Abstract: A control mechanism (1) for an engine valve (29) comprising two rotatable cams (8, 10) which engage a lever (2) at two follower regions (23, 34) at different positions, the lever (2) having a zone of application (35) linked to the valve (29) whereby rocking movement of the lever (2) consequent on rotation of the cams (8, 10) causes opening and closing of the valve (29), wherein one of the two cams (8) is in constant engagement with the lever (2) and the other cam (10) is in periodic engagement with the lever (2), a gap (26) being provided between the other cam (10) and its respective follower region (23) when the other cam (10) is not in constant engagement with the lever (2), the width of the gap (26) affecting the duration of opening and closing of the valve (29) and its stroke length. Preferably, the zone of application (35) of the lever (2) is movable longitudinally along the lever (2) to thereby vary the stroke length of the valve (29).

Abstract: A hydraulic jack support having a pair of telescopic members, one being a base and the other a bridge movable on the base, and an adjustable platform for supporting a jack engaging the base but adjustable thereon in height whereby the lifting jack is positioned on to the platform to lift the bridge in relation to the said platform and whereby the said platform can be raised for a multi-stage lift.