US3051087A

US3051087A - Fuel injection apparatus

Info

Publication number: US3051087A
Application number: US859484A
Authority: US
Inventors: Axel R Scholin
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-12-14
Filing date: 1959-12-14
Publication date: 1962-08-28
Anticipated expiration: 1979-08-28

Description

Aug. 28, 1962 A. R. SCHOLIN 3,051,087

FUEL INJECTION APPARATUS Filed Dec. 14, 1959 5 Sheets-Sheet 1 INVENTOR. AXEL R. SCHOLIN Aug. 28, 1962 A. R. SCHOLIN 3,051,087

FUEL INJECTION APPARATUS Filed D90. 14, 1959 5 Sheets-Sheet 2 N INVENTOR.

LL AXEL R. SCHOLIN ATTY.

Aug. 28, 1962 A. R. SCHOLIN FUEL INJECTION APPARATUS 5 Sheets-Sheet 4 Filed Dec. 14, 1959 INVENTOR. Axau. R. SCHOLIN ATTY.

Aug. 28, 1962 A. R. SCHOLIN 3,051,087

FUEL INJECTION APPARATUS Filed Dec. 14, 1959 5 SheetsSheet 5 INVENTOR. AxEL. R. SCHOLIN ATTY.

United States Patent 3,051,087 FUEL INJECTION APPARATUS Axel R- Scholin, 4646 N. Wolcott Ave., Chicago 40, Ill. Filed Dec. 14, 1959, Ser. No. 859,484 4 Claims. (Cl. 1034) The present invention relates to fuel injection apparatus for delivering in a controllable manner high pressure fluid such as liquid diesel oil in the case of diesel engines, or gasoline in the case of combustion engines having electrical ignition systems.

It is among the general objects of the present invention to provide an improved fuel injection apparatus for delivering a fluid, specifically a liquid, to separate points from a source of the liquid, with the fluid being maintained at a substantially constant pressure at such delivery points during the delivery thereof.

A further object of the invention is to provide an apparatus of this sort which is adaptable, with no modification whatsoever, to use in connection with internal combustion engines having the same number of engine cylinders, regardless of the disposition of such cylinders, i.e. whether the engine be of the in-line type or a V-type engine.

A still further object of the invention is to provide such a fuel injection apparatus including a series of injection pumps of the reciprocable plunger, cam-operated type and which embodies novel means for either individually or collectively controlling the effective stroke of the plungers associated with the various pumps. By individually adjusting the stroke of the plungers, it is possible to regulate the quantity of fuel fed to each cylinder so that at any given engine speed equal quantities of fuel will be delivered at equal pressures to all of the cylinders. By collectively adjusting the stroke of the plungers, throttle operation of the engine is made possible in such a manner that during each engine cycle i.e. upon one complete revolution of the engine crankshaft, equal quantities of fuel will be delivered to all of the cylinders in the proper order of timing and in amounts commensurate with any desired engine speed.

Fuel injection devices which depend for their operation upon a series of injection pumps of the reciprocable plunger type and in which the plungers are operated by means of rocker arms under the control of a common cam shaft are known and conventional devices of this character are difficult to mount and, furthermore, interchanging thereof is extremely diflicult. Most of these devices must be designed for a given type of engine and they are incapable of servicing other types of engines. The adjustments required of such devices are involved and they require considerable time and skill, even when they are preformed by trained experts in the field. Most of these devices are designed as component parts of the engine itself and, when the engines are of the motor vehicle type, servicing or replacement of the devices can be made only by skilled labor and in specially equipped workshops to which the vehicle must be brought.

The present invention is designed to overcome the above-noted limitations that are attendant upon the use of conventional fuel injection apparatus and systems of this character and, toward this end, it contemplates the provision of a novel form of injection apparatus which may readily be mounted on a vehicle and operatively connected to the combustion engine thereof by the ordinary mechanic or other operator and which, when once mounted, may readily be serviced in the field without necessitating shop servicing. The invention further contemplates the provision of such an apparatus which, for major servicing, may conveniently be removed from the 3,051,087 Patented Aug.28, 1962 "ice vehicle, taken to the shop, repaired and reassembled in the vehicle with a minimum of time and labor consumed.

The provision of an apparatus of the character briefly outlined above being among the principal objects of the invention, yet another object is to provide an injection apparatus of the rocker-operated, reciprocable plunger type wherein the various rocker arms for operating the plungers may, by the simple expedient of loosening a single fastening screw, be moved to an out-of-the-way position wherein the upper ends of the plungers are exposed and readily accessible for removal by merely pulling them from the guide sleeves in which they operate. By such an arrangement, replacement of worn plungers may be effected with little difficulty.

Another object of the invention in a rocker operated multiple pump assembly is to provide an extremely effective novel lubrication system wherein lubricant is supplied to all of the working moving parts of the assembly in adequate amounts while an excess of lubricant is automatically supplied to certain strategic locations where frictional forces would otherwise be excessive.

