US2727503A

US2727503A - Fuel supply apparatus for an internal combustion engine

Info

Publication number: US2727503A
Application number: US172253A
Authority: US
Inventors: Neville M Reiners
Original assignee: Cummins Engine Co Inc
Current assignee: Cummins Inc
Priority date: 1950-07-06
Filing date: 1950-07-06
Publication date: 1955-12-20
Anticipated expiration: 1972-12-20

Description

Dec. 20, 1955 N. M. REINERS 2,727,503

FUEL SUPPLY APPARATUS FOR AN INTERNAL COMBUSTION ENGINE Filed July 6, 1950 5 Sheets-Sheet l INVENTOR. MEQZYZGKS Dec. 20, 1955 N. M. REINERS FUEL SUPPLY APPARATUS FOR AN INTERNAL COMBUSTION ENGINE 5 Sheets-Sheet 2 Filed July 6, 1950 INVENTOR. A/ez/zllZe/Zfieinem;

$44 1, I mfw Dec. 20, 1955 N. M. REINERS FUEL SUPPLY APPARATUS FOR AN INTERNAL COMBUSTION ENGINE 5 Sheets-Sheet 3 INVENTOR. JYQUL'ZZQ fljjieneng BY %a'v- 4-,

Filed July 6, 1950 Dec. 20, 1955 N. M. REINERS FUEL SUPPLY APPARATUS FOR AN INTERNAL COMBUSTION ENGINE Filed July 6, 1950 5 Sheets-Sheet 4 I WDGQQk R. P. M. 2000 2100 INVENTOR.

Qw fla 1 Q4 14- Afez/zZle 2,72 ESQ-3 Dec. 20, 1955 N. M. REINERS FUEL SUPPLY APPARATUS FOR AN INTERNAL COMBUSTION ENGINE 5 Sheets-Sheet 5 Filed July 6, 1950 INVENTQR fyfieuzens United States Patent 2,727,503 Patented Dec. 20, 1955 ice FUEL SUPPLY APPARATUS FOR AN INTERNAL COMBUSTION ENGINE Neville M. Reiners, Columbus, Ind., assignorto Cummins Engine Company, Inc., Columbus, Ind., a corporation of Indiana Application July 6, 1950, Serial No. 172,253 20 Claims. (Cl. 123-140) The invention relates generally to fuel supply apparatus for internal combustion engines and more particularly to fuel supply apparatus for a multi-cylinder engine of the diesel type.

The general object of the invention is to provide a novel fuel supply apparatus for delivering accurately metered quantities of fuel to the respective cylinders of the engine, the apparatus being capable of being manuac tured at a relatively low cost because of its simple construction.

Another important object is to provide a novel fuel supply apparatus by which the fuel supplied to the engine under all conditions of operation may be controlled in such manner as to produce a predetermined torque curve for the engine. I

A further object is to provide a novel fuel supply apparatus which utilizes automatic governor control for determining the idling speed and the maximum speed of the engine and which includes means for controlling the torque of the engine.

Still another object is to provide a novel fuel supply apparatus embodied in a compact housing structure.

A still further object is to provide a fuel supply apparatus provided with a centrifugal governorv for controlling the fiow of fuel to the engine and having novel spring means opposing the action of the governor, said spring means being in the form of a self-contained unit adapted to be mounted adjacent the governor but not incorporated directly in the governor structure as in the usual form of governor.

It is also an object to provide a novel manual control for a fuel supply apparatus, which is provided with means permitting free movement of the manual control between its idle speed position and its maximum speed position but requiring application of an extra force to the manual control when it is moved from its idle speed position toward its stop position.

Other objects and advantages willbecome apparent from the following description taken in connection with the accompanying drawings, in which:

Figs. 1 to 4 are diagrammatic views ofa-fuel supply apparatus embodying the features of the invention and showing the position of certain elements of the apps.- ratus under different conditions of operation.

Fig. 5 is a longitudinal sectional view of the apparatus shown diagrammatically in Figs. 1 to 4.

Fig. 6 is a transverse section takensubstantially on the line 66 of Fig. 5.

Fig. 7 is a transverse sectional view on the line 7-7 of Fig. 5.

Fig. 8 is a transverse sectional view on the line 88 of Fig. 5.

Fig. 9 is a fragmentary transverse sectional view taken substantially on the line 9-9 of Fig. 5.

Fig. 10 is a fragmentary sectional view taken substantially on the line Ill-10 0f Fig. 9.

Fig. 11 is a fragmentary sectional viewtaken substantially on the line 1111:of.:Fig. 9.

Fig. 12 is a fragmentary elevationalviewlof' the-rear taken substantially taken substantially 2?, side of the apparatus at the right-hand end thereof as shown inFig.

Fig; 13 is a transverse sectional View taken on the line 13 13 of Fig. 5.

Fig. 14 is substantially an end elevational view of the left-hand end of the apparatus as viewed in Fig. 5.

Fig. 15 is an elevational view of the right-hand end of the apparatus as viewed in Fig. 5.

Fig. 16 is a graph showing a torque curve that may be obtained by an engine under the control of the present fuel supply apparatus.

