US2040847A - Fuel pump for internal combustion engines - Google Patents

Description

May 19, 1936. K. J. E. HEssELMAN FUEL PUMP FOR INTERNAL COMBUSTION ENG'NES 2 Sheets-Sheet 1 original Filed May 2o, 1951 /A I I Uff/V WW y, ATTORNEY May 19, 1936.

K. J. E. HESSELMAN FUEL PUMP FOR INTERNAL coMBUsTIoN ENGINES Original Filed May 20, 1931 2 Sheets-Sheet 2 lli .2.

.9 59 57 fig N .Al/r4 www BY y f-@ZJ Patented May 19, 1936 UNITED STATES FUEL PUMP FOR. INTERNAL COIVIBUSTION ENGINES- Knut Jonas Elias Hesselman, Saltsjo-Storangen,

Sweden ApplicatonMay 20, 1931, Serial No. 538,756.

Renewed September 24, 1935.

vember 7, 192'?` 40 Claims.

This application is a continuing application in `respect to my co-pending applications Serial Nos. 315,957 filed October 30, 1928 (Patent No.

1,912,367 granted June 6, 1933); 473,332 filed August 8, 1930 (Patent No. 1,835,490 granted December 8, 1931) and 483,833 led September 23, 1930 (Patent No. 1,949,470 granted March 6,1934); and is to be considered as relating back so far as herein continued, to the aforesaid applications for all dates and rights incident to the filing thereof.

The present invention relates to fuel pumps for internal combustion engines of the type driven by liquid fuel and has particular reference to pumps for engines of such type which are provided with cylinder valves operated through the medium of an engine driven cam shaft.

A major object of the present invention is to provide an improved form of pump construction in which one or more fuel pumps are driven from the engine cam shaft and in which the casing of each pump is provided with a projecting journaled part adapted to be seated in the cylinder casting in such a way as to absorb the torque resulting from the pressure due to actuation of the pump plunger. Other objects of the invention, together with its more specific nature and the advantages to be derived from its use will best be understood from the following detailedy description of a preferred embodiment which is illustrated in the accompanying drawings forming a part of this specification.

In the drawings,

Fig. 1 is a side elevation of a pump embodying the invention mounted in an engine which is shown partly in end elevation and partly in transverse vertical cross section;

Fig. 2 is a central longitudinal section on an enlarged scale of the pump shown invFig. 1;

Fig. 3 is a section of a part of the pump shown in Fig. 2 with the parts illustrated in a different position;

Fig. 4 is a front elevation illustrating mounting r of a plurality of pumps in a'multi-cylinder en- 4" gine; and,

Fig. 5 is a diagrammatic illustration showing the manner of connecting a, plurality of pumps in a. multi-,cylinder engine.

Turning now to Fig. 1 reference numeral I indicates the engine cylinder and 2 the cylinder head in an internal combustion engine having a crank case 3 in which is mounted the main crank shaft 4 and the usual cam shaft 5. `Piston 6 connected to crank shaft 4 bymeans of connecting r 5o rod 'I is located in cylinder I and air for com- In Sweden No- (Cl. 12S-139) bustion is admitted to the combustion chamber 8 and exhaust gases are expelled therefrom through the medium of inlet and exhaust valves located in the cylinder head 2. These valves are ordinarily alined axially of the motor and in the 5 gure one of the valves is indicated at 9.

Inlet and exhaust valves for the cylinder are l closed by means of springs I0 and are" opened by rocker arms 4II which are actuated by camsV I2 on shaft 5 through the medium of vertical push 10 rods I3.

Cam shaft 5 is driven from crank shaft 4 by any suitable means such for example, as the Vusual cam shaft gear or chain drive indicated in dotted lines at I4. 15

The cam shaft 5 is utilized to actuate the fuel pumps as well as to operate the engine Valves. In engines requiring a plurality of pumps the construction and arrangement of the several pumps With respect to the cam shaft is the same and I 20 will, therefore describe only the construction 0f one such pump. l

For the purpose of actuating the pump the cam shaft 5 is provided with a cam I5 acting on a tappet I6 which extends upwardly and outwardly 25 -a partition extending substantially parallel to the axis of the cam shaft'and enclosing the space 30 alongside the cylinder through which the tappets I6 extend. A spring'IQ seated between suitable shoulders on the plate I8 and the tappet I6 operates to keep the tappet in constant contact with the face of cam I5. As will be explained more in 35 detail later, the construction of the pump is such that the tappet I6 operates to actuate the pump von its delivery stroke, the suction stroke of the pump being effected by spring action.

