US2429806A

US2429806A - Fuel injection pump

Info

Publication number: US2429806A
Application number: US616532A
Authority: US
Inventors: Desire J Deschamps
Original assignee: DESCHAMPS FUEL INJECTION CORP
Current assignee: DESCHAMPS FUEL INJECTION Corp
Priority date: 1945-09-15
Filing date: 1945-09-15
Publication date: 1947-10-28
Anticipated expiration: 1964-10-28

Description

D. J. DESCHAMPS FUEL INJECTION PUMP 8 Sheets-Sheet 1 Filed sept. 15, 1 945 d/.I ATTORNEYS Oct.' 28, 1947. Y D. J. DESCHAMPS 2,429,806

FUEL IJEc'rIoN PUMP 8 Sheets-Sheet 2V D. J. DESCHAMPS FUEL INJECTION PUIP Oct.' 2s, 1947.

Fi1ed sept. 15, 1945 .B sheets-sheet s D. J. DE'sHAMPs FUEL INJECTION PUMP 8 Sheets-Sheet 4 Fle'd Sept. 15, 1945 I NvENToR @my l ampws, nrw z wel ATTORNEYS Oct. 2s, 1947.

Oct 28., 1947 D. JQDEscHAMAPs' 2,429,805

FUEL INJECTION PUMP v Filed sept. 15, 1945 s sheets-sheet 5 @Aw/Lrg 8 Sheets-Sheet 6 W f f 14111 f D. J. DESCHAMPS FUEL INJECTION PUMP Filed sept. 15, 1945 oct. 28,'1947.

si. lill,

f a0, ,v/WV

ATTORNEYS Oct 28, 1947. D. J. DESCHAMPS FUEL .INJECTION PUMP S Sheeths-Sheet 7 File@ Sept. 15, 1945 Oct 28 1947. D. J. DESCHAMPS FUELV INJECTION PUMP I 8 Sheets-Sheet 8 -lN'vENToR Filed Sept. l5, 1945 7m, Dam, mami'. ruuudg ArroRNEYs Patented von. 2s, 1947 FUEL iNJaorlQN v Desire J. Deschamps, Rutherford, N. J., assigner to Deschamps Fuel Injection Corporation, New York, N. Y., a corporation of New York Application September 15, 1945 Serial No. 616,532

17 claims. 1

This invention relates to fuel injection pumps and has for its object the provision of an improved high speed pump for injecting liquid fuel into the cylinders of internal combustion engines.

Pumps of this kind frequently comprise a plurality of pump cylinders usually, referred to as bushings or cylinder bushings, in which operate plungers actuated by suitable reciprocating mechanism to cause the application of pressure to the liquid fuel and its discharge through tubing to the respective engine cylinders. In one form of pump of this type widely used, the length nf the period of injection and therefore the quantity of fuel injected by each stroke of the plunger in its cylinder is varied to suit the power demands of the engine by turning the plunger axially on its cylinder.

Mechanism under the control of the engine governor or throttle lever is provided for simultaneously turning the vseveral plungers of the pump to eiect control of the output'l of the pump as a whole, that is, of all the pump cylinders taken together. Difliculties, however, have been experienced in transmitting the rotary motion to the plunger while it is reciprocating, and one of the commonest arrangements in use heretofore has been to provide a cross arm on the plunger to assist in imparting the turning movement thereto. These cross arms, however, must be made integral with the plunger and consequently the cost of the pump plungers has been high. One of the objects of the present invention is to overcome these difculties, eliminating such T-shaped plungers and providing a construction which is fully as reliable in operation and less expensive to manufacture.

Another object of the inventionvis to simplify the mechanism for turning the respective vplungers in unison.

Another object of the invention is to provide an improved mechanism for adjusting the output of the individual cylinders while the pump is operating in order to facilitate the calibration of the pump.

A further object of the invention is to provide (Cl. S-173) drawings and the f'ouowmg detailed description for the adjustment of the output of the individual cylinders from the outside of the pump housing.

A still further object of the invention is tov of one embodiment of the invention which is given by way of example. In these drawings:

Fig. 1 is a central longitudinal sectional viewl of the improved fuel injection pump taken taken on line I-I o! Fig. 3;

Fig. 2is a view in elevation looking from the left-hand of Fig. 1;

Fig. 3 is a similar view looking` from the righthand of Fig. 1;

Fig. 4 is a central longitudinal section of a single pumping unit of the pump, drawn to an enlarged scale; y

Fig. 5 is a View of certain parts shown in Fig. 4 looking at the bottom ofthat figure, some of these parts being shown broken away and some in section;

Fig. 6 is a. transverse section taken online 6--6 of Fig. `4;

Fig. 'I is a sectional view taken on line 1--1' of Fig. 2;V

Fig. 8 is a transverse section taken on line 8-8 of Fig. 1;

Fig. 9 is a partial end view of the pump looking frmlthe left of Fig. 1 with parts broken away and shown in fragmentary section on line 9-9 of Fig. 1;

