Abstract: The invention relates to heat sinks made of finned aluminum extrudates and useful for electronic devices and information devices having an electronic device incorporated therein. The heat sink of the invention made of a finned aluminum extrudate comprises a base plate, and fins arranged in parallel and provided on one surface thereof. The base plate is 25 to 400 mm in width, 25 to 400 mm in length and 2 to 5 mm in thickness, and the fins are 1 to 30 mm in height, 1 to 1.9 mm in interval and 0.1 to 0.8 mm in thickness. The thickness of the fins is reduced within a predetermined range according to the invention to thereby ensure diminished resistance to the flow of air and improved radiation performance. This also renders the heat sink lightweight, serving to reduce the size and weight of electronic devices and information devices.

Abstract: A master cylinder in which a sleeve is provided inside a cylinder main body to define a first pressure chamber in cooperation with primary and secondary pistons. A plurality of through-holes adapted to communicate with an outlet port are disposed in the sleeve in such a manner as to be longitudinally spaced away from each other. positioning means is provided between the sleeve and the cylinder main body for positioning the sleeve with respect to the circumferential direction relative to the cylinder main body. The sleeve is positioned relative to the cylinder main body in such a manner that at least one of the plurality of through-holes adapted to establish communication between the outlet port and the first pressure chamber when the pistons are at their rearmost positions is located to face the top portion of the circumferential wall of the cylinder main body.

Abstract: A tandem type master cylinder for use in a vehicle hydraulic brake system and having a pressure proportioning valve integrally connected thereto includes a piston slidably received in a bore in the master cylinder and defining a pressure chamber at least on one side thereof, and an actuating member or a slide slidable in directions parallel to the piston and having a sensing end and an actuating end projecting respectively from opposite surfaces thereof. The sensing end passes through a slit formed in the circumferential wall of the bore to project into the pressure chamber in the master cylinder. The actuating end cooperates with a valve member of the pressure proportioning valve such that when the piston is displaced beyond a predetermined normal reciprocating stroke the actuating member is slidingly displaced to tilt the valve member, thereby deactivating the pressure proportioning valve.

Abstract: A hydraulic pressure control valve for use in a dual circuit braking system of an automotive vehicle, and including a plunger slidably received in an elongated bore in a housing with opposite ends thereof being exposed to respective pressure circuits, and two pressure proportioning valve mechanisms being mounted on the housing with the axii thereof being perpendicular to the plunger, each valve mechanism including a stepped piston, an axial passage extending through the piston, a valve seat defined on one end of the passage, and a valve member cooperating with the valve seat.

Abstract: A brake pressure control valve for controlling the pressure in two pressure circuits. The control valve includes two control valve units arranged side by side in a housing, and each control valve unit comprises a piston and a spring acting on the piston to determining a valve closing pressure. A device for adjusting the spring force of either one of the springs for adjusting the valve closing pressure of one control valve unit with respect to the other control valve unit.

Abstract: A pneumatic servo booster including a shell housing having front and rear shells, a valve body incorporating therein, a valve mechanism slidably supported by the rear shell, a partitioning member cooperating with the valve body for partitioning the interior of the shell housing into front and rear chambers, and a connecting rod axially extending in the front and rear directions through the front and rear chambers and through the partitioning member with the opposite ends thereof being connected to respective shells. An annular tubular extendable member is provided for surrounding a portion of the connecting rod. One end of the tubular member is connected to the peripheral surface of a bore which is formed in the partitioning member for passing therethrough the connecting rod, and the other end of the tubular member is connected to either the front or rear shell and surrounds the connecting rod.

Abstract: Air pressure servomotor including front shell and rear shell coupled to said front shell so as to construct a housing, a diaphragm disposed in the housing, a piston plate located adjacent the diaphragm, input rod and output rod. The front and rear shells hold a cylinder structure which extends axially from the wall of the front shell to the wall of the rear shell and supports the shells axially, and which has slits running from the forward end to the intermediate portion thereof. A valve having a valve mechanism is slidably disposed in the cylinder structure and having a valve mechanism. Said input rod is connected to the foot pedal and the output rod is connected to the master cylinder. And when the foot pedal is operated to actuate the input rod, the action of the input rod is amplified by the operation of the valve mechanism and the piston plate and transmitted to the output rod therethrough, and then the master cylinder is actuated.

Abstract: A reservoir for use with a tandem master cylinder consisting of an elongated housing generally extending along the longitudinal axis of the master cylinder and including top and bottom walls and side walls, a partitioning wall provided between the top and bottom walls and extending laterally from either of the side walls toward the other side wall thereby partitioning the interior of the housing into two chambers. The partitioning wall further extends longitudinally along the other side wall and is spaced therefrom to define therebetween a corridor-like passage communicating the two chambers. The corridor-like passage has an opening which is spaced from the bottom wall by a predetermined height. A liquid level warning device receiving chamber is formed in one of the two chambers and is defined by the laterally and longitudinally extending portions of the partitioning wall and by an additional wall having a slit which extends between the top and side walls.

Abstract: A master cylinder for a vehicular brake includes a cylinder closed at one end and open at the other end, a sleeve slidably received within the cylinder, a piston assembly including a pair of pistons integrally connected together, a stop on the cylinder for confining the piston assembly within the cylinder, and a spring disposed between the sleeve and piston assembly for normally biasing one end of the sleeve against the closed end of the cylinder and the piston assembly against the stop. One of the pistons and the closed end of the cylinder define a first pressure chamber therebetween and the pistons define a second pressure chamber therebetween. In operation, the sleeve is moved towards one of the pistons in response to a difference in the amount of remaining oil between the two pressure chambers against the force of the spring.