Yet another object of the invention is to provide a fuel injection apparatus embodying a series of fuel pumps of the reciprocable plunger type having associated therewith novel means whereby any pump leakage caused by the bypassing of fuel around the reciprocating pistons will be effectively discharged from the pump cylinders so that this leakage fluid will not cause binding of the plunger or otherwise interfere with proper plunger operation.

An important and specific object of the present invention, in a fuel injection apparatus for internal combustion engines, is to provide a multiple pump system including a pump individual to each engine cylinder and wherein all of the pumps are of the reciprocable plunger type in which the plunger operates within a cylinder or bore having a fuel inlet opening in the wall thereof adapted to be cut off by passage of the plunger thereacross. In further fulfilling this object novel means are provided for collectively varying, not the amplitudeof the strokes of the various plungers as is customary with many conventional fuel injection systems, but the level at which the various pistons operate within their respective bores, thus not only advancing or retarding the actual time of cut-off, but also varying the quantity of fuel pressurized and delivered to the cylinders during the time the plungers move from the points of cut-oif to the limit of their downward stroke.

The provision of a fuel injection apparatus which is extremely simple in its construction; one which is comprised of a minimum number of parts, particularly moving parts, and which therefore is unlikely to get out of order; one which is rugged and durable and which therefor is not subject to undue wear; one which will accommodate a high range of fuel displacement; one which is small and compact considering its capacity; and one which, otherwise, is well adapted to perform the services required of it, are further desirable features which have been home in mind in the production and development of the present invention.

Numerous other objects and advantages of the invention, not at this time enumerated, will become readily apparent as the following description ensues.

In the accompanying five sheets of drawings forming a part of this specification one illustrative and preferred embodiment of the invention has been shown.

In these drawings:

FIG. 1 is a side elevational View of an automotive internal combustion engine showing the fuel injection apparatus of the present invention operatively applied thereto;

FIG. 2 is an enlarged fragmentary sectional view taken vertically through a portion of a fuel injection apparatus of FIG. 1 in the vicinity of one of a number of injection pumps employed in connection with the present invention;

FIG. 3 is an exploded view, partly in section, illustrating the telescopic assembly of certain pump elements associated with each pump assembly;

FIG. 4 is a top plan View of the structure shown in FIG. 2;

FIG. 5 is a fragmentary sectional view similar to FIG. 2 showing the parts in a different position;

FIG. 6 is a reduced sectional view taken substantially along the line 6-6 of FIG. 5 with certain rocker arm mechanism omitted in the interests of clarity;

FIG. 7 is a sectional view taken substantially along the line 77 of FIG. 4;

FIG. 8 is a fragmentary side elevational view of the structure shown in FIG. 4;

FIG. 9 is a fragmentary sectional view taken substantially along the line 9-9 of FIG. 4; and

FIG. 10 is a sectional view taken substantially along the line 10-10 of FIG. 9'.

General Considerations Referring now to the drawings in detail and in particular to FIG. 1, the fuel injection system of the present invention is shown as being operatively embodied in a composite iluid delivery apparatus or assembly which is' designated in its entirety at 10 and it is adapted to provide fluid such as diesel oil, in the case of a diesel type internal combustion engine, or gasoline in the case of a combustion engine having provision for timed electrical ignition, through a series of fuel lines 12 leading from a common fuel reservoir 14 to a series of individually connected injectors or nozzles 16 by successive pulsing operations under the control of a series of pump assemblies 17 there being one assembly for each fuel line 12 and its respective nozzle 16. The nozzles 16 are shown in FIGS. 1 and 5 as being operatively connected to the intake manifold 18 of the combustion engine 20, it being understood of course that the point of introduction of fuel into the manifold 18 for each nozzle 16 will be in the immediate vicinity of the intake valve for the particular cylinder supplied by such nozzle. The points of delivery of fuel to the various engine cylinders will vary for different types of combustion engines and the fuel lines 12, being in the form of conventional copper tubing, may be appropriately cut to length and shaped so that they may be attached by appropriate fittings such as the fittings 21 and 22 for straight line or V-type cylinder arrangements so that no modification of the appartus 10 is required to accommodate the delivery of fuel to the desired regions.

Pressurization and discharge of the fuel is accomplished by reciprocation of a series of plungers 24 associated with the various pump assemblies 17, and descent of each piston closes off a series of fuel inlet openings 26 leading from the fuel reservoir 14 to a fuel pressurizing and displacement chamber 28 with subsequent compression of the fuel below the chamber to the point where the resistance of a compression spring 30 is overcome so that fuel is caused to pass around a valve element 32 and in the form of a solid column through the fuel line 12 to the corresponding injection nozzle 16. Each plunger 24 is operable under the control of a rocker arm 33 which, in turn, is operable under the control of a cam 34. The various rocker arms 32 are mounted for rocking movement on a shaft 36 and the latter is capable of being shifted or displaced in a transverse direction in such a manner that the effective stroke of the various plungers 24 may be varied to vary the quantities of fuel displaced by the various plungers during each stroke thereof. The cams which actuate the rocker arms are driven in timed relation to the engine crankshaft and the cams are so adjusted that each plunger will displace fuel for fuel pressurization and transmission to the intake manifold for delivery to its respected engine cylinder at the precise time that the intake valve for that cylinder commences to open as is customary withfuel injection systems of this general character. The displacement of the rocker arm shaft is effected under the control of a lever 38 which, upon depression thereof causes the rock shaft 36 to be lowered so that the effective strokes. of the various rocker arms 33 will likewise be varied. When applied to automotive use, the control lever 38 will be operatively connected to an articulated motion-transmitting train to a manual or foot pedal such as the accelerator pedal of the vehicle so that the quantity of fuel fed to the engine will predetermine the rpm. of the vehicle.

