US2372559A - Fuel injection pump - Google Patents

Description

March 27, 1945. c W Q 2,372,559.

FUEL INJECTION PUMP 6 Sheets-Sheet 1 Filed NOV. 4, 1940 .605 yrrokA/f/f March 27, 1945- H, c. EDWARDS 2,372,559

FUEL INJECTION PUMP Filed No v. 4, 1940 e Sheets-Sheet 2 Zxa. Z 9

March 27, 1945. EDWARDS 2,372,559

FUEL INJECTION PUMP Filed Nov. 4, 1940 5 Sheets-Sheet s ///5 #TToR/VE/S.

March 27, 1945.

H. c. EDWARDS FUEL INJECTION PUMP 6 Sheets-Sheet 4- Filed NOV. 4, 1940 H. c. EDWARDS FUEL INJECTION PUMP March 27, 1945;

Filed Nov. 4, 1940 6 Sheets-Sheet 5 Ms #rTaRn/E/s.

Patented Mar. 27, 1945 FUEL INJECTION PULIP Herbert '0. Edwards, Massillon, Ohio, assignor to The Timken Roller Bearing Company, Canton, Ohio, a corporation of Ohio Application November 4, 1940, Serial No. 364,232

' 19 Claims.

My in which the supply pump is operated by the injection pump; to provide for initially adjusting the injection pump to the requirements of the particular engine supplied thereby; and to provide for simplicity of construction, ease and economy of operation, reduced cost of manufacture, reduction in weight and compactness of design. The invention consists in the single plunger, multiple discharge, fuel injection pump and in the parts and combinations and arrangements of parts hereinafter described and claimed.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is an end elevation of a fuel pump embodying my invention.

Fig. 2 is a central vertical section through said pump on the line 2-2 in Fig. l,

' Fig. 3 is an enlarged section similar to Fig. 2 through the upper portion of the pump on the line 3-3 in Fig. 1, r

Fig. 4 is an enlarged section similar to said Fig. 2 through the lower portion of the pump on the line 4-4 in Fig. 1, r

Fig. 5 is a fragmentatry central vertical section on the line 5-5 in Fig. 4,

Fig. 6 is a fragmentary end view of the lower or base section of the pump, showing the control shaft and the manner in which said shaft is connected to the pinion shaft to adjust the quantity of fuel delivery,

Fig. '1 is a fragmentary horizontal section on Fig. 14 is a perspective view of the pin for supporting the tapp t roller,

15 is a side elevation of the shell for supporting the tappet block,

Fig. 16 is a horizontal section through said shell on the line lG-IB in Fig. 15,

Fig. 17 is a top plan view of the tappet guide sleeve,

Fig. 18 is a central vertical section through said sleeve on the line i8-l 8 in Fig. 17,

Fig. 19 is a, central vertical section through a pump of modified form,

Fig, 20 is a. fragmentary horizontal section on the line 20-20 in Fig. 19; and

Fig. 21 is a central fragmentary vertical section through the plunger driving gear shown in Figs. 19 and 20.

The fuel pump illustrated in the accomparwing drawings is adapted for use with a six cylinder, four cycle, compression ignition engine and comprises three superposed sections, namely, an upper end or fuel supply pump section A an intermediate or fuel injection pump section B and a lower end or base section C containing the mechanism for operating the fuel injection pump.

The upper, supply pump section A comprises an upright pump housing or cylinder I, whose upper end is closed by a screw cap 2 having an axialv that is connected at its upper end by a suitable angle inlet fitting 4 to a suitable pipe or conduit 5 leading from a suitable source of fluid fuel supply (not shown). The lower end portion of the inlet passageway 3 in the cap 2 for the upper end of the supply pump cylinder or housing I is counterborcd, as at 311, to receive a downwardly or inwardly opening suction or check valve in the form of a disk 6 that is yieldably held against an annular seat provided therefor in the upper end of said counterbore by means of a coil compression spring I. This inlet valve spring 1 seats on an annular supporting plate 8 that is clamped between the lower end of the cap 2 for the upper end of the pump cylinder I and the upper end of a hollow cylindrical sleeve or liner 8 for said cylinder.

Reciprocable in the liner 9 for the pump cylinder I is a downwardly opening cup-shaped pis..

ton Ill having a central inlet port ii at the upper end thereof and a plug I2 threaded into the lower end thereof and cooperating withsald piston to form therein a chamber l3 for an inwardly opening check valve in the form of a disk 14 that is ton to close the inlet port therein by means 01' a axial bore.

.in the lower end'portion of the supply pump cylcoil compression spring l6 which seats on the upper end of said plug. Relative. rotary movement of the piston l and plug i2 therefor is prevented by means of a pin l6 that is driven through registering transverse holes provided therefor in said piston and plug. The plug I2 has a series of circumferentially spaced cylindrical holes or passageways I 1 extending vertically therethrough which establish communication between the inlet valve chamber I3 of the piston and the portion of the liner 3 below said piston. The plug 12 also has a central depending stem portion i8.

