Abstract: Before the application of an external coating having a base of polyester or epoxy resin, or of a mixture of the two by spraying with an electrostatic spray gun, the parts to be coated are subjected to an initial zinc coating treatment by electrolytic process and a layer of an acrylic paint is applied to the zinc coating and polymerized to define a bonding sublayer between the metal and the external coating.

Abstract: A cart includes a frame mounted on castors, at least two castors being provided at a first end of the cart on respective opposite sides of a mean longitudinal axis of the cart. Each castor at this first end includes a device for locking the castor against pivoting acting unidirectionally to allow the castor to pivot freely in one direction by a sufficient amount and to prevent it from pivoting in the opposite direction. The two castors at the first end of the cart on opposite sides of the mean longitudinal axis of the cart have opposite locking directions.

Abstract: A trolley castor having two flanges which freely rotate about a spindle carried by arms of a yoke is described. The flanges are separated by a distance corresponding to the usually standardized distance between the grooves of a walkway surface. Between the flanges is a brake disk which can rotate around the spindle. Fixed to an edge of the brake disk is a brake skid having a sole. An end piece, which extends into a cup formed by the yoke, is fixed to another portion of the brake disk. When the castor moves onto a grooved surface, the periphery of the flanges are engaged in the groove and the brake skid comes into contact with the ribs of the grooved walkway. This causes the brake disk to rotate slightly around the spindle until the end piece abuts the inside wall of the cup, thus immobilizing the trolley.

Abstract: The consignment device comprises a box (1) with two slots (2, 3) capable of receiving corresponding keys. The box is shaped to receive a key fitted with a receiver for a consignment coin so that the insertion of a second key unlocks a first coin-bearing key locked into a first slot, leaving the second key locked into position in a second slot. This device comprises at least one key catch (14, 15) translatable substantially perpendicular to direction of insertion of the key (27a, 27b), and at least one elements (5, 11) for locking the catch (14, 15) translatable substantially parallel to the direction of insertion of the key (27a, 27b).