Fig. 10 is a. fragmentary section similar to that of Fig.- 9 showing a modified construction, the section being taken on line Ill-I0 of Fig. 11;

Fig. 11 is'an outside view looking downward on the parts shown in Fig. 10;

Fig. 12 is a sectional view similar to Fig. 10 but i taken on line I2--l2 of Fig. 11;

Fig. 13 is a sectional view taken on line i3-l3 of Fig. 11;

Figs. 14 to 16 inclusive are views of a single cylinder aim plunger with a part of the cylinder brokenaway'and shown in section to show the porting of the plunger, the plunger being shown at three different points of its stroke;

Figs. 17 to 19 inclusive are similar views with the plunger 'at the same-point of its stroke but turned on its axis corresponding to dierent outputs;

Figs. 20 to 25 inclusive are similar v'iews of a modification and correspond respectively with Figs. 14 to 19 inclusive; and

Figs. 26 to 31 inclusive are also similar views of a further modification corresponding to Figs. 14 to 19 inclusive.

Referring now to the accompanying drawings, the pump comprises a main housing I which is a cylindrical shell extendingfsomewhat less than one-half the length of the pump and provided at its inner end with a flange 2 and at its outer end with a flange 3. A mounting flange or plate 4 is adjacent flange 2 by which the pump is secured on the mounting pad of the internal combustion engine. Housing I carries a suitable number of pump cylinders or bushings 5, the pump illustrated having y nine cylinders. Each cylinder is provided with a reciprocating plunger 6 which, through a tappet mechanism indicated generally by numeral 1, is operatively associated with the pump actuating element which is shown as a floatingwobble plate 8, butwhich may also consist of a plain wobble plate or a face cam. The respective plungers are operated in a well under-l stood manner on their working or fuel-injecting strokes by means of the actuating element 8 and on their return strokes by means of coil springs 9 appropriately. associated with the tappet mecha nism 1.

The several cylinders 5 are supported in apertures in internal flanges I and II at the opposite ends of main housing member I. the cylinders against longitudinal movement they are themselves flanged at their outer ends as indicated at I2, these flanges I2 being received within counter bores in the apertures for the cylinders in internal flanges IIL The tappet members 'I are ycarried in a tappet housing I3 provided with apertures, for guiding the tappet member 1, which are in longitudinal alignment with the apertures in the internal flanges III and Il of main housing member I which support the pump cylinders. Tapp'et housing I3 is providedy with an integral cylindrical extension I4 extending toward the inner or righthand end of the pump and terminating in a flange I5 by which the tappet housing is supported on main housing member I. The tappet mechanism and wobble plate 8 are enclosed by a cup-shaped cover member I6 having a .flange I1 which ts over flange I5, both this cover and tappet housing I3 being secured to main housing member I by a series of screws I8 which are tapped into flange 3.

Main housing I and mounting flange 4 are secured together not only by means of a series of screws I9 which are tapped into ange 2, but also by means of a hollow tubular supporting member 26 which extends substantially from end to end of the pump. Member 28 is provided with a shoulder 2l which engages the inner surface of internal flange I0 of housing I and projects through a central opening in this flange and also in mounting flange 4 and terminates in a threaded portion 22. 0n this threaded portion 22 there is a nut 23, the inner end of which is turned up tight against the outer surface of mounting flange 4. Hollow supporting member is received in a central opening in internal flange II ofvhousing I and also in a similar opening in tappet housing I3 and, being firmly secured to mounting flange 4 and the inner end of housing I, serves to rigidify the entire pump structure.

Hollow supporting member 26 also serves lto support the bearings of the shaft 24 of actuating element 8. This is a tubular shaft extending from end to end of the pump and rotating in ball bearings 25 and 26. Adjacent bearing 25 there is a ball bearing 21 constructed to take the endwise thrust on the shaft resulting ,from the'plunger reaction on wobble plate 8. Bearings 25 and A21 are disposed adjacent each other, and their inner bearing races are held in position 1by means of a nut 28 threaded on an enlargement on shaft 24.

.-bore of hollow supporting member 20 and is held therein by means of a snap ring 28, fitting into a groove in this bore. The outer bearing race of bearing 25 is held in position by 'a spacing sleeve 29, the right-hand end of whichl is incontact with a lubricant distributor housing 30. Another snap ring 3| at the right-hand end of housing 30 holds both the housing and spacing sleeve 29 in position within hollow supporting member 20. Inner ball bearing 26 is positioned against an internal rib 32 formed on the interior of supporting member 20 and by a snap ring 33.

Actuating element 8 is of the so-called floating or non-rotating type, being mounted on a pair of ball bearings 34 constructed to resist endwise thrust. The outer race's of these bearings are held in position within the hollow hub of actuating element 8 by means of a snap ring 35.

To restrain The inner races are mounted on an extension 36 on hollow shaft 24, the axis ofthisrextension being disposed at a suitable angle to that of shaft 24. These bearing races are held in position on this shaft extension by means of a nut 31.

