Fuel injection pump timing device

Claim 2

In a fuel injection pump including a drive shaft, a pump plunger, a pump plunger actuating cam rotatably driven by said drive shaft, said cam driving said plunger radially away from said drive shaft during a portion of the cam rotation including the plunger injection interval, timing means for varying the relative angular relation of said drive shaft and cam, said timing means including a sleeve disposed between and operatively connected to said cam and said drive shaft, and hydraulic means for actuating said sleeve to vary the relation of said drive shaft and cam, said hydraulic means including an input conduit for sleeve actuating fluid, the improvement comprising means for preventing the shifting of the cam with respect to the shaft during the plunger injection interval, said latter means comprising means for closing the sleeve actuating fluid input conduit during the injection interval.

Claim 3

The invention as claimed in claim 1 wherein said means for preventing the shifting of the cam comprising seal means associated with said sleeve for preventing escape of hydraulic fluid along said sleeve during the injection interval.

Claim 4

The invention as claimed in claim 2 wherein said sleeve actuating flUid input flow path passes through adjacent non-rotating and rotating elements of said pump, said means for closing the sleeve actuating fluid input flow path comprising slots in said non-rotating element communicating with a source of pressurized fluid and ports in said rotating element adapted to communicate with said slots, the circumferential length and position of said slots and the position of said ports being chosen so as to prevent communication of said slots and ports during the plunger injection interval.

Claim 5

In a fuel injection pump including a drive shaft, a pump plunger, a pump plunger actuating cam rotatably driven by said drive shaft, said cam being concentrically disposed in overlying rotatable relation with said drive shaft, said cam driving said plunger radially away from said drive shaft during a portion of the cam rotation including the plunger injection interval, timing means for automatically varying the relative angular relation of said drive shaft and cam, said timing means including a sleeve disposed in a chamber between said cam and drive shaft and operatively connected by helical splines to said cam and drive shaft, hydraulic means including conduit means for introducing pressurized fluid into said sleeve chamber to effect axial movement of said sleeve and a resultant variation of the timing relation of said drive shaft and cam, and speed sensing means operatively connected with said hydraulic means to effect automatic control of said hydraulic means, the improvement comprising means for preventing the shifting of the cam with respect to the drive shaft during the plunger injection interval, said latter means comprising means for closing said sleeve actuating fluid conduit means during the injection interval, said closing means comprising slots in a non-rotating element of said pump and ports in an adjacent rotating element, said slots and ports formed a part of said conduit means, said slots and ports being in communication during part of each revolution of the rotating member, said slots and ports being out of communication during the plunger injection interval.

Claim 6

In a fuel injection pump including a drive shaft, a pump plunger, a pump plunger actuating cam rotatably driven by said drive shaft, said cam being concentrically disposed in overlying rotatable relation with said drive shaft, said cam driving said plunger radially away from said drive shaft during a portion of the cam rotation including the plunger injection interval, timing means for automatically varying the relative angular relation of said drive shaft and cam, said timing means including a sleeve disposed in a chamber between said cam and drive shaft and operatively connected by helical splines to said cam and drive shaft, hydraulic means including conduit means for introducing pressurized fluid into said sleeve chamber to effect axial movement of said sleeve and a resultant variation of the timing relation of said drive shaft and cam, and speed sensing means operatively connected with said hydraulic means to effect automatic control of said hydraulic means, the improvement comprising means for preventing the shifting of the cam with respect to the drive shaft during the plunger injection interval, said latter means comprising means for closing said sleeve actuating fluid conduit means during the injection interval, said closing means comprising slots in a non-rotating element of said pump and ports in an adjacent rotating element, said slots and ports formed a part of said conduit means, said slots and ports being in communication during part of each revolution of the rotating member, said slots and ports being out of communication during the plunger injection interval.

Claim 7

The invention as claimed in claim 4 wherein said slots are disposed in a bearing member rotatably supporting said cam, and wherein said ports are disposed in said cam.

Claim 8

The invention as claimed in claim 4 wherein said means for preventing the shifting of the cam comprises seal rings associated with said sleeve for preventing escape of sleeve actuating fluid from said sleeve chamber during the injection interval.

Claim 9

A fuel injection pump timing device comprising a drive shaft, a pump plunger actuating cam rotatably driven by said drive shaft, said cam being concentrically disposed in overlying rotatable relation with said drive shaft and operatively connected by helical splines to said cam and drive shaft, hydraulic means including conduit means for introducing pressurized fluid into said sleeve chamber to effect axial movement of said sleeve and a resultant variation of the timing relation of said drive shaft and cam, said hydraulic means including a valve slidably disposed in a coaxial bore within said drive shaft, centrifugal speed sensing means operatively connected with said valve to effect automatic control of said hydraulic means, a rod coaxial with said drive shaft and disposed within a concentric bore in said drive shaft and passing through a concentric bore of said valve, a first spring means extending between said valve and said rod opposing the centrifugal movement of said speed sensing means, and a second spring means associated with said rod adapted to urge said sleeve toward a timing retard position when said pump speed falls below a predetermined level.

Claim 10

A fuel injection pump timing device comprising a drive shaft, a pump plunger actuating cam rotatably driven by said drive shaft, said cam being concentrically disposed in overlying rotatable relation with said drive shaft and operatively connected by helical splines to said cam and drive shaft, hydraulic means including conduit means for introducing pressurized fluid into said sleeve chamber to effect axial movement of said sleeve and a resultant variation of the timing relation of said drive shaft and cam, said hydraulic means including a valve slidably disposed in a coaxial bore within said drive shaft, centrifugal speed sensing means operatively connected with said valve to effect automatic control of said hydraulic means, a rod coaxial with said drive shaft and disposed within a concentric bore in said drive shaft and passing through a concentric bore of said valve, a first spring means extending between said valve and said rod opposing the centrifugal movement of said speed sensing means, and a second spring means associated with said rod adapted to urge said sleeve toward a timing retard position when said pump speed falls below a predetermined level.

Claim 11

The invention claimed in claim 7 including a radial pin secured to said sleeve and passing through an axial slot in said rod, said second spring means being connected with said rod to urge said pin and hence said sleeve against the force of fluid pressure in said sleeve chamber.

Claim 12

The inventiOn claimed in claim 8 including means for preventing relative movement of said rod and valve during pump operation below a predetermined speed.

Claim 13

The invention claimed in claim 7 including means for closing said conduit means for introducing pressurized fluid into said sleeve chamber during the injection of the pump plunger.

Claim 14

The invention as claimed in claim 10 including seal means associated with said sleeve for preventing escape of pressurized fluid along said sleeve during the injection interval.