LIFTING DEVICE FOR SLAB, PANEL OR SHEET MATERIALS

摘要

A lifting device (10) suited for use in the lifting and handling of heavy slabs or sheets of material is disclosed in this specification. It basically consists of a frame (12), comprising side plates (14) and (16), the upper ends of which are rigidly secured together by cross-members (18 and 20). The lower portion (16a) of side-plate (16) is angled downwardly and away from the other side-plate and carriage (30) is arranged for vertical sliding or rolling movement against this portion (16a) so that it moves inwards as it is raised. A movable plate or jaw (22) is mounted for horizontal sliding movement on the cross-members (20), being biased away from the fixed plate or jaw (14) by a spring (24). The carriage (30) is suspended from a tension-member (34) which is guided for vertical movement by the cross-members (18 and 20) and has its upper end secured to (or formed as) a lifting lug (36). When the device is placed over a slab (28) to be lifted (as shown in the figure), the raising of the carriage (30) by lifting the tensionmember (34) will cause the slab to be clamped sufficiently tightly to be lifted. Such lifting devices do not require that a standing slab (which is leaning with a stack of similar slabs against a support) to be pivoted very far before it can be engaged by the fixed jaw (14), making the handling of such slabs safer and less likely to result in material damage.