Tubular shaft 24 constitutesv merely a supporting shaft for actuating element 8, and the pump is driven by means of a quill or flexible shaft 38. This shaft is splined at 38 for connection to the pump driving shaft provided'on the engine, and its opposite end has a squared enlargement 40 which is received within a similarly formed opening adjacent the outer end of hollow shaft 24.

The gasoline or other fuel to be pumped is admitted to the pump through an inlet opening 4I, this liquid being usually supplied by means of a transfer pump which introduces it into inlet 4I at a pressure of about l5 lbs. per square inch. A second opening (not shown) similar and adjacent to inlet 4I is preferably provided for connection to a vapor removing device. The fuel entering inlet 4I is received within an annular inlet chamber 42 within main housing I and outside of hollow supporting member 20. From inlet chamber 42 the fuel is admitted to the working space 43 of each ofthe nine pump cylinders or bushings 5 through inlet ports 44 which are controlled in a manner to be described.

The fuel. is ejected from working space 43 through an outlet opening 45 drilled through mounting flange 4. Each of these outlet openings is closed by a thimble-shaped automatic or spring-actuated valve member 46. As the fuel is ejected from the working space 43 it forces valve member 46 open and escapes through an injection passage 41 which is drilled in mounting flange 4 to communicate with one of the openingsl 48 through which passes one of the holding screws (not shown) which fasten the pump to the engine mounting pad. 11; wiube understood that these screws are of a hollow construction` and that each communicates with a duct within the engine leading to the fuel injection valvey of one of the engine cylinders. Y

As indicated in the introduction, the amount of fuel injected into the engine cylinders by the operation of pump plungers 6, or in other words the volumetric outputs of the pumping spaces 43, is adjusted or regulated by axially turning plungers 6. The turning of these plungers controls the closing and opening of ports 44 in a well understood manner.

Although there is shown in Figs, 1 and 4 only a single port 44 for each cylinder 5, each cylinder bushing is in fact provided with two of these ports positioned diametriclly opposite each other (see Figs.v 14-19). The closing andv opening of these two ports is controlled lby means oity two diametrically opposite lugs 49 on 'each yof thev plungers 5. These lugs have the same congura,

tion and, as shown in Fig. 1. their upper edges 50 are nat, i. e., at right angles to the axis of surfaces 51 of fingers 55 on key driving gear 53 in all positions of the reciprocating plunger.

By means of this constructions. change in the `angular position of gear 53 will turn the plunger a similar-amount whether the plunger is stationary or reciprocating, thereby regulating or acl-- justing the helical port-controlling edges 5| and A hencethe amount the plunger, while their lower edges 5I each have the form of a'helix. -As shown in Figs. 1 and 4 plunger 5 is at the end of its inward or back stroke and the upperedges 55 of lugs y4 9 have uncovered the two ports 44, and fuel is free to ilow into the' working space 43 through'these ports from inlet chamber 42'.

As plunger 5 moves to the right on a forward or working stroke the outer edges 55 close ports 44 at the instant they pass the right-hand edges of these ports. I'he injectionof fuel into the engine cylinder will therefore start at this point. In-

.iection continues until the 'inner helical edges 5I The mechanism for turning plungers 6 whilethey are reciprocating is illustrated in Figs. 1 and 4 to 8 inclusive, Oxie of the principal parts of this mechanism is a small gear 53 arranged for free rotation on each of the cylinders 5 which, for this purpose, has an end portion 52 of reduced diameter projecting to the left of internal flange Il. The thrust of spring 9 is received by gear 53, the right-hand end of this spring bearing against a collar 54 thereon. Consequently, to enable gear 53 to turn easily, even when spring 9 is under full compression,.a ball thrust bearing 55 is placed on the right-hand side of gear 53 between it and the surface of internal ilarige Il of housing I. Each of the gears 53 has a pair of elongated fingers 55, the inner faces 51 of which are fixed in spaced parallel relation, as shown in Fig. 5.

At the left-hand end of each of plungers 6 there is a. flanged spring retaining sleeve 58, having a longitudinally projecting key portion 59, the sides of which ilt with a sliding t between the parallel spaced `surfaces 51. inner part of key portion 59 rests within a key The of fuel injected into -the engine cylinders.

Referringnow to Figs. 'l and 8, the several key driving gears 53, one for eachof the nine pump cylinders 5, are interconnected with one another by means of a large idler gear 54 which is mounted for rotation on the exterior of hollow supporting member (see Figs. 8 and 1). Gear 54 rotates on member 20 between theside of internal flange Il and a snap ring 55 fitted into an annular' groove inthe surface oi this member.

Instead of turning the several gearsv 53 by means of -a vturning or driving mechanism connected with gear 54, this gear is employed merely as an idler gear and the output control lever is arranged to actuate one of the gears 53, the motion imparted to this one gear being transmitted `to all of the others by the idler gear 64.

" Thus the control lever, indicated at 66, is xed slot cut in the surface of plunger 6. Spring- Y surface of the'plunger.

