US2180109A - Fuel pump - Google Patents

Description

Nov. 14, 1939. c. F. HIGH 2,180,109

FUEL PUMP Filed April 22, 1957 4 Sheets-Sheet 2 C. F. HIGH FUEL PUMP Nov. 14, 1939.

Filed April 22, 1937 4 Sheets-Sheetl 5 C. F. HIGH Nov. 14, 1939.

4v Sheets-Sheet 4 x|| l'I FUEL PUMP Filed April 22, 1937 f #Iy/ ligar/lll,

Patented Nav. 14, 1939 2,180,109

lUNITED STATES PATENT oel-ICE 14 Claims. (Cl. 123-139) The invention relates generally to fuel pumps intake control for an internal combustion enfor internal combustion engines and more pargine which is shiftable to change the ratio of ticularly to the control means associated with fuel to air by the agency of an automatic pressuch pumps for governing the ultimate fuel-air sure adjustment operable alternatively with a ratio of the mixture supplied to the engine. manual adjustment. 5

When a fuel pump is employed to feed small, Still another object is the provision of a fuel accurately measured charges of fuel for the inmetering device for an internal combustion endivldual cylinders of an internal combustion enl gine which is adjustable during regular throtgine, the relative proportioning of the fuel and tling of the engine to supply different quantities air supply becomes an important consideration of fuel to satisfy engine requirements under difin obtaining efficient engine performance at all ferent atmospheric conditions, the adjustments speeds, and it is customary, therefore, to probeing accomplished selectively by the operator vide a common interrelated control means for either by direct manual adjustment from the varying the fuel charge and air supply in an pilot seat or by interposing an automatic adefficient relation throughout the range of enjusting device responsive itself to changes in atgine speeds.` In attaining an eiiicient fuel-air mospheric conditions. ratio, such a common interrelated control means A further object of the present invention is the establishes a definite relationship between the provision of a new and improved fuel and air actuation or movement of the fuel volume concontrol mechanism embodying means for throttrol and the air volume control throughout the tling the fuel injection during flight to corre- 20 range of engine speeds, and itis found that varispond with the air injection in a predetera-tions in air pressure incident to altitude mined ratio and also to provide additional means changes of an aircraft engine result in a detrisealed within a housing for the device, the funcmental fuel-air unbalance. tion of which is to change the predetermined An important object, therefore, of the presentratio between the fuel and air injection during 25 invention is to provide a fuel pump for internal flight. combustion engines embodying a new and im- A still further object is the provision of a proved control means whereby an efficiently procombined fuel and air control mechanism for portioned air and fuel supply may be provided Ya combustion engine in which the regular at any atmospheric pressure and hence at any throttle adjustment of the fuel control is conf 30 altitude of engine operation. nected to the air control so that fuel and air Another object is to provide such a device will be simultaneously throttled in a predeterwherein coordinated mechanism of a. simple mined ratio, and which has in addition a mechacharacter for varying the fuel and air supply to nism for altering the ratio between the fuel and the engine may be adjusted manually to proair controls capable of being'operated during 35 vide, for any particular pressure due to a change fiight independently of the combined fuel and of altitude, an efficient fuel-air ratio throughout air control means. the range of engine speed. v AOther objects and advantages will become ap- Another object is t0 prOVide a fuel pump havparent when considered in view of the following a mxtur e Control means adapted t0 mount* ing description taken in connection with the ac- 40 ing and operation in aircraft in accordance with companying drawingsy in whicht principles familiar to most pilots' Fig. 1 is a longitudinal section of one form of More specifically, the present invention has r for its object the provision of new and improved lehugencont 01 embodymg the features fuel and air control mechanism of this character embodying means whereby the pilot may, I l; al fllaglentsl ctl, o? thef lge during flight, adjust the mechanism to deliver, o g 00 mg m e 1 ec lon o e throughout the range of engine speeds, a proparrowserly coordinated supply of fuel and air. Fig- 2 is a bottom VleW 0f the device Shown 1n A further object is to provide a fuel pump Fig- 1 partly in Section 0n the Ime 2 2 0f Flg- 1- 50 and fuel and air intake control for an internal Fg- 3 iS a fragmental Vertical SeCtiOn 0f the combustion engine which is automatically varildevice on the line 3--3 of Fig. 1. able to change the ratio of fuel to air in accord- Fig. 3a is a view of a rotating cam taken on ance with a variation in atmospheric pressure. the line 3B-3HL of Fig. 3. Another object is to provide a fuel andv air Fig. 4 is a side elevational view of the fuel 55 pump and control shown connected with the throttle of the air intake manifold.

Fig. 5 is a vertical section of the lower portion of the device featuring a modified form of manual control together with an automatic control.

Fig. 6 is a horizontal section of the modified manual control and automatic control.

Fig. 7 is a sectional view on the line 'I-l of Fig. 6 looking in the direction of the arrows.

Fig. 8 is a fragmental vertical section on the line 8-8 of Fig. 6.

Fig. 9 is a somewhat diagrammatic view of a development of a. manually operated cam segment showing the relative form of the cam slot.

