Electric power transmission system

Claim 1

An electric power transission system comprising an overhead metal trolley rail having a head and a foot separated by a vertical web integral therewith, the head being adapted to be gripped by hangers for supporting the rail, said foot projecting from opposite sides of the web and having a transversely curved lower contact surface, the opposite sides of said rail foot above its curved lower surface curving inwardly and upwardly into said web, and a trolley shoe slidable along the rail and formed from an elongated block of electrical conducting material extending lengthwise of the rail, the upper portion of the block having a central trough therein extending from end to end of the block and receiving said foot of the rail, the lower portion of the trough being curved transversely to engage said contact surface of the rail, and the opposite sides of the upper portion of the trough projecting toward each other above said foot of the rail to prevent separaton of the shoe from the rail, said opposite sides of the upepr portion of the trough having tansversely convex surfaces adjacent said curved opposite sides of said rail foot.