Abstract: A sprocket wheel for a tracked vehicle, the sprocket wheel being in the form of an annular body having teeth integrally moulded of elastomeric material, the teeth including metal inserts moulded therein and providing track engaging surfaces in the inter-tooth valleys about the sprocket wheel.

Abstract: An outrigger for stabilizing the frame of a mobile apparatus such as a vehicle with a lifting device mounted thereon. The outrigger includes a pivoted arm mounted on the frame and a main hydraulic jack for swinging the arm from a raised or retracted position for travel of the vehicle to a lowered ground engaging position upon expansion of the jack. The upper or inner end of the jack is mounted on means for swinging the inner end of the jack inwardly relative to the frame and this means may be in the form of a link pivotally connected at its inner end to the frame and at its outer end to the inner end of the jack. A secondary jack may be connected between the link and the frame so as to swing the link inwardly. The swing of the outrigger arm is thus significantly increased over known arrangements so as to permit the outrigger to travel from a point well below the normal ground level to a retracted position which will permit highway travel.