The piston I8 is retracted by means of a coil tension spring l9 whose upper endportion is threaded on the threaded portion of the plug 12 below the piston and whose lower end portion is threaded on the exterlorly threaded upstanding central tubular flange 28a of an annular spring seat member 28 that is clamped between the lower end of the liner 9 and an annular seatv in the pump cylinder I. The cylinder l is provided below the spring seat 28 with an axial bore 2|,

which opens through the lower end of said cylinder, and with a series of circumferentially spaced discharge passageways 22 that lead downwardly from the space below said spring seat and open into an annular groove 23 formed in the lower end of said cylinder concentric with said Reciprocable in the axial bore 2| inder, or housing I, is a push rod 24 whose upper end is disposed in abutting relation to the lower end of the depending stem portion l8 of the piston plug [2. The lower end portion of the pump cylinder I is exteriorly threaded, as at 25, for connection with the injection pump section B.

The intermediate-or fuel injection pump section B of my combined supply and injection pump assembly comprises a pump housing or cylinder 26 having an outstanding base flange 21 and a central cylindrical bore 28. The base flange 21 of the injection pump cylinder or housing 26 seats on and is secured by cap screws 21a to the top of the base section C of the pump. The bore 28 extends through the pump housing or barrel 26 from top to bottom thereof and has an enlarged or counterbored upper end portion 29 threaded to receive the exteriorly threaded lower end portion 25 of the supply pump cylinder or housing I. Just below the lower end of the enlarged upper end 29 of the axial bore 28 of the fuel injection pump cylinder 26 is a slightly smaller counterbore, forming a chamber 38 for a downwardly opening valve in the form of an annular disk 3| which is yieldably held against the lower end of the supply pump cylinder I and cov- 'ei's the annular groove 23 therein. The valve 3|, which serves as the final discharge valve of the supply pump and the inlet valve of the injection pump, is yieldably held in closed position by a coil compression spring 32 that is located in the valve chamber or counterbcre 38 and seats on the bottom thereof.

Mounted for axial sliding and rotary movement in the axial bore 28 of the injection pump cylinder below the valve or pressure chamber 30 is a. cylindrical plunger 33 that is disposed below and in axial alinement with the supply pump push rod 24, which extends downwardly into the valve chamber 30 through the central opening in the annular check valve 3| therein and is urged downwardly in the direction of said plunger by the pull of the tension spring [-9. The injection pump cylinder has a plurality of horizontal fuel delivery or discharge passageways 34 therein,

one for each of the six working cylinders of the engine supplied by said pump. The discharge passageways 34 are disposed radially of the pump plunger bore 28 and are spaced apart equally around the axis thereof with their inner ends opening through the wall of said bore below the chamber and with their outer ends opening through the outer surface of the injection pump cylinder 26 and threaded to receive closure Caps 35 therefor. The radially disposed passageways 34 have vertical branches 34a that extend upwardly therefrom through the top of the pump cylinder or housing 26. These branch passageways are spaced apart equal distances around theaxls of the pump and are threaded at their upper ends to receive tube nuts 36 that connect to said passageways injection lines or conduits 31 that lead to the injection nozzles (not shown) for the respective working cylinders of the engine.

The injection pump cylinder 26 has a single horizontal by-pass or overflow passageway 38 therein disposed radially thereof below the level of the discharge passageways 34 and preferably along a plane passing midway between two adjacent discharge passageways. One end of the bypass 38 opens into the plunger receiving bore 28 of the cylinder 26 'below the level of the dis-. charge passageways 34 and the other end opens through the exterior side face of said cylinder and is threaded to receive a cap member or closure 38. As'shown in Fig. 13, the by-pass passageway 38 is provided near its inner or inlet end with an outwardly opening check valve 40 that 36 is yieldably held against a seat provided therefor in said passageway by a coil compression spring 4| located in said passageway with one end seated against the cap 39 for the outer end thereof and with the other end bearing against said valve.

40 The by-pass passageway 38 has a vertical branch 38a, which extends downwardlytherefrom outwardly of the valve 48 therein, a branch 38b,

* which leads horizontally outwardly from the tion stroke. spaced longitudinal pressure relief grooves 43 in branch 38a and a vertical branch 380, which leads downwardlyfrom the horizontal branch 38b and opens through the bottom of said base flange 21 of the injection pump cylinder 26.

As shown in the drawings, the pump plunger 33 has an annular groove 42 therein far enough below the upper end thereof to communicate with the by-pass passageway 38 when said plunger nears and is at the end of the downward or suc- The plunger also has six equally the periphery thereof that lead downwardly from the lower edge of the annular peripheral groove 42 far enough to establish communication between the by-pass passageway 38 and said annular groove during the entire length of either the suction or pressure stroke of said plunger when any one of the six longitudinal grooves is in communication with the inlet end of said by-pass passageway. The injection pump plung'er also has a single longitudinal peripheral distributing groove 44 that extends from the annular groove42 through the top of said plunger and is adapted to provide continuous communication between said annular groove and the pressure or valve chamber 38 above the upper or working end of'said plunger. When the plunger 33 is rotated, the single longitudinal peripheral distributing groove 44 therein is adapted to successively register with the six discharge ports 34 in the pump cylinder during the reciprocating movement of said plunger, and the six longitudinal pressure relief grooves 43 are sacrum. 3'

adapted to successively register with the by-pass passageway 38.

The lower or base section C of the injection pump comprises a housing 45 which contains the mechanism for continuously reciprocating and rotating the pump plunger 33. This mechanism comprises a cam shaft 46 extending horizontally through the lower portion of the housing 45 below and at the right angles to the pump plunger 33. The cam shaft 46 is driven by or in unison with the engine at one-half engine speed and has six lobe-shaped cams 41 of identical contour spaced apart equal distances circumferentially of said cam shaft in theplane of. the axis of the pump plunger 33. The cam shaft 46 is Supp rted in suitable roller bearings 48 mounted in alined openings in opposite ends of the housing 45. Surrounding the cam shaft adjacent to the driven end thereof is a suitable oil seal 49 that is supported in an opening'provided therefor in a plate 50 that is removably secured to said housing by cap screws 50a.

