GB2188172A

GB2188172A - Fuel pumping apparatus

Info

Publication number: GB2188172A
Application number: GB08702101A
Authority: GB
Inventors: Domingo Cabarrocas Pruneda
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1986-02-24
Filing date: 1987-01-30
Publication date: 1987-09-23
Anticipated expiration: 2007-01-30
Also published as: GB2210936B; GB8702101D0; JPS62199959A; GB2210936A; GB2188172B; DE3705806A1; GB8825702D0; ES8702583A1; FR2594893A1; IT1203346B; US4751903A; FR2594893B1; IT8719467A0; ES552311A0

Description

GB 2 188 172 A SPECIFICATION suit in axial movement of the distributor

member and variation of the amount of fuel supplied bythe Fuel pumping apparatus apparatus.

According to another aspect of the invention in an This invention relates to a fuel pumping apparatus 70 apparatus of the kind specified said spill path means for supplying fuel to an internal combustion engine includes a non-return valve which is setto open at a and of the kind comprising a housing, a rotary dis- pressurewhich is greaterthan the pressure of fuel tributor member mounted in the housing, a trans- supplied to the bore during the outward movement verse bore in the distributor member, a pumping of the plunger but less than the pressure of fuel in the plunger in the bore, a cam ring surrounding the dis- 75 bore during inward movement of the plunger.

tributor member and defining a plurality of inwardly In the accompanying drawings:

extending cam lobes which impart inward move- Figure 1 is a sectional side elevation of an example ments to the plungerasthe distributor member of a fuel pumping apparatusto which the inventions rotates, passage means in the distributor member may be applied, communicating with the bore, said passage means 80 Figures2,3,4and 5are sectioned through parts of being arranged to communicate in turn with a plura- the apparatus seen in Figure 1, lity of outlets in the housing during successive in- Figure 6is a perspective view of parts of the appar ward movements of the plunger, means for supply- atus of Figure 1 with portions thereof broken away ing fuel to the bore to effect outward movement of forthe sake of clarity, the plunger in the periods between successive in- 85 Figures7,8,9and 10are diagrams illustrating the ward movements of the plunger, an axially movable operation of the spill means of the apparatus of sleeve located aboutthe distributor memberthe Figure 1, sleeve and distributor member defining spill path Figures 11, 12and 13showto an enlarged scale means whereby fuel can be spilled from said bore part of the apparatus of Figure 1 in different settings, during the inward movement of the plunger, the re- 90 Figure 14shows a modification tothe part of the lative axial position of the distributor member and apparatus seen in Figures 11 -13, sleeve determining the amount of fuel which is supp- Figure 15shows a modification in accordance with lied through the outlets and governor means forcon- thefirst aspect of the invention to the apparatus trolling the axial setting of the sleeve within the shown in Figure 1, housing. 95 Figure 16shows an end view of the apparatus in When the engine associated with the apparatus is corporating the modification of Figure 15, powering a vehicle, it isthe practice to providewhat Figure 17is a diagram similarto Figure 7 of the is known in the art as "torque control". This can be modification, achieved within the governor mechanism and it Figure 18is a view similarto Figure 1 showing a comprises some way of varying at leastthe max- 100 modification in accordance with the second aspect of imum amount of fuel which can be supplied to the the invention, engine in accordance with the engine speed. When Figure 19is a viewsimilarto Figure 1 showing a the governor mechanism is of a mechanical type this further modification to the apparatus of Figure 1, is not always easy and an object of the invention is to Figure 20is an end view of part of the modification provide an apparatus of the kind specified in a form 105 of Figure 19, and in which variation of the amount of fuel suppliedto Figure21 shows a variation of the modification the engine in accordance with the engine speed can seen in Figure 19.

