Fuel injection pumps for i.c. engines

Claim 2

In a fuel injection pump for an internal combustion engine having a pair of reciprocable pumping plungers which are moved inwardly to affect a pumping stroke by means of rollers carried by shoes engaging the plungers, the rollers cooperating with cam means, and a leaf stop having end portions in the path of movement of the shoes, the improvement wherein the contacting surfaces of said shoes and the end portions of said leaf stop are shaped so that relative movement of said shoes and end portions of said leaf stop in an axial direction will effect a variation in the permitted outward movement of said plungers.

Claim 3

In a fuel injection pump for an internal combustion engine having a pair of reciprocable pumping plungers which are moveD inwardly to affect a pumping stroke by means of rollers carried by shoes which engage said plungers, rollers engaging cam means, a leaf stop with end portions lying in the path of movement of said shoes, fuel delivery means for conveying fuel displaced by said plungers during inward movement thereof and fuel inlet means for supplying fuel to the space between said plungers during outward movement thereof the improvement comprising a recess defined in the contacting surfaces of said shoes to cooperatively engage the end portions of said stop, said shoes being movable relative to the ends of said stop to permit additional outward movement of said shoes to take place, thereby permitting an additional quantity of fuel to be supplied by said pump.

Claim 4

In a fuel injection pump for an internal combustion engine having a pair of reciprocable pumping plungers which are moveD inwardly to affect a pumping stroke by means of rollers carried by shoes which engage said plungers, rollers engaging cam means, a leaf stop with end portions lying in the path of movement of said shoes, fuel delivery means for conveying fuel displaced by said plungers during inward movement thereof and fuel inlet means for supplying fuel to the space between said plungers during outward movement thereof the improvement comprising a recess defined in the contacting surfaces of said shoes to cooperatively engage the end portions of said stop, said shoes being movable relative to the ends of said stop to permit additional outward movement of said shoes to take place, thereby permitting an additional quantity of fuel to be supplied by said pump.

Claim 5

In the fuel injection pump as in claim 2 wherein the improvement further comprises said stop having end portions which define a plurality of axially spaced teeth, the contacting surfaces of said shoes being provided with recesses into which upon relative movement of said shoes and said leaf stop, said teeth of said stop can enter, thereby increasing the permitted outward movement of said shoes.

Claim 6

In the fuel injection pump in claim 3 wherein the improvement further comprises a distributor member having said leaf stop mounted thereon, and in which said shoes are movable axially relative to said distributor member.

Claim 7

A pump as claimed in claim 4 including actuating members engageable with the shoes respectively, said actuating members being coupled to a member slidable axially upon the distributor member but rotatable therewith.

Claim 8

In a fuel injection pump for an internal combustion engine having a pair of reciprocable pumping plungers movable inwardly to affect a pumping stroke by means of rollers carried by shoes to engage said plungers, said rollers cooperating with cam means, and having a stop which has end portions in the path of movement of said shoes limiting the outward movement of said plungers, the improvement comprising actuating members of channel form, the internal side walls of said channel form actuating members engaging the ends of said respective shoes, the interior base wall of said channel form actuating members having an aperture formed therein through which said respective plunger projects to cooperate directly with said respective shoe.

Claim 9

In a fuel injection pump for an internal combustion engine having a pair of reciprocable pumping plungers movable inwardly to affect a pumping stroke by means of rollers carried by shoes to engage said plungers, said rollers cooperating with cam means, and having a stop which has end portions in the path of movement of said shoes limiting the outward movement of said plungers, the improvement comprising actuating members of channel form, the internal side walls of said channel form actuating members engaging the ends of said respective shoes, the interior base wall of said channel form actuating members having an aperture formed therein through which said respective plunger projects to cooperate directly with said respective shoe.

Claim 10

The improvement of the fuel pump as claimed in claim 6 in which said actuating members are resiliently loaded towards the excess fuel position.