From the above brief description it will be seen that the invention is predicated upon the use of variable displacement pumps for supplying fuel to the various engine cylinders, each pump including a reciprocable plunger which, upon descent thereof, establishes a cut-01f for the opening leading to the pressurization chamber. Because the cams which control the reciprocation of the plungers are constant displacement cams, the actual stroke of the plungers within their respective pump cylinders does not vary in amplitude, but the range of movement of the plunger is shifted as the common shaft on which the rocker arms are mounted for tilting movement is shifted vertically in one direction or the other. With the plunger reciprocating at a given amplitude through a high range of movement within the cylinder, movement of the plunger past the cut-off point will be slight so that a relatively small quantity of fuel will be pressurized in and displaced from the pressure chamber and thus fed to the injection nozzle. With the plunger reciprocating at a lower range Within the pump cylinder but with the same amplitude, the cutoff point will be reached earlier in the cycle so that the balance of the downward stroke of the plunger thereafter will displace a greater quantity of fuel. Such is the essence of the present invention. The specific details of the structure which has been illustrated herein for carrying out these principles of the invention are merely exemplary and they will now be described in considerable detail, together with certain other refinements associated therewith as, for example, a novel splash lubrication system employed for maintaining the working parts of the system adequately lubricated.

The Casing and Framework Structure Referring now to FIGS. 5 and 6 the fuel injection assembly 10 briefly described above involves in its general organization a main body or casing 40 of generally cupshape rectangular design and including a substantially flat bottom wall 42,

side walls

44 and 46 respectively, and front and

rear end walls

48 and 50 respectively. The casing 40 is adapted to be fixedly secured in any suitable manner, either directly to a portion of the engine block 51 or to a portion of the vehicle chassis 554, the casing 40 bring illustrated herein as being mounted on a horizontal member 56 suitably supported on the chassis.

The upper end of the casing 40 is open but is maintained normally closed by means of a suitable cover plate 52 which is lbolted as at 54 to the flanged upper rim 56 of the casing, a suitable gasket 58 being interposed between the cover plate 52 and rim 56. The cover plate 52 is formed with a pair of depending oil-collecting and distributing

ribs

60 and 62 respectively, the nature and function of which will be made clear presently; A filling opening 64 is provided in the cover plate 52 and is adapted to be closed by a closure plug 66. A drain plug 67 is provided for the casing bottom wall 42.

The side wall 44 is provided with a thickened portion or section 70 defining an upwardly facing shelf or ledge 71 and this thickened portion of the side wall is extended downwardly as at 72 (see also FIG. 5) beyond the level of the bottom wall 42 of the casing 40. A series of vertical bores 74 are drilled through the thickened part 70 of the wall 44 and the various pump assemblies so that the fuel inlet opening to the pressurizing chamber 28 will be cut off almost at the commencement of each downward stroke of the plunger 24 and the plunger will force the solid column of liquid in the chamber 23, bore 120 and tubing 12 a greater distance after the end of the plunger has passed the cut-off point with respect to the opening 26 so that an appreciably greater quantity of fuel will be fed through the injection device 16. It will be understood of course that intermediate adjustments of the shaft 36 between the uppermost and lowermost positions of which it is capable of assuming will result in proportionate displacements of fuel and the feeding of proportionate volumes of fuel through the injection device 16 to the intake manifold 18.

The Rocker Arm Assemblies Referring now to FIGS. 2 and 4, the shaft 36 on which the rocker arms 33 are mounted has its ends fixedly secured to the distal ends respectively of a pair of lever arms 160 which are capable of limited oscillatory movement about the aXis of a pair of studs 162 which are threadedly received in the front and

rear end walls

48 and 50 respectively of the casing 44). Clamping nuts 164 serve to clamp the distal end regions of the lever arms 160 against respective shoulder 166 provided near the opposite ends of the shaft 36. The two lever arms 160, together with the shafts 36, constitute in effect a rigid U-shaped frame-like structure of which the shafts 36 constitute the bight portion, and which bight portion is capable of limited movement throughout a very small arc tangent to a vertical plane. The individual rocker arms 33 have enlarged central portions 170 provided with spacer bosses 172 on opposite sides of the arm, the shaft 36 extending through the spacer bosses, and the latter serving to maintain the rocker arms 33 in their spaced relationship along the shaft 36 with little or no side play between these rocker arms.

