Trolley rails with expansion joints between them

Claim 1

A multiple trolley conductor unit, comprising a pair of tubular rails formed of insulating material and disposed end to end but with a space between them for thermal expansion, each rail having a front side provided with parallel slots extending lengthwise thereof for receiving current pick-up members movable lengthwize of the rails, a partition wall extending across the inside of the tubular rail and closing the inner sides of the slots, the opposite side walls of each slot being provided beside said partition wall with a pair of opposed grooves extending lengthwise thereof, a rigid electrical conductor bar in each slot of each rail with its edges retained in the pair of grooves therein, whereby the bars are spaced from the open sides of the slots, the partition wall at said end of one rail being spaced inwardly of the rail from that end to expose the backs of the adjacent end portions of said bars, the conductor bars of the other rail having projecting end portions offset rearwardly the thickness of the bars and overlapping said exposed backs of the bars in said one rail, means fastening the overlapping ends of the bars together, rigid insulating side strips disposed between the bars bridging the space between said rail ends and extending along the bars and into said slots in both rails, the side walls of the slots beside the strips being recessed to receive the strips, and means securing said strips in the slots in one of the rails, the sTrips being slidable in the slots of the other rail to accommodate longitudinal expansion and contraction of the rails.