused to move back and forth, which motion is transmitted through fulcrum bearing 56 to lever 52, and thence to translational motion of pump operating element 58. The translational motion of element 58, combined with the opposing force of spring 28, causes the diaphragm 22 to alternately decrease and then increase the volume of pumping chamber 15.

As the volume increases fuel is 4admitted by inlet check valve 18 and as the volume is decreased fuel is expelled through outlet check valve 20 to the engine for mixture with air and combustion in the piston chambers. The quantity of fuel that is pumped to the engine each cycle of the diaphragm 22 depends of course on the amount of movement of the diaphragm. This movement is in turn controlled by the position of fulcrum bearing 56 between

levers

51 and 52.

When the throttle on the engine is closed, as in the typical and usual engine idling condition, the pressure within sensor housing chamber 33 is low since the air intake manifold pressure is low, and the diaphragm 37 is withdrawn into chamber 3 3, pulling fulcrum bearing 56 up to a raised position where the stop members 61 govern the interaction between

levers

51 and 52. It is to be recalled that this is due to stop members 61 being slightly higher than the diameter of fulcrum bearing 56. In view of the function performed by stop members 61, it would not be inappropriate to refer to them as idle clearance feet or idle delivery feet.

As the engine throttle is opened, air intake manifold increases and the diaphragm 37 is pushed downward, pushing fulcrum bearing 56 downward between levers 51 and S2. As can be readily seen, the position of bearing 56 causes more fuel to be pumped by diaphragm 22 as it moves downward between the two levers, until its downward progress is stopped by the bottoming of sensor housing diaphragm 37. The'spring 47 in the sensor housing is chosen so that, for normal operating conditions, the fulcrum bearing 56 is fully extended when the intake manifold pressure, the pressure in chamber 33, approaches atmospheric pressure.

As the cam 50 rotates, the fulcrum bearing 56 is released from contact with

levers

51 and 52 as the cam nadir passes the cam follower 57 of lever 51, which release is due to the size of the stop members 61 and the parallel position of the levers at this juncture in the cycle. At this time then, the fulcrum bearing 56 is free to move either up or down in response to even slight pressure changes in chamber 33, the intake manifold pressure.

Thus the present invention provides a fuel injection system that is not only simple but which is responsive to small changes in intake manifold pressure.

It will be apparent that the unit will operate with the sensor housing 12 removed because of the stop members, or idle delivery feet, 61. Thus, even with the engine running, the senor housing could be removed to adjust the full throttle open position, or full power position, of fulcrum bearing S6 on rod 40.

It will also be apparent that the quantity of fuel pumped by diaphragm 22 can be changed by changing the sizes of the clamp ring 23 and retainer screw 24. Such size changes will `change the envelope of the diaphragm. This means that the unit can be adapted to most engines, even though of different make and horsepower rating, by a relatively simple parts change. Preferably, the clamp `ring 23 and retainer screw 24 are selected to create a freely idling engine with the sensor housing removed. y

An ,alternate structural configuration that can be employed in thlis area is to use a diaphragm 22 without any retainer screw or clamp ring. In this configuration, the

diaphragm

2,2 is clamped or secured directly between the pump housing 11 and the transmission housing 10. The spring 28 can be removed and replaced by a spring'outside the pumping -chamber acting on pump `operating element 58 to keep it in Contact with `lever 52. The simplest way to do this is to provide element 58 with a head and place the spring concentrically about element 58 and beneath the head. In this structural configuration element 58, actuated by lever 52, pushes diaphragm 22 into the pumping chamber during one-half of the pumping cycle, and the normal pressure provided at the inlet check valve forces the diaphragm out of the chamber during the other half ofthe cycle. It is to be recalled that this invention is preferably used with a fuel pump to supplyv fuel to the inlet check valve under some pressure;

This alternate structure reduces the amountofmass that must be moved back and forth during pumping operations, and lends itself to applications Where it is desired to employ a plurality of pumps in the most efiicient manner. The invention, of course, can employ a variety of variable displacement` pumps, andy is not limited to use of the preferred embodiment structure disclosed by the drawings and specification. y y