One end of each rocker arm 33 is bifurcated as at 174 and a pin 176 extends between the two bifurcations. A roller 178 is mounted on the pin and this roller constitutes a cam follower for the adjacent cam 34 which it overlies. The other end of the rocker arm 33 carries an adjusting screw 180 which is threadedly received in the arm and is adapted to be clamped in any desired position of adjustment by means of a clamping nut 182. The head portion of the adjusting screw 180 is provided with a hardened semi-spherical bearing surface 183 designed for engagement with the extreme upper end of the adjacent plunger 24 of the respective pump assembly 17.

(The Rocker Arm Adjusting Mechanism) Still referring to FIGS. 2 and 4 and additionally to FIGS. and 6, the means for collectively adjusting the position of the various rocker arms 33 comprises a manually or pedally operable rock shaft 190, the rear end of which is rotatably supported in an anti-friction hearing assembly 192 carried by the rear end wall 50 and the other end region of which is rotatably supported in a similar bearing assembly 194, with the shaft projecting completely through this latter bearing assembly. An adjustment foot 196 has a bifurcated end 198 adapted to be adjustably clamped by a screw to the front end of the shaft 190 and the distal end of the foot 196 is designed for cooperation with a limit stop screw 202 (FIGS. 4 and 5) which is threaded through the horizontally turned end 204 of an L-shaped bracket 206 which is clamped by means of 6 screws 208 in a vertical position to the front end wall 48 of the casing 140.

Mounted upon the rock shaft 190 adjacent the ends of the shaft and within the confines of the end walls 48 and are a pair of collars 210 each of which is formed with a radially projecting finger 212 adapted to project between a pair of bifurcations 214 provided at the extreme distal ends of the lever arms 160. The rear end of the rock shaft 190 projects completely through the bearing 192 and is adapted to have clamped thereto by means of a clamp- Cir ing screw 216 the split end 218 of the previously vertical operating lever 38. The distal end of the lever 220 is provided with an attachment hole 222 therethrough by means of which this lever may, through the medium of a suitable linkage mechanism or the like (not shown) be operative ly connected to a foot pedal which may constitute the accelerator pedal of the vehicle which is propelled by the combustion engine.

The various rocker arms 33 are mounted for free and independent rocking movement on the shaft 36 and the cam followers 73 are normally maintained in rolling contact with their respective cams 34 under the influence of the springs 134 which normally urge the plungers 24 upwardly to their fully retracted positions. The springs 134 therefore not only serve to maintain the plungers 24 elevated but they also serve to apply yieldable torque to the rocker arms 33 tending to rotate them in a clockwise direction as viewed in FIG. 2 so that the cam followers 178 will rest upon the cams 34 and, by a second class lever action, normally urge the shaft 36 on which the rocker arms 33 are mounted in an upward direction, to in turn urge the supporting levers 164 of the shaft 36 to swing in a clockwise direction about the axis of the studs 162. These latter levers 16!) will in turn, through the medium of the bifurcations 214 bearing against the fingers 212 serve to urge the collars 210, and consequently the rock shaft 1% in a counterclockwise direction so that the distal end of the lever 38 will be raised to the fullest extent of which it is capable, the final position of the lever being determined by the setting of the adjusting screw 202' (FIG.

From the above description it will be seen that upon depression of the lever 38, the rock shaft will be turned in a clockwise direction as viewed in FIG. 2, so that under the influence of the fingers 212 provided on the collars 210, the bifurcated distal ends 214 of the two lever arms 16d will be lowered, thus carrying with them the shaft 36 on which the various rocker arms 33 are mounted. Since the cams 34 are not adjustable about their common axis of rotation, the net effect of the lowering of the shaft 36 will be to cause the operating ends of the rocker arms 33 to oscillate at the same amplitude of displacement but in a lower region wherein the plungers 24 are caused similarly to reciprocate at the same amplitude but with an earlier cut-off as previously described.

The Cam Shaft and Its Driving Mechanism Referring now to FIGS. 1, 4 and 7, the various cams 34 are preferably circular in contour and the cylindrical operating surfaces thereof have their centers offset from the longitudinal axis of the cam shaft upon which they are mounted. This cam shaft is shown at 233 and each of the cams 34 is formed with a sleeve portion 232 through which there extends a pair of set screws 234 by means of which the angular position of the cam 34 ion the shaft 233 may be adjusted and the cam thereafter locked in any selected angular position of adjust- T116111. It will be understood of course that the various earns 34 will be angularly adjusted on the cam shaft 233 so that the rise portion of each cam portion will, through the medium of a rocker arm 33, effect lowering of its respective pump plunger 24 during the time that the intake valve of the engine cylinder which is being served by the particular cam and plunger is in its opening cycle, and that the decline portion of the cam will be encountered by the cam follower roller 178 after the intake valve has become closed. As best seen in FIGS. 4 and 6, the cam shaft 233 extends longitudinally through the casing 43 and has its rear end region reduced as at 235 and supported in a roller bearing 236 carried by the rear end wall 5% of the casing 43. The front end region of the cam shaft 236 is similarly reduced as at 237 and is supported in a roller bearing assembly 238 carried by the front end wall 48 and held in position thereon by a retainer plate 240 which is removably se- 17 are operatively installed within these vertical bores and operate in a manner that will be described subsequently. The thickened portion '70 of the side wall 44; of the casing ltl is formed with an outwardly facing rectangular recess 76 of relatively large proportions, this recess being separated from the operating chamber 7% provided within the casing 40 by means of a relatively thin wall section 80. The recess 76, in combination with a generally rectangular cup-shape closure plate 82 defines the previously mentioned fuel supply reservoir 14. The closure plate '82 has an open flanged rim 84 which is bolted as at 86 to the thickened wall portions 70 exteriorly thereof. A suitable gasket 83 elfects a seal for the reservoir 14. A fuel feed opening 94) (FIGS. 5 and 7) is provided with a suitable fitting 92 by means of which a fuel line, fragmentarily shown at 94 may be connected to the reservoir 14, this fuel line leading from a suitable source of fuel such as the gasoline of diesel oil tank (not shown) of the vehicle. A primary cup assembly 95 communicates through the plate 32 with the reservoir 14.