While there is illustrated in the drawings and shall hereinafter be described in detail a preferred form of the invention, it is to be understood that the invention is not limited to the particular construction and arrangement shown, it being contemplated that various changes may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims.

In the form chosen for the disclosure herein presented, the invention is intended and adapted for use with the internal combustion engines of aircraft machines and is embodied in a fuel and air supply system wherein when the fuel supply to the engine is varied the air supply is correspondingly varied, in order to maintain a constant predetermined ratio between the two under the control of a common accelerator. 'I'here is further provided an independent adjustment by means of which the ratio between the fuel and air can be varied in order to satisfy the demand made necessary by operation of the aircraft engine under varied atmospheric conditions at different altitudes or under different barometric pressures. In the embodiment illustrated by the drawings, substantially the entire device is shown, enclosed within a single casing I0 which supports various parts of the device. The casing is in three sections fastened together by appropriate means. Within the upper casing section II a cam plate I2 is properly journaled. 'Ihe midsection I3 contains a plurality of piston and cylinder devices whose function it is to eject selected quantities of fuel to the corresponding engine cylinders. A lower section I4 forms a sealed compartment I5 within the casing in which are supported various parts of the throttling and adjusting mechanism. A portion of the air intake manifold I6 is shown in Fig. 4 connected for simultaneous operation with parts of the device supported in the lower section I4 of the casing.

It is desired to transmit to the engine liquid fuel and air through separate passages, but so to regulate the respective quantities of fuel and air that the proper proportion is maintained between them so that a more nearly perfect combustion will take place within the engine. With this in mind, it will be apparent that in view of the fact that the proportion of liquid fuel supplied to the engine is considerably smaller in volume than the quantity of air supplied, means will have to be included in the device to reduce the motion of a common throttling mechanism so that only a very small portion of the motion will be used in adjusting the quantity of liquid fuel while a correspondingly larger portion of the motion will be used to regulate the quantity of air.

It will be further evident, particularly when the combustion engine to be supplied with fuel is used in an aircraft, that due to changes in altitude or barometric changes the same volume of air will not be drawn in with a given throttle valve setting or that the same volume of air will not necessarily contain the same quantity of oxygen needed for combustion. To compensate for such a variation it will be necessary from time to time to change the fuel-air ratio. Since such a. change should be independent of the common throttling mechanism, an independent adjusting mechanism is supplied by means of which a pilot may, by the manipulation of a suitable controll change the setting of the valve which admits fuel so that in response to the common throttling'mechanism a different quantity of liquid fuel will be admitted as compared to the usual quantity of air. In thc embodiment shown, the mechanisms controlling both the throttling and the adjusting functions are all substantially housed within the same casing.

Although it is desirable to have the adjustment of the fuel-air ratio under the control of the pilot, occasions arise when it is convenient to have the change made automatically and for the preferred form of fuel control disclosed herein there is shown and described both a direct manual adjustment and a manual adjustment combined and alternatively operable with an automatic adjustment responsive to changes in atmospheric conditions, either of which may be used with the same common throttling mechanism.

So that the operation may be more easily understood, the description is devoted first solely to the application of a direct manually operated adjusting means for changing the fuel-air ratio. Having had the general principle thus presented, the construction of a device featuring an automatic adjustment together with a selective manual adjustment'to be subsequently described, will be readily understood.

In Fig. 4, fuel is introduced to the device at an inlet' 20 in the lower section I3 of the casing Il where it fills a chamber 24 together with the lower sealed compartment l5. Either gravity or pump pressure may be utilized to drive the fuel into the device. Excess fuel not passed to the engine `finds its way from the chamber 24 out through the port 25 from which it. passes up-v ward through a passage (not shown) within an enlargement 23 on the casing (Fig. 4) from which it is led to a fuel passage 2i at the upper section II of the casing I0. A plugged hole 2|' is shown which may be opened and have attached thereto a return line to conduct fuel back/ to the supply tank. From the sealed compartment I5 fuel is conducted past a fuel metering valve device indicated generally by the numeral 2B and passes through appropriate passages 21 in the casing and is discharged periodically, by suitable pistons to be subsequently described. from the outlet ports 28, 29, 30, etc., depending upon the timing of the engine. Each outlet port supplies a separate cylinder of the combustion engine and the frequency of the discharge is correspondingly timed to suit the engine operation.

Since it is desired to vary the quantity of liquid fuel admitted in order to suit different operating conditions, the position of the metering valve device 26 is designed to be changed in response to various manual or automatic adjusting mechanisms. The valve device itself consists of primarily a tapered metering pin 3| attached to a downwardly extending cylindrical portion 32 which has a recess 33 at the bottom in which is supported a bearing member 34 in the form arcaico of a ball. An internal section on arm 36 is shown which is one of a number of elements of a spider within the chamber 24, all of which are joined in a central portion 36. The central portion has inserted at the lower side a plug element 31 forming a seat 38 for the metering pin and also a supporting sleeve 39 for the cylindrical portion 32. Liquid fuel from the chamber 24 and 'from the compartment I5 joined thereto may be passed through passages 40 in the plug 31 and thence upward past the metering pin to the passages 21. A coiled spring I is shown surrounding the lower part of the plug 31 which tends to yieldingly extend the cylindrical portion 32 and the metering pin 3| outward with respect'to the seat 38, thus tending to open a passageway for the passage of liquid fuel.