The cams 41 on the cam shaft 46 are adapted to successively engage a tappet roller located thereabove. This tappet roller is rotatable on a bushing 52 journaled on a pin 53 carried by a tappet block 54. This tappet roller pin 53 has its ends mounted in alined openings provided therefor in a pair of spaced lugs 55 that depend from the tappet block 54; and the tappet roller 5| and bushing 52 are supported on said pin between said depending lugs, The tappet block 54 has the general-form of an upright cylinder and is mounted in a cylindrical sheet metal shell 56 which is provided on one side with a cylindrical opening adapted to receive the adjacent end of the tappet roller pin 53 and on the opposite side with a rectangular opening 51 adapted to snugly receive a similarly shaped lateral extension or head 56 formed on the other end of said pin, thereby preventing rotation of said pin relative to said tappet block and shell.

The tappet shell, block, roller, bushing and pin assembly is vertically reciprocable in .an upright cylindrical guide sleeve 59 that is disposed in' a vertical bore 60 that leads upwardly through the top of the housing 45 from the cam shaft receiving opening which extends horizontally therethrough; and said tappet guide sleeve has an outstanding peripheral flange 6| at its upper end that rests on an annular seat 62 provided therefor in said vertical bore. The tappet guide sleeve 56 extends downwardly across the ends of the tappet roller pin 53, thereby preventing endwise movement of said pin, and has a longitudinal internal groove 63 therein which snugly receives the rectangular head 58 of said pin, whereby the tappet block 54 is slidable axially of said guide sleeve but is held against rotation therein. The outstanding top flange 6| of the guide sleeve 59 is held down on the annular seat 62 provided therefor in the vertical bore 60 of the housing 45 by two diametrically opposed screws 64 that are threaded horizontally through opposite sides of said housing and have tapered or pointed inner end portions 64a that seat in correspondingly tapered recesses 6|a provided therefor in the I upper, outer corner portion of said top flange of said guide sleeve, thereby preventing both axial and rotary movement thereof.

The tappet block 54 is disposed in vertical alinement with the pump plunger 33 located thereabove and has a diametrical T-slot 65 in the top thereof adapted to receive a grooved lower end portion 66 of said plunger, whereby said plunger axis.

tappet block and plunger are connected together for joint reciprocating movement but may be disconnected by relative movement crosswise of the The upward or pressure stroke is imparted to the pump plunger 33 by the came 41 of the cam shaft 46 and the tappet roller 5| operatively connected to the lower end of said plunger; and the downward or suction stroke is imparted to said plunger by a coil compression plunger retracting spring 61 which surrounds the- .reciprocable tappet shell 56 and the fixed tappet cycles are being imparted thereto by one complete rotation of the cam shaft 46. As shown in the drawings, the plunger rotating mechanism comprises -a spur gear 68 driven from the cam shaft 46 and having an axially slidablebut nonrotary connection with the pump plunger 33. This connection preferably comprises a series of circumferentially spaced longitudinal splines on the plunger that slidably engage a similar series of longitudinal grooves 10' in the hub 66a of the gear 68. This gear is located in the vertical bore 60 of the housing 45 on a circular supporting plate 1| supported in said bore on the flanged upper end of the tappet guide sleeve 59. The supporting plate 1| has a, central circular opening through which the plunger 33 extends; and the gear 68 has its hub portion 68a extended upwardly far enough to abut against the bottom of the injection pump housing 26, whereby said gear is held against vertical movement between the underside of said housing and the upper surface of said supporting plate.

The plunger rotating gear 68 is rotated from the continuously driven horizontal cam shaft 46 through an upright shaft 12 mounted for rotary and axial sliding movement in a vertical bore 13 provided therefor in the housing 45 at one side of said cam shaft. As shown in the drawings, the cam shaft 46 has a helical gear 14 thereon intermeshing with a helical gear 15 on the shaft 12, The vertical shaft 12 also has a spur pinion 16 on the upper end thereof that intermeshes with the spur gear 68 on the plunger 33. The upper end of the supporting bore 13 for the pinion shaft 12 is counterbored, as at 11, to accommodate the spur pinion 16 on the upper end of said shaft; and the upper end of this counterbore is closed by a removable cover plate 18, said counterbore being deep enough to permit limited vertical movement of pinion 16 therein between the bottom thereof and the underside of said cover plate. The lower end of the bore 13 has a bushing 19 press-fitted therein flush with the --bottoxnpQhe housing 45; and the pinion shaft grooves cooperate with the annular spaces therebetween to form a rack onsaid pinion shaft;

Intermeshing with the'rack 80 on the vertical pinion shaft 12 is a sector pinion 8] that is supported on a horizontal control shaft 8-2 journaled in the housing 45, whereby said pinion shaft may be raised or lowered relative to the spur gear 33 on the plunger 33 and the helical gears 14 on the cam shaft 45 by rocking said control shaft. As stated above, the driving connection between the horizontal cam shaft 43 and the vertical pinion shaft 12 comprises the intermeshing helical gears 14 and I so that, when the pinion shaft is raised or lowered by means of the sector pinion 3|, slight rotary movement is imparted to the pinion shaft and the plunger 33 driven thereby due to the oblique angle of the teeth of said intermeshing helical gears, thus changing the positions of the longitudinal pressure relief grooves 43 in the pump plunger 33 relative to the overflow or bypass port 33 to thereby vary the volume of fuel delivered to the engine.

