Something resembling a shoe (sense 1 or 4) in shape, position, or function. Electr. traction. A block attached to an electric car in such a…

a short metal cable forming an electric connection between consecutive lengths of rail in a railway or tramway.

A device for conveying electricity from a conductor rail to a tram or train.

Of things: An apparatus, vessel, etc., used for collecting something (variously applied in technical use). So collector ring, collector shoe (see…