The alternate configuration shown in FIGURE 2 is intended for use where great changes in Iatmospheric pressure are encountered, such as in aircraft. The sensor housing chamber 33 is sealed, by seal 66, so'that the intake manifold pressure is compared with a constant reference, i.e., the force or pressure exerted by the evacuated bellows 62. With a closed throttle, the air intake pressure is low and the bellows is vfully expanded, extending fulcrum bearing 56 far downlbetween levers 51 and 52. In this configuration the

fulcrumsoflevers

51 and 52 are reversed fr-om rthat shown in FIGURE 1` so that engine idle occurs when rod 40 is fully extended. As `the intake manifold pressure builds up due to the opening f the throttle, the bellows contracts, fulcrum bearing 56 rises, ,and more fuel is pumped by diaphragm 22. y

If a plot of the stroke of pump operating element 58 vs. fulcrum bearing 56 position were made, it would not be quite a straight line, yor linear relationship. This means that at middle throttle openings, `the engine will get slightly less rich fuel mixture than at the full throttle and idle throttle settings. If this is considered a handi` cap, depending on the engine, the use to which it is put, and other factors, alinear relationship can be achieved by rotating the

levers

51 and 52 ninety degrees with regard to each other. This is illustrated in FIGURE 3.

As still another alternative, if it is desired to have the invention operate directly off the engine crankshaft, and avoid use of shaft 49 of FIGURE l and the usual pulley and, V-belt, then the configuration illustrated in FIGURE 4 can be employed. Here the transmission housing 10 is fastened directly to the engine crankcase, the cam 50 is disposed right on the crankshaft of the engine, and

lever 51 extends, into the crankcase to vride on cam 50v and be actuated thereby. The parallel adjustment of

levers

51 and 52 lat cam nadir, as previously explained, can be achieved a number of ways, such as by moving transmission housing up or down, or by providing means for adjusting

fulcrums

53 and 54 up and down.

Although specific embodiments of the present invention have been described and illustrated, it is to be understood that the same are by way of illustration and example and that the invention is not limited thereto, as

many variations will be readily apparent to those versed in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims:

1. A fuel pumping system for an internal combustion engine having'a crankshaft and anintake manifold, said system comprising a diaphragm type fuel pump Vadapted for connection to an engine and having a pump operating element, a pressure sensitive apparatus adapted for connection to the intake manifold of an internal cornbustion engine, said apparatus having a diaphragm movable in response to intake manifold pressure and a fulcrum rod contacting said diaphragm and movable thereby, a cam adapted for rotation in response to rotation ofa crankshaft ofan internal combustion engine, a linkage means having two levers with substantially oppositely disposed fulcrums, said levers being disposed substantiallyparallel to each other, said fulcrum rod positioned between said levers and by its position affecting the amount of movement that actuation of one lever imposesupon the other, oneof said levers contacting said cam to be actuated thereby and the other lever contacting said pump operating element, rotation of said cam causing movement of said pump operatingelement to pump fuel to the engine, the quantity of fuel pumped by said fiel pump being controlled by the position of said fulcrum rod between said levers, and at least one of said levers having 'a stop member extending towards said other lever and being of such dimensions that said fulcrum rod is substantially freed from Contact with said levers for an interval corresponding to a portion of the rotation of'said cam, and said fulcrum rod during said interval being freely movable by said diaphragm of said pressure sensitive apparatus so that small changes in intake manifold 'pressure will affect the position of said fulcrum rod;

v2. A fuel pumping system for an internal combustion engine having -a crankshaft and an intake manifold, said system comprising a diaphragm type fuel pump connected to supply fuel to the engine and having a pump operating element, a pressure sensitive apparatus connected to the intake manifold of the engine, said apparatus having a diaphragm movable in response to intake manifold pressure, Va flexible rod connected at one end to said diaphragm and being movable thereby, a fulcrum element being disposed onV said flexible rod, a cam adapted for rotation in response to rotation of the engine crankshaft, a linkage means having two levers with substantially oppos-itely disposed fulcrurns, said levers being disposed substantially parallel to each other, said fulcrum element being positioned between said levers and by its position affecting the amount of movement that actuation of one lever imposes upon the other, one of said levers contacting said cam to be actuated thereby and thev other lever contacting said pump operating element for actuation thereof, rotation of said cam causing movement of said pump operating element to pump fuel to the engine, the quantity of fuel pumped by said fuel pump being controlled by the position of said ful- Crum element between said levers, and at least one of said-levers having a stop member extending towards said other leverl and being of such dimensions that said fulcrum rod is substantially freed from contact with said levers for an interval corresponding to a portion of the rotation of said cam, and said flexible rod during said interval being freely movable by saidv diaphragm of said pressure sensitive apparatus so that small changes in intake manifold pressure will affect the position of said fulcrum element.