In order to initially adjust the pump injection to the requirements of the particular engine supplied thereby use is made of the vernier effect between the number of teeth on the plunger gear 33 and the number of teeth on the pinion 15 on the pinion shaft 12. In-the present case, the pinion 15 has five teeth and the plunger gear 33 driven thereby has twenty-six teeth, so that a seventy-two degree change in angular adjustment of the plunger 33 relative to the cam shaft 45 is obtained by moving said pinion relative to said cam shaft a distance corresponding to one tooth space. However if, at the same time, the plunger gear 33 is rotated in the opposite direction a distance corresponding to five tooth spaces,

which is equivalent to about sixty-nine degrees, f

an adjustment of less than three degrees on the cam shaft can be obtained, which amounts to one and one-half degrees on the crank shaft of the engine.

As shown in Fig. 13 of the drawings, the housing 45 has a passageway 33d opening through the outer end thereof whose inner end opens through the top of said housing in line with the outlet end of the branch 38c of the by-pass passage way 33 in the injection pump cylinder or housing 23 and is connected to said outlet end of said branch of said by-pass by means of a ferrule 34 that seats within registering ends of said passageways. the housing 45, which passageway communicates with and constitutes a part of the by- pass passageway 33, 33a, 7 33b, 330 leading from the plunger receiving bore 23 in said housing, communicates with a conduit 33c which leads to the fuel supply tank (not shown) or to a suitable hydraulic governor (not shown) such as the governor-showri in my copending application Serial No. 397,714, filed June 12, 1941.

If desired, the supply pump A may be used for hydraulically operating an angularly adjustable coupling (not shown) between the cam shaft and the driving shaft (not shown) therefor, for advancing or retarding the timing of the fuel injection. Such a timing coupling is shown in my copending application Serial No. 397,715, filed June 12, 1941. As shown in Fig. 12 of the drawings, the connection between the supply pump and the angularly adjustable shaft coupling comprises a passageway 22a leading from one of the discharge passageways 22 in the supply pump housing I into an annular clearance space or chamber between the lower end portion 25 of said housing and the counterbored upper end portion 29 of the plunger bore 23 in the housing 23 and a passageway 35a leading downwardly from the chamber 35 through the housing 23 to the lower end thereof where it is connected by a ferrule 33 to a passageway 35b, which opens Theouter end of the passageway 3311 in coil tension spring I9, thereby opening the inlet through the side of the housing 45 and communicates with a conduit 35c leading to said shaft coupling.

As shown in Figs. 6 and 7 of the drawings, the horizontal control shaft 32 is journaled in bushings 31 located in almed openings provided therefor in opposite walls of an outwardly opening pocket or recess 83 in one end of the housing 45 just above the cam shaft 43 therein. The hub of the sector pinion 8| is sleeved on the control One end of the shaft 82 has a retaining collar 92 pinned thereon and the opposite end has the hub of a manually operable control lever 33 pinned thereon. The controlshaft supporting bushings Bl have flanged outer ends 31a that overlap and are clamped to the outer face ofthe housing 45 by means of cap screws 94. The main body portions of the bushings 81 have a loose fit in the openings provided thereforin said housing so that said bushings, together with the control pinion journaled therein, may be shifted transversely in said openings to take up excessiie back lash between the sector pinion 3| and the rack 33 on the pinion shaft 12 and the bushings are then clamped to said housing by means of the cap screws 94. As stated above, the control shaft 82 may be manually operated by means of the control lever 33 to adjust the quantity of fuel delivery. The quantity of fuel delivery may also be automatically controlled according to the speed and load conditions of the engine by the hydraulic governor hereinbefore referred to, such governor being operated by the varying pressure transmitted thereto through the by-pass passageway 38 of the pump and the hub of the sector pinion 3| being provided with a forked extension 35 which provides means for mechanically connecting said pinion with said governor for operation thereby.

The operation of the hereinbefore described pump is as follows:

When the injection pump plunger 33 is pulled downwardly in its cylinder 23' by the plunger retracting spring 37, the down or suction stroke is imparted to the supply pump piston in by the valve 3 and drawing fluid fuel from the supply pipe 5 into the upper end of the supply pump cylinder I. When the supply pump piston I3 moves upwardly in its cylinder l against the tension of the retraction spring I3 during theup or pressure stroke of the injection pump plunger 33, the inlet valve 3 closes and cuts on communication between said cylinder and the supply pipe 5, and the inlet valve l4 in the upper end of said piston is forced off its seat by the pressure of the fuel trapped in said cylinder above said piston and this fuel is transferred from the space above said piston to the space therebelow and fills the passageways l'l in the piston plug [2 and the passageways 22 and the annular groove '-..3 in the lower end of said cylinder; and when the injection pump plunger 33 again moves downwardly during its suction stroke, the valve 3|, which closes said annular groove, is opened and the through said discharge passageways.

asmue fuel in the supply pump cylinder between the valves 14 and 3| is transferred to the Pressure chamber 33 of the injection pump cylinder 23 by the pressure produced by said piston as it is pulled downward by the extended spring l3.

