Abstract: To provide a plunger type master cylinder capable of reducing invalid stroke and preventing residual pressure without impairing durability of a seal ling (70). A piston (91) of the master cylinder has a recess (93) at its outer peripheral surface and a relief port (900) in its recess (93). The seal ring (70) has a seal coupling part (70s) on the inner periphery of the distal end part of an inner peripheral lip (701). The seal coupling part (70s) is located at the opening of the relief portion (900) on the piston (91) side when the brake is in a non-operating position. The distance between said seal coupling part (70s) and said relief port (900) is short. The seal ring (70) additionally has first and second projection parts (7006, 7002) on the inner peripheral surface of the inner peripheral lip (701). By this, a flow passage for working fluid can be obtained on the inner periphery side of the inner peripheral lip (701).

Abstract: To provide a plunger type master cylinder capable of reducing invalid stroke and preventing residual pressure without impairing durability of a seal ling (70). A piston (91) of the master cylinder has a recess (93) at its outer peripheral surface and a relief port (900) in its recess (93). The seal ring (70) has a seal coupling part (70s) on the inner periphery of the distal end part of an inner peripheral lip (701). The seal coupling part (70s) is located at the opening of the relief portion (900) on the piston (91) side when the brake is in a non-operating position. The distance between said seal coupling part (70s) and said relief port (900) is short. The seal ring (70) additionally has first and second projection parts (7006, 7002) on the inner peripheral surface of the inner peripheral lip (701). By this, a flow passage for working fluid can be obtained on the inner periphery side of the inner peripheral lip (701).

Abstract: A sensor element including an insulative base (11), a heating resistor (12), an oxygen pump cell (13), an oxygen detection cell (14), and a diffusion-chamber-forming member (161) having a rate-controlling introduction portion (163) and defining a diffusion chamber (16) in cooperation with electrodes (1321, 1421), wherein these components have been subjected to simultaneous firing (i.e., cofiring) to form a unitary sensor element. A partition wall (162), which extends from the diffusion-chamber-forming member and is made of alumina, is joined to a surface of a solid electrolyte (131) between two electrodes (1321, 1322) of an Ip cell. Preferably, a region within 20 ?m from the plane of junction joining the partition wall (162) to the solid electrolyte (131) contains no portion whose amount of non-alumina substances exceeds by 2% by mass (by weight) or more the amount of non-alumina substances of the diffusion-chamber-forming member (161).

Abstract: A multi-layer gas sensor element is described which comprises a solid electrolytic member, a substrate, and a porous member, wherein each of the substrate and the porous member has a thickness larger than that of the solid electrolytic member with respect to a lamination direction; the substrate and the porous member face each other and sandwich the solid electrolytic member; a ceramic component constituting the substrate in the highest volume percent is the same as the ceramic component constituting the porous member in the highest volume percent thereof; and the volume percent (R2) of the ceramic component contained in the porous member is 80% or more the volume percent (R1) of the ceramic component contained in the substrate.

Abstract: A sensor element including an insulative base (11), a heating resistor (12), an oxygen pump cell (13), an oxygen detection cell (14), and a diffusion-chamber-forming member (161) having a rate-controlling introduction portion (163) and defining a diffusion chamber (16) in cooperation with electrodes (1321, 1421), wherein these components have been subjected to simultaneous firing (i.e., cofiring) to form a unitary sensor element. A partition wall (162), which extends from the diffusion-chamber-forming member and is made of alumina, is joined to a surface of a solid electrolyte (131) between two electrodes (1321, 1322) of an Ip cell. Preferably, a region within 20 &mgr;m from the plane of junction joining the partition wall (162) to the solid electrolyte (131) contains no portion whose amount of non-alumina substances exceeds by 2% by mass (by weight) or more the amount of non-alumina substances of the diffusion-chamber-forming member (161).

Abstract: A multi-layer gas sensor element is described which comprises a solid electrolytic member, a substrate, and a porous member, wherein each of the substrate and the porous member has a thickness larger than that of the solid electrolytic member with respect to a lamination direction; the substrate and the porous member face each other and sandwich the solid electrolytic member; a ceramic component constituting the substrate in the highest volume percent is the same as the ceramic component constituting the porous member in the highest volume percent thereof; and the volume percent (R2) of the ceramic component contained in the porous member is 80% or more the volume percent (R1) of the ceramic component contained in the substrate.

Abstract: A ceramic heater for heating a sensor such as an oxygen sensor has a ceramic substrate and a heater pattern formed on the substrate. A heater pattern 22 is tightly interposed between first and second alumina substrates 15 and 21. This heater pattern 22 has a meandering heating section 25 and a pair of leads 26 for connecting both ends of the heating section 25 to two terminals at the base side end. The heating section 25 is divided into a tip side subsection 25a located near the tip side end of the device, and a base side subsection 25b. Specifically, the wire width is made greater in the tip side subsection 25a than in the base side subsection 25b so that the resistance per unit length is lower in the tip side subsection 25a. The thus-designed heater section 25 produces a less amount of heat in the tip side subsection than in the base side subsection, and this distribution of heat generation can reduce the possibility of cracks and breakage of a wire.

Abstract: An object of the present invention is to provide a master cylinder in which the buckling of spring is prevented and the packing is not damaged. To achieve this object, in a master cylinder in which a return spring is disposed between the end wall of a cylinder and a piston, and a packing fitted to the piston slides on the inner peripheral wall of the cylinder, the return spring 30 comprises a cylindrical large-diameter coil portion A with a diameter almost in contact with the inner peripheral wall of the cylinder 12 and a small-diameter coil portion B with a diameter enough smaller than the diameter of the inner peripheral wall of the cylinder 12, and the installation length of the small-diameter coil portion B is set so as to be nearly equal to a length of the range in which the packing 24 slides.

