Railway vehicle trucks

A railway truck, said truck having a longitudinal axis extending in the direction of movement of the vehicle,

• a support structure comprising a horizontal plate having central means defining a rectangular aperture having a major axis which is directed transversely to the longitudinal axis of the truck and a minor axis which is parallel to the longitudinal axis of the truck, said support structure further comprising two tubular transverse supports rigid with opposite ends of the plate in the direction of the longitudinal axis of the truck,
• two shafts rotatably mounted in said tubular supports,
• bushes of elastomeric material interposed between said shafts and said tubular supports,
• a respective pair of arms carried by each shaft with each arm carrying a transversely projecting wheel axle,
• a respective wheel mounted on each said wheel axle,
• a helical suspension spring and an hydraulic shock absorber associated with each arm and extending upwards therefrom,
• rectangular sliding block means mounted in said rectangular aperture of the support structure for substantial sliding movement along said major axis of the aperture and limited displacement along said minor axis of the aperture, the sliding block having a central hole the axis of which is vertical,
• an upper plate element adapted to be connected to a vehicle body,
• a truck pivot pin carried by said upper plate element and projecting downwardly therefrom, the pivot pin extending through said hole in the sliding block and terminating below said horizontal plate of the support structure,
• a lower plate element fixed to the lower end of said pivot pin,
• a first elastomeric-material annular element clamped between said upper plate element and the upper surface of said horizontal plate, and
• a second elastomeric-material annular element clamped between the lower surface of said horizontal plate and said lower plate element, each of the annular elements of elastomeric material having a rigidity about the longitudinal axis of the truck which is less than the rigidity about the transverse axis of the truck.