Referring to Fig. 2, the pump is shown therein 40 in detail. It comprises a casing 20 having two projecting arms 2I and 22, these arms being preferably at right angles to each other. Arm 2l provides a cylindrical journal adapted Yto seat in a cooperating bore 23 in the side of the cylinder 45 casting, and arm 22 'provides a bore 24 for the reception of the pump plunger 25. The end of plunger- 25 extending -beyond arm 22 is provided withga head 26, the lower face of which is adapted to be directly contacted by the upper end of the 50 tappet I6. The upper face of head 26 acts as a retainer for a spring 21, this spring operating to actuate the pump plunger on the suction stroke. Y g n The partition plate I8 is provided with out- 55 wardly extending ears 28 carrying the rotatably mounted shaft 29, thisshaft being situated outside of the arm 22 ofthe pump casing. Shaft 29 is provided with an arm 36 adapted to contact the lower face of the plunger head 26 to limit the length of the suction stroke of the pump. In order to vary the length of the suction stroke of the pump, shaft 29 is rotated by means of a lever 3| or the like which may be controlled either by hand or by means of a suitable speed governor. Opposite the head 26 the shaft 29 is grooved as at 32 for a purpose which will be explained later.

Arm 22 is threaded at 33 and over this threaded portion there is screwed a sleeve 34 having an inwardly turned flange 35 at its lower end, the inne'r diameter of this flange being somewhat less than the diameter of the collar 36 forming the upper portion of head 26. portion 33 the arm 22 is provided with a cylindrical recess 31 into which projects a key 38. Key

38 is removably seated in an opening in the sleeve` 35' and is retained in position by Va spring steel clip 39 seating in a suitable external groove in sleeve 34. The bore 24 communicates at its upper end with the pump chamber 40 which, it is to be noted, is considerably below the level of the center line of the arm 2|.

Opening laterally into the pump chamber 40 is the inlet passage 4| controlled by the pump inlet valve |12. Valve 42 seats against a hardened seat in a sleeve 43 which is seated in the bore of a threaded plug 44 screwed into a suitable recess in the main body portion of the casing. A second sleeve 45 having an inturned flange at its inner end, acts as a retaining member for the valve spring 46. Sleeves 44 and 45 are'preferably a tight fit in plug 44 so that upon removal of this plug the entire .valve assembly will be removable as a unit. A removable plug 41 screwed in the outer wall of the casing provides means for inserting and removing the inlet valve assembly.

The delivery channel leading from the pump chamber 40 .is in the form of a small diameter bore 48 preferably in alinement with the inlet passage 4|. n at the axis of arm 2| by means of a substantially vertically extending bore 50 closed at its upper end by means of plugl 5|. Because of the diiilculty of making a small diameter bore of sufilcient length to extend to the end of the arm 2|, the outer end of this arm is bored to a relatively large diameter as at 52 and a plug 53 is inserted in this ibore, this plug having a bore 54 there- YYthrough of the same diameter as and registering with the bore 49.

In the outer end of bore 52 are two dischargel or delivery valve assemblies 55, each of these assemblies comprising a ball valve seated against a suitable tubular seat-forming member 56 by means of a spring 51. vOutside of the outermost delivery valve assembly is an annular plug 58 which provides an abutment for the outer valve spring 51 to bear against and which also serves to center the injection nozzle 59 carried at the end of the arm 2|. 'I'he plug 58 serves as a centering means by engaging a recess in the face of the plate-like base 60 of nozzle 59. Nozzle 59 is secured to theI .end of arm 2| by means of a cap 6| screwed over y the externally threaded end of arm 2| and engagingA the base 60 of the nozzle. Cap 6| is provided with a tubular extension 62 which serves to protect the relatively delicate tubular portion Above the threaded Bore 48 is connected with bore 49 nozzle assembly is removed from the engine.

Nozzle 59 is provided with one or more fuel delivering orifices 64 and in order to prevent rotation of the nozzle when cap 6| is screwed into position (which rotation might throw the delivery orice or orices out of their proper position) the base of the nozzleI is provided with a projection or lug 65 adapted to engage a suitable notch 66 in the end wall of the arm 2|.