be readily achieved. With reference to Figure 1 of the drawings the Afurther problem can arise with an apparatus of apparatus includes a hollow housing part 10 which is the kind specified when the apparatus is arranged to 110 provided with a flange 11 whereby it can be mounted supply fuel to an engine having say more than four on the casing of the associated engine. Extending cylinders and when the sleeve is movable angularly into the housing part 10 is a drive shaft 12 which is about the axis of rotation of the distributor member coupled in use to a rotary part of the engine so asto to allow variation of the commencement of fuel debe driven in synchronism with the engine. Facing the livery. In an extreme angular position of the sleeve it 115 drive shaftthe housing part 10 is provided with an is possible forthe spill path means to be opened opening which is closed by a second housing part 13 while fuel is being supplied to the bore to effect out- in which is located a fixed sleeve 14within which is ward movement of the plunger and in this situation journalled a rotary distributor member 15. The open the plunger may not be moved outwardly its max- end of the sleeve is closed by a thrust plate 16sec imum amount. 120 ured to the housing part 13. The distributor member According to one aspect of the invention in an is coupled to the drive shaft 12 by means of a dog and apparatus of the kind specified said distributor slot connection 17 and the distributor member is bi member is axially movable within the housing,the ased into contactwith thethrust plate by means of a apparatus including resilient means biasing the disspring 18 housed within the drive shaft.

tributor member in one axial direction, meansfor 125 Formed in the distributor member 15 is a pairof generating a fluid pressure which varies in accord- radial bores 19 (Figure 4) in each of which is mounted ance with the speed atwhich the apparatus is driven, a pair of pumping plungers 20. Attheir outer ends a piston movable by said fluid pressure againstthe the plungers are engaged by cam followers re action of a spring, a profile and said distributor s.pectively each cam follower including a shoe 21 member whereby movement of said piston will re- 130which carries a roller 22. The shoes as seen in Figure 2 GB 2 188 172 A 2 4are mounted in slotsformed in an enlarged portion instantatwhich the port is covered bythe leading 23 of the drive shaftwhich surrounds the distributor axially extending edge of the land depends uponthe member.The rollers 22 can engagewiththe internal angularsetting of the sleeve,this being determined peripheral surface of an annularcam ring 24which in bythe position of the piston 40.

the example shown in Figure 1 is secured within the 70 The axial setting of the sleeve 37 is determined by housing part 10. The cam ring is provided with a a governor mechanism and this comprises a plura plurality of pairs of cam lobes 25which engagethe lity of governorweights 45which are housed in a rollers asthe distributor member is rotated to impart cage 46 secured to a gearwheel 47 mounted about a inward movementsto the cam followers and the support shaft48 secured in the housing part 10. The plungers. In the example there are two pairs of cam 75 gearwheel 47 is driven by a ring gear49which is lobes and the apparatus is intended to supplyfuel to mounted on the drive shaft 12 and conveniently a four cylinder engine. shockabsorbing inserts 50 are employed. The shaft The cam followers are located againstaxial move- 48 carries an axially movableflanged sleeve 51,the ment by a pair of side plates 33,34, disposed on op- flange of which is engaged bythe weights 45 posite sides of the cam followers,the plate 34 being 80 whereby as the weights move outwardly, axial located by a spring clip 35 and the plate 33 being loc- movement will be imparted to the sleeve 51. The ated bythe cam ring 24. The plate 33 also serves to governor mechanism includes a first lever 52 which provide axial location forthe drive shaft 12. The side has a central web and side flanges and is pivotally plates can be engaged by lateral projections on the supported in the housing part 10 by means of a pair shoes 21 to limitthe extent of outward movement of 85 of screws 53. Also provided is a second lever 54 the shoes and plu ngers. which is also supported for pivotal movement on the Extending within the distributor member 15 is an screws 53 and which carries a pin 55 the axis of axial passage 26 which at its end remote from the which is offsetfrom that of the screws. The pin 55 plungers is plugged and which at its other end opens carries a third lever 56 having an arm which extends into the bores 19. At one pointthe passage 26 com- 90 downwardly and around the sleeve 37 and is prov municates with a delivery passage 27 which is posi- ided with a pin 57 (Figure 5) which locates in a groove tioned to register in turn with outlet ports 28formed 58 formed in the sleeve 37. The pin 57 and groove 58 in the sleeve 14 and the housing part 13 during suc- allow angular movement of the sleeve 37 underthe cessive inward movements of the pumping action of the piston 40,while atthe sametime pivotal plungers. The ports 28 conneetwith outlet unions 29 95 movement of the lever 56 aboutthe pin 55will cause respectively which in use are connectedto the injecaxial movement of the sleeve 37.

