GB833857A - Hydraulic adjusting mechanism particularly for brakes - Google Patents

Abstract

833,857. Hydraulic brakes. GOODRICH CO., B. F. May 14, 1958, No. 15499/58. Class 103 (1). In a brake-adjusting mechanism for hydraulic brakes, a cylinder 18 is placed in each line 13, 14 leading from the master cylinder 11 to the wheel brakes 15; the cylinder comprising a main piston 25 interposed between the inlet 23 and outlet 24 of the cylinder 18 and a valve means 36 provided in the main piston 25 to permit adjustment of the volume of fluid in the fluid link between the main piston 25 and the wheel brake cylinder to adjust the brakes. In operation, fluid from master cylinder 11 moves main piston 25 to the left and displaces fluid to actuate the brakes. If, however, brake lining wear has taken place, an increased volume of fluid will be required to actuate the brakes fully and under these conditions the pressure applied to the piston portion 35 of the valve means 36 through openings 45 will be effective to lift valve means 36 and permit fluid to flow through openings 45, 41 and 27 to increase the volume of fluid in the link between the outlet end of cylinder 18 and the wheel brake cylinder until a condition of pressure balance obtains and the valve is closed by spring pressure when the inlet pressure is released to trap the fluid in the line and permit adjustment of the brakes. Should fluid have been added to compensate for heat expansion, fluid may escape as the brake drum cools by forcing open the valve means 36 until the required pressure balance is achieved.