The pump casing 20 provides an oil inlet chamber 61 having an oil inlet at 68 and an oil'outlet at 69. 1

' The casing also carries a pump release valve 10 arranged-to interrupt the effective delivery or discharge stroke of the pump plunger and to return the oil,Y displaced by the plunger after the release valve is opened to the suction side of the pump. The valve seat for the release valve y1|! is preferably formed by a separate plate 1| of' hardened steel or other suitable material held in place within the pump casing by a distance piece 12 against which the inner end of a retaining sleeve 13 which is screwed into the casing abuts. Th.' distance piece 12 is provided with a plurality of ports or openings 14 .aording communication with a channel 15 in the pump casing whichleads to the inlet chamber 61. Valve 10 has a. downwardly projecting stem 16 adapted to be contacted by the inner end of plunger 25 before the latter reaches the end of. its discharge stroke for thev purpose of lifting the valve determining the eiective discharge stroke of the plunger. It will be noted that clearance is provided between the stem 16 and the valve seat member 1| so that oil may flow freely from the pump chamber 40 to the inlet chamber 61 upon opening o`f valve 1|). Valve 10 is provided with an upwardly extending stem in the form of a plunger 1-1 slidably mounted in the sleeve 13 which serves as a guide. An external spiral groove 18 is provided on the plunger 11, this groove operating to permit the escape of air from the pump chamber when valve 10 is'opened.

The release valve is closed by means of a spring 19 compressed between a spring retaining ring 88 and the lower flange of a cup shaped spring retaining member 8| resting on a suitable shoulder 'I'he manner in which the pump is held in posi-v tion in the cylinder will be largely obvious from Fig. 1. In order to facilitate insertion and removal of the arm 2| in the cylinder bore 23, this arm is preferably provided with two spaced cylindrical Journals 81 and 88, the latter being of slightly larger diameter than the former. 'I'hese journals are made aclose sliding fit within corresponding portions of the bore 23 and between these journals the diameter of the arm 2| may be made.somewhat smaller as at 89.

In order to prevent rotational displacement of the pump after it is mounted, the cylinder castlng carries a projecting pin 96 adapted to seat in a corresponding recess 9| in the pump casing.

In multi-cylinder engines when two or more pumps are employed they may advantageously be held in position in pairs (as shown in Fig. 4) by means of clamps 92 through which anchoring studs 93 secured to the cylinder block pass. Other suitable means may, however be employed for removably securing the pumps in position.

I prefer to supply the pumps with oil by means of a circulating system and have illustrated such a circulating supply system in Fig. 5. The arrangement shown in Ythe gure comprises a feed conduit 94 supplied by means of any suitable form of engine driven pump 95 and a return conduit 96 for returning excess fuel to the supply tank. The

engine illustrated is of the conventional six cylinder type and it will be observed that the several pumps are connected in parallel between the vconduits 94 and 96 by means of branch inlet conduits 91 and branch discharge conduits 98. It will also be observed that oil is supplied through conduit 94 at one end of the motor and is returned by way of conduit-96 from the opposite end of the motor, this arrangement aiording the most even distribution of ow through the several pumps.

The operation of the pump will be largely evident from the foregoing description. Oil is drawn into the pump chamber 4U on the suction stroke of the plunger from the supply chamber 61 and on the discharge stroke is delivered through the injection nozzle 59 until the upper end of the plunger contacts the stem 16 on the releasing valve to lift the valve and terminate the eiective discharge stroke. The length of stern 16 is such that valve 10 is opened by the pump plunger while the latter is still traveling at a relatively high velocity and the consequent sudden release in pressure provides for sudden cessation of ow through the injection nozzle at a time when the oil is flowing therethrough at high velocity. This prevents poor atomization due to deceleration of ow at the end of the injection period.

It will be apparent that when the release valve 'lll is opened by the pump plunger, the oil thereafter returned from the pump chamber to .the inlet chamber 61 during the remainder of the upward stroke of the pump plunger will tend to pro-- duce pressure pulsations within chamber 81. In order to eliminate such pulsations the diaphragm 84 is provided. A circulating oil supply system such as is shown in Fig. 5 will tend to keep the inlet chamber 81 under a slight pressure and a spring such as spring 85 is preferably employed in conjunction with such a system for the purpose of balancing the normal constant pressure maintained in chamber 8T by the circulating pump 95.

The removal of air from the oil is highly important and in the vform of pump herein illustrated any air carried into the pump is eifectively removed from the pump chamber. `As will be observed from Fig. 2, the release valve 'l0 is at the upper end of the pump chamber where any air carried into the chamber will automatically tend to collect. The upper end of this chamber is opened upon each discharge stroke of the pump so that air has no opportunity to remain within the pump chamber. Whenever the release valve is opened a free passage for ow of air is provided through the groove 18 and openings 82 to the upper part o f chamber 61 from which the air is carried to gether with the excess oil through the outlet 69 communicating with the branch outlet pipe 98.

