Abstract: The invention relates to a relief valve and intends to provide a relief valve which can reduce the difference between the dynamic set pressure and static set pressure of the relief pressure and its variation.An internal circumferential surface of the pilot valve element 214 to which a support 227 is inserted is expanded to form a sub valve chest 231, a support and sub valve element 232 externally fitted to the sealing member 229 is arranged in this sub valve chest 231, the clearance between the inner circumferential surface of the sub valve element 232 and the support 227 is sealed with the sealing member 229, and at the same time the sub valve element 232 is pressed against the sub valve seat 238 formed in the inner circumferential surface of the pilot valve element 214 by oil pressure exerted on the sub valve element 232 from the pressure chamber 208 side to seal the clearance between the sub valve element 232 and the support 227.

Abstract: In the preferred and illustrated embodiment of a reciprocating pump, a plunger for pumping a liquid, a piston for reciprocating the plunger and a selector valve for changing a pilot flow passage between a supply passage communicating a pressure chamber with a supply port and a discharge passage communicating the pressure chamber with a discharge port are disclosed. The selector valve is switched by a pilot valve means. A pilot valve body of the pilot valve means is so designed to engage with the piston for predetermined distances to and from the ends of the respective forward and backward strokes of the piston and to be moved to the switching position where the pilot valve body opens one of the pilot supply passage working against the selector valve and the pilot discharge passage and close the other of the pilot passages and the pilot valve body is released from engagement with the piston and held at the switching position for a predetermined distance after the stroke of the piston is reversed.

Abstract: In the preferred and illustrated embodiment of a reciprocating pump, a plunger for pumping a liquied, a piston for reciprocating the plunger and a selector valve for changing a pilot flow passage between a supply passage communicating a pressure chamber with a supply port and a discharge passage communicating the pressure chamber with a discharge port are disclosed. The selector valve is switched by a pilot valve means. A pilot valve body of the pilot valve means is so designed to engage with the piston for predetermined distances to and from the ends of the respective forward and backward strokes of the piston and to be moved to the switching position where the pilot valve body opens one of the pilot supply passage working against the selector valve and the pilot discharge passage and close the other of the pilot passages and the pilot valve body is released from engagement with the piston and held at the switching position for a predetermined distance after the stroke of the piston is reversed.

Abstract: A rotary actuator for converting a linear reciprocatory movement of a piston into a rotary reciprocatory movement of an output shaft through a connecting member. The rotary actuator includes a cylinder case formed with a pedestal in a position in which the output shaft extends vertically out of the cylinder case. The pedestal is formed with a substantially square elevated portion, and a depressed portion defined by the elevated portion. A plurality of projections spaced apart from each other by a predetermined angle are formed integrally with the pedestal in the depressed portion to constitute dividing lines of a scale for indicating the angle of rotation of the output shaft by means of a pointer.

Abstract: A solenoid valve including two valve members which are operable independently each other, wherein the inlet port and the outlet port may communicate only when both valve members are operated. The solenoid valve further includes annular opening and closing members slidably fitted around the respective first valve bodies of the two valve members and the synchronizing members. The synchronizing members are movable synchronized with each valve member and are coupled to the annular opening and closing member of other valve member.

Abstract: A case guard device for an air filter and a lubricator of a compressed air system having a main body connected to piping, and a transparent case formed of synthetic resinous material and attached to the main body. The case guard device includes a transparent case guard formed of synthetic resinous material open at its bottom and enclosing substantially the whole case while a gap is defined between the case and the case guard, and a retainer holding the case guard connected thereto by a projection-and-opening arrangement and latched onto the main body by bringing each of more than three locking portions into locking engagement with one of more than three pins on the main body.

Abstract: A double acting electromagnetic valve is composed of a tubular main body internally having a valve chamber, a pair of magnetic cores each having a concentric polar arrangement thereby to provide an E-shaped axial section, secured respectively on both sides of the main body, the cores being made of a magnetic material exhibiting high residual magnetism, a magnetic member slidably received in the valve chamber, two coils each encased in an annular recess formed between the central pole leg and the circumferential pole leg of the magnetic core, fluid passages provided through the central pole legs of the magnetic cores, a valve seat formed at an end of each fluid passage exposed to the valve chamber, and valve means provided on the slidable magnetic member to abut against the valve seats.

Abstract: A solenoid operated valve has a valve body forming a chamber provided with a valve seat at its center. A fluid port communicating to an aperture formed in the center of said valve seat and another fluid port communicating to said valve chamber through a passage. An electromagnet body of a ring shaped cross section is mounted to the valve body from above overlying the valve chamber. The electromagnet body is divided by a central yoke and an outer enclosure formed with an outer yoke at its end facing said valve chamber. The lower ends of said central yoke and that of said outer yoke have tightly fit therebetween a lower flange of a solenoid coil bobbin of inserted in the coil chamber, formed thereby and seals off the valve chamber from the coil chamber.

Abstract: In a device for measuring blood sedimentation rate automatically, a light-sensitive paper sheet is disposed so as to be movable relative to a blood sedimentation measuring tube, such as Westergren tube; a slit is provided between the light-sensitive paper and the measuring tube; and lamp means are provided on one side of the measuring tube opposite to the slit. Thus, the shade of the sedimented red blood corpuscles in the measuring tube formed as the light pulses from the lamp means passes through the measuring tube is projected on the light-sensitive paper through the slit with the feed of the paper and light pulses occurring in exact synchronism, and the rate of the blood sedimentation can be automatically recorded on the paper.