The liquid fuel having been permitted to pass the metering pin must be ejected at proper intervals through the outlet ports 28, 23, 30, etc. To accomplish this, a combined reciprocating and rotating piston 42 is employed. The piston reciprocates in and out of a cylindrical chamber 43 subject, to impulses given it by the cam plate I2. By an appropriate, means the cylinder is likewise rotated a small fraction of a turn and this rotation, together with the appropriate reciprocation Aperiodically raises a port 44 in the piston presenting it at such periods to its corresponding passage 21, admitting a quantity of fuel depending upon the amount admitted by the position of the metering pin. After a quantity of liquid fuel has been admitted to the piston, it is reciprocated downwardly closing the port 44 and, by this downward motion liquid entrapped thereby within a pocket 45 and the chamber 43 is forced outward to its corresponding outlet passage when the piston is rotated to present the port 44 to the passage.

The piston 42 has a head at ,the top in which is formed a socket 46 and around which protrudes an annular shoulder 41. Within the midsection I3 of the casing is a bushing 48 adjacent each cylinder which supplies a support for a helical spring 49. There is likewise a chamber 50 formed within the mid-section I3 in which the top portions of the pistons reciprocate flooded with a bath of oil. The topmost portion of the cylinder 42 extends through an aperture 5I in a partition 52 located between the upper section II and middle section I3, the edges of the aperture 5I l forming a stop for limiting the upward motion of the cylinder by reason of being urged upward by the spring 49.

A ball and socket joint is formed by the socket 46 together with a bearing member 53 which has a cam shoe 54 at the top. It will be noted thata lower face 55 of the cam plate I 2 slopes from one side to the other so that as the cam plate rotates the cylinder 42 will be alternately pressed downward through the ball land socket joint through an expelling stroke, and upward through a loading stroke, the latter stroke being accomplished through the agency of the spring 49.

A cam groove 56 is formed in the bottom face 55 of the cam plate I2 and has aparticular shape in order properly to oscillate the pistons. A cam follower 51 associated with each piston extends into the cam groove so that each time the piston is driven through a reciprocating stroke it is likewise given a partial rotation for the purpose previously described, that of rotating a port in the cylinder to a proper position for expelling liquid fuel. A more detailed description of this portion of the structure is given in my Patent No. `2,060,076, issued November 10, 1936. The cam plate I2 has an axial hollow shaft 56 formed integrally with it, the hollow shaft being journaled in a bearing hub 63 located above the upper section I I oi the casing I0 by means of a friction bearing 60. Above the bearing hub 59 is a fixed flange 6I located on a drive shaft 63 for holding the parts in place at the upper end. The lower end of the drive shaft 63 is secured to the cam plate by means of a oneway clutch 62 described in detail in my application Serial No. 124,063, filed February 4, 1937,

and the cam plate is secured longitudinally to the cam shaft 63 by means of a castellated nut 65 and cotter pin 66. In order to take up thrust upon the rotating mechanism just described, a radial thrust bearing 64 is supplied, held in position in the casing by a screw 64', for rotatably guiding the axial hollow shaft 58 in the upper section of the casing. Lubricating oil may be introduced at an inlet 61 near the top, from which it may pass through a system of conduits 61 within the device to supply lubricating fluid to the moving parts. A return outlet 6I is shown in Fig. 4 for the lubricating oil.

The metering pin is caused to move upward and inward against its seat by means of rotation of a fuel cam 10 and the cam is in turn rotated through a system of llevers from the pilots seat. It will be noted (Fig. 3a) that the contacting surface 1I of the cam is shaped so that a diiferent displacement will be given to the metering pin depending on the degree of rotation. It should be further noted that the surface 1I is a warped surface in which one end follows the contour of the cam, the other traversing a wavy line which approaches and reeedes variously from the center y of rotation. The purpose of the warped surface will be subsequently disclosed.

As best seen in Fig. 3, the fuel cam 10 is nonrotatably supported upon a horizontal cam shaft 12 which rides in and out of a horizontal sleeve shaft 13. The horizontal cam shaft 12 is urged outwardly by a coiled spring 14 located in the inner hollow space 15 within the sleeve shaft. A threaded plug 14' holds the spring in place and closes the space 15. At the end of the horizontal shaft`12, opposite from the spring, a shoulder 16 is formed which bears against the inner side of the cam 10 and tends to push it outward. The cam is secured to the shaft by a nut 11 and the entire assembly is urged inward against the force of the coiled spring by means of a first class lever 18 and an auxiliary adjusting mechanism indicated generally as 19.