Abstract: The level detecting device comprises a detector inserted in a reservoir to detect the level of oil liquid, lead wires leading signal from the detector, and a terminal connected to the lead wires. The terminal is fixed to a cap covering an opening of the reservoir and the cap is removably engaged to a cylindrical projection arranged around the opening of the reservoir.

Abstract: A servo booster including a piston plate for receiving a differential pressure produced across two chambers which are defined in a shell casing, a cylindrical valve body having a valve mechanism therein for controlling the pressure across the two chambers, an aperture and a head portion formed respectively at the center portion of the piston plate and at an end portion of the valve body and being engageable with each other at a predetermined angular position, and the relative movement of the valve body and the piston plate in the direction of the axis of the servo booster being prevented by rotating the head portion through a predetermined angle in the aperture, wherein the improvement comprises a rotation preventing member rigidly mounted on the piston plate and having one portion thereof in fitting engagement with the valve body to prevent the relative rotation of the valve body and the piston plate.

Abstract: A brake pressure control valve controls the hydraulic pressure supplied to rear wheel brakes in two independent circuits of a dual hydraulic braking system of a vehicle. The valve includes two valve bodies slidably received in a bore of a housing and movable toward one another upon receiving hydraulic pressure, valve seats formed respectively in the valve bodies, a free piston assembly the opposite ends of which are mounted slidably and sealingly on the valve bodies, and valve members mounted on opposite ends of the free piston assembly and defining valve heads cooperating with the valve seats in the valve bodies.

Abstract: A fluid pressure operated servomotor such as a vacuum booster including a power piston having a differential pressure acting thereacross, an input rod for actuating a valve mechanism mounted in the power piston, a reaction lever disposed between the power piston and an output rod for transmitting a force to the output rod and transmitting a reaction force to the input rod. A return spring for urging the power piston in the return direction acts through the reaction lever on the power piston, whereby the reaction force is not transmitted to the input rod until the force transmitted to the output rod exceeds a predetermined value.

Abstract: A hydraulic braking pressure control valve for use in a vehicle includes a first inlet and outlet connected to a first pressure circuit, a second inlet connected to a second pressure circuit, a first piston having therethrough a liquid passage which normally connects the first inlet and outlet, a second piston receiving liquid pressure in the second inlet for displacing the first piston against the biassing force of a pressure control spring, and a valve mechanism associated with the first piston for closing the liquid passage when the first piston is displaced by a predetermined distance by the second piston. A plunger is provided with one surface thereof facing the first piston with the pressure control spring interposed therebetween and the other surface thereof receiving liquid pressure from the first pressure circuit, and an inertia valve is provided for cutting off the supply of liquid pressure to the other surface of the plunger at a predetermined deceleration of the vehicle.

Abstract: An improved hydraulic master cylinder for use in a vehicle braking system wherein the housing of the master cylinder is formed of a material such as synthetic resin, aluminum alloy or the like and a cylindrical liner formed of corrosion-resistant and wear-proof metal is mounted in the housing to receive a piston slidably therein.

Abstract: A master cylinder including a housing, a cylinder defined in the housing, a piston slidably fitted in the cylinder, a spring urging the piston toward an open end of the cylinder, a push rod for actuating the piston against the force of the spring to compress hydraulic fluid in the cylinder, and a stopper ring retained in the open end of the cylinder for abutting with the push rod to define the non-actuated position of the piston, wherein a seal is disposed between the inner periphery of the cylinder and the stopper ring and between the stopper ring and the push rod when the piston is in its non-actuated position.

Abstract: A fluid pressure servomotor has a casing having a movable wall therein dividing the interior of the casing into two chambers, a valve body connected to the movable wall and receiving a valve mechanism communicating one of the chambers selectively with the other chamber or with a source of fluid pressure such as atmospheric pressure, an input rod mounted in the valve body to operate the valve mechanism, and a spring urging the input rod outwardly of the valve body.

Abstract: A brake pressure control valve including an inertia member being movable in response to the inertia force acting on the member, particularly when the rate of deceleration caused by braking action exceeds a predetermined amount, so as to close a fluid passage for controlling braking pressure, in which a stop member is mounted in a housing of the pressure control valve and being operable manually from the outside of the valve so as to abut with the inertia member for preventing the fluid passage from being closed by the inertia member.

Abstract: A cap assembly for the reservoir of a vehicular brake comprising a cap body and a cap cover, the cap body including a first cylindrical portion adapted to be received in the opening of said reservoir, a flange integrally formed with and radially and outwardly extending from the first cylindrical portion and a second cylindrical portion extending from the side of the flange opposite the side of the flange adjacent from the first cylindrical unit; and the cap cover including a third cylindrical portion adapted to fit on the second cylindrical portion of the cap body and closed at one end; the second and third cylindrical portions having mating radial tongue and groove engaging means and the closed end of the third cylindrical portion covering the second cylindrical portion to thereby close the opening of the reservoir. A method for producing a cap assembly for the reservoir of a brake which comprises a cap body and a mating cap cover connected together by means of tongue and groove engagement.

Abstract: A master cylinder has a first piston and a second piston slidably disposed respectively in two piston chambers of different diameters, reduced diameter stems projecting from the opposing end portions of the pistons respectively, a flange formed around the outer periphery of each of the stems, and a split sleeve consisting of two or more co-operating elements and having stepped portions in the inner circumference thereof at the opposite ends respectively, the split sleeve being restrained in a cylindrical shape with the stepped portions engaging with respective flanges thereby connecting the two pistons with each other.