During the first part of the up-stroke of the irri ection pump plunger 33, the valved supply pump piston I3 is forced upwardly in its cylinder by the pressure of the fluid fuel on the portion of the push rod 24 located in the pressure chamber 33.

upon the spacing of the six vertical grooves 44 below said annular groove.

It is noted that, when the supply pump piston III is at the end of its upward stroke, there is a very small clearance between the top of said piston and the annular valve spring supporting plate 3', whereby a. high degree of vacuum is obtained when the pump is in operation. As shown in the drawings, the supply pump C is provided with three valves, 3, l4 and 3|. While the upper valve 3 may be omitted, this valve insures adequate filling of the space above the piston ill with fuel under all conditions of operation and also tends to dampen out hydraulic surges within the fuel supply line or conduit 5. Retraction of the fuel in the delivery lines 31 leading to the injection nozzles may be regulated to prevent dribble from injection stroke, different injection speeds being I obtained by the use of cams with slightly difierent speeds. The injection plunger 33 makes one complete reciprocating cycle for each injection and it makes one complete rotationfor each complete engine ,cycle. There are, however, six cam lobes 41 on the cam shaft 43, whereby the injection plunger 33 is given six reciprocating cycles for each rotation that it makes.

During the pressure stroke of the pump plunger 33, pressure rise begins when the lower edge of the annular groove 42 in said plunger closes the by-pa-ss passageway 33 and ceases when one of the six longitudinal pressure relief grooves 43 located in said plunger below said annular groove registers with said by-pass. The quantity of fuel delivered through each of the discharge passageways 34 may be varied by manipulating the control lever 93 to rock the sector pinion 3| which shifts the pinion shaft 13 vertically and thus rotates the plunger 33 relative to the cam shaft 43. Thus, if one of the pressure relief grooves 43 of the plunger 33 is in register with the by-pass passageway 38 during the entire working stroke of said plunger, the fuel is discharged through said by-pass passageway instead of the discharge passageway 34 and there is no discharge of fuel When, however, the sector pinion is operated to locate a pressure relief groove 43 a maximum circumferentially distance from the discharge passageway 34 at the time the by-pass passageway 33 is covered, the time of opening of said by-pass is delayed thus bringing about the delivery of a maximum quantity of fuel through the discharge passageway. As stated above, the plunger 33 is constantly rotated and reciprocate-d in phase relation to the cam shaft 43; but this phase relationship between said plunger and cam may be changed to vary the volume of fuel delivered to the engine cylinders by operating the control lever 93. At each discharge or up stroke of the plunger 33, the distributing groove 44 therein registers with a different discharge passageway 34 and each pumping stroke is identical with any other and delivers the same quantity of fuel to a different engine cylinder. In this way, it is easy to obtain equal discharges to all cylinders without very great accuracy in the manufacture of the pump plunger and cylinder, the accuracy of the start of injection depending only upon the squareness of the lower edge of-the annular said nozzles by varying the pressure of the closing spring 4| for the check valve 43 in the bY- pass passageway 33. The non-rotary'but axial sliding connection between the injection pump plunger 33 and the driving gear 33 therefor at the lower end thereof is simple and inexpensive and greatly reduces the weight of the reciprocating parts.

In the modified pump constructionshown in Figs. 19 to 21, inclusive, the supply pump oomprises the housing I hereinbefore referred to and a. member 33 threaded into the upper end of said .end of said piston seats against the underside of an annular spring seat 30b and forces the same upwardly against an annular shoulder provided therefor in said cylinder.

Located in the axial bore-of the member 33 above the spring seat 23!; is a downwardly opening upper valve 30 and an upwardly opening lower valve Ma. The upper valve 3a seats against a downwardly facing annular valve seat provided therefor in the axial bore of the member 33 and the lower valve I4a seats on top of the annular springseat IM and covers the central opening therethrough. The valves 3a and l4a are yieldably held against their respective seats by means of a single coil compression spring 91 interposed 33 through radial ports 33a in the cylinder 9a opposite said space, while said annular passageway is in continuous communication at its lower end with the upper ends of the passageways 22.

The piston I30 is forced upwardly in its cylinder 3a by a push rod 24a that is reciprocable in the axial bore 2| in the lower end portion of the supply pump housing. In this construction, the

upper end of the push rod 24a bears against the lower end of the piston ifla; the lower end of said push rod is positively connected to the upper end of the injection pump plunger 33a for mechanical operation thereby instead of being hydraulically operated asin the case of the push said collar.

rod 24 hereinbefore described. The direct mechanical connection between the push rod 5.4a and the plunger 33a comprises a diametral T- he'ad on the-upper end of said plunger that slidably fits within a diametral T-groove in the lower end of said push rod, such connection permitting the plunger and push rod to be connected 33 through the push rod 24a secured thereto.

