Abstract: A reaction transmitting mechanism for brake booster in which a reaction from an output shaft is transmitted to an input shaft through a reaction disc, a reaction transmitting member and a valve plunger. An annular member is fitted over the valve body, and is formed with a stepped opening, in which a stepped tubular reaction transmitting member is slidably fitted. The reaction transmitting member is formed with a through-opening, in which the front end of the valve plunger is slidably fitted. The right end face of the flange-like portion of the reaction transmitting member is disposed in opposing relationship with the valve body and the step in the valve plunger. As a result of such arrangement, a more free choice of servo ratios used upon actuating and releasing the brake is allowed as compared with the choice enabled in the prior art.

Abstract: An improvement is obtained in the valve body construction of a check valve which is insertable into the interior of a flexible hose, which valve body comprises a valve body portion having one of an inlet port and an outlet port, and a valve end piece having the other of the inlet and outlet ports, wherein the valve end piece is formed with annular grooves extending in the circumferential direction thereof along the opposite sides across a joint surface between the valve body portion and the valve end piece. With this advantageous construction, there will be no burrs extending outwardly from the joint surface when assembled by welding the mating members.

Abstract: A brake booster is disclosed which reduces an idle stroke of an input shaft, by bringing a key member which is mechanically coupled to a valve plunger into abutment against an inner wall surface of a shell when the brake booster is inoperative. The shell includes a cylindrical projection which extends rearwardly from the center thereof, and the cylindrical projection is formed with a flange which extends radially inward, with its inner periphery cut away to define an opening. A valve body includes a cylindrical portion which extends through the opening to the outside thereof. By disposing the key member for abutment against the inner wall surface of the flange, a reduction in the length of the key member is enabled. A seal member seals the cylindrical portion of the valve body, and is located rearwardly of the flange and is received within a housing which is disposed outside the shell.

Abstract: The invention relates to a reaction transmitting mechanism for use in a brake booster in which a reaction from an output shaft is transmitted to an input shaft through a reaction disc and a valve plunger. A reaction transmitting member is interposed between the reaction disc and the valve plunger so that a reaction from the reaction disc is transmitted to the valve plunger through a plurality of paths including and not including the reaction transmitting member. When the brake is actuated, the reaction is transmitted through the reaction transmitting member. On the other hand, when the brake is released, the transmission of a reaction through the reaction transmitting member is halted. In this manner, it is possible to change the servo ratio between the actuation and the release of the brake.

Abstract: A power servo of the fluid differential type having a power piston and a diaphragm defining two cavities maintained at a differential pressure. An air passage is formed to release any air present in a space between the diaphragm and the disc portion of the power piston. The air passage may be formed as a split groove in the flange or as a hole through it. The groove may be either circumferential or axial to allow air to escape into the atmospheric chamber of the power servo.