The horizontal shaft 12 has a squared portion 12' for holding it non-rotatably in a squared hole in the sleeve shaft 13 which at the same time permits the horizontal shaft to shift horizontally so that the plane of rotation of the cam can be moved to the right or left, meanwhile, the rotative position depends directly on the rotating movement given to the sleeve shaft. Non-rotatably att-ached to the outer or right-hand end of the sleeve shaft 13 is a rocker arm 82 which is held in this position by a pair of lock nuts 83 and 8,4, the outer nut 84 being additionally locked in position by means of a pin 85. Attached to the free end of the rocker arm 82 is a rod 86 which has an adjusting swivel 81 at the approximate center for changing its relative length. The other end of the rod 86 is swivelled to a rocker arm 88 which is attached to a butterfly valve 89 located in the air intake manifold I6. By this means the action of the metering valve corredirection.

sponds with the action of the air intake valve. Both valves are jointly operated by a common throttle connection 89 which is operated from the pilots seat.

It has been found desirable to have a substantial portion of the rocking parts of this cam mechanism located within the casing and to accomplish this the cam mechanism parts referred to are located and supported by the lower section I3 of the casing and will be observed to be located in the compartment which is always flooded with liquid fuel. Consequently the mounting of the horizontal shaft 12 which supports the cam must besealed to prevent any leak of liquid fuel at this point.` A multiple packing joint is therefore supplied consisting of an inner bushing 9| and an outer bushing 92, the central portions of both being located in a-chamber 93 at the left side, of the lower section Il of the casing. The parts 9| and 92 are threadable one into the other so that they will be securely tightened against gaskets 94 and 95 to make a fluidtight joint with the lower section I3 of the casing. Located within the bushings 9| and 92 is a central axial passage for supporting the rotating sleeve shaft 13 which must rotate in order to properly move the cam during operation. An additional packing 98 effectively seals this passage and is spring pressed into place by means of a coiled spring 99 bearing against a packing ring |00 to press the packing 98 into contact with the sleeve shaft.

The device is provided with an idling adjustment consisting essentially of a screw 96 fixed at its inner end in the part 9| and extending loosely through the lower casing section |4 and a rotatable adjusting nut 91 provided with spanner wrench holes. The nut 91 is rotatable but is held against axial movement by pins 91 extending through the hub on section I4 and into an annular groove 91" formed in the nut 91. When it is desired to change or adjust the idling position, the fuel cam is rotated to idling position, the parts 9| and 92 are loosened slightly and the nut 91 turned so as to move the whole mechanism bodily upward or downward a slight amount in order to change the setting of the metering pin at the idling position. When this has been satisfactorily adjusted, the parts 9| and 92 are again locked in adjusted position.

As viewed in Fig. 1, when it is desired to increase the flow of liquid fuel past the metering pin, the fuel cam 10 is rotated in a clockwise This rotation is accomplished by means of rocker arm 82, the rod 86 and the throttle connection 89 previously described. As the cam is rotated clockwise the cylindrical` portion 39 is urged downward by the spring 4|, thus permitting the metering pin to be withdrawn, enlarging the passage at the seat 38 for the passage of liquid fuel. At full open position a flat face |0| on the cam abuts one side of a stationary shoulder piece |02 and at idling position a pin |03 abuts the other side of the stationary shoulder piece |02. In the idling position a flat resilient land is provided for the metering pin, which consists of a piston |04 slidably secured by a loose fitting pin |05in a recess near the outer face of the cam, as viewed in Fig. 3. The piston |04 is urged upward against the ball 34 in the cylindrical portion of the metering pin by means of a coiled spring |08 which bears at its bottom end against the horizontal cam shaft 12. While the cam is held in one position so that it rotates always in the same plane, there will be maintained a constant ratio between the quantity of liquid fuel admitted to the engine and the quantity of air admitted through the air intake manifold for all of the various 'rotative cam positions, since when the cam is rotated to change the setting of the metering pin, the opening of the air intake valve is likewise changed. 0x1 occasions when it is desired to change the fuel-air ratio, parts best seen in Figs. ll and 3* are manipulated. Such a change can be accomplished by shifting the plane of rotation of the cam so that the ball 34 in the cylindrical portion of the metering pin is extended further outward in a downward direction as the warped face 1| of the fuel cam is extended, as viewed in Fig. 3, outward or to the left. A shift of the shaft 12 carrying the fuel cam toward the left as indicated makes it necessary that metering pin open a greater amount as the spring 4| forces the ball 34 against a different portion of the sloping warped face 1| of the fuel cam, although the latter is rotated only the same amount as it may previously have been rotated for a desired engine speed.