The sloping outer surfaces of the two-piece ring 6I engage an inner 4conical surface 62 provided at the left-hand portion of sleeve 58. These parts are held in locked position by the pressure of spring 9, the left-hand end of which engages a flange ,53 on sleeve 58.l Sleeve 58 being thus xed at the end of plunger 6, key 59 4is Yheld immovably in key slot 50 and reciprocates with the plunger, the key,` however, vbeing of suicient length so that it is engaged by the on the end of a shaft A51 which is arranged to rotate on an outward extension 58 at one side of main housing I, as shown in Figs. 2, 3 and 6. On the inner end of shaft 51 there is a. gear 59 which engages the teeth of the nearest gear 53. The number of teeth in gear 59 may be so chosen as to provide any desired angular movement of output control member 55 in adjusting the pump from zero to maximum output.

It will be understood that it is important to have the outputs of the respective pumping cylinders varied uniformly in order to maintain equality of load between the various engine cylinders. This requires exact adjustment of the ,helical control 'edges 5| of the several pump plungers. Such precise adjustment is ordinarily diflicult to obtain in a gear driven mechanism, but in the mechanism as above described itis attained because of the fact thatthe pressure of the liquid in the working spaces 43 of the pump cylinders, when it is released through uncovering of the spill ports 44 by the helical control edges 5I, acts upon these helically inclined edges in such a way as to tendto turn all of the plungers in the same direction. The same sides of the respective gear teeth are therefore always maintained in contact and backlash between them is prevented.

Consequently there is never a reversal of the pressure between any of these gear teeth, either between those of any of the gears 53 and idler gear 54 or between the teeth of gear 59 and those of the gear 53 with which it meshes; In other words, the movement of output control lever 55 transmits force through the gear train to move .gears -53 in only -one direction of movement of the control lever. In its .opposite direction of movement the force transmission is also .in the opposite direction, that is, the uid pressure on the helical edges 5l tends to cause gears 53 to rotate and this rotation is restrained by the output control lever 55 and the teeth of the gear train.

7 The utilization of gear 54 as an idler gear and the application of actuating gear 59 directly to one of the plunger rotating gears 53 has the advantage of placing the actuating mechanism on the outside of the pump and frees the central actuating mechanism.` I

The tappet mechanism' 1 is of thimble-like construction as shown in Fig. 4, the skirtl 10 of the thimble being cylindrical so as to slide in 1 the guiding apertures in tappet housing I3 and guide the slippers 1I, maintaining them in alignment with their respectiveplungers 6.as they are actuated in their reciprocating movement by the wobble plate 8. Skirt 10 has a predetermined length in order to operate as an eiective guide means and spring 9 is telescoped within skirt 10 for a substantial portion, of its length. The inner end of plunger 6 bears directly against lthe end of tappet 1, thev compression of spring operating at all times to urge the tappet and slipper 1I` against the surface of the wobble plate 8. Tappet 1 floats between the end of the plunger and the wobble plate, there being no connection attaching the tappet to the plunger.

In the pump of the present invention the pump cylinders or bushings 5 are not mounted Iier-l manently in housing I by means of a press fit," as is customary, but these parts are assembled with a sliding ilt. This makes it possible to remove individual cylinders for servicing and in addition facilitates manufacture of the pump. It is possible to finish grind and lap or hone the bore of the cylinder bushings as separate and interchangeable units instead of requiring that such finishing operations be done after the bushings have been pressed in place in the housing.

There is an objection to assembling the bushings in the housing with a press fit, as it sets up stress in the walls of the bushings which later on sometimes causes distortion of the bore and sticking of the plunger. Also, when the bushings are inserted with a press iit the metal remains' under stress of compression so that temperature changes, stress put on the parts when the pump is in operation, and other factors may cause deformation of the bore of such bushings.

By mounting the pump cylinders 5 with a sliding iit in housing I, provision is made for another feature of the present invention, namely, the calibration or adjustment of the several cylinders of the pump to produce equal outputs from all cylinders. This is of importance because, although the cylinder bushings and other parts of the pump which may affect the output are machined within small tolerances, the accumulation of these tolerances when taken for the several parts which concur in vthe motion of the plungers and in the location of the .ports may be great enough to cause important discrepancies in the timing of the porting and thus of the outputs of the several pumping units of the pump.

Consequently, it is necessary to provide some means for adjusting the individual pumping units to obtain uniformity of output in the calibration of the pump. As shown in detail in Fig. 9, provision is made for rotating each of the pump cylinders 5 independently of the others, so that the cylinder ports 4,4 can be angularly adjusted with respect to the `helical edges 5I of the port control lugs 49 on the plungers. To accomplish this cylinders 5 are provided opposite the internal flange, I I of housing I with a series of worm gear teeth 12 preferably formed by milling cuts equally spaced around the circumference of the cylinder, and an adjusting screw 13 having threads 14 engaging these teeth is provided.

