Patent ID: 8317160
Filing Date: 2012-11-27
Classification: B66B,B66D,E04G

Abstract:
1. An apparatus comprising: a platform; a hoisting machine mounted on the platform; a rigging operable to raise and lower the platform, said rigging passing through a traction sheave mounted on the hoisting machine, said fraction sheave coupled to a restraint device, said restraint device located proximate to where said rigging passes through said traction sheave and positioned substantially at a position of maximum lifting of said rigging, wherein a gap is formed between an outer radius of said rigging and said restraint device such that the outer radius of said rigging is allowed to pass through said traction sheave while to limit lateral displacement of said rigging is limited; wherein said restraint device comprises: wherein said first and second edges respectively have an indication of a degree of wear so that a user can flip the restraint device from the first edge to the second edge in order to replace the first edge which is indicating wear.