tion nozzles respectively of the associated engine. At The lever 56 has an upwardly extending arm 59 another pointthe axial passage 26 communicates which has a dished portion in which is formed an with a pair of inlet passages 30 (Figure 6), formed in aperture through which the end portion of the shaft the distributor member and opening to the periphery 100 48 extends. The sleeve 51 is engaged with the dished thereof. The inlet passages 30 are arranged to com- portion of the arm 59. Mounted on the end portion of municate with inlet ports 31 formed in the sleeve 14, the arm 59 is a leaf spring 60 the free end of which during the time the plungers are allowed to move extends towards the pin 55 and is curved for engage outwardly bythe cam lobes. The ports 31 open at ment with the first lever 52. Moreover, interposed be their outer ends into a circumferential groove 32 105 tween the arm 59 and the lever 52 is a light coiled which is in communication with the outlet of a low compression spring 61. The end of the lever 52 re pressure pump to be described. mote from the pin 56 is connected to one end of a The housing parts 10 and 13 define a cavity36 preloaded tension spring 63 through the inter through which the distributor member extends and mediary of a preloaded compression spring 64 and slidable on the portion of the distributor member in 110 the other end of the spring 63 is connected to an arm the cavity is a sleeve 37 from which extends an arm 65 carried by a shaft66 extending to the exteriorof 38. The end of the arm is located within a circum- the apparatus and connected in useto thethrottle ferential groove 39 formed in the periphery of a spr- pedal of the vehicle with which the apparatus is ing loaded piston 40 which is housed within a cylin- associated.

der. 115 The second lever 54 as seen in Figure 5 is engaged The sleeve 37 on its internal peripheral surface def- in a collar 67 which is adjustably mounted in a cover ines a pair of grooves 41,42 which are shown in dotforthe housing part 10 whereby the position of pin ted outline in Figure 6. The grooves at one end being 55 can be adjusted.

open to the cavity36 and extending part way across Fuel is supplied to the bores containing the the surface of the sleeve. In the example the groove 120 plungers 20 and to the cylinder containing the piston 41 extends axially whereas the groove 42 is inclined. 40byaiowpressurefuel pump the rotor 68 of which The grooves define between them a wedge shaped is mounted about and keyed to the drive shaft 12. As land 43 thetask of which is to cover one of four equ- shown in Figure 3, the rotor carries fourvanes 69 ally spaced ports 44 which are formed in the distribu- which are spring biased outwardly into engagement tor member and which open into the axial passage 125 with the inner surface of a ring 70 which is secured 26. Clearly the number of degrees of rotation of the within the housing part 10 and the inner surface is distributor member during which the one port 44 is eccentrically disposed relative to the axis of the dis covered bythe land (the remaining ports 44 being tributor member. The ring 70 is sandwiched between covered bythe internal surface of the sleeve) dep- a port plate 71 and an end plate 72,the latterserving ends upon the axial position of the sleeve and the 130 as an end thrust plate for the drive shaft. The port 3 GB 2 188 172 A 3 plateincludesan inlet port73and an outletport74, should be noted that the spring 61 is clear of the lever the former being connected to a fuel inlet 75 on the 52. When the associated eng ine sta rts and the exterior of the housing and the latter bei ng connec- throttle is released, the parts of the mechanism will ted to a transverse dril 1 i ng 76 (Figure 2) which con- assumethe position shown in Figure 12. Itwill be tains a pressurecontrol valve77 of conventional de- 70 seen thattheweights have opened out undertheac sign andwhich operatesto ensure that the outlet tion of centrifugal forcethus pivoting the lever56 pressure of the low pressure pump varies in accord- aboutthe pin 55 and compressing the leaf spring 60 ance with the speed atwhich the apparatus is driven. to the extent that the spring 61 is brought into oper From the drilling 76 the fuel is supplied to the groove ation. In particular it will be noted that the sleeve 37 32 and from the groove 32 byway of a passage 78to 75 has moved to a position in which the amount of fuel the cylinder containing the piston 40. supplied to the engine is sufficient for engine idling.

