Jidosha Kiki Co., Ltd.

Satoru Satoh

Michio Kobayashi

Haruo Suzuki

Morihiko Shimamura

A brake booster such as a tandem brake booster including a center plate disposed within a shell is disclosed. The center plate is connected to a valve body disposed within the shell by seal means in the form of a diaphragm, thus allowing the entire length of the valve body and hence of the brake booster to be reduced as compared with the prior art arrangement.

Brake booster with tubular guide member

A parking maintaining apparatus includes a solenoid-operated open/close valve which opens or closes a constant pressure passage providing a communication between a valve mechanism and a constant pressure chamber of a brake booster. A relief valve is provided which relieves a pressure within the constant pressure passage into the constant pressure chamber when such pressure exceeds a given value. The provision of the relief valve allows the pressure within a variable pressure chamber to be maintained at or below the given value through the valve mechanism under a parking maintaining condition, whereby the pressure within the variable pressure chamber can be rapidly displaced as the parking maintaining condition is to be terminated, thus eliminating a partly braked condition.

Parking maintaining apparatus for brake booster

A brake booster is provided in which a hydraulic pressure applied to a power piston is controlled by controlling a valve mechanism in response to a movement of an operating rod which is mechanically interlocked with a brake pedal. A valve plunger connected to the free end of the operating rod forms the valve mechanism, and is provided with a stop member, which limits a rear position of the valve plunger by abutment against the internal surface of a closed shell or a support mounted thereon when the brake booster is inoperative. As a consequence, the cross-sectional area of a flow path for the hydraulic fluid can be increased while maintaining an optimum depression of the brake pedal. Since such result is achieved by the stop member which is disposed within the closed shell, the arrangement can be constructed with a reduced weight and size as compared with a conventional arrangement in which the stop is disposed on the exterior of the shell.

Controller for valve mechanism of brake booster

A tandem type power servo booster including a housing having front and rear shells with front and rear pistons within the housing. The rear piston is coupled to a valve and an inner cylindrical member extends from the valve with the front piston secured to it. A push rod is inserted into the cylindrical member and a bias spring is also disposed therein. The front piston and the cylindrical member are formed from pressed metal and the inner diameter of the cylindrical member is larger than an outer diameter of the recessed portion.

Growing community of inventors

Saitama, Japan

Satoru Satoh