In any system involving the flow of liquid through an orifice, the amount of such flow depends on three factors, namely, the area of the orifice, the pressure condition across the orifice, and the length of the time that the orifice is open. The principle involved in such flow may be applied to a fuel supply apparatus for an internal combustion engine to control the flow of fuel to the engine so that accurately metered quantities of fuel are supplied to the respective cylinders thereof. in the present instance, the fuel supply apparatus includes an orifice of constant size so that, of the three essential factors, the area of the orifice is a constant in determining the flow. The factor of time is usually dependent upon engine speed and thus cannot be readily varied to provide the necessary control of the operation of the engine. For example, the time factor may be dependent upon the time that a port in a fuel injector is open, and since the opening of such port is usually controlled by cam means embodied in the engine, the period of time fuel is admitted to the engine is thus directly related to the speed of the engine.

The remaining factor, of the three mentioned above, is the pressure applied to the fuel for causing flow through the orifice, and in this instance such pressure is controlled by a pressure regulator and a pump which together provide the desired pressure characteristics through out the range of operation of the engine. Thus, by suitable variation of the pressure characteristics obtained with the pressure regulator and the pump, any desired torque curve for the engine may be obtained. The pressure regulator is of a type which by-passes fuel from the delivery side of the pump, and the quantity of fuel so by-passed is determined by the pressure of the fuel delivered by the pump, the actual working pressures thus obtained being such that the proper amount of fuel is metered through the orifices to produce the desired torque throughout the operating speed range of the engine.

The present fuel apparatus is illustrated as including fuel injectors for the respective cylinders of a multicylinder engine, which are connected to a common rail, the latter being in turn connected. to a fuel supply line or conduit from the pump. In injectors of this character, each is provided with a cam-operated plunger which opens and closes a supply port or orifice the injector in timed relation to the operation of the engine and thus determines the time of opening of such port.

Ina fuel supply apparatus of the character herein contemplated, if the fuel were maintained under a constant pressure, the fixed area of opening for the metering orifice would result in a greater fuel delivery to the engine as its speed decreases. This becomes apparent in considering the character of the fuel injector since, as the engine speed increases, the supply port is opened by the plunger for a shorter time as the speed of the engine increases and, conversely, the time of opening of the supply port is increased as the speed of the engine decreases. As a result, when the engine speed is pulled down by an increased load for agiven throttle setting, the torque curve of the engine-Would rise because of the increased supply of fuel.

At :fullthrottle, the engine torque curve would rise above acceptable limits under such conditions, thus overloading the engine.

The present invention overcomes this difficulty by varying the pressure applied to the orificeto compensate to a predetermined extent for the variation in lengthof time of the periods of opening of the supply ports in the injectors. As heretofore mentioned, such variation in pressure is provided by the characteristics of the pressure regulator and the pump. The invention .in its preferred form contemplates the use of an engine-driven governor for determining the maximum speed of the engine and for maintaining the engine at a desired idling speed. hand throttle is also provided to control the engine at speeds between idling speeds and the maximum speed.

One embodiment of the invention, shown diagrammatically in Figs. 1 to 4 and structurally in the remaining figures, is of such form that it may be mounted on one side of the engine, and in this instance it comprises a pump casing 20 (see Fig. 5) adapted to be secured to the engine as by bolts 21. Secured at one side of the pump casing is a main casing 22 and in turn secured to the main casing is a control head 23. Fuel for the engine is adapted to be drawn from the fuel supply tank (not shown) through piping 24 (see Fig. 8) connected to an elbow fitting 25 secured in the main casing 22 and leading to a passage -26 therein, constituting the intake passage of an enginedriven pump 27. The pump in the present instance is illustrated as of the gear type but, of course, other suitable forms may be used. The intake passage 26 opens into an intake chamber 30 formed in the main housing 22, and the pump 27 discharges the fuel into a discharge chamber 31, also provided in the main housing 22.. The discharge chamber 31 is provided with a discharge passage 32 leading to a nozzle 33 (see Figs. 5 and 6) for discharging the fuel from the pump 27 into a float tank 34 secured to the lower side of the main casing 22.

It is desired to maintain the fuel in the float tank 34 at a predetermined level and for this purpose a float controlled valve 35 is provided in the float tank 34 to shut off the flow of fuel supplied by the pump 27 when the fuel reaches such level. When the valve 35 is closed, a relief passage 36 controlled by a pressure relief valve 37 permits the fuel delivered by the pump 27 to be returned'by a passage 40. (see Figs. 6 and 8) to the intake chamber 30 of the pump 27. I

The means for supplying fuel under pressure to the engine comprises, in the present instance, a second pump 41 (see Figs. 5 and 7) which is herein illustrated as a gear pump mounted in the pump casing 20 adjacent and aligned with the first pump 27. The two pumps are separated by a plate 42 interposed between the pump casing 20 and the main casing 22 and clamped therebetween. The pump 41 draws fuel from the float tank 34 through an intake passage 43 formed in the float tank 34 and in the main housing 22. The intake passage leads to an intake chamber 44 formed in the pump casing 20, and the pump 41 discharges the fuel into a discharge chamber 45 which is also formed in the pump casing 20. From the discharge.

chamber 45, fuel flows through a passage or conduit 46 formed in the main casing 22 to control means and thence to the engine. The pressure of the fuel is adapted'to be regulated by a pressure regulator, indicated generally at 50 (see Figs. 5 and 6), mounted in the main casing 22v and'controlling the flow of fuel from the passage 46 through a by-pass passage 51 which returns the by-passed fuel to the intake chamber44 of the second pump 41.

The control means for controlling the flow of fuel through the passage 46 is mounted in the control head 23 and comprises generally a hand throttle 52 (see Figs. 5 and 9), a governor-operated control plunger 53, and a shut-off valve 54. Fuel after passing through the latter flows through a passage formed in the control head 23 and adapted to be connected by a pipe 55, indicated onlyin diagrammatic views in Figs. 1 to 4. The pipe 55 is connected to a common rail 56, and connected to such. rail is a plurality of fuel injectors, indicated generally at 57 one being mounted'in each cylinder of the engine.