The operation of the apparatus will now be descri- In the event of an increase in the speed of the engine bed ignoring forthe moment the governor mech- above the desired idling speed the weights will move anism. As shown in Figure 6 the distributor member out further and the lever 56 wil 1 pivot against the ac- is at a position such thatthe passages 30 are in regi- 80 tion of the springs 60 and 61 to reduce the amount of ster with the inlet ports 31 sothatfuel from the low fuel supplied to the engine and hence the engine ressure pump has filled the bore 19 and the plungers speed and vice versa. Figure 13 shows the situation have been moved outtheir maximum extent as det- when thethrottle pedal isfully depressed. The lever ermined bythe side plates33,34, It should be noted 52 has been moved once again into contactwith the thatthe delivery passage 27 is out of registerwith the 85 stop 52A and has caused the lever 56to pivotabout outlets 28 and also thatthe ports 44 as seen in Figure the pin 55to movethe sleeve 37 to increasethe 7, are covered by the sleeve 37. As the distributor amount of fuel supplied to the engine to its max member rotates, the ports and passages 31,30 will imum allowed value. In addition the weights have move out of register and the passage 27 will move been forced inwardly. This situation will prevail until into registerwith an outlet 28. Atthe same time a 90 the centrifugal force acting on theweights is suf port44will be opened to the groove 43 (Figure 8) and ficientto causethe weightsto move outwardly the plungerswill starttheir inward movement. The againstthe action of the preloaded spring 63 and fuel displaced bythe plungers will flowthrough the when this occurs the leverwill pivotto movethe port44 and groove 41 until the port 44 is covered by sleeve 37 to reduce the amount of fuel supplied to the the leading edge of the land 43. When this occurs as 95 enginetherebyto limitthe engine speed to a safe shown in Figure 9, theflowof fuel through the port maximum value. The governor mechanism as des 44will cease and fuel will flowthrough the delivery cribed therefore is of the so called "two speed" type passage 27 and the outlet28 in communication in which the engine idling speed and its maximum therewith. The flow of fuel will continue until the port speed are controlled. Intermediate these speedsthe 44 is uncovered (Figure 10) bythetrailing and in- 100 setting of the sleeve 37 and hence the amount of fuel clined edge of the land whereafterthe remaining supplied to the engine depends on the setting of the quantity of fuel displaced bythe plungers will flow throttle pedal.

through the port 44to the cavity36. Figure 13 also shows the stop 67 which determines If the sleeve 37 is moved towards the plungers the the position of the lever 54 and the setting of the pin port 44will be covered for a shorter time in terms of 105 55. If the stop is adjusted so as to cause the lever 54to deg rees of rotation of the distributor member and move in the anticlockwise direction aboutthe axis of thereforethe amount of fuel supplied to the engine the screws 53, the sleevewill move in a direction to will be reduced and vice versa. If the sleeve 37 is increase the amount of fuel supplied and vice versa.

moved in the direction of the arrow in Figure 6 the The stop 67 therefore enables the maximum amount timing of the start of fuel delivery will be retarded 110 of fuel which can be supplied to the engine in the and vice versa. Since the angular position of the normal operation of the engine, to be adjusted.

sleeve is determined by the piston an increase in te Figure 14 shows a modification which is intended outlet pressure of the low pressure pump, as occurs for use with an engine which is provided with a with an increase in the engine speed, will result in turbo-supercharger. The lever 54A is a modif ied ver- advancement of the start of fuel deliveryto the ension of the lver 54 and the position of the lever dep gine. ends upon the pressure of air applied to a spring loa Considering now the operation of the governor ded diaphragm 76, the air pressure being depicted mechanism and with reference to Figures 11 -13 by the arrows 77. The diaphragm is connected to a which showthe mechanism to an enlarged scale and rod 78 upon which is mounted a grooved bush 79.

