Abstract: An anti-lock hydraulic brake system for vehicles incorporating a master cylinder (21) and wheel brakes, (30, 31) connected to the master cylinder (21) through connecting lines (32, 34), as well as an anti-lock apparatus having sensors for the associated wheel brakes (30, 31) by which, in the event of excessive deceleration of a vehicle wheel, the wheel brake will be disconnected from the master cylinder (21) by a valve (11) and will be connected to a relieving device. The relieving device is composed of a slave cylinder (1), whose piston (2) is in operative engagement with a movable wall of an actuating device operating with vacuum, which movable wall is displaceable to assume a control position in opposition to the force of a resilient element, for example a steel spring, the piston chamber (44) in front of the piston (2) being connected via a by-pass line (35) which contains a valve (23) with the brake line (32, 34) communicating with the intermdeiate chamber (45) of a separating valve ( 11).

Abstract: A hinge mechanism for a luminaire for outdoor lighting which allows the lower housing including the lamp refractor to be pivoted to a position enabling access to the luminaire interior. When it is desired that the lower housing be detached, the hinge retainer is released to permit detachment of the lower housing. The hinge mechanism includes a transverse rod resting in a trough formed by one or more channel supports. To prevent the rod from being removed from the channel, a U-shaped spring holder is held in a position where each U leg normally extends over the opening of the hinge channel support. These spring holders retain the channel in the trough. To detach the hinge, the base of the U is manually grasped and retracted to withdraw the spring legs from its extending position. The rod in channel engagement may be detached to remove the refractor housing from the luminaire.