GB628106A - Improvements in adjusting devices, suitable for brake rigging - Google Patents

Abstract

628,106. Hydraulic slack-adjusters for brakes. ROUMENS, J., and FLOURY, R. June 2, 1945, No. 13910. Convention date, May 24, 1944. [Class 103 (i)] [Also in Group XXIV] The slack in brake-operating rigging is automatically increased or decreased by altering the length of a liquid column D disposed between two members 1 and 6 connected to the control means and to the braking means respectively. During the initial operating period before the brake-blocks meet the wheels the pressure in chamber D is insufficient to open valve 10 so that the members 1 and 6 move integrally. If there is insufficient slack the brake blocks meet the wheels before the flange 23 meets the fixed stop 24 and the pressure in D rises to open valve 10 so that liquid flows from D to G through passage 13 so increasing the slack. This continues until the flange 23 meets the fixed stop 24, so pulling spring-biassed piston 17 to the right, permitting valve 8 to close chamber D and lock members 1 and 2 in adjusted relation. If the rigging is too slack the flange 23 meets the stop 24 before the brakeblocks meet the wheels so that valve 8 is closed before valve 10 is opened and piston 4 moves integrally with cylinder 1 since chamber D is closed while piston 17 is held and displaces liquid from F through valve 15 to E. During the return stroke this displaced liquid is forced by spring-biassed piston 17 through valve 20 into D while liquid flows from G into F, so that slack is taken up. If the rigging is correctly adjusted flange 23 meets stop 24 and the brake-blocks meet the wheels simultaneously so that valve 8 closes as valve 10 opens while the piston 17 is not appreciably displaced. To obviate formation of a void in chamber G this chamber may be connected to a reservoir containing liquid or liquid and air. Several valve constructions reducing the number of valves and springs needed and several casing constructions are described.