Regulation of the amount of oil delivered for each stroke of the pump plunger is governed by varying the length of the intake stroke through movement of the control shaft 29.

It is highly important that the accuracy of the adjustment governing the stroke of the pump be not disturbed and one of the objects of the present invention is to provide a pump which may be readily removed for inspection or repair and then replaced without disturbing any adjustment governing the quantity of fuel delivered by the pump. As will be evident from the drawings the position of the pump is fixed by the seating of arm 2| in the cylinder bore 23. This fixes the position of the release valve 'I0 governing the termination of the delivery stroke. Shaft 29 is rotatably fixed with respect to the cylinder and since the position of this shaft governs the .length of the suction stroke, it is important that it be maintained in accurate alinement.

When it is desired to remove the pump, the sleeve 34 onthe arm 22 is screwed upwardly from the position shown in Fig. 2 to the positionshown in Fig. 3. lThis lifts the head 26 on the pump plunger above the level of the bottom of the groove 32 in shaft 29 and upon release of the clamping means securing the pump to the cylinder block permits the pump to be Withdrawn from the cylinder without necessitating removal of shaft 29. The sleeve 34 may also be screwed into the position shown in Fig. 3 in case it is desired to render the pump inoperative because of breakage of some part thereof or because of failure of the cylinder with which the pump is associated to function properly for any other cause.

The key 38 prevents the sleeve 34 from being inadvertently screwed off of the stem 22 and. providesa positive lock preventing the plunger from falling out of the pump with consequent damage, when the pump is removed from its operating position. Ii' it is desired to remove the pump plunger for any reason this may readily be done by removing the retaining clip 39 and key 38 after which the sleeve 34 may be screwed off and the plunger removed.

It is not necessary to remove the pump if it is desired to remove the inlet valve assembly. Removal of this assembly may readily be accomplished merely byremoving the cover plate 99 and unscrewing the plugs 41 and 44.

The release valve assembly may readily be removed upon unscrewing the cover plate 83.

It Will be evident that the discharge valve and injection nozzle assembly may be readily disassembled by unscrewing the cap member 6|, it being of course obviously necessary to remove the pump before this can be accomplished.

As will be evident from Fig. 1 the pump arrangement is extremely compact, the pump or pumps being so positioned as to not interfere with other auxiliary equipment necessary for the engine. By placing the .pump chamber at a level below that of the arm 2|, the entire pump may be kept below the level of the top of the cylinder and in a position where it does not in terfere with the usual intake or exhaust manifolding |00, at the side of the cylinder head.

Due to the manner in which the arm 2| is mounted in the cylinder, it will be evident that this arm is capable of readily absorbing the torque or bending movements due to pressure created by the pump plunger, thus eliminating the dimculty arising from any part of. the mech-v anism bending or springing out of position due to forces encountered in operation.

It will be apparent that many changes and modiflcations `may be made within the scope of the present invention, which is defined in the appended claims.

What I claim is:

1. A fuel injecting unit for internal combustion engines comprising a casing providing a pump chamber, an arm providing a journal adapted to seat. in an engine cylinder to fix the position of the pump, a discharge passage leading from the pump chamber to the end of said arm, an injection nozzle removably secured to the end of said arm and in communication with said passage, a second arm having a bore communicating with the pump chamber, a pump plunger in said bore, said plunger having a portion projecting from said arm,4 and a sleeve adjustably mounted on the second mentioned arm and adapted to engage the projecting portion of the plunger to hold the same in retracted position.

2. A fuel pump of the plunger type for internal combustion engines comprising a casing providing a pump chamber and a'fuel inlet chamber, an 'inlet valve and a release valve for providing communication between the pump chamber and the inlet chamber, a pump plunger adapted to contact said release valve to open the same during the discharge stroke of the plunger, a laterally projecting arm on said casing providing a journal adapted to seat in an engine cylinder to fix the position of the pump, and a pump discharge passage leading from the pump chamber to the end of said arm.

3. A fuel pump for airless injection of fuel into internal combustion engines comprising .a pump casing having a pump chamber, a laterally extending arm providing a journal adapted to seat in an engine cylinder to x the position of the pump, said arm having an axial bore of relatively large diameter extending inwardly from the outer end thereof, a pump discharge passage of relatively small diameter in said casing providingcommunication between the pump chamber and said bore,'and a sleeve Within said bore, said sleeve having a small diameter bore registering with one end of said discharge passage and providing a continuation thereof to a point adjacent to the outer end of the arm.