The fuel fills the space between the valves 6a and a, the annular passageway 98 and all of the space beneath the piston Illa down to the closed valve 3|. This upward movement of the piston Illa in the cylinder also prevents fuel that leaks into said cylinder from accumulating therein in sufficient quantity to interfere with such movement of said piston, excess fuel insaid cylinder being forced out through the valve Ila by the positive up-stroke of said piston. When the push rod 24a is pulled downwardly by the downward travel of the plunger 33a, the supply pump piston Illa is forced downwardly in its cylinder So by the expansive action of the spring I90. which is strong enough to overcome any vacuum in said cylinder and the fuel trapped'in the supply pump by the closing of the valves 6a and No is forced downwardly through the pas the collar 99a, abuts against the shoulder or seat 99b provided therefor in the discharge passageway 34, thus cutting .off communication between the pressure chamber and the discharge passageway. The diametral passageway 99c ofthe dis charge valve 99 enters the smaller valve sup-' porting portion of the discharge passageway 34 and cuts off flow of the fuel through said valve before it reaches the end of its closing movement. Continued movement of the valve to closed position serves to relieve the pressure that still exists in the discharge line between said valve and the hydraulically opened injection nozzle and thus permitting said nozzle to close rapidly without leakage or after dribble of the fuel therefrom into the combustion chamber of the engine.

sageways 22 and the annular groove in the housi ing, thus forcing the valve 3| off its seat and permltting the fuel to flow into the pressure chamher-Ill of the injection pump, which operates in the manner hereinbefore described to force the fuel through the discharge passageways 34.

In the modified construction, each of the discharge passageways 34 of the injection pump has an outwardly opening piston valve 99 slidably mounted in the inner. end portion thereof. This valve has a peripheral'collar 99a thereon near the outer end thereof, and the outer end portion of the discharge passageway 34 is enlarged to form an outwardly facing annular seat 99b for The collar 99a is yieldably held against the seat 99b by means of a coil compres- .-sion spring I00 mounted in the enlarged outer end of the passageway 34 between said collar and the cap 35 for the outer end of said passageway. The discharge valve 99 has a diametral passageway 99c extending therethrough inwardly of the collar 99a and an axial passageway 99d leading from said diametral passageway and opening through the inner end of said valve. By

this arrangement, the pressure of the fuel against lieved by establishing communication between said chamber and the by-pass passageway 38, the discharge Or delivery valve 99 is forced inwardly by the closing spring I00 thereof until In the modified construction, the spur gear 68b for'rotating the injection pump plunger 33a dur-' ing the reciprocating movement of the-latter is rigidly secured to the lower end of said plunger for axial movement therewith and is thus movable vertically relative to the spur driving pinion 13 therefor on the .upper end of the upright pinion shaft 12. The connection between the gear 68b and the plunger 33a comprises a pair of clamping screws IOI that extend through a split hub portion 680 of said gear on opposite sides of said plunger. These screws firmly clamp the split hub portion 580 of the gear 68b to the plunger 33a and seat in an annular groove 33b provided therefor in the plunger, thus preventin relative axial and rotary movement of said gear and plunger. With this constructed proper phase relation between the metering grooves 44 and the plunger 33a and the cam shaft 46 is obtained by rotating the plunger relative to the gear 581) and then clamping said gear to the plunger in the desired position of rotary adjustment.

Obviously, the hereinbefore described fuel injection pump admits of considerable modification without departing from the invention. Therefore, I do not wish to be limited to precise arrangements shown and described.

What I claim is:

1. A unit fuel injection and supply pump assembly for an internal combustion engine comprising a fuel injection piston and a fuel supply piston in axial alinement with said fuel injection piston for feeding fuel thereto, and means interposed entirely between the adjacent ends of said fuel injection and fuel supply pistons, whereby said fuel injection piston is adapted during its movement in the direction of said fuel supply piston to exert an end thrust on said fuel supply piston-to thus operate the latter in the same direction.

2. A unit fuel injection and supply pump assembly for an internal combustion engine comprising an injection pump section and a supply pump section for. feeding fuel to said injection pump section, said injection pump section including a reciprocable plunger, and said supply pump section including a reciprocable piston disposed (amuse mentioned pump for feedlng'fuel thereto. said first mentioned pum including a reciprocable plunger and said second pump including a reelprocable piston disposed in axial alinement with said plunger, means whereby said plunger is adapted during its movement in the direction of said piston to exert an end thrust on said piston plunger and said said second pump including a reciprocable piston disposed in axial alignment with said plunger, and means whereby saidplunger is adapted during its movement in the direction of said piston to exert an end thrust on said piston and thus operate said piston in the same direction.

5. A fuel pump construction for an internal combustion engine comprising a fuel injection pump and a second pump operated by said first mentioned pump for feeding fuel thereto, said first mentioned pump including a. reciprocable plunger and said second pump including a reciprocable piston disposed in axial alignment with said plunger, means whereby said plunger is adapted during its movement in the direction of said piston to exert an end thrust on said piston and thus operate said piston in the same direc tion. and separate means cooperating with said plunger and said piston for operating them in the opposite direction.

6. A fuel pump construction for an internal combustion engine comprising a fuel injection nected to said plunger and the other end disposed 'in endwlse abutting relation to said piston.

whereby said plunger is adapted in one direction of its sliding movement to force said piston in a corresponding direction of its sliding move ment, and separate springs for operating said plunger and said piston, respectively, in the opposite direction.

9. .A fuel pump construction for an internal combustion engine comprising a fuel injection pump, a second pump operated by said first mentioned pump for feeding fuel thereto, said first mentioned pump comprising a cylinder and a plunger reciprocable therein, said second pump comprising a cylinder and a piston reciprocable therein in axial alinement with said plunger. said second cylinder having an outlet communicating at one end with said first cylinder and having an inlet at its opposite end, a valve in said inlet adapted to be opened by the suction produced by said piston in one direction of its movement, a valve in said outlet adapted to be opened by the pressure produced by such movement of said piston. said piston having a. passageway extending therethrough adapted to establish communication between said inlet and outlet, a valve in said passageway adapted to be opened by the pressure produced by said piston in the other direction of. its movement. a push rod disposed between and in abutting relation to said plunger and piston. and a spring for urging said piston in the directicn of said plunger.