These screws, for each of the cylinders 5, are positionedinapertres drilled'in ange I which openinto a circular recess 15 extending around the pump housing. Adjusting screws 13 each have an enlarged portion 16 having inner and outer shoulders at either side and beyond which is vasquared end adapted to receive an adjusting wrench. Enlargement 18 is received within, a

`counter bore at the outer end of the adjusting screw aperture.

The adjusting screw is held fixed to prevent vlongitudinal movement as it is turned in either direction to eiect the turning and adjustment of the pump cylinder 5. For this purpose the inner shoulder of enlargement 16 cooperates with a shoulder formed at the bottom of the eountersunk portion of the screw aperture and the outer shoulder of enlargement 16 is positioned against a snap ring 11 which is received within annular groove in the counter bore.

VTo obtain a close fit between these two shoulders which will allow rotation of screws 13 substantially without endwise movement, shim washers 18 are placed at the innershoulder of enlargement 16. In order to facilitate the assembly of screws 13 in their apertures a supply of these' washers in varying thicknessesl is provided so that an exact fit of the inner and .outer shoulders of enlargement 16 can be obtained.

It will be understood that in calibrating the pump each of the cylinders 5 of the pumps nine pumping units is adjusted by applying a wrench to its adjusting screw 13 until the cylinder produces a predetermined volumetric output. Then adjusting screw 13 is locked in position by means of a locking/,screw 18, the inner end of which is forced against the surface of' enlargement 16 as shown in Fig. 9. Locking screws 19 are protected against unintentional release by means of screws which close the apertures in which screws 19 are threaded.

The outer ends of the apertures in which adjusting screws 13 are located are closed by screw Both these screw plugs 8| and screws 60 are accessible for removal within the annular recess 15 in the pump housing, and this recess maybe closed to protect these parts and to improve the appearance of the pump by means of a nexible band 82 encircling the pump and clamped in position by means of a connecting screw 83.

In the modification shown in Figs. 1 to 13 inclusive, the construction of the parts for adjusting the cylinders 5 is identical with that just described except the arrangement for locking the parts in adjusted position after calibration. Instead of providing the locking screw 19 for engaging the enlargement of adjusting screw 13, the cylinder bushings 5 are locked directly by means of a friction shoe 84 (Figs. 12 and 13). One of these shoes 84 is provided between each two bushings 5 in a suitable opening provided in internal flange IIa. v j

Shoes 84 have arcuate surfaces at their oppositev ends so arranged that when the shoe is forced outwardly these surfaces will be wedges into frictional engagement with the cylindrical surfaces of the two bushings 5. Each shoe 84 is provided with an adjusting screw 85 which is accessible within annular recess 15a in the pump housing at a point adjacent alternate screw plugs 8| which cover adjusting screws 13. With this construction, after each two cylinder bushings 5 have been adjusted by turning their respective adjusting screws 13 to bring their output to the desired standard, their u common locking screw 85 is turned up, forcing the shoe '84 at its inner end into engagement with these cylinders.

The leakage of liquid from pumping space 43 back to the inlet chamber 42 is prevented by the engagement of the inner face of flange I2 of cylinder bushing with the shoulder formed at the bottom 'of the countersunk portion of the cylinder aperture in internal ange I0 of the pump housing. A lapped fit is preferably provided at this point. It will 'b e understood that the pres sure between these two surfaces increases with the increase of the pressure in pumping space 43 as the plunger advances. In order to maintain the surfaces in contact with one another atall times a spring washer 86, shown in enlarged View in Fig. 4, is provided. To prevent leakage of fuel from inlet chamber 42 between the surface of cylinder bushing 5 and the aperture of internal flange I I, a composition softrubber packing ring 81 is provided in suitable grooves 88 (Fig. 4) formed in the surface of each cylinder bushing.

The pump is lubricated by oil underpressure supplied from the pressure lubricating system of n in each of the piungers also serves to lubricate the inter-fitting surfaces of key member 59 and key driving fingers 56. Lubricant escapes from radial passages |03 between the outer surface of cylinder bushings 5 and their apertures, both to 1ubricate these surfaces and the ball thrust bearings 55 and gears 53 and 64.

The lubricant collects in the portion of the pump to the left of internal flange I I, and returns to the interior of the engine. For this purpose a horizontal passageway |0911 (Fig. 3) is.

drilled through a rib |09b formed on the outside cylindrical surface of main housing I. Passageway |09a extends from the left-hand face of internal ange II to the right-hand face of external flange 2.- The right-hand end of this passageway communicates with a series of drilled passages shown in dotted lines in Fig. 3, which convey the lubricant to the lowermost of a' series of circular openings in extension ||1 (Fig, l), through which the lubricant flows into the interior of the engine housing. A Vent passageway |09 is drilled through lubricant distributor 95.

