Improvements in or relating to air pressure operated apparatus
944,223. Fluid-pressure brakes. CLAYTON DEWANDRE CO. Ltd. May 12, 1961 [May 18, 1960], No. 17554/60. Heading F2F. A fluid pressure vehicle brake servo-unit comprises two end-toend arranged piston and cylinder devices, one piston transmitting thrust to the other by means interconnecting the corresponding cylinder ends to provide unified additive thrust. A pair of cylinders 1, 2 are secured together to a flanged plate 3 by a split clamping ring 5. Admission of compressed air at 14 to the left of a piston 8 is communicated by ports 13, 15 and hollow piston rod 9 to the corresponding side of a second piston 10. The piston rod 9 abuts the piston rod 11 of piston 10 to provide additive thrust to the output stud 12. Return springs 8a, 10a respectively are provided for the pistons and filtered air is allowed to pass to the space behind the piston 8 through a breather 16. A breather for the piston 10 may be provided in a mounting stud.