During flight it is frequently desired to change the fuel-air ratio from the pilot seat. To make such an adjustment effective upon the device a suitable manual adjusting means is provided. 'I'his means consists of the flrst class lever device previously referred to as 18. which is pivotally secured to the lower section |4 of the casing by means of a screw |01 and a lock nut |01'. One end I0 of the lever 18 pushes directly against the horizontal shaft 12 and the other end is provided with a roller I2 adapted to ride on an annular adjusting cam face ||3 formed on a head ||4 of a shaft ||4. The head ||4' is provided with a pin |08 which abuts stationary stop pins |09 on the casing. This last mentioned shaft is rotated by means of a rocker arm ||5 nonrotatably attached to the shaft by means of the lock nuts ||6 and ||1 which are keyed to the shaft. The rocker arm ||5' has a direct independent connection ||8 to an adjustment on the instrument board in the cockpit. It will thus be observed that by rotation of the shaft ||4' the cam face ||3 will be shifted so as to change the position of the first class lever 18. When the shaft is rotated in a direction so as to permit the end I0 of the first class lever to move outward, as viewed in Fig. 3, which corresponds to an upward movement, as viewed in Fig. 2, the fuel cam 10 will be urged in a corresponding direction by means of the coiled spring 14 which movement will shift the plane of rotation of the cam. The adjustment described will permit the cylindrical portion 92 of the metering pin to more nearly approach the center axis oi' the fuel cam 10 as the cam is rotated in this newly adjusted position, so that a different opening of the metering pin being provided to establish a new fuel-air ratio for the engine when the cam is subjected to different regular adjustments of the common throttle throughout the range of engine speeds.

Because the parts associated with the first class lever 18 are located in the compartment I5 within the casing, it is desirable also to seal the shaft ||4 in order to prevent fluid leaks. To that end there is supplied a packing nut |8 and a packing sleeve ||9 which secure a packing ring |20 by means of a coiled spring |2| bearing against a packing washer |22.

It will be evident then that the rocker arm 82 controlling the fuel cam 10, together with the air control rocker arm 88, have a range of relative throttling positions, whereby to control the engine speed by supplying a fuel and air mixture at a constant ratio but in different quantities. Furthermore the ratio or proportion of fuel to air may by a suitable mechanism be varied at will, while the engine is in operation, in order to adjust or tune it to respond more efficiently to different pressure conditions in the atmosphere.

There are times during flight, however, when it is advantageous for a pilot not to be compelled manually to make constant changes in the fuelair ratio and for this reason an automatic pressure adjustment coupled alternatively to the manual adjustment is of singular utility.

To provide an automatic adjustment together with an manual adjustment, a mechanism of the type illustrated in Figs. through 9 is incorporated in the invention. This mechanism is supported in a lower casing or section I4 attached to the mid-section |3 of the casing I0 in the same general manner as has been previously described for the mechanism supported in the lower section I4 shown in Figs. l through 4. The throttle control occupies the same relative position as does also the manually operated portion of the adjusting means, the difference being primarily in the addition of an automaticl adjusting portion located axially with respect to the horizontal fuel cam shaft 12.

A fuel cam is designed in a form slightly different from the fuel cam 10 originally referred to in order to provide for a combination of connections, one for the manually operated portion of the adjusting means and another for the automatic portion. 'Ihe cam has a warped surface of the same type as has been previously described and is fixed non-rotatably to the shaft 'i2 which is shiftable from left to right and vice versa. It will be noted, however, in this modification that the inner hollow space 'l5 is empty since no spring is necessary to shift the shaft toward the left. The shifting in both directions is accomplished directly by the manipulation of either the manual or the automatic adjusting means.

Although the principle of operation of the inanually operated portion of the adjusting means is the same in this modification as in the form illustrated in Figs. 1 through 4, some changes in design are requisite in order to have the manually operated portion of the adjusting means cooperable with the automatically operated portion thereof. With this in view, there is provided aA two-piece arcuate cam segment |30, parted substantially at the middle to form two opposed halves, forming a portion of what may be termed a manual mixture control cam which is nonrotatably fixed to a shaft |3I suitably journaled in a lower section |4 of the casing |0. The shaft is rotated in the usual manner by means of a mixture control rocker arm H5 locked to the shaft by the nuts H6' and Ill. Here also a packing nut H8' cooperating with a packing sleeve H9', a packing ring |20' and a coil spring |2I serve to hold a packing washer |22 in its recess in order to rotatably seal the shaft |3| in place. It will thus be apparent thatby rotating the rocker arm I I5 the mixture control cam can be rotated to a desired position.

Motion induced by the mixture control cam is transferred to the fuel cam 10 which operates on the metering valve, by means of what may be termed a mixture control yoke consisting of a rst class lever |35. The lever is fulcrumed more or less at its mid-point to a block or base |36 by means of a rivet |31 so that the lever is free to swing when urged in either direction by the mixture control cam. The device is unique in that the block or base |36 is pivoted by means of projections |38 journaled in the opposite halves of the cam segment in concentric alinement with the shaft |3| attached thereto, as will be most apparent in Fig. 8. The halves of the cam segment |30 are held together by means of screws |39.