An alternate means of supplying lubricating -oil to the lubricating system just described is'provided in case the engine on which the pump is to be used'has an oil supply opening in the vmounting pad. Mounting flange or plate 4 is ing |20 passes through flange 4 and communiwhich makes a running yfitwith the central part Distributor 95 has a radial passage 91'between groove 94 and an outer annular space 98 between distributor 95 and housing 30. Opening through the cylindrical part of housing 3 0 there are a number of radial openings 99 through which the oil may flow to an annular groove |00 on the interior wall of hollow supporting member 20. A

number of radial passages |0I conduct the lubricant from groove |00 to a large annular groove |02 formed in the aperture through internal flange I I which receives hollow supporting member 20.

From this large annular groove |02 there are spaced openings |03, one leading to each of the apertures in which cylinder bushings 5 are positioned. The lubricant then passes through suitable grooves and an inclined passageway |04 to an annular groove |05 in the surface of plunger 6 from which it lubricates the surface of the plunger and is also conducted through a radial opening |06 to a longitudinal passage |01 in the plunger (Fig. 4) which delivers lubricant at its left-hand end to the tappet mechanism 1.

Some of the lubricant escapes between the end of the plunger and the tappet whichabuts against it and flows through passages I08`in the cylindrical skirt 10 to lubricate the surface of this skirt in itsv guiding aperture in the tappet housing.

Lubricant also 'flows through apertures (not shown) in the tappet mechanism to the interior of slippers 1| and lubricates the surface of the wobble plate 8 and bearings 34 and 35. Lubricant escaping from the end of longitudinal aperture |01 'cates with a groove |2| machined in the outer end surface of main pump housing A tube |22 conveys the oil from this groove to a drilled passage |23 in internal flange I and this passage communicates with annular groove |02.

Referring again to Figs. 14 to 19 inclusive, these figures show the porting and controlling lug arrangement of the cylinders and plungers for fixed timing of the beginning of the injection period. Figsi 14, l5 and 16 show different positions of one ofthe plungers 6 during a single working stroke, the controlling lugs`49 being turned to the angular position where the pump has zero effective stroke land consequentlyno output.

In Fig. 14 the plunger is ready to commence a forward or working stroke. In Fig. 15 the plunger has advanced until the forward edges 50 of control lugs 49 have covered inlet ports 44. At the same instant the helical lower edges of lugs 49 are commencing to uncover the lower edges of ports 44 which serve as pressure relief or spill gates. At this instant the liquid fuel which 'fills compression space 43 above the plunger, begins to be forced outward through., kports 44 to return to inlet chamber 42. In Fig.

in Fig. 19 the plunger is shownturned to the position of maximum effective stroke.

Figs. 20 to 25 inclusive correspond with Figs. 14 to 19 inclusive, to illustrates. pump cylinder 5 having therein a modified form of plunger 6d whose port controlling lugs 49a are arranged to provide xed timing of the ending Iof the injec- 14 to 19 inclusive. Figs. 20, 21 and 22 show the same plunger 6a in different positions of its stroke as previously described in connection with Figs. 14, 15 and 16. Figs. 423, 24 and 25 show the plunger 6a at the instant of start of the injection period for three different pump outputs as described in connection with Figs. 17, 18 and 19.

Figs. 26 to 31 inclusive shows a second modiflcation of the port controlling lugs on the, plunger, in this instance to produce fixed timing of the center of the injection period. For this purpose controlling lugs 49h are provided with helical control edges at both ends. Thus helical edges 50D control the start of the injection period and control edges Bib the ending of the injecthat is to say, for fixed timing of the start of the injection, fixed timing of the ending of the injection, and fixed timing of the center of the injection, it will be observedfrom Figs. 14 to 31 inclusive that substantial amounts of fuel must be returned to the inlet fuel chamber 42 while the plunger continues Vto 'the end of its stroke after the end of the injection, the amounts being particularly large in the case of fixed timing of the beginning and fixed timing at the center of the injection. l

It is important, particularly with the injection of volatile fuel such as gasoline, that the injection periodbe terminated with great rapidity, that is to say, substantially without lapse of time. In order to bring this about it is necessary to provide for the fuel to flow from the working space 43 to and through the two ports 44 at a low velocity so as to reduce the pressure drop in the fuel passages. This brings about quick reduction in the pressure within working space 43 and consequently quick closing of the discharge valve 46. f

InA order to accomplish this the plunger construction of the present invention includes a large axial passageway H0 extending from ther end of the

plungers

6, 6a and 6b to a point opposite the extreme ends of the port controlling lugs 49, 49a and 49h. At this point there is pro-` vided in the outer `surface of the plunger a circular groove III of ample depth and width. as shown in Figs. 4 and 14 to 31 inclusive. Groove Il merges into the somewhat triangular spaces Il! disposed inwardly of the helical control edges 5I as shown in Figs. 14 to 19 inclusive. Connecting axial passageway I I0 with groove ill are two large cross passageways I I3.

By this arrangement of fuel passageways thev area of such passageways is ample to provide for the ow of the fuel from working space 43 to the spill ports 44 at low velocity so as to bring about an extremely quick reduction of the pressure With' l2 in the working space at the instant the spill ports are uncovered.

