Mobile load-lifting machines

Claim 1

A mobile load-lifting machine of the character described comprising a rear chassis structure; a front chassis structure slidably engaging said rear chassis structure longitudinally for fore and aft chassis extension and retraction of the machine; ram means acting between the chassis structures for operating them for such relative sliding movement according to load-handling requirements of the machine; a rear pair of wheels carried by said rear chassis structure; a front pair of wheels carried by the front chassis structure, one of said pair of wheels being carried by pivotal mountings from the corresponding chassis structure and inturnable about said pivotal mountings for slewing movement of the machine; further ram means acting between the corresponding chassis structure and the pivotal mountings for operating the inturnable wheels for inturning movement; angularly movable lever means carried from the corresponding chassis structure between the inturnable wheels and linked to the pivotal mounting of the latter for angular movement with inturning movement of said wheels; and angularly movable stop member carried from the corresponding chassis structure and cooperating with the angularly movable lever means for limiting angular movement of the latter and likewise inturning movement of the inturnable wheels, and guide means carried by the other chassis structure with which the corresponding chassis structure is slidably engaged and slidably cooperating with the stop member for effecting angular adjustment thereof on relative sliding movement of the chassis structures so that the extent of inturning movement of the inturnable wheels is appropriately varied in accordance with chassis extension and retraction of the machine.