The injectors are of a Well-known type and each is illustrated in the present instance as comprising a fuel-receiving chamber 60 in which is mounted a plunger 61 adapted, on downward movement in the chamber, to force fuel therefrom through appropriate openings into the upper end of the cylinder. Fuel is introduced into the chamber 60 from the common rail 56 through a port 62 which, in this instance, constitutes an orifice of fixed area. The plunger 61 is adapted to open and close the orifice 62 by the movementof the plunger and such movement is effected by cam mechanism driven by and forming a part of the engine. Thus, the period of time that the orifice 62 is open is decreased upon increase in engine speed or, oppositely stated, increases upon decrease in engine speed.

From the foregoing, it is apparent that the size of the orifice 62 remains constant, but the period of time that it is open varies inversely with the speed of the engine. Therefore, if the pressure of the fuel applied to the orifice 62 were constant, the quantity of fuel passing through the orifice each time that it is opened would increase with a decrease in speed of the engine. Consequently, if the hand throttle 52 were fully opened for maximum flow of fuel to the engine, and an increase in load is placed on the engine, tending to decrease its speed from maximum, the increase in the period'of time that the orifice 62 is opened would increase the flow of fuel to each cylinder and the torque curve of the engine would rise. Under full throttle conditions, such rise would be excessive and the engine would become overloaded.

To compensate for such condition to the desired extent in order to provide a suitable torque curve, the pressure of the fuel applied to the orifice 62 is varied to provide a predetermined pressure increase as the speed of the pump increases, so that the desired quantity of fuel is supplied to each cylinder at each stroke of the piston therein. Such regulation of the pressure of the fuel is accomplished by the pressure regulator 50, taking into account the characteristics of the pump 41. In the present instance, the pressure regulator 50 is of such character that upon increase in discharge pressure developed by the pump 41, an increased quantity of fuel is bypassed by the regulator 50, the regulator being thus responsive to the pressure in the fuel passage or conduit 46. To this end, the pressure regulator 50 comprises an elongated cup-shaped member 63 (see Fig. 6) slidably mounted in a bore 64 formed in the main casing 22. Adjacent the open end of the cup-shaped member 63, the bore 64' is enlarged, as at 65, and the fuel passage or conduit 46 intersects the enlarged portion 65 so as to permit fuel to flow therein. The cup-shaped member 63 adjacent its open end is provided with a series of radial apertures 66 permitting the fuel to enter the interior of the member 63 from the enlarged portion 65.

The closed end of the cup-shaped member 63 is engaged by a spring 67 which is located in a chamber 68 at the left end of the bore 64 and which tends to hold the member 63 in the position shown in Fig. 6. However, as the fuel supplied through the conduit or passage 46 increases in pressure, the member 63 is forced to the left, as viewed in Fig. 6, against the pressure of the spring 67. Extending through the wall of the member 63. adjacent the closed end thereof is a series of smali apertures 69 which, in the present instance, are arranged along a spiral so that, as the member 63 is forced to the left, fuel can flow through the apertures 70 when theyare moved beyond the left end of the bore 64. With increasing pressure of the fuel in the passage 46, the member 63 is moved farther to the'left and, because of the spiral arrangement of the'apertures 70, an increasing number of these apertures are progressively opened to permit an increasing rate of flow of fuel therethrough. The fuel thus-by-passed through the apertures 70 is re- -(see Figs. 5, 9, l and 11).

controlled plunger 53. The

.shut oif all how of fuel to the ,10) so that the flow of sang-s03 turned through the passage 51 to'the intakeside 'of t he pump 41.

It will be apparent-from thcforegoing that by properly determining the size of the apertures 70'and the arrangement thereof, the pressure in-the main supply passage 46 can be regulated in any way desired so that at any given engine speed, a-predetermined pressure will exist in the supply passage or conduit 46. Since it is this pressure which is eventually-applied to the fixed orifice 62 in the injectors, the quantity of 'fuel'suppliedto the engine on each stroke .of each of its pistons may-thus be determined and any desired torque curve may thereby be obtained. Considering the condition heretofore described when the engine is operating at full throttle and an increased load on the engine causes a reductionin speed thereof, the regulation of pressure atforded by suitable design of the pressure regulator 50 will compensate to any desired extent for the longer period of opening of the orifice 62.

As heretofore mentioned, the fuel in the main supply conduit 46 is conducted to thehand throttle 52 which, in this instance, comprises a rotatable valve member 70 The valve member 70 is mounted in a bore 71 formed in thecontrol head 23 and intersected by a passage 72 connecting with the supply conduit 46. The valve member 70, at its full diameter, cuts off the flow of fuel through the passage 72, but it is provided with a groove 73 extending for only a portion of the periphery of the valve member so that, when the valve member 70 is suitably rotated, fuel may how in the passage 72 through the groove 73, as

.will be evident from an inspection'ofFig. 10.

The passage 72 communicates with a radial passage 74 see Fig. provided in a sleeve 75 mounted in the control head 23. The sleeve 75 receives .the governor latter is. provided .with a reduced portion 76 intermediate its ends which, with the bore of the sleeve 75, provides a longitudinally extending annular space within the sleeve 75 into which the fuel flows from the passage 72. Also extending radially through the sleeve 75 is a passage 77 communicating with the annular space within the sleeve-75 .and thus communicating with the passage 72. The radial passage 77 in the sleeve 75 connects with a passage 80 formed in the .control head 23 and intersecting the bore 71 in which the valve member 70 is positioned, as clearly shown in Figs. 5, 9 and 11. The passage 80 is connected through the pipe 55 to the common rail 56 on the engine.

