Abstract: A hoist for removing an object to enable an individual to work on the object includes a first substantially vertical support mounted on a floor surface. A second substantially vertical support mounted on the floor surface and being spaced a predetermined distance away from the first substantially vertical support. The first and second substantially vertical supports include an upper surface. A substantially horizontal member extending across the upper surfaces of the first and second substantially vertical supports. A first vertical lift is operatively positioned within the first substantially vertical support. A second vertical lift is operatively positioned within the second substantially vertical support. The first and second vertical lifts selectively raising the member relative to the floor surface. A winch is operatively mounted on the substantially horizontal member for lifting the object relative to the member for enabling an individual to work on the object.

Abstract: A trolley conductor bridging means in an electrically powered trolley vehicle transportation system where said trolleys run by contact with a solid conductor and where said conductors are interrupted to provide a door clearance opening is disclosed wherein said means when closed provides for continuous electrical power and mechanical indistinguishable connection across said interruption and wherein said means is opened and closed automatically by the downward and upward force of the transverse moving door. The downward and upward force of said door is translated to the bridge by a cam follower motion of the door edge with the bridge cams and said door is kept electrically non-conductive by insulation of the bridge cam surfaces.