4.v A fuel pump of the character described comprising a. casing having a laterally projecting arm adapted to seat in an engine cylinder to fix the position of the pump, said arm having two spaced cylindrical bearing surfaces, the outer of` .said surfaces being of smaller diameter than the inner surface and the diameter of the arm between said-surfaces being less than that of either of said surfaces, and means for preventing said cylindrical bearing surfaces from turning with respect tothe cylinder in which they are seated.

5. A fuel pump of the plunger type for internal combustion engines comprising a casing pro-y viding a pump chamber and an inlet chamber,

inlet and discharge passages communicating with the pump chamber, a release valve above'said pump chamber providing communication between places in the pump chamber and in the inlet chamber above said passages, and a pump plunger extending into thepump chamber, said release valve having a part extending into said pump chamber and positioned so as to be opened by the plunger on each discharge stroke thereof whereby to provide a passage for escape of air from the pump chamber to the inlet chamber upon opening of said release valve.

6. A fuel pump of the plunger type for internal combustion engines comprising a casing providing a. -pump chamber and an inlet chamber, inlet and discharge passages communicating with the 'y pump chamber, a release valve providing communication between said inlet chamber and a point in the pump chamber above said passages, said release valve comprising an upwardly extending stem and groove means providing a channel for escape of air from the pump chamber past said stem when the release valve is opened.

'7. A liquid fuelpump of the plunger type for internal combustion engines comprisinga pump casing providing a pump chamber and an inlet chamber, a release valve adapted to be opened by the pump plunger on eachv discharge strokethereof, said release valve comprising a stem extending into said inlet chamber, a spring locatedv in said inlet chamber and a cup-shaped springretaining member engaging said stem for causing said spring to close the release valve.

8. A liquid fuel pump for internal combustion engines comprising a casing providing a pump chamber and having inlet and outlet passages communicating with said chamber, a release valve for closing the upper end of said chamber above the level of said passages, a pump plunger, me ins for reciprocating said plunger to cause it to directly open said release valve at a xed point in the discharge stroke of the plunger, and meansfor stopping the plunger at selected points during the suction stroke of the plunger to meter the quantity of fuel drawn into the pump.

9. A fuel pump for internal combustion engines comprising a casing providing a pump chamber and an inlet chamber, a valved inlet passage for flow of fuel from the inlet chamber to the pump chamber, a passage for flow of excess fuel and of air from the pump chamber to the inlet chamber, said passage being arranged above the pump chamber so es to automatically free it of air when the passage is opened, a release valve adapted to be opened by the pump plunger for controlling said last named passage, and means for circulating fuel through said inlet chamber.

l0. A fuel pump of the plunger type for internal combustion engines comprising a casing providing a pump chamber and an inlet-chamber, means previdng for ow of fuel from the inlet chamv l chamber.

l1. A fuel pump of the plunger type. for internal combustion engines comprising a casing providing a pump chamber and an inlet chamber, means providing for flow of fuel from the inlet chamber to the pump chamber, means for discharging excess fuel from the pump chamber to the inlet chamber during the discharge stroke of the pump plunger, said inlet chamber being defined in part by a. flexible diaphragm for absorbing pressure pulsations in the chamber due to return thereto of fuel from the pump chamber.

12. A fuel pumping system for internal combustion engines comprising a pump of the plunger type having a pump chamberand a fuel inlet chamber, a pump release valve adapted to return culating fuel through said inlet chamber, and

spring means acting on said diaphragm to balance the -pressure exerted thereon by the pressure required to circulate fuel through the inlet chamber.

13. A fuel supply system for a multi-cylinder internal combustion engine .comprising a fuel pump for each cylinder, each of said pumps having a laterally extending arm journaled in a cylinder to fix the operative position of the pump with respect to the cylinder, and common clamping means for removably securing a plurality of pumps .in operative position.

14. In an internal combustion engine having a cylinder, a fuel pump having a casing providing a pump chamber and having an extension removably secured to the Wall of said cylinder to x the position of the pump casing with respect to the cylinder, a pump plunger projecting from said casing, engine driven means for actuating said plunger, a rotatable shaft having an arm adapted to contact the end of said plunger to regulate the length of the suction stroke of the plunger, the axis of said plunger passing between said shaft and said cylinder, and said plunger being retractable to permit removal of the pump laterally from the cylinder past said shaft.