The valve member'70 is also utilized as a shut-off valve to intercept flow in the passage 80 and thus to engine when desired. To this end, the valve member 70 is provided with a second groove 81 which extends, for only a portion of the periphery of the valve member 70, permitting flow through the passage 80 when the valve member 70 is suitably rotated and shutting oif flow through the passage 80 when tr e full diameter of the valve member 70 is located at the intersection of the passage 80. with the bore 71.

The inclusion of the hand throttle 52 and the shut-off valve 54 both in the same valve member 70 simplifies the structure and correlates the operation of the two. Thus, the peripheral groove 81 constituting the shut-off valve 54 permits the valve member 70 to be rotated to open the passage 86 when the engine is to be started. The peripheral groove 73 may be so positioned that the passage 72 remains closed until the throttle has been moved to the above idle-speed position, so that the flow of fuel for idle-speed operation of the engine may occur through other passages hereinafter described. Continued rotation of the valve member 70 above idle-speed position opens the passage 72 for the flow of fuel and the amount of flow therethrough' may be determined by the depth of the groove 73, the latter having gradually decreasing depth at one end, as indicated at 82 (see Fig.

. h 9u hq, Pass s. m y

thus be varied manually. -When the valve memb'er 70 is turned to its'maximum speed position, the full depth of the curve 73 is available for the flow of fuel through the passage 72. During the turningmovement of thevalve member 73 from the stop position toward the maximum speed position, the groove 81 permits flow through the passage to the engine.

For idle-speed operation, a by-pass passage 83 is provided in the control head 23 and extends from the main supply passage 46 to a radial passage 84 formed in the sleeve 75' supporting the governor-controlled plunger 53. The radial passage 84 opens into the bore Within the sleeve 75 and communicates with the annular space formed by the reduced portion 76 on the control plunger 53 when the engine is operating at idle-speed. The annular space is of suflicient length to connect all three passages 84, 74 and 77, with the main passage 74 located between the other two. The fuel thus may flow through the by-pass passage 83, the radial passage 84, and the annular space within the sleeve 75, to the passage 77 through which the fuel is conducted to the engine. The passage 83 constitutes a bypass around the hand throttle 52 and thus is not intersected by the bore 71 receiving the valve member 7%. Therefore, fuel may flow through the bypass passage 83 when the throttle 52 is closed. When the throttle 52 is open, the control plunger 53 closes the bypass passage 83.

The control plunger 53 Within the sleeve 75 is adapted to be actuated by a governor, indicated at 85 (see Fig. 5) which is here illustrated as being of the centrifugal type. The governor comprises two sets of weights of different size, the larger being indicated at 86 and the smaller ones indicated at 87. In the illustration in Fig. 5, the weight 86 is shown as being opposite the weight 87. However, this is merely for purposes of illustration and actually there are two weights 86 diametrically opposite each other and two weights 87 diametrically opposite each other, but positioned at 90 degrees to the weights 86. Both sets of weights are pivotally mounted, as at 96, on a rotatable head 91 driven by the engine. The weights are provided with inwardly extending arms 92 engaging a collar 93 in which the adjacent end of the control plunger 53 is secured. The controlplunger 53 extends through the sleet/e75 beyond the control head 23 and, at its outer end, carries a thrust nut 94. Bearing against the latter is a forked end 95 of a rock lever 96 pivoted, as at 97, on the adjacent end face of the control head 23.

The opposite end of the rock lever 96 is adapted to engage spring means in the form of a self-contained unit mounted in the control head 23. The lever 96 carries an adjustable thrust element 109 secured to the end of the lever as by a pair of locking nuts 101 and bearing against a head Hi2 formed on the end of a thrust member 193 constituting a portion of the self-contained spring unit for opposing the centrifugal action of the governor 85. The thrust member 103 is threaded in a plunger 104 slidably mounted in a sleeve 105. The inner end of the thrust member 103 is reduced, as at 106, and supports a spring seat 107 against which a low-pressure spring 110 bears, the latter being enclosed within the sleeve and bearing at its opposite end against a shoulder 111 formed therein. The spring thus resists inward movement of the thrust member 103 and, because of the rock lever 96, movement to the right of the control plunger 53 through the action of the centrifugal weights is thereby resisted. The two sets of

weights

86 and 87 are of such character that, as they move outwardly under the centrifugal force exerted at idling speed, the control plunger 53 is moved to the right sufliciently to compress the spring lid, in the self-contained spring unit,

to a limited extent.

The larger weights 36 are provided with fingers 112 .which engage the rotating head 91 of the governor to ,preventfurther outwardmoveinent of the weights 8 6 ing 114 of the self-contained spring end of the reduced portion with the radial when the engineispeed is slightly above idling speed. At the time the fingers 112 on the larger weights 86 engage the rotating head 91, the thrustmember 103 in the selfcontained spring unit has moved the plunger 104 inwardly to a sufiicient extent to cause a flange 113 on the plunger 104 to engage the adjacent end of the sleeve 105. The sleeve 105 is slidably mounted in a cylindrical housunit, and movement of the sleeve 105 is resisted by a second and heavier spring 115., Thus, slightly above idling speed, the larger weights 86 are limited in their outward movement and the plunger 104 is limited in its movement relative to the sleeve 105.

