1. In a conveyor system of the kind comprising: a main trackway having a continuous longitudinal slot in its base; a branch trackway of the same cross-sectional shape as the main trackway; a plurality of load carriers which are freely movable in the trackway; and guide elements on the carriers which project through said longitudinal slot and below the trackway, a track switch comprising: a frog connected between the main and branch trackways and having in its base, slots which merge with said slots in the trackways; a load carrier diverter mounted externally of the frog for action on portions of the carrier guide elements which project below the base of the frog, the diverter being pivotally movable between a ''''straight-through'''' position in which the load carriers are unaffected and travel straight through the switch, and a divert position in which the diverter acts on the said portions of said carrier guide elements projecting below the frog to divert the trolleys into the said branch trackway; and means for moving the diverter between said straight-through and divert positions, said diverter comprising an assembly formed by a carrier plate mounted above the frog to pivot about a vertical axis passing through the latter, and a pair of side plates which depend from the carrier plate at opposite sides of the frog and which have inwardly-directed bottom marginal portions, the opposed edges of which form guide edges.

8. A load carrier diverter for a frog, comprising: a carrier plate adapted to be mounted above the frog to pivot about a vertical axis passing through the latter; a pair of side plates which depend from the carrier plate at opposite sides of the frog and have inwardly-directed bottom marginal portions, the opposed edges of which form guide edges; and means for effecting pivotal movement of the diverter between an inoperative position and a divert position in use.