10. A fuel pump construction for an internal combustion engine comprising a fuel injection pump. a second pump operated by said first mentioned pump for feeding fuel thereto, said first mentioned pump comprising a cylinder and a plunger reciprocable therein. said second pump comprising a cylinder fixed to said first men-' pump and a Second pump operated by said fi t o tioned cylinder and a piston reciprocable in said mentioned pump for feeding fuel thereto. said first mentioned pump including a reciprocable plunger and said second pump including a reciprocable piston disposed in axial alinement with said plunger, and a push rod interposed between but non-mechanically connected to the opposing ends of said plunger and piston and operable by the pressure or fuel in said first mentioned pump on the plunger opposing end of said push rod during the movement of said plunger in fuel feed direction to force said piston in a corresponding direction.

7. A fuel pump construction for an nternal combustion engine comprising a fuel injection pump and a second pump operated by said first mentioned pump for feeding fuel thereto. said first mentioned pump including a plunger and said second pump including a piston disposed in axial alinement with said plunger. and a push rod interposed between the opposin ends of said plunger and piston with one end positively connected to said plunger and the othqr end disposed in endwise abutting relation to saidpiston where by said plunger is adapted in one direction of its sliding movement to force said piston in a'c'orrespending direction of its sliding movement.

8. A fuel pump construction for an internal combustion engine comprising a fuel. injection pump and a second pump operated by said first mentioned pump for feeding fuel thereto. said first mentioned pump includin a plunger and said second pump including a piston disposed in axial alinement with said plunger. and a' push rod interposed between the opposing ends ,of said plunger and piston with one end positively consecond cylinder in axial alinement with said plungen said second cylinder having an inlet at one end thereof and an outlet at the other end thereof communicating with said first mentioned cylinder. an inwardly opening check valve in said inlet, a check valve for said outlet adapted to be opened by the suction produced by said plunger. a push rod disposed in axial alinement with said plunger and said piston with one end rigid with said plunger and with the opposite end in abutting relation to said piston. and a spring for urgin said piston in the direction of said plun er.

11. A fuel injection pump for a multi-cylinder injection engine comprising a cylinder having an inlet passageway. a plurality of discharge passageways, and a.by-pass passageway. a plunger working in said cylinder, means for simultaneously reciprocating and rotating said plunger in said cylinder, means formed on said plunger for successively placing said discharge passageways in communication with .thepressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said sageway, a plunger working in said pump cylin-..

the end of its suction stroke, a single longitudinal peripheral groove extending from said annular groove through the working end of said plunger and adapted to successively register with said discharge passageways in intermittently successive positions of the reciprocating movement or said plunger, and a series of circumferentially spaced longitudinal peripheral grooves of a number corresponding to the number of said discharge passageways extending from said annular groove far enough to establish communication between said annular groove and said by-pass passageway in all positions of the reciprocating movement of said plunger.

18. The combination as set forth in claim 12, in which means are provided for rotatably adjusting said plunger relative to the driving means therefor to thereby change the positions of said series of longitudinal grooves relative to said bypass port and thus vary the fuel amounts delivered by said pump. I

14. A fuel injection pump for a multi-cylinder injection engine comprising a cylinder having an inlet passageway, a plurality of discharge passageways, and a by-pass passageway, a plunger working in said cylinder, means for simultaneously reciprocating and rotating said plunger in said cylinder, means formed on said plunger for successively placing said discharge passageways in communication with the pressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means formed on-said plunger for placing said pressure space in communication with said by-pass passageway when any one of said discharge passageways is in communication with said pressure space, said plunger reciprocating and rotating means comprising a cam shaft for. reciprocating said plunger and a connection between said cam shaft and plunger for rotating the latter, and means for adjusting said connection to change the phase relationship between said cam shaft and said plunger.

15. A fuel injection pump for a multi-cylinder injection engine comprising a cylinder having an inlet passageway, a plurality of discharge passageways, and a. by-pass passageway, a plunger working in said cylinder, means for simultaneously reciprocating and rotating said plunger in said cylinder, means formed on said plunger for successively placing said discharge passageways in communication with the pressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means formed on said plunger for placing said pressure space in communication with said by-pass passageway when any one of said discharge passageways is in communication with said pressure space, said plunger rotating means comprising a drive shaft having a helical gear helical gears to thereby change the phaserelationship between said plunger and drive shaft and thus vary the volume of fuel delivery.

16. A fuel injection pump for a multi-cylinder injection engine comprising a cylinder having an inlet passageway, a plurality of discharge passageways, and a by-pass passageway, a plunger working in said cylinder, means for simultaneously reciprocating and rotating said plunger, means for successively placing said discharge passageways in communication with the pressure space of said'cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means for placing said pressure space in communication with said bypass passageway when any one of said discharge passageways is in communication with said pressure space, said plunger reciprocating and rotating means comprising a drive shaft having a cam thereon for reciprocating said plunger, avpinion shaft disposed transverse to said drive shaft and having a helical pinion intermeshing with and driven by a helical gear on said drive shaft and a spur pinion intermeshing with a spur gear on said plunger, and means for shifting said pinion shaft endwise whereby said pinion shaft and said plunger are rotated relative to said drive shaft due to the oblique angle of the teeth of said intermeshing helical gears to thereby change the phase relationship between said drive shaft and said plunger, said means comprising a rock shaft disposed transversely of said pinion shaft, and a pinion mounted on said rock shaft and intermeshing with a rack provided therefor on said pinion shaft.