During such action of the governor, the control plunger 53 is moved to the right and, at the time the larger weights 86 are limited in their outward movement, the reduced portion 76 of the control plunger 53 has moved to the right far enough so that the plunger closes the radial passage 84 leading from the by-pass 83. The 76 on the plunger 53 adjacent the radial passage 84 is tapered, as at 116, so that as the plunger moves to completely close the radial passage 84, the flow therethrough is gradually reduced by the taper 116. Thus, in operation of the engine, fuel may flow through the by-pass passage 83, and the radial passage 84 to supply fuel to the engine at idling speed. However, should the engine tend to increase its speed above such idling speed, the control plunger 53 is moved to the right by the action of the centrifugal weights to gradually reduce and ultimately shut off the flow of fuel through the radial passage 84. During this period, only the spring 110 in the self-contained spring unit is compressed by movement of the centrifugal weights. Should the speed of the engine tend to fall below the desired idling speed, the weights move inwardly and thus the control plunger 53 is moved to the left to increase the fiow through the radial passage 84, the spring 110 through the rock lever 96 effecting such movement of the control plunger 53.

The governor 85 is also ut' ized to determine the maximum speed of the engine by its action on the control plunger 53. In this action, the larger weights 86 do not function since they are prevented from moving outwardly by the fingers 112 when the engine is operating at a speed slightly above idling speed. For limiting the maximum speed, only the smaller weights 87 are utilized. As the engine approaches the maximum speed, outward movement of the smaller weights 87, through the control plunger 53 and the rock lever 96, causes the flange 113 on the plunger 104 to engage the adjacent end of the sleeve 105 and to force the sleeve to the left, as viewed in Fig. 5, against the action of the heavier spring .115, the lighter spring 110 being compressed at that time. The movement of thesmaller weights 87 in this manner shifts the control plunger 53 to the right and as the tapered part 116 of the reduced portion 76 thereof becomes aligned aperture 74, flow of fuel through the passage 72 is thereby reduced and eventually stopped when the full diameter of the control plunger 53 closes the radial passage 74. The design is such that this occurs at a desired maximum speed for the engine. When the speed of the engine falls below the maximum, the heavier spring 115 through the rock lever 96 moves the control plunger 53 to the left to permit full flow. through the passage 72.

The pivotal support for the rock lever 96 is in the form of a bracket 119 secured to the end face of the control head 23 between the spring unit and the control plunger 53. To protect the end of the control plunger 53, the rock lever 96 and the partsof the spring unit, a cover 117 is rigidly secured to the control head 23.

In most governors of the type herein disclosed, the spring means which opposes outward movement of the centrifugal weights is incorporated as part of the governor itself. In the present instance, if the spring means were so arranged, it would involve an undesirable elongation of the entire apparatus since it would have to be is adapted to be moved is the operating range positioned between the, centrifugal weights and the sleeve in which the control plunger 53 reciprocates. By makingthe springv means as a self-contained unit: and connecting it to the governor through a lever such as the rock lever 96,-the spring-unit may be positioned at one side of and in generally parallel relation to the control plunger I 53 so that the entire fuel apparatus, and particularly the casing structure, may thereby be shortened. Also, by making the springmeans in the form of a self-contained unit as herein shown, the assembly of the structure is facilitated since the spring unit itself may be readily assembled separately fromthe governor. In the present instance, the spring unit is mounted in'the control head and is merely held therein by a flange 118 formed on the housing 114 and engaging the control head 23. I I As heretofore mentioned, both the pump 27 and the pump 41 as well as the governor are driven by the engine. To this end, asingle drive shaft 120 (see Fig. 5) is provided, which extends throughthe pump casing 20'and into the main casing 22. At its outer end, the drive "shaft 120'is provided with a coupling member 121 adapted to be connected to and driven by the engine. The shaft 120 is-journaled in a bearing 122 provided. in the pump casing 20 and the inner portion of the shaft extends into, and has a driving connection with, a tubular shaft portion 123 formed on the weightcarrying head 91 of the governor. The tubular shaft portion 123 is journaled in a bearing 124 provided in'the main casing 22. Thev tubular shaft portion 123 extends into the pump casing 20 and carries one of the gears of. each of the gear pumps 27 and 41. Theother gears of the two pumps are mounted on a stub shaft 125 journaled at one end in the pump casing 20 and at its other end in the main casing 22. The drive'shaft 120 is thus aligned with the control plunger 53.

Themanual operation of the rotatable valve member 70, which includes the shut-off valve 54 and the throttle valve 52, is effected by means of a lever (seeFig. 15) mounted on one end of the valve member 70 externally of the control head 23. Since the valve member from a stop position through an idling speed position to a maximum speed position, it is desirable to have these three positions indicated to the operator by the action effected through the lever 130; To this end, means is provided to confine the movement of the valve'member 70 position and its maximum speed position and to indicate during such movement, the point of idle speed position. Furthermore, it is desirable tohave the valve member 70 so arranged that it may be readily moved between idling speed position and maximum speed position, which for the engine, and to require a different character of operation on the part of the operator of the engine when he wishes to move the valve member 70 to its stop position, so that he will not unintentionally move the valve member to a position below the idling speed position when he desires to continue operation of the engine. a I

