Railway brakes

A tread brake for a railway vehicle including a frame and a wheel having an axis and mounted on the frame by a spring suspension, the brake comprising a braking element comprising an elongate rod of friction material, a power actuator carrying said braking element and operable to drive the rod longitudinally in a substantially radial direction relative to the wheel for applying an end face of said rod against the periphery of the wheel to brake rotation of the wheel, an arm mounting the actuator to said frame for movement relative thereto, said arm being connected to the actuator and directly to the frame by respective pivots both substantially parallel to the wheel axis, a member fixed with respect to the wheel axis, and a rigid link coupling the actuator to said member, said rigid link being immovably fixed to the actuator and being connected to said member by a pivot having an axis substantially parallel to the wheel axis, said rigid link being arranged to move the actuator in response to displacement of the wheel axis relative to the frame so that the actuator applies said end face of the rod against the wheel substantially radially of the wheel axis whatever the position of the wheel axis relative to the frame, said rigid link and said arm mounting said actuator and said rod on the same side of the wheel axis and in the same plane as the wheel.