Abstract: A disc brake free from dragging torque while being in non-braking state. In this brake, a gap between the friction surface of a rotary disc and the acting surface of an actuator for urging a braking pad assembly onto the disc is made progressively larger into a wedge shape toward the axis of the disc. The torque receiving surface of a torque receiving member is made so slant as to produce a component for moving the pad assembly in a direction away from the axis of the disc in a wedging manner into the gap. The pad assembly is of corresponding shape to the above-mentioned gap and the torque receiving surface.

Abstract: An auto-adjusting mechanism in a disc brake comprising axially movable adjust bolt, adjust nut threaded on adjust bolt, cylindrical piston for transmitting the operating force of a pad-urging-piston to the adjust nut when the piston has moved beyond a predetermined value, spring structure for biasing cylindrical piston toward adjust nut. The cylindrical piston is integrally moved, while the wearing of the brake pads is insignificant, with the piston, but when the wearing has progressed largely, it is abutted on the adjust nut to be separated from the piston, with a result of leaving the thrust force from the spring structure act solely on the adjust nut and rotatingly propelling the nut for compensating the increased brake clearance. And this cylindrical piston is, when the braking fluid pressure in the cylinder body is raised beyond a predetermined value, separated from the adjust nut overcoming the urging force of the spring structure. The over adjustment is prevented in this way.

Abstract: A resin composition includes 20 to 70 parts by weight of unsaturated polyester being radically copolymerizable, having an average molecular weight between 500 and 5000, and having a degree of unsaturation between 150 and 190, 1 to 25 parts by weight of thermoplastic resin having an average molecular weight between 10.sup.4 and 10.sup.7, 30 to 70 parts by weight of ethylenically unsaturated compound being radically reactive with said unsaturated polyester resin and being able to dissolve said unsaturated polyester and said thermoplastic resin, on the basis of the total amount of said unsaturated polyester resin, said thermoplastic resin and said ethylenically unsaturated compound being 100 parts by weight, 0.05 to 1.0 parts by weight of fiber-like conductive material having a length between 1 and 10 millimeters and an aspect ratio between 2 and 10.sup.

Abstract: In an emergency brake system for a vehicle having a brake booster to increase braking pressure applied to wheel brake cylinders from a master cylinder, a cut-off valve is provided within an exhaust pipe of an internal combustion engine for the vehicle and operatively connected to a manual shift lever, and a selector valve is disposed within a communication passage connecting a servo-chamber of the brake booster to an upstream of the cut-off valve in such a manner that the servo-chamber is normally communicated to a source of pneumatic pressure in response to operation of the master cylinder. The cut-off valve is normally opened when the shift lever is in a first position and is closed upon shifting the lever to a second position from the first position to create back pressure acting on the engine. The selector valve is switched-over upon shifting the lever to the second position to apply the back pressure from the exhaust pipe into the servo-chamber through the communication passage.

Abstract: A pneumatically operated brake booster comprises a hydraulic cylinder disposed within a hydraulic braking circuit connecting a master cylinder to wheel brake cylinders to increase the braking pressure trapped within the wheel brake cylinders and a servomotor for pneumatically activating the hydraulic cylinder in response to hydraulic pressure from the master cylinder. The servomotor has a spring loaded diaphgragm piston forming a negative pressure chamber and a variable pressure chamber, the former being in connection to a source of negative pressure and the latter being connected to the atmospheric pressure in response to master cylinder pressure applied to the hydraulic cylinder. The brake booster includes a control valve which is provided to selectively connect the variable pressure chamber of the servomotor to such a positive pressure source as exhaust pressure to obtain additional pressure in an emergent braking operation of the vehicle.

Abstract: In a fluid pressure control valve unit incorporated between a master cylinder and rear wheel brake cylinders, a spring loaded stepped sleeve member associates with a differential piston to provide a cut-off valve. In case the front-wheel braking system is not operated due to some damage, the sleeve member moves from its usual position to apply the braking pressure directly to the rear-wheel brake cylinders.

Abstract: A dew-sensing hygroscopic element includes a pair of electrodes and a dew-sensing hygroscopic material arranged between the electrodes which detects dew by the change of impedance between the electrodes. The dew-sensing hygroscopic material comprises polyvinyl alcohol having a saponification equivalent of 20 to 65 as a base material and contains an organic electrolyte.