At one end the first class lever is provided with a roller |40 which rotates freely upon the lever and travels over the surfaces at either side of a cam slot |4| formed between the halves of the cam segment |30. Since the cam slot |4| is disposed in a position at an angle to the plane of rotation of the cam segment |30, the roller will be moved back and forth as the segment is rotated. At its other end the lever is bifurcated as at |42 and loosely engages a portion of the fuel cam 10'. It will be noted that the cam 10' has an annular recess |43 in which the bifurcated portions of the lever are permitted to ride and since there is an annular shoulder |44 at the right side and a similar annular shoulder |45 on the left side, as viewed in Fig. 6, the motion caused by tilting the lever |35 in either direction will be transferred directly to the cam 'l0' causing it to change the plane of its rotation ac cordin'gly. It will be apparent then that the fuel-air ratio of the metering device can be `altered manually at the will of the operator 1ndependently of the throttling means. shaft |3I is being rotated the fulcrum of the lever |35 will pivot with respect to it and the lever will be held in position, subject to being tilted in one direction or the other depending on which side of the cam slot |4| is pushing against the roller |40.

The automatic means previously referred to is operative alternatively with the manual adjusting means just described in such a way that either one or the other is always controlling the ratio of the fuel-air mixture. In the form illustrated in Figs. 5 and 6, the automatic means is shown to consist of a pressure responsive bellows forming a resiliently extensible member so mounted that it will expand or contract with changes in atmospheric pressure and transmit its adjustment directly to the fuel cam.A A threaded extension is provided on the left hand side of the lower portion I4' of the casing and to it a cup-like member |5| forming a receptacle is attached by means of a sleeve member |52. In the member |52 are spanner wrench holes |52 used for securing the member in place and for adjusting it once in place. Within the receptacle is a resiliently extensible bellows |53 mounted at its base upon the sleeve member |52 at a point |54 where it is sealed tightly in order to make an air-tight pocket |55 within the receptacle. A cap |56 closes the upper or left hand end of the bellows.

In order to attach the bellows to the cam 'I0' there is provided a connecting pin |51 secured at one end by means of a pin |58 to the cap |56 and swivelly attached at the other end to the fuel cam 10' by means of a button and claw fitting |59. In order properly to mount the pin |57 the extension |50 is provided with a sleevelike portion |6| and has a hollow space |62 in which are positioned elements of a packing gland consisting of a packing |63, a packing ring |64, a coiled spring and a retaining nut |66, which is eective in preventing any fuel ac- While the y cumulating in a chamber l from filling an air space |61 within the bellows.

In the wall of the receptacle |5| there is positioned a valve |68 over which is screwed a cap |69 and by this means a greater or lesser amount of gas can be forced into the sealed pocket |55. On the opposite side of the bellows a bleed hole is drilled through the sleeve member |52 in order that the space |61 within the bellows may be subjected to atmospheric pressure. It will be understood from this that since the quantity of gas sealed within the pocket |55 remains constant any change in atmospheric pressure on the opposite side of the bellows will tend to expand the bellows or contract it, causing the cap |56 to move toward the left or right. Such motion induced in the cap will be directly transmitted by means of the pin |51 to the fuel cam 10', producing a corresponding adjustment in the fuel-air ratio.

When it is desired to calibrate the bellows, gas can be introduced through the valve |68 to an amount such that the pressure on the sealed side of the bellows is in proper proportion to atmospheric pressure. A mechanical calibration is also available by resorting to the expedient of screwing the sleeve member |52 on or off the extension |50. The bellows may thus be distended or contracted to produce a greater or lesser tension on the pin |51 and a corresponding reactance to atmospheric pressure.

In order that the automatic pressure adjustment may function freely and not be restricted by the manually operated portion of the adjusting means, the cam slot |4| has been specially constructed, as will be more clearly seen in the development of the cam slot shown diagrammatically in Fig. 9. It will be noted that one of the sloping ends of the cam slot has a unlform width, this being the portion |4I of the slot used when it is desired to adjust the device directly by means of the rocker arm l5'. Since the roller |40 is but slightly smaller in diameter than the space between the faces of this portion of the cam slot, it will be urged in one direction or the other depending upon the direction of rotation of the cam segment. When it is desired to have the automatically adjusted portion operate independently, the cam segment can be rotated so that the roller |40 passes to an enlarged portion.|4| of the slot |4|, shown at the left end as viewed in Fig. 9. The left end of the slot is considerably wider than the diameter of the roller |40 and has the effect of permitting it to tilt freely back and forth therein. Therefore, when the pilot wishes, as a matter of convenience, to have the automatic adjusting means operate he has only to rotate the mixture control cam until the enlarged portion 4| of the slot |4| engages the roller |40, then when the bellows |53 moves the cam 10' to the right or left the lever |35 is free to tilt in one direction or the other without being restricted by the surfaces of the cam slot. When it is again desired to make the adjustments manually, the mixture control cam is rotated back again so that the walls of the end |4| of the cam slot bear directly against the roller |40 and force it in one direction or the other at the will of the operator. There is sufficient resiliency in the automatically operated portion so that no `evil effects will result from forcing it the comparatively small distance in one direction or the other necessary to produce manually the desired adjustments of the cam 10'.