In addition to these passageways there are also preferably provided the diagonally opposite longitudinal grooves I I4, the primary purpose of which, however, is to facilitate manufacture; specifically the milling of the port controlling lugs 49. 'Ihese grooves assist in conveying the liquid from the working space 43 to the triangular spaces H2 (Fig. 14) and thence to the ports 44.

Referring again to Fig. 1, 4and particularly to the outlet or discharge valves 46, it has hereto- In the automatic valve construction of the present pump valve member 46 is of thimble shape having a cylindrical body portion Iliand a reduced end portion terminating in a semi-spherical valve H6. Cylindrical skirt portion H5 nts in a cylindrical guide opening which is machined in an annular projection i I1 on mounting flange or plate 4. A coil spring H8 tted within skirt Il1 at one end and held at its opposite end by a removable plug I|9 maintains the valve in engagement with its seat. This construction has the advantages of a ball check valve without the difilculty of guiding a loose ball.

Valve member 46 with its cylindrical skirt and semi-spherical valve end concentric with the skirt, can be produced without difficulty -by ordinary production methods. Furthermore, the machining of the valve seat at the right-hand end of opening is eliminated. It is only necessary to drill opening 45 concentric with the aperture in which cylindrical skirt H5 is guided. It is not necessary to machine a seat for the valve but the edges of this hole 45 are left sharp, the seat being formed by the hammering of the valve itself. In

thi-s way a very narrow seat is formed which is preferable to a wide valve seat and the hammering of its edges produces a hard surface because of the cold working of the metal.

The pump of the present construction has numerous advantages, some of which have been mentioneddescribing it. It will be understood that the various features of the pump may be modified as to the precise arrangement and embodiment as described herein, and that changes of this nature can be madeA without departing from the scope of the invention which is set forth in the appended claims.

I claim:

1. In a pump having a relatively reciprocable plunger and cylinder and whose plunger is rotatable to vary the pump output, mechanism for turning said plunger while it is reciprocating comprising a key member, a longitudinal key slot therefor in the surface of the plunger, means for positioning said key in the slot, a key driving member having a slidable connection with said key, means for mounting the same for rotation concentric with the plunger, and means for turning said key driving member.

2f In a pump having a relatively reciprocable 13 plunger and cylinder and whose vplunger is rotatable 'to vary the pump output, mechanism for turning said plunger while it is reciprocating comprising a single longitudinal key slot in the.

" for -rotation concentric with the plunger, and

means for turning said driving member.

3. In a pump having a relatively reciprocable i plunger and cylinder and whose plunger is rotatable to vary the pump output, a coil spring surrounding said plunger to move the same on one Y of its strokes, a sleeve-like pump output control member mounted for rotation on .the cylinder adjacent its inner end, means interconnecting said sleeve-like member and said plunger opera'ble to transmit rotational movement therebetween while the plunger is reciprocating, means interconnecting the outer ends of said spring and plunger, and the inner end of said spring engaging one side of said output control member,

whereby said control member, spring and plunger turn as a unit to adjust the output of the pump.

4. In a pump having a relatively reciprocal plunger and cylinder-and whose plunger is rotatable to vary-the pump output, a coil spring -surrounding said plunger t0 move the same on one of its strokes, a spring retainer fixed to said plunger adjacent its outer end, a longitudinal key slot inthe surface of said plunger, a key member projecting from said spring retainer and positioned thereby in said slot, a sleeve-like pumpv output control member mounted for rotation yon said cylinder adjacent its. inner end, a pair of fingersprojecting from said member parallel with the plunger, said fingers having parallel faces engaging the opposite sides of said key to transmit the rotation of said control member to said plunger' while the plunger is reciprocating, a shoulder on said control member adjacent said fingers, said coil spring having its ends engaging respectively said shoulder and said spring retainer, whereby said control member, spring and plunger turn as a unit to adjust the output of the pump.

5. In a multi-cylinder pump having relatively reciprocable plungers and cylinders and whose y plungers are rotatable in their respective cylinders to vary the output thereof, means for turning said plungers simultaneously to vary the pump output, a housing supporting said cylinders to allow rotation of each cylinder individually to adjust the output thereof, each of said cylinders having vworm gear teeth thereon, an outwardly directed aperture in said housing adjacent each cylinder, an adjusting screw disposed in said aperture having its threads engaging said teeth, means to position said screw against longitudinal movement in said aperture during rotation of the screw, and means for clamping the screw in adjusted position.l

6; In a multi-cylinderpump having relatively vreciprocable plungers and cylinders and whose plungers are rotatable in their respective cylinders to vary the output thereof, means for turning said plungers simultaneously to vary the pump output, a housing supporting said cylinders to allow rotation of each cylinder individually to adjust the voutput thereof, each of said cylinders 14 cylinder, and an adjusting'screw disposed in. said aperture having its threads engaging said'teeth,

a pair of oppositely directed shoulders on said screw and cooperating shoulder means within 'said aperture to position said screw against longitudinal movement during rotation vof the screw, and means for clamping said screw in adjusted 7. In a multi-cylinder pump having relatively reciprocable plungers and cylinders and whose plungers are rotatable intheir respective cylinders to vary the output thereof, means for turning said plungers simultaneously to vary the pump output, a housing supporting said cylinders to allow rotation of each cylinder individually to adjust the output thereof, each of said cylinders shaving worm gear teeth thereon, an outlwardly directed aperture in said housing adja-` y cent each cylinder, an adjusting screw disposed in said aperture having its threads engaging said teeth, a circular recess in the exterior of said housing, the outer ends of said adjusting screws being disposed within said recess, and a removable ilexible band covering said recess.