15. In an internal combustion engine, a cylin- Ader having inlet and discharge valves, a cam shaft for operating said valves, a fuel pump having an arm journaled in the cylinder .to fix the position of the pump with respect to the cylinder, said pump comprising a plunger projecting from the pump casing, a tappet adapted to actuate said plunger by contacting the projecting end thereof, a cam on said cam shaft for actuating said tappet, a control shaft located outside the axis of the tappet and the pump plunger, means associated with said shaft for controlling the length of the suction stroke of the plunger and means for holding said plunger in retracted position to permit removal of the pump past said 16. In aninternal combustion engine, a cylinder having a counterbored opening through the wall thereof, a fuel pump comprising an integral body having a bore forming a pump chamber and an arm having a shoulder adapted to seat against the bottom of the counterbore and bearing sur- 17. In an internal combustion engine, a cylinder block forming a plurality of cylinders, each having a counterbored opening through vthe wall thereof, a fuel pump for each cylinder comprising 'an integral body having a bore forming apump chamber and an arm having a shoulder adapted to seat against the bottom of the counterbore and bearing surface adapted to engage the side wall of -said opening to center lthe pump with respect to the opening, there being a fuel discharge passage through said arm communicating with said chamber, common clamping -means for removably securing a plurality of pumps ,to said block, a plunger'reciprocable in each of said bores, means for reciprocating 'saidplungers, and control means operated by a common member for stopping the suction stroke of each of said plungers at a selected point.

18. In an internal combustion engine, a pluthrough the wall thereof, a fuel pump for eachcylinder, each pump comprising a body having a bore forming a pump chamber and an arm adapted to seat in one of said openings to fix the position of the pump with respect to the cylinder, a plunger in each of said bores, means for removably securing said pumps in position with said arms seating in said openings, means for causing reciprocation of the pump plungers, and control means operated by a common member for stopping each of said plungers at like selected points in their respective suction strokes.

19. In an internalcombustion engine having a combustion chamber, the combination with a cylinder having an opening through the wall thereof communicating with the combustion chamber, of a fuel pump comprising a body having a bore forming a pump chamber and an arm having a fuel discharge passage therethrough communicating with the pump chamber, said body having bearing surface for fixing the position of the pump with the arm in said opening, a valve seating in said body for relieving pressure in the pump chamber and havinga part extending into said chamber, a plunger-in said bore having an inner end adapted to contact the valve part in said chamber to open said valve at a xed point in the discharge stroke of the plunger, means for actuating the plunger by contacting the outer end thereof, means for removably securing said pump in position with said arm in said opening,l

. ing a bore forming a pump chamber and an arm having a fuel discharge passage therethrough communicating with the pump chamber, said arm having bearing surfacev adapted to fix the vposition of the pump with -respect to the cylinder by seating against the side Wall of said opening, a valve' seating in said body for relieving the pressure in the pump chamber and having a part extending into said chamber, a plunger in said bore having an inner end adapted to contact the valve part in said chamber to open said valve at a fixed point in the discharge stroke of theV plunger, means for actuating the plunger by contacting the outer end thereof, means for removably securing said pump in positionwith said arm in said opening, and control means for stopping the suction stroke of said plunger at selected points.

21. In an internal combustion engine having a combustion chamber, the combination with a cylinder having an opening through the Wall thereof communicating with the combustion chamber, of a fuel pump comprising a body having abo`re forming a pump chamber and an armI having a fuel discharge passage therethrough communicating with the pump chamber, said body having bearing surface for fixing the position of the pump with the arm in said openingg;

an injection nozzle removably secured to the end of said arm and adapted toproject into said chamber when the pump is Iin iixed position, a

valveseating in said body for relieving pressure in the pump chamber and having a part extending into.- said chamber,` a Vplunger in said bore' having an inner end adapted to contact the valve part in said chamber to open said valve at a combustion chamber, a cylinder having a cylindrical opening through the Wall thereof com-` municating with the combustion chamber, a fuel pump comprising a body having a bore forming a pump chamber and a cylindrical arm having a. fuel discharge passage therethrough communieating with the pump chamber, said arm having bearing surface adapted to x the position" of the pump body with respect to the axis of said opening by seating against the wall thereof,

-means for removably securing said pump in position with said arm in said opening, means for preventing turning movement of the pump bodyv with respect to the opening, a fuel injection nozzle removably secured to the end of said arm and having an orifice for projecting fuel from the nozzle at an angle to the axis of s aid open'- ing, means for holding said nozzle in a predetermined position of rotation with respect tosaid arm, a plungerjn said bore, and means for actuating said plunger by contacting the outerl end thereof.

23. In a fuel injecting unit for internal combustion engines, a, body portion adapted to seat in an engine cylinder having a passage therethrough for discharge of fuel, an injection nozzle, means for removably clamping the injection nozzle to the end of said body portion, means for centering the nozzle with respect to said passage, means for insuring the positioning of said nozzle in a given fixed position of rotation with respect to said body portion, and means for insuring the positioning of said body portion in a given xed position of rotation with respect to the cylinder.