In the present'instance, means is provided to control operation of the valve member 70 in this manner and,

as shown in Figs. 12 and 15, such means comprises a lever 131, preferably mounted on the valve member 70 at the opposite end from the lever 130. The lever 131 is provided with a pin adapted to engage'a detent 133 pivotally supported, as at 134, on the control head 23. The detent 133 is provided with an arcuate surface 135 adapted to be engaged by the pin 132. To define the maximum speed position forthe lever 131, a shoulder 136 is formed on the detent 133 at one end of the arcuate surface 135 so that the pin 132 engages the shoulder 136 when the lever has been moved to its maximum speed position. To define the idle speed position, the arcuate surface 135, at its opposite end, is provided with a shoulder 137 for the pm 13210 engage. Thus, the lever 131 is freely movable to the range between its stop 132 on its free end, which is' 9 between the positions defined by the shoulders 136.and 13' While the shoulder 136 vhich defines the maximum speed position absolutely prevents any further movement of the lever 131 beyond that point, so that the engine can never be set above the predetermined maximum speed, the shoulder 137 is formed so that the lever 131 may be moved to a stop position. To this end, the shoulder 137 constitutes, in effect, a cam surface so that, by exerting an extra force on the lever 130, the pin 132 will swing the detent 133 about its pivot 134 so that the pin 132 can move beyond the shoulder 137 in that direction. To hold the detent 133 against such pivotal movementexcept when an extra force is exerted on the lever 130, a coiled spring 149 is attached to the free end of the detent 133 and is anchored by a bracket 141 mounted on the control head 23. The spring 140 thus resists swinging movement of the detent 133 but permits such movement when the pin 132 is forced against the shoulder 137 and cams the latter out of the Way. When the pin 132 has moved beyond the shoulder 137, it engages a second short, arcuate surface 142, at the end of which is provided-a notch 143, constituting the stop position. When the pin 132 seats in the notch 143, the spring 14%) holds the detent against the pin and thus tends to retain the lever 13} in the stop position.

With a fuel supply apparatus as heretofore described, the control of the pressure obtained by the pressure regulator 50 provides a means whereby any desired torque curve for the engine can be attained. Thus, when the engine is slowed down by an increase in load, instead of having an increased quantity of fuel supplied to the engine because of the longer period of time that the controlling orifice is open, the control of the pressure'con pensa tes to any desired extent for such condition. With the present structure, for example, a torque curve such as is illustrated by the fuli line in the graph of Fig. 16 may be obtained, or, if desired, the torque of the engine may fall off, as indicated by the dotted line in Fig. 16, When the engine is operated at lower speeds. While this is merely an example of a torque curve that can be obtained, it is obvious that a torque curve of any desired shape may be attained by suitable design of the pressure regulator a) with regard to the control of the pressure at the various engine speeds throughout the speed range of the engine.

I claim:

1. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven by the engine, means operable by the engine for determining the period of admission of fuel to the engine and periodically opened and closed in fixed timed relation to the speed of the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, and a pressure regulator connected to said conduit for varying the pressure in said conduit in response to such pressure to compensate to a predetermined extent for the variation in length of the periods of admission of said means.

2. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven by the engine and having a rate of delivery greater than is required to supply the engine, means operable by the engine for periodically admitting fuel to the engine and having a period of admission in fixed relation to the cycle of the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, a by-pass connected to said conduit for discharging a portion of the fuel delivered by said pump, and a pressure regulator in said by-pass for controlling the flow of fuel therethrough and cooperating with said pump to provide a predetermined variation in fuel pressure in said conduit-With variation in engine speed and thereby controlling the 10 rate of flow to the engine during the periods of admission, said pressure regulator varying tothe pressure ofthe fu'el in said conduit in response to such pressure, whereby variations in length of the periods of admission of said means are compensated for to a predetermined extent.

3. fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted -to be driven by the engine and having a rate of delivery-greater than is required to supply the engine, means operable by the engine for periodically admitting fuel to the engine and having a period of admission in fixed relation to the cycle of the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, a by-pass connected to said conduit for discharging a portion of the fuel delivered by said pump, and a pressure regulator in said by-pass for controlling the flow of fuel therethrough and cooperating with said pump to provide-a predetermined variation in fuel pressure in said conduit with variation in engine speed and thereby controlling the rate of flow to the engine during the periods of admission, said pressure regulator comprising a flow controlling member movable to vary the area of discharge of fuel through said conduit for varying the pressure in said conduit in response to such pressure, and a spring opposing the movement of said member, whereby the pressure in said con duit is varied to compensate to a predetermined extent for variations in length of the periods of admission of said means.

4. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven by the engine and having a rate of delivery greater than is required to supply the engine, means operable by the engine for periodically admitting fuel to the engine and having a predetermined period of admission in fixed relation to the cycle of the engine, whereby the length of the periods of admission varies inversely with thespeed of the engine, a conduit connecting said pump and said means, a by-pass connected to said conduit for discharging a portion of the fuel delivered by said pump, and a pressure regulator in said by-pass for controlling the flow of fuel therethrough and cooperating with said pump to provide a predetermined variation in fuel pressure in said conduit with variation in engine speed and thereby controlling the rate of flow to the engine during the periods of admission, said pressure regulator comprising a flow controlling member having a series of holes adapted to be progressively opened by movement of said member by increase in pressure in said conduit, and a spring tending to resist such movement, whereby the pressure in said conduit is varied to compensate to a predetermined extent for variations in length of the periods of admission of said means.

5. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven by the engine, means operable by the engine for periodically admitting fuel to the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, a pressure regulator connected to said conduit for varying the pressure therein to compensate to a predetermined extent for the variation in the length of the periods of admission of said means, and a governorcontrolled valve in said conduit between said regulator and said means and operable at speeds above idling speed only for limiting the flow in said conduit to determine the maximum speed of the engine.

6. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven "by the engine, means operable by the engine for periodically admitting fuel to the engine and having a period of admission in fixed relation to the cycle of the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, a pressure regulator connected-to said conduit cooperating with said pump to provide a predetermined'variation in fuel pressure in said conduit with variation in engine speed and thereby controlling the rate of flow to the engine during the periods of admission to compensate to a predetermined extent for the variation in the length of the periods of admission of said means, and a manually operable valve in said conduit between said regulator and said means for manual control of the speed ofthe engine.

7. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven by the engine, means operable by the engine for periodically admitting fuel to the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, a pressure regulator connected to said conduit for varying the pressure therein to compensate to a predetermined extent for the variation in the length of the periods of admission of said means, a governor-controlled valve in said conduit between said regulator and said means and operable at speeds above idling only for limiting the flow in said conduit to determine the maximum speed of the engine, and a manually operable valve in said conduit betweensaid regulator and said governor-controlled valve for manual control of the speed of the engine at below said maximum speed.

8. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump adapted to be driven by the engine, means operable by the engine for periodically admitting fuel. to the engine, whereby the length of the periods of admission varies inversely with the speed of the engine, a conduit connecting said pump and said means, a pressure regulator connected to said conduit for varying the pressure therein to compensate to a predetermined extent for the variation in length of the periods of admission of said means, governor-controlled means in said conduit between said regulator and said fisrt-mentioned means for limiting the flow in said conduit to determine the maximum speed of the engine, and a manually operable valve in said conduit between said regulator and said governor-controlled means for manual control of the flow of fuel in said conduit, said conduit having a by-pass extending around said manually operable valve to said governor-controlled means and independent of control by said manually operable valve to supply fuel for operating the engine at idle speed, and said governor-controlled means controlling the flow of fuel through said by-pass.

9. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump operable by the engine, means operable by the engine for periodically admitting fuel thereto, whereby the length of the periods of admission varies inversely with the speed of the engine, governor-controlled means connected to said first-mentioned means for controlling the flow of fuel thereto, a pressure regulator connected to the delivery side of said pump for varying the pressure of the fuel delivered by said pump to compensate to a predetermined extent for the variation in the length of the periods of admission of said first-mentioned means, a main conduit and a by-pass conduit both extending from the delivery side of said pump to said governor-controlled means, and a manually operable valve in said main conduit, said governor-controlled means being arranged, when said manually operable valve is open, to close said by-pass conduit and to limit the flow through said main conduit to determine the maximum speed of the engine, and when said manually operable valve is closed, to limit the flow through said by-pass conduit to determine the idling speed of the engine.

10. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump operable by the engine, means operable by the engine for periodically admitting fuel thereto, whereby the length of the periods of admission varies inversely with the speed of the engine, governor-controlled meansconnected to said first-menspeeds '12 tioned means for controlling the flow of fuel thereto, said governor-controlled means comprising a valve body having a bore therein and a valve plunger movable in said bore, a pressure regulator connected to the delivery side of said pump for varying the pressure of the fuel delivered by said pump, a main conduit and a by-pass conduit both extending from the delivery side of said pump to said bore, and a manually operable valve in said main conduit, said valve plunger being adapted, when said manually operable valve is closed, to limit the flow through said by-pass conduit to determine the idling speed of the engine, and adapted, when said manually operable valve is open, to close said by-pass conduit and to limit the flow through said main conduit to determin the maximum speed of the engine.

11. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump operable by the engine, a conduit extending from said fuel pump, governor-operated means connected to said conduit for controlling the flow of fuel therethrough, a delivery conduit connected to said governor-operated means for con ducting fuel to the engine, and a single manually operable valve member extending into both conduits for separately shutting off the flow of fuel therethrough.

12. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump operable by the engine, a main conduit extending from said fuel pump, governoroperated control means connected to said main conduit, a delivery conduit connected to said governor-operated means for conducting fuel to the engine, a manually operable valve member extending into both conduits and having separate portions adapted to control the flow of fuel through the respective conduits and a by-pass conduit extending from said main conduit around said valve member to said governor-operated means, the portion of said valve member in said main conduit being adapted to shut off flow of fuel therethrough with said governoroperated means permitting flow through said by-pass conduit while the portion of said valve member in said delivery conduit is in open position to permit flow therethrough, the latter portion being adapted to be closed to shut off all flow of fuel to the engine.

13. A fuel supply apparatus for an internal combustion engine, comprising casing structure, a fuel pump mounted in said casing structure and operable by the engine, governor-operated control means in said casing structure, said casing structure having a main passage connecting said pump and said governor-operated means, and a delivery passage extending from said governor-operated means and adapted to be connected to the engine for delivering fuel thereto, said casing structure also having a bore therein intersecting both of said passages, and a manually operable valve member in said bore and having separate portions adapted to control the flow of fuel through the respective passages, said casing structure also having a by-pass passage extending from said main passage around said bore to said governor-operated means, the portion of said valve member in said main passage being adapted to shut off flow therethrough with said governor-operated means permitting flow through said by-pass passage while the portion of said valve member in said delivery passage is in open position to permit flow to the engine.