in different operational positions. in Figure 11 the 120 The lever 54A is provided with a projection 54B parts of the mechanism are shown in the positions which locates in the groove in the bush and the which they are caused to adoptwhen trying to start arrangement is such that as the air pressure in the engine. Itwill be noted thatthe lever65 has been creases the lever 54A will be moved in a direction to moved by depression of the throttle pedal of the veh- cause movement of the sleeve 37 in the direction to icleto move the lever 52 into contact with a stop 52A. 125 increase the amount of fuel supplied to the associa The lever 56 underthe action of the leaf spring 60 has ted engine. The stop 67A is in this case a simple stop rotated aboutthe pin 55 to urge the weights inwardly which limits the extent of movement of the lever 54A their maximum extent and to move the sleeve 37 to a underthe action of the diaphragm and ittherefore position in which an excess quantity of fuel will be determines the maximum amount of fuel which can supplied to the engine for starting purposes. It 130 be supplied to the engine when the turbo superchar- 4 GB 2 188 172 A 4 geris in operation, the springs which biasthedia- will be understood thatthe reduction of thefuel phragm actingtQ positionthe rod 78ata pred- quantitywith increasing speedtakes placewhatever etermined and adjustable position so asto limitthe thesetting ofthe lever65.

maximum amountoffuel which can besuppliedto Figure 16showsan end view of the apparatus with the engine when the turbo supercharger is notgenethe plate 16A and the enlarged portion thereof within rating sufficient pressureto operate the diaphragm. which the cylinder 80 is formed. Also illustrated in Itwill be noted thatthe arm 38 during movement of this figure is the housing of an electromagnetically the sleeve 37 by the governor mechanism is freeto operable valve 88 which is energised to allowfuel move in the groove 39 in the piston 40 and byvirtue flowfrom the low pressure pump to the groove 32 of the groove 58 on the sleeve 37 movement of the 75 and which is de- energised to preventflow of fuel piston can effect angular movement of the sleeve to when it is required to stop the associated engine.

vary the timing of fuel delivery, independently of the In the case of an apparatus intended to supplyfuel governor mechanism. to an engine having more than four cylinders for ex Figures 15 and 16 illustrate a modification to the ample a six cylinder engine the spacing between the apparatus described, the modification being forthe 80 ports 44 is reduced as also is the spacing between purpose of providing what is known in the art as the inlet ports 30 and the inlet passages 31. In addi "torque controV. As described the process of limi- tion of course there will be an appropriate adjust ting the engine speed by the governor mechanism ment of the number of cam lobes 25 on the cam ring takes place suddenly. This is because the spring 63 24 and an adjustment in the disposition of the will yield when its preload force is attained and this 85 plungers and possiblytheir number. If the rate of fuel will permitthe weights 45 to move outwardly so that delivery is to remain the same as forthe four cylinder the force generated bythe weights will increase engine the leading flanks of the cam lobes and the thereby resulting in further extension of the spring disposition and sizes of the grooves 41 and 42 must and a further increase in the force generated bythe remain the same as also will the diameters of thevar weights and so on. The sleeve 37 will theefore be 90 ious ports and passages. The space required forthe moved very quicklyto reduce the fuel. The effect two extra cam lobes must therefore be taken from therefore is thatthe torque produced bythe engine the trailing flanks of the cam lobes and the space or suddenlyfalls and is restored almost as quickly as gap between the trailing flank of one cam lobe and the engine speed fails. In orderto avoid this undesir- the leading flank of the next cam lobe. The effect of able effect, "torque control " is provided which has 95 course is thatthere is less timeto fill the bores 19 the effect of reducing the amount of fuel supplied to containing the plungers 20 with fuel. In an extreme the engine as the engine speed increases and part- angular position of the sleeve 37 when the latter has icularly as the maximum governed speed of the en- been set to provide maximum advance of the timing gine is approached. The provision of "torque con- of fuel delivery, it is possible for a port 44to be troV in the sense of reducingthe fuel with increasing 100 brought into registerwith the groove 41 beforethe speed, is achieved by allowing the distributor inlet ports 31 and inlet passages 30 have moved out member 15 to movetowards the right as seen in of register. As a resuitthe fuel pressure in the pas Figure 1 which has the same practical effect so far as sage 26 in the distributor member may fall so thatthe fuel delivery is concerned, as moving the sleeve 32 plungers 20 do not reach the limit of theirtravel, they towards the left. 105 may move inwardly. In each case this may mean that As shown in Figure 15 the thrust plate 16 is repla- the plungers are not being driven inwardly bythe ced by a thrust plate 16Awhich defines a cylinder80 cam lobes atthe instantwhen the port 44 is covered in which is located a piston 81 which is biased by a bythe leading edge of the land 43. As a resuitthe coiled compression spring 82. The longitudinal axis timing of the commencement of fuel deliverywill be of the piston is disposed at right angles to the axis of 110 laterthan that dictated bythethe angularsetting of rotation of the distributor member. Thethrust plate the sleeve 37 and in addition, the quantity of fuel is provided with an opening which is aligned with the supplied will be reduced.