Claim 11

The improvement of the fuel pump as claimed in claim 7 including fluid pressure operable means for moving the actuating members towards the normal maximum fuel position.

Claim 12

The improvement of the fuel pump as claimed in claim 6 in which said actuating members are disposed obliquely in complementary slots in the distributor member, whereby as the actuating members move axially the rollers will also move angularly about the axis of rotation of the distributor member.

Claim 13

The improvement of the fuel pump as claimed in claim 9 in which said actuating members are moved against the action of resilient means by a fluid pressure operable piston.

Claim 14

The improvement of the fuel pump as claimed in claim 10 including aring disposed intermediate the actuating members and the pistons.

Claim 15

The improvement of the fuel pump as claimed in claim 11 in which said ring is carried on helical splines formed on the distributor member.

Claim 16

The improvement of the fuel pump as claimed in claim 6 including catch means operable to retain the actuating members in the excess fuel position, wherein said catch means comprises a pair of outwardly spring loaded catch members located within a bore in the distributor member, said catch members engaging respectively in a pair of detents in a sleeve constituting the member to which the actuating elements are coupled.

Claim 17

The improvement of the fuel pump as claimed in claim 13 in which a further pair of detents are provided said further pair of detents acting to retain the acTuating members in the normal maximum fuel position.

Claim 18

The improvement of the fuel pump as claimed in claim 14 including means operable to move the actuating members to the excess fuel position and further means operable to move the actuating members to the normal maximum fuel position.

Claim 19

The improvement of the fuel pump as claimed in claim 15 in which said further means comprises a centrifugally operable device responsive to the speed of rotation of the associated engine.

Claim 20

The improvement of the fuel pump as claimed in claim 16 in which said centrifugally operable means forms part of the governor of the pump.

Claim 21

The improvement of the fuel pump as claimed in claim 16 in which the teeth and recesses have inclined side walls to facilitate relative axial movement thereof.

Claim 22

The improvement of the fuel injection pump as claimed in claim 6 further including fuel delivery means for conveying fuel from the space defined between said respective plungers during inward movement thereof, fuel inlet means for supplying fuel to the space defined between said plungers during outward movement thereof, catch means cooperatively connected with said actuating members to retain said members in a first fuel delivery position, and spring means cooperatively acting with said actuating members to allow further outward movement of said plungers to a second increased fuel delivery position once said catch means is released.

Claim 23

The improvement of the fuel pump as claimed in claim 19 in which said catch means comprises a pivotal member having one end shaped to engage and retain the member to which the actuating members are coupled, resilient means acting to retain the pivotal member in this position and fluid pressure operable means for moving said pivotal member out of engagement with said member thereby to allow the actuating members to move the shoes to the normal maximum fuel position.

Claim 24

The improvement of the fuel pump as claimed in claim 20 including means for moving the actuating members to the excess fuel position.

Claim 25

The improvement of the fuel pump as claimed in claim 21 in which the spring means biasing the actuating members encircles rods respectively coupling the actuating members to the aforesaid member.

Claim 26

The improvement of the fuel pump as claimed in claim 22 in which the teeth and recesses have inclined side walls to facilitate relative axial movement thereof.

Claim 27

The improvement of the fuel pump as claimed in claim 22 in which said resilient means comprises a coiled compression spring acting upon the member coupled to the actuating members.

Claim 28

The improvement of the fuel pump as claimed in claim 24 including a further coiled compression spring which acts upon said member after a predetermined movement thereof against the action of said coiled compression spring, the pump including additional contoured stop members for the shoes, and the fluid pressure for actuating said fluid pressure operable means being derived from a source whose output pressure varies in accordance with the speed at which the engine is driven.

Claim 29

The improvement of the fuel pump as claimed in claim 25 in which said source comprises a feed pump which supplies fuel to the injection pump said feed pump being provided with a pressure control valve.

Claim 30

The improvement of the fuel pump as claimed in claim 26 in which said fluid pressure operable means comprises a plurality of pistons.