14. A fuel supply apparatus for an internal combustion engine, comprising casing structure, a fuel pump mounted in said casing structure and operable by the engine, gov- 'ernor-operated control means in said casing structure,

said casing structure having a main passage connecting said pump and governor-operated means and a delivery passage extending from said governor-operated means and adapted to be connected to the engine for delivering fuel thereto, said casing structure also having a bore therein intersecting both of said passages, and a manually rotatable valve member in said bore having a pair of grooves extending for only portions of the periphery of the valve member andrespectivelyaligned with said passages to control the flow of fuel through the respective passages, said casing structure also having a by-pass passage extending from said main passage to said governoroperated means and spaced from said bore, said valve member being rotatable to turn the groove associated with said main passage out of communication therewith to shut off the flow of fuel therethrough with the groove associated with said delivery passage maintaining communication therewith, said governor-operated means permitting flow through said by-pass passage when said valve member is so turned.

15. A fuel supply apparatus for an internal combustion engine, comprising casing structure having a bore therein, a fuel pump mounted in said casing structure and operable by the engine, a governor-operated control plunger mounted in said bore, said casing structure having a main passage connected to said pum a by-pass passage connected to said main passage, and a delivery passage for conducting fuel to the engine, all of said passages opening into said bore at points spaced longitudinally thereof, and manually operable valve means mounted in said casing structure and extending into said main passage between said by-pass and said bore and into said delivery passage for controlling the flow or" fuel through said main passage and said delivery passage, said plunger being shiftable in said bore to control the flow of fuel through said by-pass passage for determining the idling speed of the engine and to control the flow of fuel through said main passage to determine the maximum speed of the engine.

16. A fuel supply apparatus for an internal combustion engine, comprising casing structure having a bore therein, a fuel pump mounted in said casing structure and operable by the engine, a governor-operated control plunger mounted in said bore, said casing structure having a main passage connected to said pum a by-pass passage connected to said main passage, and a delivery passage for conducting fuel to the engine, all of said passages opening into said bore at points spaced longitudinally thereof with said main passage between the other two passages, and manually operable valve means mounted in said casing structure and located in said main passage between its connection with the by-pass passage and the bore and in said delivery passage for controlling the flow of fuel through said main passage and said delivery passage, said plunger having a reduced portion of sufiicient length to provide space in said bore connecting all three passages, said plunger being shiftable to control the flow through said by-pass passage when the engine is operating at idle speed and to control the flow of fuel through said main passage to determine the maximum speed of the engine.

17. A fuel supply apparatus for an internal combustion engine, comprising casing structure having a bore therein, a fuel pump mounted in said casing structure and operable by the engine, a governor-operated control plunger mounted in said bore, said casing structure having a main passage connected to said pump, a by-pass passage connected to said main passage, and a delivery passage for conducting fuel to the engine, all of said passages opening into said bore at points spaced longitudinally thereof with said main passage between the other two passages, said casing structure having a second bore spaced from the first-mentioned bore and intersecting said main passage between its connection with the by-pass passage and the first mentioned bore and intersecting said delivery passage, and a manually operable valve member mounted in said second bore having portions for controlling the flow of fuel through the respective main passage and delivery passage, said plunger cooperating with the first-mentioned bore to provide space within said bore communicating with all three passages, and said plunger being shiftable in said first-mentioned bore relative to the by-pass passage to control the flow of fuel therethrough when the engine is operating at idle speed and relative to said main passage to control the flow of fuel therethrough to determine the maximum speed of the engine.

18. In a fuel supply apparatus for an internal combustion engine, casing structure having a bore therein, a governor-operated control plunger mounted in said bore, said casing structure having a main fuel supply passage, a by-pass passage connected to said main passage, and a delivery passage for conducting fuel to the engine, all of said passages opening into said bore at points spaced longitudinally thereof with said main passage positioned between the other two passages, said plunger having a reduced portion of sufficient length to provide space in said bore connecting all three passages with the end of the reduced portion adjacent said by-pass passage tapering to the full diameter of the plunger, said plunger being shiftable longitudinally in the bore upon changes in engine speed whereby the tapering portion of the plunger will gradually close said by-pass passage when the engine speed exceeds idling speed and will gradually close said main passage when the engine speed reaches maximum, and valve means in said main conduit between said by-pass passage and said bore.

19. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump operable by the engine, a conduit extending from said fuel pump, governor-operated means connected to said conduit for controlling the flow therethrough, a delivery conduit connected to said governor-operated means for conducting fuel to the engine, a single valve member extending into both conduits for controlling the flow therethrough, manually operable means for actuating said member and adapted to move said valve member from a stop position through an idle speed position to a maximum speed position, and means for controlling the movement of said member comprising a lever connected to said member, and a spring actuated detent bearing against said lever and permitting free movement of the lever between its idle speed and maximum speed positions and adapted to oppose movement of said lever by the action or" its spring when said lever is moved from idle speed position toward stop position.

20. A fuel supply apparatus for an internal combustion engine, comprising a fuel pump operable by the engine, a conduit extending from said fuel pump, governor-operated means connected to said conduit for controlling the flow therethrough, a delivery conduit connected to said governor-operated means for conducting fuel to the engine, a single manually rotatable valve member extending into both conduits for controlling the flow therethrough, a lever connected at one end to said valve member and movable thereby from a stop position through an idle speed position to a maximum speed position and hav ing a pin projecting from its other end, a detent pivotally mounted adjacent said lever and having an arcuate surface engaged by said pin during movement of said lever between idle speed position and maximum speed position, said arcuate surface having a stop shoulder engageable by said pin at maximum speed position and a cam shoulder engageable by said pin at idle speed position whereby movement of said lever from idle speed position toward stop position eifects movement of said detent, and a spring connected to said detent to resist cam ming movement of said detent by said pin.

References Cited in the file of this patent UNITED STATES PATENTS