Abstract: An arc-shaped flange 32 is provided protrusively on the peripheral surface at the top end of a filter 30, and guide ribs 33 extending downward are formed on the lower surface at both sides of the flange 32, so that the ribs 33 are slid in a cutout 12 formed in an annular rib 11 to guide the filter 30, and the cutout 12 is covered by the flange 32 when the filter 30 is put into a tank body 10.

Abstract: Disclosed are improved method and apparatus for testing printed circuit board in which method and apparatus a selected printed circuit board is stretched to be unbent, thus permitting measuring probes to come to contact to selected points on the printed circuit board exactly for measuring, thus preventing undesired deviations of selected measuring points caused by the bending of the printed circuit board in hitting selected measuring points by probes. The printed circuit board tester includes a pair of clamps for gripping the opposite lateral edges of the printed circuit board standing upright; a drive devices for driving the clamps close to or apart from each other; and stretch control device between the drive devices and one of the clamps for applying a controlled stretch to the printed circuit board.

Abstract: An inlet union for master cylinder of the present invention is so constructed that a flange portion is disposed at the periphery of a duct member, a circular raised portion whose outside diameter is smaller than that of the flange portion is integrally formed, at least one convex portion protruding radially is disposed at the outer periphery of the circular raised portion, attaching holes for the duct members are disposed in the top plate of an attaching cover, a plurality of concave portions corresponding to the convex portion of circular raised portion of the flange portion are disposed at the inner periphery of the attaching hole so that the convex portion of the duct member selectively engages with the concave portion of the attaching cover, and a mounting portion is formed at the inner periphery of the attaching cover to mount the outer periphery of the flange portion.

Abstract: A cap which is so constructed that parts manufacture and product assembly are facilitated. The construction is such that a cap for a master cylinder reservoir connects a cover cap and a body cap with each other and a diaphragm is disposed in a space formed therebetween to provide a valve function. The cover cap has a concentric cylindrical portion and an annular protrusion, while the body cap has a funnel portion at its center and an annular disc portion at the periphery of the funnel portion. The diaphragm is fitted between the inner periphery of annular protrusion of the cover cap and the outer periphery of the funnel portion of the body cap. The diaphragm forms a suction valve and an exhaust valve together with the cylindrical portion and the annular disc portion, respectively.

Abstract: The present invention relates to a cap for reserve tanks, wherein said cap has a vent path. The cap consists of an upper member and a lower member, wherein an annular rib is defined in the upper surface of the lower member. The annular rib is forced into abutment with the lower surface of said upper member so as to form an inner chamber and an outer chamber between said upper and lower members. A portion of said annular rib is extended in the central direction of the annular rib, and a groove or a hole is formed in the extention of the annular rib, said groove or hole allowing communication between said inner and outer chambers.

Abstract: An improved printed circuit board inspection apparatus in which its inspection probes are made to contact with a selected part or printed circuit section on a printed circuit board for making an inspection on the selected part or printed circuit section in terms of their performances or functions. The printed circuit board inspection apparatus uses two guide sets each having at least one pair of inspection probes and driving means to drive said inspection probes in X- and Y-directions to selected coordinate positions in the printed circuit board. A central processing unit controls said driving means so that the inspection probes of one guide set are used to make an inspection at a selected coordinated position while the other inspection probes are traveling to another selected coordinate position for subsequent inspection according to a predetermined program.

Abstract: The hydraulic brake pressure control valve is provided including a valve casing mounted on a master cylinder of a hydraulic brake system. A valve piston is provided with a stepped configuration with an enlarged diameter portion and a reduced diameter portion. The valve piston is mounted slidably and longitudinally along the longitudinal bore of the valve casing. The valve piston is normally urged into a non-operating position and is shiftable longitudinally in an opposite direction from the non-operating position under the effect of a difference in the cross-sectional areas of the enlarged and reduced diameter portions, upon which hydraulic brake fluid pressure acts. The stepped valve piston is defined with a brake fluid passage extending longitudinally therein providing communication between brake fluid passages adjacent the reduced diameter portion and the enlarged diameter portion of the stepped valve piston.

Abstract: The present invention relates to a fluid reservoir unit designed for reserving a liquid such as brake oil and the like as applied in the field of hydraulic brake system, especially of such construction that there is provided a force ring adapted to engage in cooperation with the top surface of the circumferential edge of a diaphragm covering the opening at the top end of the reservoir body of cylindrical shape, the force ring being defined at its outer circumferential surface with a flanged portion having threads for the purpose that when installing the diaphragm and the force ring onto the cap to be threadedly engaged with the outer circumference of the top end of the reservoir body, the threads in the flanged portion is led to working position while engaging threadedly with the female threads defined in the inner circumferential surface of the cap, so that the flanged portion may be put to dwell loosely rotatably in the inside of the female threads.

Abstract: A waterproof seal ring, to be fitted between the contacting surfaces of a master cylinder body and the front wall of a power booster housing surrounding a bulge of the housing through which a push rod is inserted and having a downwardly extended passage groove formed in the lower part of the wall, has a circumferential vent groove formed on the pressure-contact side of the ring. The vent groove is communicated at the lower end with the passage groove in the front wall of the booster housing and at the upper end with the space inside the bulge.