' 8. In a multi-cylinder pump having relatively reciprocable plungers and cylinders and yvhose plungers are rotatable in their respective 'cylinders to vary the output thereof, means for turning said plungers simultaneously to vary the pump output, a housing supporting said cylinders for individual rotation of each cylinder, mechanism associated -with said housing for turning each of said cylinders independently of the others to adjust the cylinder output, and' mechanism carried by said housing and coacting with the outside walls of said cylindersto lock the same in adjusted position.

9. In a multi-cylinder pump'having relatively I reciprocable plungers and cylinders and whose plungers are rotatable in their respective cylinders to vary the output thereof, means for turning said plungers simultaneously to vary the pump output, a housing supporting said 'cylinders for individual rotation of each cylinder, mechanism for turning each of said cylinders independentlyl of the others to adjust the cylinder output, friction shoes engageablewith the surfaces of said respective cylin'ders, and means for moving said shoes into and out of such engagement. y

10. In a multi-cylinder pump having relatively reciprocable plungers and cylinders Aand Whose plungers are rotatable in their respective cylinders to vary the output thereof, means for turningv said plungers simultaneously to vary the pump output, 'a housing supporting said cylinders for individual rotation of each cylinder, mechanism for turning each of said cylinders independently of the others to adjust the cylinder output,

,a friction shoe positioned in said housing between each pair of cylinders, and means for moving said shoe into and out of engagement with both of having worm gear teeth thereon, anvoutwardly A said cylinders simultaneously.

11. In a multi-cylinder pump having relatively reciprocable plungers and cylinders and whose plungers are rotatable in their respective cylinders to vary the output thereof, means for turningssaid plungers simultaneously to vary the pump output,

a housing supporting said cylinders for individual rotation of each cylinder, a circular recess in the exterior of said housing, mechanism within said recess for rotating. each of said cylinders independently of the others to adjust the cylinder output, and mechanism forl frictionally locking.

said cylinders in adjusted position, said mechathe same disl put, and mechanism for frictionally locking said cylinders in adjusted position, both of said mechanisms having means for operating the same accessible from the exterior of said housing.

13. In a multi-cylinder pump, a plurality of cylinders arrangedin parallel relation in a. circular row, plungers in said cylinders and means for reciprocating the same, said plungers being rotatable in the respective cylinders to vary the output thereof, the output being controlled by a spill port in each cylinder uncovered by a lug on the plunger having an edge disposed at an angle to the axis of the plunger, an output vcontrol gear arranged to rotate on the inner en'd of each of .said cylinders, means interconnecting said re- 16 actuating member operatively associated with the tappet mechanisms of said pumping units, a main housing member having a circular row of apertures therein to support said cylinders, a central longitudinal opening in said housing, a

mounting ilange for the pump adjacent one end of said housing and having a corresponding'opening therein, an elongated hollow supporting member. positioned in said central opening, means on said hollow supporting member to secure said housing and said mounting iiange together, a shaft for said actuating member, and bearings for said shaft disposed within said hollow supporting member.

17. In a multi-cylinder pump having a plurality so.. said housing, means on said hollow supporting member to secure said housing and said mounting flange together, anda tappet housing remov- 14. In a pump having a relatively reciprocating a fuel inlet port in the side thereof, a plunger therein adapted to control said por-t, means' for reciprocating said plunger, an outlet passage from the cylinder, a valve seat in said passage, a pressure-operated valve cooperating with sal'd seat comprising a thimble-shaped member having a cylindrical skirt and terminating in a semi-spherical valve portion, a spring acting on said valve to bias said semi-cylindrical portion against said seat, and guiding means cooperating with said cylindrical skirt.

` 16. In a multi-cylinder pump having a plurality of pumping units arranged in parallel relation in a circular row, each comprising a cylinder,A a plunger therein and tappet mechanism, a rotary ably secured tothe outer end of said main housing and having a central opening to receive and engage said hollow supporting member.

DESIRE J. DESCHAMPS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date l 1,697,853 Coursen Jan. 8, 1929 1,933,081 Stephan Oct. 31, 1933 2,160,735 HoiIer May 30, 1939 2,206,914 Muller July 9, 1940 2,215,827 Ditto Sept. 24, 1940 $376,856 Hatch May 29, 1945 2,388,462 Beeh Nov. 6, 1945 FOREIGN PATENTS- Number Country Date 146,963 Great Britain Oct. 6, 1921 OTHER REFERENCES