The Pump Assemblies The various pump assemblies 17 are identical in construction, and therefore it is believed that a description of one of them will suflice for them all. There is one pump assembly for each fuel injection nozzle 16 and each pump assembly comprises an outer guide sleeve 1% (FIGS. 2 and 3) which is press-fitted or otherwise secured within its respective vertical bore 74 with its upper end extending upwardly as at 14M above the edge 71. Each vertical bore 74 intersects the recess 76 so that the vertical wall face 192 of the recess is cut back a slight distance with the medial region of the guide sleeve 1W traversing the recess and being completely surrounded by the fuel within the reservoir 14. Each pump assembly further includes a tubular valve seat-forming member which is telescopically received within the lower end of the guide sleeve Mill and which is provided with an enlarged head or flange 1% at its lower end defining a valve seat 1%. The bore 74 is reduced as at Hit where it passes through the depending portion 72 of the thickened part 70 of the wall 44 thus affording an upwardly facing shoulder 112, and between which shoulder and the lower rim of the guide sleeve 1% the head like is fixedly clamped.

The valve seat 108 is designed for cooperation with a conical face 114 provided on the valve 32. The valve 32 is normally maintained in its closed position on the seat 108 by means of the previously mentioned compression spring which encircles a valve stem 118 and bears at its lower end against the bottom wall of a socket 120 provided in a sealing plug 122 forming a part of the fitting assembly 42. The character of the various fitting assemblies will be made clear subsequently.

The valve element 32 is provided with a pilot stem 124 having a bore 126 extending therethrough axially thereof. The axial bore 126 intersects a transverse bore 28 to permit passage of fuel from the pressure chamber 28 through the valve and into the reduced bore lllll when the valve 32 is moved from its seat 108.

Each pump plunger 24 includes a head portion 130 which is slidable within the guide sleeve Ni), and it also includes a reduced stem portion 132 which is slidable within the seat-forming tube 194. A compression spring 134 surrounds the stem portion 132 of the plunger 24 and bears at its lower end against the upper end of the seat-forming tube 1G4 and at its upper end against the annulus provided at the lower end of the head portion 130 of the plunger 24. The plunger 24 is thus normally urged upwardly within the guide sleeve toward a fully retracted position.

The previously mentioned inlet opening 26 exists by virtue of the provision of a series of radially disposed registering holes provided in the guide sleeve ltltl and tube 1&4 respectively, these two holes moving into exact alignment when the two parts are telescopically assembled on each other to provide the inlet opening 26 (FIG. 5). The inlet opening 26 thus establishes communication between the reservoir 14 and the pressure chamber 28 within the pump.

(The Pump Fittings) The fittings 22 for the various pump assemblies 17 utilize conventional or slightly modified automotive fitting hardware. The sealing plugs 122 have elongated shank portions 1% which are threadedly received as at 142 in the reduced portions of the bores 74. The bottom of the socket in each plug 122 is drilled as at 144 to provide a channel which communicates with the central bore 146 in a nipple member 148 which surrounds the shank and which is clamped against the underneath base of the depending portion 72 of the casing 40 by means of a sealing plug 122. The bore 138 communicates with the tubing 12 and the latter is clamped to nipple member by means of a threaded collar 150.

(Operation of the Pumping Instrumentalities) In the operation of the various pump assemblies, the plunger 24 of each assembly is normally maintained in its retracted position under the influence of the spring 134, this elevated or fully retracted position of the plunger being illustrated in FIG. 5. As will be described subsequently, the extent to which the plunger 130 may be retracted is a function of the elevation of the vertically movable rocker arm shaft 36. For example, in FIG. 2, the shaft 36 has, under the influence of the lever arm 33, been shifted to a lower position than that in which it is shown in FIG. 5 so that the fully retracted position of the plunger 24 is not as high a position as is the case in connection with the disclosure of FIG. 5.