24, In afuel injecting unit for internal combustion engines, a body portion adapted to extend through the wall of an engine cylinder, said body portion having a bore for discharge of fuel and an end portion of said bore being of substantially larger diameter than-necessary for the discharge of fuel, an injection nozzle, means for removably clamping said nozzle to the end of said body portion and means for centering the nozzlewith respect to said bore comprisingI an annular element extending into said end portion of the bore and extending into a suitable cooperating recess in the nozzle.

25. In a fuel injecting unit for internal combustion engines, a body portion adapted to extend through the wall of an engine cylinder, said body portion having a bore for' discharge of fuel and an end portion of said bore being of substantially larger diameter than necessary for the discharge of fuel, an injection nozzle, an annular element in threaded engagement with said body portion for removably clamping said nozzle to the end of the body portion and means for centering the nozzle with respect to said bore comprising an annularv element extending into said end portion of the bore and extending into -a suitable cooperating recess in the nozzle.

26. In a fuel'injecting unit for internal combustion engines, a body portion adapted to extendA through the Wall of an engine cylinder, said body portion having a bore for discharge of fuel and an end portion of said bore being of substantially larger diameter than necessary for` theA discharge of fuel, an injection nozzle, means for removably clamping said nozzle to the end of the body portion, and means for centering the nozzle with respect to said bore comprising an annular element extending into said end` portion of the bore andextending into a suitable cooperating recess in the nozzle, said nozzle and said body portion having cooperating surfaces for insuring the positioning of said nozzle inA a given fixed position of rotation with respect to said body portion.

27. In a fuel injecting' unit for internal combustion engines, a body portion adapted to extend through the wall of an engine cylinder, said body portion having a bore for discharge of fuel and an end portion of said bore being of substantially larger diameter than necessary for the discharge of fuel, an injection nozzle, an annular element in threaded engagement with said body portion for removably clamping said nozzle-to the end of said portion, and means for centering the nozzle with,

respect to said bore comprising an annular element extending into said endr of the bore and extending into a suitable cooperating recess in the nozzle, said nozzle and said body portion having cooperating surfaces for.v insuring the posi,- tioning of said nozzle in a given fixed positionof rotation with respect to said body portion.

28. In a fuel injecting unit for internal combustion engines, a body portion adapted to extend through the Wall of an engine cylinder, said body portion having a bore for discharge of fuel and the major portion of said bore being of substan-i tially larger diameter than necessary for the discharge of fuel, a, plurality of tubular inserts in said bore including an endinsert projecting from the end of. said body portion, an injection nozzle having arecess and means for removably" clamping said injection nozzle to the end of said'body portion, said end insert extending into said recess to center the nozzle.

29. In a'fuel injecting unit for internal combustion engines, a body portion adapted to extend through the wall of an engine cylinder, said body portion having a bore for discharge of fuel andthe major portion of said bore being of substantially larger diameter than necessary for the dischargeof fuel, a plurality o1' tubular inserts in said bore including an insert having discharge valve means therein and an end insert projecting from the end of said body portion, an injection nozzle havl ing a recess, and means for removably clamping said injection nome to the end of'said body portion, said end insert extending into said recess to center the nozzle.

, 30. In' a fuel pump of the plunger type for in-f ternal combustion engines,.a casing providingna pump chamber and an inlet chamber above the pump chamber, inlet and release valves providing communication between said fchambers, a pump plunger,` said release valve being located above the pump chamber and being adapted to be opened by said plunger, said inlet valve being located laterally of the pump chamber, said casing having an opening in the side wall thereof for removal of said inlet valve and a removable closuretor said opening.

31. In a fuel pump ,of the plunger type for in l ternal combustion engines, a pump casing providing a pump chamber andan inlet chamber ad- 7o" jacent to said pump chamber, inlet and release l valves lproviding' communication-between said ,I

chambers, a guidey extending into said inlet cham-l` ber, said release valve having a steme'xtending through said guide, a-cup shaped spring retainer engaging said stem, a spring in said inlet chamber engaging said retainer to seat the release valve, and a pump plunger adapted tol unseat the release valve to return excess fuel from the pump chamber to the inlet chamber.

