US Patent 7681747 Crane

A crane to be fitted in a window opening or the like, between two opposing surfaces, has a strut (14) which is first braced between the surfaces (20a, 20b), and a boom (13) which extends away from the strut. A winch (5) on the crane winds up a lifting cafe (12) which runs over a pulley (3) at the outer end of the boom (13). The top and bottom ends of the strut have end plates (15, 7) which are designed to hold the crane rigidly between the two surfaces, but without damaging any surface finish on either surface. The boom (13) can be swung about the axis of the strut (14) to bring the load carried by the crane in towards the position of the operator.