There has thus been provided a mechanism for maintaining a predetermined fuel-air mixture to be supplied to a combustion engine having a double alternative adjustment, one part operated automatically and the other part manually by means of which the ratio of fuel to air can be changed to suit different atmospheric conditions while the metering means is in operation. Substantially all of the parts are compactly housed and sealed within a casing supporting the various mechanisms, all of which may be constantly lubricated by the liquid fuel itself.

I claim as my invention:

1. A fuel and air supply system for an internal combustion engine comprising an air intake manifold and a valve having means for actuating the same, a fuel distributing device having a plurality of fuel impelling elements for supplying fuel to the engine, fuel control means for varying the fuel supply to the engine, a shiftable cam element rotatable in contact with said fuel control means, and manually operable throttle means interconnecting the cam element and the actuating means of the air intake valve so that the ratio of fuel to air supply to the engine is maintained at a definite ratio irrespective of the quantity of fuel admitted to the engine throughout the range of engine speeds, and independent adjusting means directly operable upon said shiftable cam element to shift the position thereof with respect to said fuel control means and cause a change in the fuel-air ratio dependent upon the respective movements of the fuel control means and the air intake valve.

2. A fuel and air supply system for an internal combustion engine comprising, in combination, an air intake manifold, air control means therein, a fuel source for supplying measured quantities of fuel to the engine, fuel control means for varying the quantity of fuel supplied by said fuel source including an adjustable member, an axially shiftable rotating means of varying diameter contacting the adjustable member for changing the position of said member, manually operable throttle means interconnecting said rotating means and said air control means so that the quantity of air passing said air control means is changed in accordance with a definite ratio to correspond with the quantity of fuel admitted by the fuel control means throughout the range of engine speeds, means for adjusting the rotating means axially to effect a change in the ratio of movement between the adjustable member and the air control means, and manual control means for said last mentioned means having an operation independent of the throttle means.

3. A fuel and air supply system for an internal combustion engine comprising, in combination, an air intake manifold, an air intake control means therefor, an adjustable fuel supply means, fuel control means for varying the quantity of fuel supplied by said supply means, rotatable and axially shiftable cam means for adjusting said fuel control means, said cam means having a warped surface, manually operable throttle means interconnecting said cam means and said air control means so that the ratio of the quantity of fuel to the quantity of air is maintained at a definite value throughout the range of engine speeds for a given axial position of said cam means, means for adjusting the cam means axially independently of the throttle means in order to render e'ective a different portion of the warped surface of said cam means to cause a change in the fuel-air ratio, and manual control means attached to said adjusting means for effecting an independent adjustment thereof.

4. A fuel and air supply system for an internal combustion engine comprising, in combination, an air intake manifold, an air intake control means for the manifold, an adjustable fuel supply means, an axially shiftable and rotatable cam element having a warped circumferential surface cooperating with a part of the fuel Asupply means and operable upon rotation to change the adjustment of the fuel supply means, throttling means for imparting desired rotation to said cam element and for actuating said air intake control means, an adjusting mechanism for altering the effect of cam rotation upon the adjustable fuel supply means comprising a lever and a cam in contact therewith for shifting said cam element axially to render a different portion ofy the warped surface of said cam element, effective for controlling said adjustable fuel supply, and control means for imparting desired movement tosaid second mentioned cam.v

5. A fuel and air supply system for an internal combustion engine comprising an air intake manifold, a control valve therefor having means for actuating the same, a fuel pumping device for supplying fuel to the engine, fuel control means for varying the quantity of fuel supplied to the engine including a control element, a shiftable cam means having a warped surface for contact with said control element for changing the position thereof, manually operable throttle means interconnecting the cam means and the actuating means for the air control valve so that the ratio of the quantity of fuel to the quantity of air supplied to the engine is maintained ata definite amount throughout the range of engine speeds, and independent adjusting means directly operable upon the shiftable cam means to shift the cam means axially in order to present a different portion of the warped surface of the cam means to the control element and cause a change in the fuel-air ratio.

6. A fuel and air supply system for an internal combustion engine comprising, in combination, an air intake manifold anda valve therein having means for actuating the same, variable fuel supply means having a control element for determining the quantity of fuel supplied thereby to` the engine, a shiftable cam means pressing against said element for changing the position of said element to vary the adjustment of said fuel supply means, said cam means having a warped surface with which said control element cooperates, manually operable throttle meansV interconnecting the cam means and the actuating means for the air intake valve so that the ratio of the quantity of fuel to the quantity of air is maintained at a definite amount throughout the range of engine speeds, and adjusting means directly operable upon the shiftable cam means to shift the position thereof relatively to the air valve in order to change the fuel-air ratio.

7. In a fuel and air supply system for an internal combustion engine, air control means, fuel control means, and actuating mechanism for the air and the fuel control means comprising a rotatably mounted sleeve, manually operable linkage interconnecting said ,sleeve and said air control means simultaneously to rotate said sleeve and to actuate said air control means, a cam element having a warped circumferential surface the radii of the surface varying both when considered in an angular direction and also in a direction axially of said cam, said cam being mounted in said sleeve for rotation therewith and for movement longitudinally thereof and the cam surface cooperating with the fuel control means to vary the quantity of fuel supplied thereby as the cam is rotated, and means for shifting said cam axially relative to said fuel control means and said sleeve to render a different portion of the cam effective to govern the fuel control means, thereby to vary the ratio of fuel and air supplied to the engine.

