A lifting apparatus including a beam assembly, a lifter affixed to a surface of the beam assembly for lifting weighted objects toward or away from the beam assembly, a cable extending from the lifter, a first leg pivotally connected to one side of the lifter on the beam assembly and a second...http://www.google.fr/patents/US5772183?utm_source=gb-gplus-shareBrevet US5772183 - Portable lifting apparatus for demountable positioning in an overhead location
Portable lifting apparatus for demountable positioning in an overhead ...