axis of the distributor member and in which is loc- The aforesaid problem is overcome by modifying ated a pin 83 which at one end engages the distribu- the apparatus as shown in Figures 17 and 18. In the tor member and at the other end engages with the 115 example the sleeve 37A is modified bythe provision piston 81. The intermediate portion of the piston sur- of an inner sleeve 90 in which is formed slits 91,92 face defines a profile so that as the piston moves arranged in the same manner as the grooves 41,42 againstthe action of the spring 82 the distributor so as to define a wedge shaped land 93. In this case member underthe action of the spring 18 will move the slits do not extend to the edge of the sleeve but towardsthe right. The cylinder at its end remote 120 they communicate with a groove 94formed in the from the spring is closed by a plug 84 and fuel is inner surface of the sleeve 37A, the groove 94 com admitted to a chamber defined bythe plug from the municating with the space 36, byway of a non return outlet of the low pressure pump. The portion of the valve 95 which controls flow of fuel through a spill cylinder 80 containing the spring is vented and this passage 96. The valve 95 is setto open at a pressure end of the cylinder is closed.by a plug 86 which car- 125 which is higherthan the pressure developed bythe ries an adjustable abutmentforthe spring 82. By low pressure pump but lowerthan the pressure adjustment of theforce exerted bythe spring the which is developed during fuel deliveryto the assoc speed atwhich the piston startsto move can be iated engine. If therefore a port 44 is exposed tothe varied and the extent of movement of the piston can slit 91 during the filling phase no fuel will flowfrom be controlled by means of an adjustable stop 87. It 130 the port 44to the slit and thereforethe plungers will GB 2 188 172 A 5 move outwardlytheir maximum extent. When the apparatus is driven, a piston movable by said fluid port 44 is opened to the slit 92 to terminate fuel de- pressure against the action of a spring, a profile def livery the valve 95 is opened by the pressure dev- ined on said piston and means engaging said profile eloped bythe inward movement of the plungers. and said distributor member whereby movement of In the arrangements so fardescribed the adjust- 70 said piston will result in axial movement of the dis ment of the start of delivery of fuel is effected by tributor member and variation of the amount of fuel adjustment of the angular setting of the sleeve 37. supplied by the apparatus.

Claims

With this arrangement therefore the start of delivery
2. An apparatus

according to Claim 1 in which the of fuel can take place at different points on the lead- axis of said piston is disposed at right angles to the ing flanks of the cam lobes. In order to ensure that 75 axis of the distributor member, said profile being the start of delivery of fuel takes place atthe same formed on an intermediate portion of the piston sur points on the leading flanks of the cam lobes irres- face and said means engaging the distributor pective of the timing of fuel delivery it is proposedto member and the piston comprising a pin.

adjustthe angularsetting of the cam ring 24 in syn-
3. An apparatus according to Claim 2 including chronism with the sleeve 37. Figure 19 therefore 80 means for adjusting the force exerted by said spring shows the cam ring 24 coupled by means of a radial and a stop to limitthe extent of movement of the peg 97 to a piston 98 the piston 98 being spring loa piston againstthe action of the spring.