3. Structure as claimed in claim 2 wherein said pressure sensitive apparatus comprises a housing having a substantially cylindrical chamber therein, said chamber having an inlet port connected to the intake manifold of the engine, a diaphragm disposed across said chamber and movably responsive to pressure in said intake mauifold, said chamber having an exit port, and said flexible rod being disposed through said exit port and connected at one end to said diaphragm.

4. A fuel pumping system for an internal combustion engine having a crankshaft and an intake manifold, said system comprising a diaphragm type fuel pump connected to supply fuel to the engine and having a pump operating element, a pressure sensitive unit having a housing and a substantially cylindrical chamber therein, a substantially evacuated bellows fixed within said chamber so as to expand and contract therewithin in response to pressure changes, said chamber having a first port connected to the intake manifold, said chamber having a second port, a flexible rod disposed through said second port and fixed to said bellows to be movable thereby, an air seal disposed about said rod in said second port and providing an air tight seal in said second port, said rod hav-ing a fulcrum element disposed thereon exterior to said housing of said pressure sensitive unit, a cam adapted for rotation in response to rotation of the engine crankshaft, a linkage means having two levers with substantially oppositely disposed fulcrums, said levers being disposed substantially parallel to each other, said fulcrum element being positioned between said levers and by its position affecting the amount of movement that actuation of one lever imposes upon the other, one of said levers contacting said cam to be actuated thereby and the other lever contacting said pump operating element for actuation thereof, rotation of said cam causing movement of said pump operating element to pump fuel to the engine, the quantity of fuel pumped by said fuel pump being controlled by the position of said fulcrum element between said levers, and at least one of said levers having a stop member extending towards said other lever and being of such dimensions that said fulcrum element is substantially freed from contact with said levers for an interval corresponding to a portion of the rotation of said cam, and said rod and fulcrum element during said interval being freely movable by said bellows of said pressure sensitive unit so that small changes in intake manifold pressure will affect the pos-ition of said fulcrum element.

5. A fuel pumping system in combination with an internal combustion engine having a crankcase, a crankshaft within said crankcase, and an air intake manifold, said system comprising a transmission housing secured to said chankcase, a sensor housing fixed to said transmission housing, `and a pump housing fixed to said transmission housing, a -diaphragm type fuel pump being disposed within said pump housing, a pump operating element disposed to contact and operate said diaphragm type fuel pump and extending into the interior of said transmission housing, said sensor housing having a pressure sensitive apparatus therein connected externally of said sensor housing to the intake manifold of the internal combustion engine, said apparatus having a pressure sensitive element movable in response to intake manifold pressure, a fulcrum member contacting said pressure sensitive element and movable thereby, said fulcrum member extending into the interior of said transmission housing, a cam disposed on the crankshaft of the engine and rotatable therewith, a linkage means within .said transmission housing, said linkage means having two levers with substantially oppositely disposed fulcrums, said levers being disposed substantially parallel to each other, said fulcrum member positioned between said levers and by its position affecting the amount of movement that actuation of one lever imposes upon the other, one of said levers extending into said crankcase and contacting said cam and actuated thereby, the other lever contacting said pump operating element, and rotation of `said cam causing movement of said pump operating element to pump fuel to the engine, the quantity of fuel pumped by said fuel pump being controlled by the position of said fulcrum member between said levers, and at least one of said levers having a stop member extending towards said other lever and being of such dimensions that said fulcrum member is substantially freed from contact with said levers for an interval corresponding to a portion of the rotation cycle of said cam, and said ful- Crum member during said interval being freely movable by said pressure sensitive element so that small changes in intake manifold pressure will affect the position of said fulcrum element.