8. In a fuel and air supply system for an internal combustion engine, air control means, fuel control means, and actuating mechanism Yfor the air and fuel control means comprising a rotatably mounted element, manually operable linkage interconnecting said element and said air control means simultaneously to rotate said element and to actuate said air control means in a predetermined relationship, a member mounteddn said element for rotation therewith and for movement longitudinally thereof, said member being operatively associated with the fuel control means to vary the quantity of fuel supplied thereby to the engine, said member upon rotation While in one axial position relative to said element varying said fuel control means to maintain a predetermined fuel-air ratio throughout the movement of the manually operable linkage and upon rotation while yin a diiferent axial position. relative to said element maintaining a different fuel-air ratio, and means for shifting said member axially relative to said elementY 9.A fuel discharge mechanism for supplying fuel to a combustion engine comprising a pump device connected to the engine, a fuel control element, throttling means operatively associated with said element and operable to move the element so as to vary the fuel supplied to the engine, automatic adjusting means for said throttling means comprising means responsive to atmospheric pressure having an operative connection with the throttling means for varying the setting of the throttling means in accordance with pressure variations, and a manual adjusting means for said throttling means comprising a cam and lever means connected with the throttling means for shifting the setting of said means at will, said cam and lever means being provided with a loose connection in one position of adjustment to allow shifting of the throttling means by the pressure responsive means unrestricted by action of the manual adjusting means.

10. A fuel discharge mechanism for supplying fuel to an internal combustion engine comprising a pump device connected to the engine, a fuel control element, throttling means operatively associated with said element and operable to move the element so as to vary the fuel supplied to the engine, pressure responsive adjusting means having an operative connection with the throttling means for varying the setting of the throttling means with changes in atmospheric pressure, and a manual adjusting means comprising a rotatable cam segment having a cam slot therein with an enlarged portion, a pivoted lever means having at one end a cam follower movable in the slot in said cam segment and having its other end engaged with the throttling means for variably shifting the setting of said means alternatively with said pressure responsive means, said cam segment being rotatable to position said cam follower in the enlarged portion of said slot to allow shifting of the throttling means by the pressure responsive means unrestricted by action of the manual adjusting means.

11. In a fuel and air supply system for an internal combustion engine, .in combination, a fuel control means, a shiftable element for adjusting said control means, an automatically operable pressure responsive means for shifting said element, and a manually actuable means operable to take over the shifting of said element comprising a rotatably mounted cam segment having a cam slot therein enlarged at one end, lever means fulcrumed on a block pivotally mounted in the cam segment and having at one end a cam follower received in the slot and having its other end engaged with the control means for variably shifting the setting of said means alternatively with the shifting occasioned by said pressure responsive adjusting means, said cam segment being movable manually to govern the shifting of said element or to a position with respect to the cam follower allowing shifting of the control means by the pressure responsive means unrestricted by the manually actuable means.

12. In a mechanism for supplying fuel and air to an internal combustion engine, in combination, a valve controlled air intake, a variable fuel supply, a control element for varying the quantity of fuel supplied by the fuel supply, throttling means connected with the valve in said air intake and operatively associated with said control element so as to vary the control element and the valve simultaneously and in corresponding amounts, and a manual adjusting means comprising a cam segment having a cam way therein and a lever pivotally mounted in the cam segment and having at one end a cam follower movable by the cam way and having another end engaged with the throttling means for variably shifting the setting of said means to provide for varying the control element by different corresponding amounts when said throttling means is moved throughout said range of relative positions.

13. In a /fuel supply system for an internal combustion engine, in combination, a fuel control means and governing mechanism for the fuel control means comprising a throttling means governing mechanism for said fuel control means comprising a rotatable member having means for actuating the same manually, an element mounted in said member for rotation therewith and for axial adjustment relative thereto, said element being operatively associated with said fuel control means to vary the quantity of fuel supplied to the engine as the element is rotated, said element being constructed to modify the effect of its rotation upon the fuel control means depending upon the axial position of said element relative to said member, pressure responsive means connected with said element for shifting the same axially in accordance with pressure variations, and manually actuable means operable to permit unrestricted shifting of said element under the control of said pressure responsive means or to wrest shifting of said element from said pressure responsive means, said manually actuable means comprising a rotatably mounted segment having a cam slot therein, a lever pivotally mounted intermediate its ends and at one end carrying a cam follower engaging the cam slot and at the other end engaging said element, said cam slot through a portion of its length conning said cam follower to prevent pivoting of the lever relative to the cam slot and throughout the remainder of its length being enlarged to permit movement of said lever whereby the pressure responsive means is placed in control of said element, and manual means for rotating said segment to place the cam follower in a desired portion of said cam slot.

CARL F. HIGH.

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