Railway switch

A switch for a railway system having a common track, a first branch track constituting an upper branch track, and a second branch track constituting a lower branch track, each track comprising a pair of rails with one rail of the pair disposed above the other, said switch comprising fixed support means between said common and branch tracks, a first pair of fixed switching rails, constituting an upper pair of fixed switching rails, on said fixed support means associated with the upper branch track, a second pair of fixed switching rails, constituting a lower pair of fixed switching rails, on said fixed support means associated with the lower branch track, a pair of movable switching rails movable between a raised position in which the pair extends between the common track and the upper pair of fixed switching rails and a lowered position in which the pair extends between the common track and the lower pair of fixed switching rails, a plurality of movable supports carrying the movable switching rails mounted on the fixed support means at spaced intervals therealong, each movable support being guided for movement transversely with respect to the direction of length of the movable switching rails and generally in the plane of these rails, and means engageable with said movable supports for moving each support through a predetermined range of movement with respect to the fixed support means transversely with respect to the direction of length of the movable switching rails and generally in the plane of said movable switching rails, the range of movement of the movable supports progressively increasing from the movable support adjacent the common track to the movable support adjacent the branch tracks, said means for moving the movable supports comprising an elongate actuator bar mounted on the fixed support means for reciprocation along its axis longitudinally of the fixed support means, said actuator bar having cam means thereon at spaced intervals corresponding to the spaced intervals of the movable supports, said cam means being engageable with the movable supports on reciprocation of the bar for moving the supports through said predetermined range of movement, said cam means comprising a pair of cams associated with each movable support projecting from the actuator bar on opposite sides of the bar in a plane parallel to the plane of the movable switching rails, the cams of each pair being offset with respect to one another longitudinally of the bar, one cam of the pair having a camming surface engageable with a respective movable support on movement of the bar in one direction for moving the support to one extreme of its range of movement, and the other cam of the pair having a camming surface engageable with the support on movement of the bar in the opposite direction for moving the support to the opposite extreme of its range of movement.