# US 4,391,258 A · Arrangement for driving a mechanism in an internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,391,258 A - Document ID: US4391258A - Status: Granted - Kind: A - Application number: 06/238,654 - Filed: 1981-02-26 - Granted: 1983-07-05 - Earliest claimed: 1980-03-06 - Assignees: Saab-Scania Aktiebolag - Inventors: Dick V. Claesson - Web page: https://patentgrep.com/patent/US4391258A ## CPC - F02B 67/04: of mechanically-driven auxiliary apparatus - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) ## Abstract The present invention relates to an arrangement for mechanically driving a mechanism connected to an internal combustion engine. A push rod is mounted between the mechanism and a shaft rotatably mounted in the engine, one end of said rod being adapted to actuate the mechanism and the other end being adapted to resiliently engage against an arcuate surface on said shaft and to be given oscillating translation motion by said shaft on rotation. The invention is distinguished in that the end of the push rod engaging against the shaft is provided with two extensions at least partially embracing the arcuate surface on the shaft, said extensions guiding the position of a rod in a plane transverse to the shaft when said shaft rotates. The push rod thus requires no extra guidance and is simple to fit and to dismantle. The push rod preferably comprises two parts joined to each other via a jointing sleeve allowing a given degree of angular latitude between said parts. The arrangement is applicable to driving fuel pumps in internal combustion engines. ## Claims ### Claim 1 In apparatus for mechanically driving a mechanism associated with an internal combustion engine: a driven rotatable shaft having a rotation axis, said shaft having a peripheral groove which has side walls and a bottom wall forming a continuously curved cam surface which is eccentric to the rotation axis of said shaft; a push rod having a first end drivingly connected to said mechanism and a second end having a fork configuration including two extensions which are oriented radially on either side of the cam surface and, between said extensions, a curved surface engaging said cam surface so that rotation of said shaft imparts oscillating axial motion to said push rod and swinging movement to said second end of said push rod, said two extensions residing in said groove and being engageable with the side walls of said groove whereby said swinging movement of said second end of said push rod is accommodated, whereby said second end of said push rod is guided by said side walls in the longitudinal direction of said shaft and whereby no extra guidance is needed in the axial direction of said push rod, wherein said push rod comprising first and second longitudinal portions and means connecting said first and second portions in end-to-end relationship in a manner to accommodate angular play during said transverse movements of said first end, said first longitudinal portion incorporating said first end and said second longitudinal portion incorporating said second end. ### Claim 2 Arrangement for mechanically driving a mechanism connected to an internal combustion engine, a push rod being adapted between the mechanism and a shaft rotatably mounted in the engine, one end of said push rod being adapted for actuating the mechanism and another end of said push rod being adapted for resiliently engaging against an arcuate surface on the shaft and to be given oscillating translation motion by said shaft on rotation, characterized in that the arcuate surface on the shaft is located in a peripheral groove in the shaft, the end of the push rod engaging said arcuate surface having two extensions reaching into said groove and at least partially embracing said arcuate surface, for controlling the position of said push rod end radially and axially in relation to the axis of rotation of said shaft, the push rod comprising a first push rod part incorporating said extensions and a second push rod part forming said one end being connected with said first push rod part via an angular play-permitting jointing sleeve, wherein the extensions are oriented radially on either side of the arcuate surface on the shaft and wherein the extensions are at least partially provided with arcuate surfaces engaging against the arcuate surface on the shaft. ### Claim 3 (depends on 2) Arrangement as claimed in claim 2, characterized in that the arcuate surface on the shaft is an eccentrically located cylindrical surface. ### Claim 4 (depends on 2) Arrangement as claimed in claim 2, characterized in that said first push rod has a length, which is considerably greater than the width between its extensions. ### Claim 5 (depends on 4) Arrangement as claimed in claim 4, characterized in that the jointing sleeve is connected with play to one of said first and second push rod parts whereby the first and second push rod parts can be given a mutual angular attitude. ### Claim 6 (depends on 5) Arrangement as claimed in claim 5, characterized in that the mechanism is a diaphragm-type fuel pump. ### Claim 7 (depends on 6) Arrangement as claimed in claim 6, characterized in that the driving shaft is the cam shaft of the internal combustion engine.