Considering, for the time being, only the operation of the plunger 24 with the rocker arm setting of FIG. 5, it will be seen that reciprocation of the plunger 24 will carry the same from its full line retracted position to its dotted line advanced position wherein the lower end of the plunger 24 moves past the cut-oif opening 26. Upon rotation of the cam 34, the rocker arm 33 will cause the plunger 24 to reciprocate between its full and dotted line position as shown in FIG. 5 and, because the cam 34 is a fixed cam in the sense that its eccentricity cannot be changed, the amplitude of the stroke of the plunger 24 will be unvaried and the plunger will reciprocate at a relatively high level with respect to the guide sleeve 100 and sear-forming tube 194. Upon each descent of the plunger 24 the lower end of the latter will be carried past the cut-off opening 26 only a slight distance so that a small volume of fluid will be pressurized in the chamber 28 and forced past the normally closed valve 32 against the action of the compression spring 30. Since a solid column of fluid exists in the pressurizing chamber 28, reduced bore lit and tubing 12, a limited amount of fuel will be forced through the injection device 16 and into the intake manifold during each stroke of the plunger 24. The shaft 36 is capable of vertical adjustment as will be described presently between the elevated limit wherein only suflicient fuel is passed through the injection device 16 to maintain the engine at idling speed, and a lowered position wherein a maximum amount of fuel is forced through the injection device 16 during each downward stroke of the plunger 24.

Considering now the disclosure of FIG. 2, the shaft 36 which supports the various rocker arms 33 is shown in a lowered position and the fully retracted position of the plunger 24 is shown in full lines. The rocker arm now operates from the fixed cam 34 in such a manner that it has the same amplitude of oscillation as when the shaft 36 is in the elevated position of FIG. 5, the plunger 24 will also reciprocate with the same amplitude of displacement, but this plunger 24 will operate within the sleeve 1% and tube 104 at a lower elevation, so to speak,

cured to the wall 48 by screws 242. The front reduced end 237 of the shaft 230 carries a gear 244 exteriorly of the casing 240* and this gear meshes with the timing gear 246 of the engine. The entire fuel injection assembly 10, including the exterior gear 244, are shown in FIG. 1 as being enclosed by an outer removable box or casing 247.

The Lubrication System In order to lubricate the moving parts within the chamber 78 provided by the casing 4d, a splash system of lubrication is provided whereby a suitable liquid lubricant which is maintained in the form of a pool 2% is maintained in constant agitation within the chamber and is caused to drip from the two previously mentioned ribs 6 5 and s2. so as to supply lubricant to localized regions of the mechanism which require a more thorough lubrication than other regions thereof. Accordingly, a pair of centrifugal lubricant slinger wheels 2534 (FIGS. 5 and 6) are mounted in spaced relationship within the chamber 78 on a shaft 256 which extends longitudinally across the casing and has its opposite ends supported in bearing sleeves 25S rcmovably secured in the

ends walls

48 and 50 by means of retainer plates 269. The shaft 256 carries a gear 262 which meshes with a similar gear 264 mounted on the cam shaft 23% so that the shaft 256, and consequently the slinger wheels 254 will be driven from the cam shaft 236. Each slinger wheel 254 is provided with notches 2&6 in the periphery thereof to enhance the agitation of the lubricant 25% so that a greater quantity of lubricant will adhere to these wheels and be flung outwardly under the influence of centrifugal force against all of the various moving parts within the chamber 73. The rib overlies and is substantially parallel to the rocker arrn shaft 36 so that lubricant collecting on the underneath face of the cover plate 52 will drip from this rib directly onto the medial regions of the rocker arms 33 and thus find its way to the bearing surfaces between these rocker arms and the shaft 36. Similarly the rib 62 is disposed above and extends parallel to the cam shaft 236 so that lubricant will drip directly onto the various cams 34 and cam follower rollers 178 to adequately lubricate them. The gear 262 projects into the pool of lubricant 250 and will thus pick up lubricant from the pool and transmit the same to the gear 264. Other moving parts within the casing 78 such as the actuating finger 212 and bifurcated end 214 of the lever arm 160 will receive adequate lubrication by the application thereto of lubricant flung from the Wheels 254.

Assembly, lllaintenance and Special Considerations Referring now specifically to FIG. 5, it is contemplated that due to the maintenance of small tolerances during the manufacture of the various moving parts of each pump assembly li', there will be practically no leakage of fuel past the pressurizing or operating end of the plunger 24 to the annulus existing between the reduced portion 132 of the plunger and the tube Hi4 when the fuel injection apparatus is first put into service and during a long period of time thereafter. However, after a period of time, there may be slight wear between the two sliding parts so that a small amount of fuel leakage will take place. Although this amount of leakage Will be extremely small, in the absence of any provision for overflow of fuel from the annulus existing between the reduced portion 132 of the plunger 24 and the guide sleeve 1%, this annulus is likely, in time, to become filled with fuel, thus establishing a solid and incompressible liquid column which ordinarily would prevent descent of the plunger 24 and possibly result in damage or breakage to the various moving parts of the apparatus. To relieve such a condition, each guide sleeve 1% has formed therein a small aperture 270- which registers with a similar aperture 272. formed in the thickened wall portion 70 of the end wall 44 so that fluid may escape from the annulus surrounding the reduced end 132 of the plunger 24 into the chamber 78 and mingle with the pool of liquid lubricant 258* in this chamber. To prevent the turbulent lubricant in the chamber 278 from entering the annulus, a series of spring fingers 274 are provided on a flat spring strip 276 which is held in position against the inside face 278 of the thickened portion 74} by means of a clamping bolt assembly 280. The spring fingers 27d depend from the strip 276 and each finger is adapted to cover one of the holes 272 provided in the thickened portion 79 of the rear end wall 44 so that it will operate in the manner of a check valve to allow pressurized fluid in the annulus surrounding the reduced end 132 of the plunger 24 to pass outwardly and into the chamber '73 while at the same time preventing return passage of fluid through the hole 272. It will be appreciated that extremely minute quantities of entrapped fuel are involved so that dilution of the lubricant 250 with fuel is not appreciable. Any fuel which does pass into the chamber 73 from the annulus surrounding the plunger stem 132 is itself a mild lubricant so that the efficiency of the 1ubricant in the pool 25% is at no time endangered.