17. A fuel injection pump for a multi-cylinder injection engine comprising a cylinder having an inlet passageway, a plurality of discharge passageways, and a by-pass passageway, a plunger working in said cylinder, means for simultaneously reciprocating and rotating said plunger in said cylinder, means formed on said plunger for successively placing said discharge passageways in communication with the pressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means formed on said plunger for placing said pressure space in communication with said by-pass passageway when any one of said discharge passageways is in communication with said pressure space, said plunger reciprocating and rotating means comprising a tappet roller carried by said plunger, a drive shaft having a series of cams thereon adapted to successively thereon, a pinion shaft having a helical pinion intermeshing with and driven by said helical gear and a spur pinion, a spur gear on said plunger and intermeshing with and driven' by said spur gear, and means for shifting said pinionshaft endwise whereby movement is imparted to said pinion shaft and the plunger driven thereby are rotated relative to said drive shaft due to the oblique angle of the teeth of said intermeshing engage said tappet roller, a spring for retracting said plunger and for holding the tappet roller thereon in engagement with said cam, a gear on said plunger and a driving connection between said drive shaft and said gear.

18. A fuel injection pump for a multi-cylinder injection engine comprising a cylinder having an inlet passageway, a plurality of discharge passageways, and a by-pass passageway, a plunger working in said cylinder, means for simultaneously reciprocating and rotating said plunger in I said cylinder, means formed on said plunger for successively placing said discharge passageways in communication with the pressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means formed on said plunger for placing said pressure space in communication with said by-pass passageway when any one of said discharge passageways is in communication with said, pressure space, said plunger reciprocating and rotating means comprising a tappet.

roller carriedby said plunger, a drive shaft having a seriesoi cams thereon adapted to successively engage said tappet roller, a spring for retracting said plunger and for holding the tappet roller thereon in engagement with said cams, a

gear on said plunger and a driving connection said cylinder, means for successively placing said discharge passageways in communication with the pressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means for placing said pressure space in communication with said by-pass passageway when any one 7 of said discharge passageways is in communication with said pressure space, said plunger reciprocating means comprising a tappet roller carried by said plunger, a drive shaft having a series of cams thereon adapted to successively engage said tappet roller and a spring for retracting said plunger and for holding the tappet rolierthereon in engagement with said cam. comprising a gear on said plunger and a driving connection between said drive shaft and said gear, and means for rigidly securing said gear to said plunger for sliding movement therewith, said securing means permitting relative rotary adjustment of said gear and plunger.

HERBERT C. EDWARDS.

CERTIFICATE or coRREc'moN.

Patent No. 2,372,559.

It is hereby certified that error appears in the March 27', 1914.5.

HERBERT C. EDJARDS.

print ed specifi cation of the above mmibered patent requiring correction as follows: Page 8, second column,.1ines 10 and 11;, page 9,

umn, line 2, after "means" page 9, first column, line first column, line 17, and second colinsert the yvords -form ed on said plunger--;

, before Play-pass"- insert --a'--,- and second column, line 7, before means" insert "and rotating-; line 10, strike out "and" and insert instead a comma; line 12, strike out "comprising"; and that the said Letters Patent should be read iv ith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of September,

(Seal) A. D. l9 L5.

Leslie Frazer First Assistant Commissioner of Patents.

roller carriedby said plunger, a drive shaft having a seriesoi cams thereon adapted to successively engage said tappet roller, a spring for retracting said plunger and for holding the tappet roller thereon in engagement with said cams, a

gear on said plunger and a driving connection said cylinder, means for successively placing said discharge passageways in communication with the pressure space of said cylinder in intermittently successive positions of the rotary and reciprocating movement of said plunger, and means for placing said pressure space in communication with said by-pass passageway when any one 7 of said discharge passageways is in communication with said pressure space, said plunger reciprocating means comprising a tappet roller carried by said plunger, a drive shaft having a series of cams thereon adapted to successively engage said tappet roller and a spring for retracting said plunger and for holding the tappet rolierthereon in engagement with said cam. comprising a gear on said plunger and a driving connection between said drive shaft and said gear, and means for rigidly securing said gear to said plunger for sliding movement therewith, said securing means permitting relative rotary adjustment of said gear and plunger.

HERBERT C. EDWARDS.

CERTIFICATE or coRREc'moN.

Patent No. 2,372,559.

It is hereby certified that error appears in the March 27', 1914.5.

HERBERT C. EDJARDS.

print ed specifi cation of the above mmibered patent requiring correction as follows: Page 8, second column,.1ines 10 and 11;, page 9,

umn, line 2, after "means" page 9, first column, line first column, line 17, and second colinsert the yvords -form ed on said plunger--;

, before Play-pass"- insert --a'--,- and second column, line 7, before means" insert "and rotating-; line 10, strike out "and" and insert instead a comma; line 12, strike out "comprising"; and that the said Letters Patent should be read iv ith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of September,

(Seal) A. D. l9 L5.

Leslie Frazer First Assistant Commissioner of Patents.

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