32. In a fuel pump of the plunger type for internal combustion engines, a pump casing providing a pump chamber and an inlet chamber adjacent to said pump chamber, inlet and release valves providing communication between said chambers, a removable element providing a seat for the release valve, a guide removably secured in said casing, said guide extending into said inlet chamber and serving to clamp said removable element in position, said release valve having a stem extending through said guide, a cup shaped spring retainer engaging said stem, a spring in said inlet chamber engaging said retainer to seat the release valve, and a pump plunger adapted to unseat the release valve to return excess fuel from the pump chamber tothe inlet chamber. v

33. In a fuel pump of the plunger type for internal combustion engines, a pump casing providing a pump chamber and an inlet chamber adjacent to said pump chamber, inlet and release valves providing communication between said chambers, an annular element at the end of the pump chamber providing a seat for the release valve, a guide threaded into the casing, said guide extending into said inlet chamber and serving to clamp said annular element in position, said release valve comprising a shouldered plunger having a pin portion projecting through said annular element into the pump chamber and a plunger portion extending through said guide, a spring retainer engaging said plunger portion, a spring in the inlet chamber engaging said retainer to seat the release valve, and a pump plunger adapted to contact said pin portion to unseat the release valve whereby to return excess fuel from the pump chamber to the inlet chamber.

34. In a fuel pump for internal combustion engines, a casing providing a purnp chamber and having an arm providing a cylinder for a pump plunger, a plunger in said cylinder having a portion projecting from the casing, a spring engaging the projecting portion of the plunger to move it outwardly of the casing on its suction stroke, and an adjustable sleeve engaging said casing and the plunger vfor limiting outward movement of the plunger.

35. In a fuel pump for internal combustion engines, a casing providing a pump chamber and having an arm providing a cylinder for a pump plunger, a plunger in said cylinder having a portion projecting from the casing, a spring engaging the projecting portion of the plunger to move it outwardly 'of the casing on its suction stroke, and an adjustable sleeve threaded over said'arm and engaging the plunger for holding the plunger inwardly of the outer end of its stroke against the action of said spring.

36. In a fuel pump for internal combustion engines, a casing providing a pump chamber and having an arm providing a cylinder for a pump plunger, a plunger in said cylinder having a portion projectingfrom the casing, a spring engaging the projecting portion of the plunger to move it outwardly of the casing on its suction stroke, a sleeve threaded over said arm and engaging the plunger for holding the plunger inwardly of the outer end of its stroke against the action of said spring, and means providing a stop for limiting the outward travel of said sleeve.

37. In a fuel pump for internal combustion engines, a casing providing a pump chamber and having an arm providing a cylinder for a pump plunger, a plunger in said cylinder having a portion projecting from the casing, a spring engaging the projecting portion of the plunger to move it outwardly of the casing on its suction stroke, a sleeve threaded over said arm and engaging the plunger for holding the plunger inwardly of the outer end of its stroke against the action of said spring, and means providing a stop for limiting the outward travel of said sleeve comprising an v annular recess in said arm and a part on said sleeve projecting into said recess.

38. In a fuel pump for internal combustion engines, a casing providing a pump chamber and having an arm providing a cylinder for a pump plunger, a plunger in said cylinder having a portion projecting from the lcasing, a spring engaging the projecting portion of the plunger to move it outwardly of the casing on its suction stroke, a sleeve threaded over said arm and engaging the plunger for holding the plunger inwardly of the outer end of its stroke against the action of said spring, and means providing a stop for limiting the outward travel of said sleeve comprising an annular recess in said arm and a part on said sleeve projecting into said recess, said part being removable from the sleeve to permit the sleeve to be screwed off the arm, whereby to permit removal of the plunger from the casing.

39. In an internal combustion engine, a cylinderhaving a bore through the side wall thereof, a fuel pump comprising a casing having a laterally projecting arm providing a journal engaging the wall of said bore, a pump plunger projecting from said. casing substantially at right angles to said arm, engine driven means for forcing said plunger inwardly of the casing on its discharge stroke, means separate from the pump adapted to contact said plunger to control the length of the suction stroke thereof, `the axis of Said plunger passing between the last mentioned means and the cylinder, and means associated With the pump casing for holding the pump plunger in retracted position to permit removal of said pump laterally of the cylinder.

40. In apparatus of the character described, a cylinder block having a plurality of cylinders, a bore through the side wall of each of two adjacent cylinders, a fuel pump for each cylinder, each pump comprisinga casing ,having a laterally projecting arm providing a journal engaging the wall of one of said bores, means providing cooperating abutment surfaces for preventing turning movement of the pumps about the axes of their respective arms, and a yoke engaging two adjacent pumps for removably clamping the same in operative position to said cylinder block.

KNUT JONAS ELIAS HESSELMAN.

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