The various internal operating parts of the fuel injection assembly 10 of the present invention are readily accessible by virtue of the removable cover plate 52 and the removable reservoir-forming closure plate 32. With the cover plate 52 removed the adjusting screws and lock nuts 182 are accessible for purposes of adjustment, as also are the set screws 23% by means of which the angularity of the various cams 34 relative to the cam shaft 230 may be altered. The fuel injection assembly may, by simple adjustment, be rendered suitable for use in connection with motors having different fuel combustion or firing orders by properly setting the angularity of the various cams 34 any desired firing order may be accommodated.

Plunger removal and replacement may readily be effected by loosening the clamping screw Zilt) (FIGS. 4 and 5) so that the foot member 1% is free upon the shaft whereupon this latter shaft is capable of unlimited turning movement so that the fingers 212 of the collars 210 may leave the bifurcations 214 at the distal end of the lever arms 166 and also the entire U-shaped frame assembly including the lever arms 169 and shaft 36 to be elevated to the dotted line position wherein it is illustrated in FIG. 5. With this assembly thus elevated, the upper ends of the various plungers 24 are accessible and may be pulled vertically outwardly from the guide sleeves 100 for purposes of inspection, replacement of the springs 134 or plungers 24.

From the above description it is thought that the construction and operation of the herein described fuel injection system will be readily apparent. The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification, since various changes in the details of construction may be resorted to without departing from the spirit of the invention. Only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described the invention which I claim as new and desire to secure by Letters Patent is:

1. Liquid fuel injection apparatus comprising in combination, a casing structure defining a fuel reservoir, a plurality of injection pump assemblies, each pump assembly including a tubular vertically disposed pump body providing a pumping bore, there being a fuel inlet cut-off opening in the wall of said pump body, the various pump bodies being at least partially submerged within the liquid fuel in the reservoir with said cut-off openings in direct communication with the liquid fuel, a pump plunger reciprocable in said bore and having an end thereof movable past said cut-off opening in sealing relationship with respect thereto, the portion of the bore forwardly of the cut-01f opening constituting a fuel pressurizing and displacement chamber, said casing structure also defining an internal operating chamber, a vertical wall separating said reservoir from the operating chamber, a pair of lever arms pivoted within the operating chamber for limited swinging movement about a horizontal axis, a horizontal shaft extending between said lever arms and capable of limited vertical displacements upon movement of the lever arms, a series of rocker arms, one for each plunger, mounted medially of their ends on said shaft, a cam shaft extending across the chamber and parallel to said shaft, one end of each rocker being designed for engagement with one of said plungers and the other end being designed for engagement with the cam shaft, a rock shaft extending across the chamber and parallel to the cam shaft, the distal end of each lever arm being provided with a bifurcation, a finger on said rock shaft and projecting into respective bifurcations on the lever arm, and an operating lever connected to said rock shaft and disposed exteriorly of the chamber.

2. Liquid fuel injection apparatus comprising in combination, a casing structure defining a fuel reservoir, a plurality of injection pump assemblies, each pump assembly including a tubular pump body providing a pumping bore, there being a fuel inlet cut-off opening in the Wall of said pump body, the various pump bodies being at least partially submerged within the liquid fuel in the reservoir with said cut-off openings in direct communication with the liquid fuel, a pump plunger reciprocable in said here and having an end thereof movable past said cut-off opening in sealing relationship with respect thereto, the portion of the bore forwardly of the cut-off opening constituting a fuel pressurizing and displacement chamber, said casing structure also defining an internal operating chamber and lubricant reservoir, a vertical wall separating said fuel reservoir from the operating chamber, a rocker arm for each plunger and having one end thereof designed for operative engagement with an end of the plunger, a rocker arm shaft within said operating chamber and common to all of the rocker arms and on which the arms are pivotally mounted medially of their ends, a cam shaft within said operating chamber and having cams thereon designed for engagement with the other ends of the rocker arms, an additional shaft extending across said operating chamber below the level of said rocker arm and cam shafts, a plurality of slinger wheels mounted on said additional shaft, means operatively connecting said cam shaft and additional shaft in driving relationship, a pool of lubricant within said operating chamber and lubricant reservoir, manually operable means, operable at will for shifting the position of said rocker arm shaft in the general direction of movement of the plimgers to simultaneously vary the position of the range in which the plungers reciprocate in their respective pumping bores, a removable cover plate for said operating chamber and lubricant reservoir, and a pair of lubricant collecting and distributing ribs formed on the underneath side of said cover plate, one of said ribs being substantially coextensive with, parallel to and in vertical register with said rocker arm shaft for drip lubrication of the latter and the rocker arms thereon, the other rib being substantially coextensive with, parallel to and in vertical register with said cam shaft for drip lubrication thereof and of the cams thereon.

