IC engine ignition circuit contact breaker arm - has injection moulded pivot bush and cam follower with injection channel compensating for thermal deformation of arm

摘要

The contact breaker arm is for engine ignition circuits. The pivot bush (5) and the cam follower (7) are injection moulded from a single point (10) using a minimal amt. of material. The material is passed to the bush and the follower via a curved channel (13) set along one side of the arm (2) and spaced slightly away from it. The design is such as to absorb any deformation caused by heating and subsequent alteration of the relative position of the bush and follower. The arm cross-section is a shallow 'U' shape, the base of the 'U' being parallel to the bush axis. The cam follower is pressed out from a supporting shoulder (5).