ded and exposed to the outlet pressure of the low
4. Afuel pumping apparatus for supplying fuel to pressure pump in the same manner as the piston 40. an internal combustion engine comprising a hous- The latter piston is no longer required its duty being 85 ing, a rotary distributor member mounted in the taken over by a peg 99 secured to the cam ring and housing, a transverse bore in the distributor which is located in a slotformed in the end of the member, a pumping plunger in the bore, a cam ring lever38. If the peg 99 is disposed parallel to the axis surrounding the distributor member and defining a of the distributor member no variation in timing will plurality of inwardly extending cam lobes which im occur as the axial position of the sleeve is varied. 90 part inward movements to the plunger as the dis However, if the peg 99 is inclined as shown in Figure tributor member rotates, passage means in the dis 21 then as the sleeve 37 is moved axiailyto varythe tributor member communicating with the bore, said quantity of fuel delivered to the engine itwill also be passage means being arranged to communicate in moved angularly by a small amountto varythetim- turn with a plurality of outlets in the housing during ing of delivery of fuel. Bythis arrangementtherefore 95 successive inward movements of the plunger, thetiming of fuel delivery can be madeto advance as means for supplying fuel to the bore to effect out the amountof fuel supplied to the engine is in- ward movement of the plunger in the periods be creased. tween successive inward movements of the plunger, an axially movable sleeve located aboutthe distribu CLAIMS 100 tor memberthe sleeve and distributor memberdef ining spill path means wherebyfuel can be spilled 1. A fuel pumping apparatus for supplying fuel to from said bore during the inward movement of the an internal combustion engine comprising a hous- plunger,the relative axial position of the distributor ing, a rotary distributor member mounted in the member and sleeve determining the amount of fuel housing, a transverse bore in the distributor 105 which is supplied through the outlets, governor member, a pumping plunger in the bore, a cam ring meansfor controlling the axial setting of the sleeve surrounding the distributor member and defining a within the housing, said spill path means including a plurality of inwardly extending cam lobes which im- non-return valvewhich is setto open at a pressure part inward movementsto the plunger as the dis- which is greaterthan the pressure of fuel suppliedto tributor member rotates, passage means in the disthe bore during the outward movement of the plun tributor member communicating with the bore, said ger but lessthan the pressure of fuel in the bore dur passage means being arranged to communicate in ing the inward movement of the plunger.

turn with a plurality of outlets in the housing during
5. An apparatus according to Claim 4 in which successive inward movements of the plunger, said sleeve is provided with a pair of slitswhich are means for supplying fuel to the boreto effect out- 115 circumferentially spaced and which define between ward movement of the plunger in the periods be- them a wedge shaped land, the slits and a port in the tween successive inward movements of the plunger, distributor memberforming part of said spill path an axially movable sleeve located aboutthe distribu- means, said sleeve being housed within afurther tor memberthe sleeve and distributor memberdef- sleevewhich forms a passage extending tothe in ining spill path means wherebyfuel can be spilled 120 terior of the housing from said slits, said non-return from said bore during the inward movement of the valve being located in said passage.

plunger, the relative axial position of the distributor
6. An apparatus according to Claim 5 including member and sleeve determining the amount of fuel an arm connected to said further sleeve and means which is supplied through the outlets, governor connected to said arm forvarying the angular setting means for controlling the axial setting of the sleeve 125 of said sleeve aboutthe axis of rotation of the dis within the housing, said distributor member being tributor member.

axially movable within the housing, resilient means biasing the distributor member in one axial direc tion, means for generating a f luid pressure which varies in accordance with the speed at which the 6 GB 2 188 172 A 6
7. Afuel pumping apparatus for supplying fuel to an internal combustion engine substantially as hereinbefore described with referenceto the accompanying drawings.

Printed for Her Majesty's Stationery office by Croydon Printing Company (L) K) Ltd,8187, D8991685. Published byThePatentOffice,25 Southampton Buildings, London, WC2A lAY, from which copies maybe obtained.

1