6. A fuel injection system for an internal combustion engine having an intake manifold, said fuel injection systern comprising a rst and second lever and a pump apparatus of the variable displacement type, means for causing said first lever to oscillate with uniform amplitude in response to the speed of sai-d engine, a fulcrum disposed between said first and second levers and being variable in its position, means associated with said engine and said fulcrum for altering the position of said fulcrum in response to changes in intake manifold pressure, said second lever disposed to ybe substantially in contact with said fulcrum, said fulcrum being substantially in contact with said first lever and causing said second lever to oscillate with varying amplitude according to changes in the position of said fulcrum, a stop means associated with said second lever to prevent effective contact between said fulcrum and said levers during a portion of each cycle of operation, means associated with said second lever and said pump apparatus for transmitting the varied oscillations of said second lever to said pump apparatus.

7. In a fuel injection system for an internal combustion engine, which fuel injection system has a variable displacement pump, apparatus for varying the stroke of the pump, said apparatus comprising a first and second lever, means associated with said first lever to cause said first lever to oscillate with uniform amplitude, a fulcrum dis` posed between said first and second lever, means associated with said fulcrum for altering its position between said levers, said second lever disposed to be substantially in contact with said fulcrum and caused by said fulcrum to oscillate with varying amplitude according to changes in the position of said fulcrum, a stop means acting on said second lever to prevent effective contact between said fulcrum and said levers during a portion of each cycle, `and means for transmitting the varied oscillations of said second lever to the variable displacement pump.

References Cited UNITED STATES PATENTS 1,726,303 8/1929 Knudsen 123-139.2 2,562,656 7/1951 Blakeslee 123-l40.2 2,880,714 4/1959 Clark 123-1403,

LAURENCE M. GOQDRIDGE, Primary Examiner.`

Claims

1. A FUEL PUMPING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE HAVING A CRANKSHAFT AND AN INTAKE MANIFOLD, SAID SYSTEM COMPRISING A DIAPHRAGM TUPE FUEL PUMP ADAPTED FOR CONNECTION TO AN ENGINE AND HAVING A PUMP OPERATING ELEMENT, A PRESSURE SENSITIVE APPARATUS ADAPTED FOR CONNECTION TO THE INTAKE MANIFOLD OF AN INTERNAL COMBUSTION ENGINE, SAID APPARATUS HAVING A DIAPHRAGM MOVABLE IN RESPONSE TO INTAKE MANIFOLD PRESSURE AND A FULCRUM ROD CONTACTING SAID DIAPHRAGM AND MOVABLE THEREBY, A CAM ADAPTED FOR ROTATION IN RESPONSE TO ROTATION OF A CRANKSHAFT OF AN INTERNAL COMBUSTION ENGINE, A LINKAGE MEANS HAVING TWO LEVERS WITH SUBSTANTIALLY OPPOSITELY DISPOSED FULCRUMS, SAID LEVERS BEING DISPOSED SUBSTANTIALLY PARALLEL TO EACH OTHER, SAID FULCRUM ROD POSITIONED BETWEEN SAID LEVERS AND BY ITS POSITION AFFECTING THE AMOUNT OF MOVEMENT THAT ACTUATION OF ONE LEVER IMPOSES UPON THE OTHER, ONE OF SAID LEVERS CONTACTING SAID CAM TO BE ACTUATED THEREBY AND THE OTHER LEVER CONTACTING SAID PUMP OPERATING ELEMENT, ROTATION OF SAID CAM CAUSING MOVEMENT OF SAID PUMP OPERATING ELEMENT TO PUMP FUEL TO THE ENGINE, THE QUANTITY OF FUEL PUMPED BY SAID FUEL PUMP BEING CONTROLLED BY THE POSITION OF SAID FULCRUM ROD BETWEEN SAID LEVERS, AND AT LEAST ONE OF SAID LEVERS HAVING A STOP MEMBER EXTENDING TOWARDS SAID OTHER LEVER AND BEING OF SUCH DIMENSIONS THAT SAID FULCRUM ROD IS SUBSTANTIALLY FREED FROM CONTACT WITH SAID LEVERS FOR AN INTERVAL CORRESPONDING TO A PORTION OF THE ROTATION OF SAID CAM, AND SAID FULCRUM ROD DURING SAID INTERVAL BEING FREELY MOVABLE BY SAID DIAPHRAGM OF SAID PRESSURE SENSITIVE APPARATUS SO THAT SMALL CHANGES IN INTAKE MANIFOLD PRESSURE WILL AFFECT THE POSITION OF SAID FULCRUM ROD.