3. Liquid fuel injection apparatus comprising a casing having a bottom wall, upstanding side walls, a front end wall, and a rear end wall, a cover plate removably closing the upper end of said casing and defining with the various Walls thereof a closed internal chamber, one of said side walls being formed with a relatively thick wall portion below the upper edge thereof and defining an upwardly facing ledge below thelevel of said cover plate, said relatively thick wall portion being formed with a series of vertical bores therein, closure plate secured to the outer face of said one side wall and, in combination therewith 12 defining a fuel reservoir exteriorly of the chamber, said bores normally establishing communication between said reservoir and chamber through said ledge, there being a fuel inlet cut-oif passage in the wall of each bore establishing communication between the reservoir and the interior of the bore, the portion of the bore below the cut off passage constituting a fuel pressurizingand displacement chamber, a pump plunger reciprocable in each bore and having an end thereof movable past the cut-off passage, a fuel line establishing communication between said chamber and one of the fuel injector nozzles, a check valve disposed in said fuel line, a rocker arm for each plunger within the chamber, said rocker arm having one end in operative engagement with the plunger above the ledge, a rocker arm shaft in said chamber on which all of the rocker arms are pivotally mounted, a cam shaft in the chamber and having cams thereon designed for engagement with the outer ends of the rocker arms, said relatively thick wall portion being provided with a series of drain passages above the level of the cut-off passages and establishing communication between said bores and said internal chamber for the flow of leakage fuel from the reservoir into the chamber, and manual means operable at will for shifting the position of the vertical range in which the plungers reciprocate in their respective bores.

4. Liquid fuel injection apparatus comprising a casing having a bottom wall, upstanding side walls, a front end wall, and a rear end wall, a cover plate removably closing the upper end of said casing and defining with the various walls thereof a closed internal chamber, one of said side walls being formed with a relatively thick wall portion below the upper edge thereof and defining an upwardly facing ledge below the level of said cover plate, said relatively thick wall portion being formed with a series of vertical bores therein, a closure plate secured to the outer face of said one side wall and, in combination therewith defining a fuel reservoir exteriorly of the chamber, said bores normally establishing communication between said reservoir and chamber through said ledge, there being a fuel inlet cut-01f passage in the wall of each bore establishing communication between the reservoir and the interior of the bore, the portion of the bore below the cut off opening constituting a fuel pressurizing and displacement chamber, a pump plunger reciprocable in each bore and having an end thereof movable past the cut-off opening, spring means normally urging said plunger upwardly in said bore, a pair of lever arms within said casing and having their proximate ends pivoted to the end walls of said casing in the vicinity of the other side wall for vertical swinging movements about a common horizontal axis, a rocker-supporting shaft rigidly connected to the distal ends of said lever arms, a cam shaft extending across the chamber and parallel to said rocker-supporting shaft, a rocker arm for each plunger pivoted to said shaft and having one end operatively engaging the upper end of the plunger above said ledge and having its other end operatively engaging said cam shaft, a rock shaft extending across the chamber and parallel to the rocker-supporting shaft, the distal ends of said lever arms being bifurcated, fingers on said rock shaft and extending and confined between the bifurcations of the lever arms respectively, a limit stop abutment on said casing, a cooperating limit stop abutment on said rock shaft to limit the turning movement of the rock shaft in one direction, means for disabling the cooperation between said limit stops whereby said rock shaft may be turned to such an extent that the fingers on the rock shaft are released from their confinement between said bifurcations so that the lever arms, together with said rocker-supporting shaft and the rocker arms thereon may be swung vertically upwardly about said common horizontal axis to an out-of-the-way position wherein the upper ends of the plungers are accessible for withdrawal of the plungers from said bores, and a manually operable lever mounted on said rock shaft for 13 applying turning movements to the latter in either direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,076,436 Lemp Oct. 21, 1913 1,730,116 Brockway Oct. 1, 1929 1,871,872 Baur Aug. 16, 1932 2,083,021 Hegn June 8, 1937 2,114,565 Kovach Apr. 19, 1938 14 Maniscalco Aug. 15, 1939 Simons Oct. 17, 1939 Widmer Dec. 12, 1950 Edwards July 10, 1951 Voit et a1 Mar. 27, 1956 Brunner May 29, 1956 Seifert et a1 Apr. 22, 1958 FOREIGN PATENTS Great Britain Dec. 22, 1930 France Jan. 21, 1929