Abstract: A pressure compensation valve has a check valve portion with a check valve bore with an inlet port and an outlet port in a valve body, a valve in the check valve bore for establishing and blocking communication between the inlet port and the outlet port, a pressure reduction valve portion constructed by forming a pressure reducing valve bore having a first port, a second port and a third port and being coaxial with the check valve bore in the valve body, a spring-biased spool in the pressure reduction valve bore to define a first pressure chamber communicating with the first port and a second pressure chamber communicating with the third port at both sides, making the second port communicate with the third port by a pressure of the first pressure chamber, and blocking communication between the second port and the third port by the pressure in the second pressure chamber.

Abstract: A pressure compensation valve comprises a check valve portion having an inlet port that is connected to a discharge path of a hydraulic pump, an outlet port that is connected to an inlet side of a directional control valve, and a valve for controlling an area of opening between both ports. A pressure reduction valve portion has a spool that defines at its both sides a first pressure chamber and a second pressure chamber, respectively, and is adapted to be slidable to allow the valve to be thrusted in a first direction in which the area of opening is increased under a self-load pressure applied to the first pressure chamber and to be slidable to allow the valve to be thrusted in a second direction in which the area of opening is decreased under a pressure within the second pressure chamber.

Abstract: In a hydraulic apparatus for traveling, a left direction switching valve is formed by forming a spool bore having a pump port, an actuator port and a return port in a first valve block, and by disposing a spool within the spool bore for establishing and blocking communication of respective of the ports to another of the ports, a right direction switching valve is formed by forming a spool bore having a pump port, an actuator port and a return port in a second valve block, and by disposing a spool within the spool bore for establishing and blocking communication of respective of the ports to another of the ports, and a switching valve is formed by forming a spool bore having a primary port and a drain port in a third valve block, and by disposing a spool within the spool bore for establishing and blocking communication between respective of the ports and another of the ports.

Abstract: A planarizing material comprising a resin capable of having its practical temperature for a planarizing step set at a level lower than 200.degree. C., and a melamine-type heat-curing agent and/or an epoxy-type heat-curing agent.

Abstract: A multiple valve includes first and second valve units respectively having first and second valve bodies. The first and second valve bodies have respective spool bores therein; and a respective spool is inserted in the spool bore of each of the first and second valve bodies. The first and second valve bodies of the first and second valve units also have inlet ports, tank ports, and first and second blocks having mounting holes, the blocks and a respective valve body being fixedly coupled together by means of stud bolts. The first block has a first threaded hole on one side surface thereof for receiving the stud bolt, and a second threaded hole on another side surface thereof for receiving a cover bolt. A pump passage, a main passage and a tank passage extend between the one side surface and the another side surface of the first block, and a stud bolt extends through the second block and is engaged with the first threaded hole.

Abstract: A pressurized fluid supply system, in which a plurality of pressure compensation valves are connected to a pump discharge line of a hydraulic pump in parallel, and direction control valves are provided at the outlet side of each pressure compensation valve to supply a discharged pressurized fluid from the hydraulic pump to a plurality of actuators. The pressure compensation valves include a check valve portion establishing and blocking communication between the pump discharge line and the inlet port of the direction control valve, and a pressure reduction valve portion for supplying a reduced pressure from the pump discharge line. The check valve portion shifts in a valve opening direction in response to an inlet pressure and shifts in a valve closing direction in response to an outlet pressure. The pressure reduction valve portion has a first and a second pressure chamber.

Abstract: An operating lever device constructed such that the members thereof having a comparatively high rigidity can be used in such a way as to minimize the wear-down thereof and enable the angle of inclination of the lever to be detected precisely over a long period of time. The operating lever device is arranged such that any one of a plurality of rod members (22) which are inserted slidably while they are constantly urged upward into the device body (10) can be pushed down by the tilting of a lever (20) so as to rotate either a first shaft (23) or a second shaft (24) through a retaining member (27) or (28) held in contact with the lower end of the rod member (22). Thus, the angle of inclination of the lever (20) can be detected precisely by either one of rotational angle sensors (25, 26) mounted on at least one end of each of the first and second shafts.

Abstract: An improved anti abnormal-pressure/vacuum valve has a sleeve-like valve provided with a projection at its front end projecting into an actuator-side port, and a pressure introducing tube in a spool valve slidable in the sleeve-like valve for introducing oil pressure into a valve pressing chamber at the rear of the sleeve-like valve has its front-end portion disposed inside a front-end surface of the spool valve. This converts a dynamically varying pressure in the actuator-side port into a statically varying pressure in the valve pressing chamber so as to prevent the sleeve-like valve from being accidentally separated from its valve seat when oil pressure in the actuator-side port varies dynamically.

Abstract: A process for producing cationic synthetic rubber latexes by the emulsion polymerization of a conjugated diene or a conjugated diene and a comonomer copolymerizable with the conjugated diene, wherein the polymerization is carried out in the presence of a cationic emulsifier consisting of one or more organic or inorganic acid salts of a .beta.-hydroxy- or .beta.-hydroxymethyl-alkylpolyamine of the general formulae: ##STR1## wherein X is a hydroxyl or hydroxymethyl group, R.sub.1 is a hydrogen atom or an alkyl group of 1 to 20 carbon atoms, R.sub.2 is a hydrogen atom or an alkyl group of 1 to 20 carbon atoms, R.sub.1 + R.sub.2 together contain 8 to 20 carbon atoms, and n is an integer of 1 to 3, an ethylene oxide and/or propylene oxide adduct thereof, or an organic or inorganic acid salt of such an adduct, or a mixture thereof, and in the presence of colloidal alumina.

Abstract: A pilot operated pressure and vacuum relief valve which is adapted to open both at times when fluid pressure in a system in which the valve is connected exceeds a predetermined high value and at times when such pressure falls below a predetermined lower value.Said valve comprises a housing, a first valve means slidably inserted in said housing, a second valve means slidably inserted in said first valve means, a regulating member inserted in said first and second valve means, extending from the front end portion to rear end portion of said first valve means, and first and second springs disposed in said housing and said first valve means located and constructed so as to bias said first valve means and said second valve means respectively.

Abstract: A process for producing acrolein which comprises catalytic oxidizing propylene in the vapor phase with oxygen and steam in the presence of novel catalyst, having superior nature in activity, and composed of oxides of Mo, Co, Fe, Bi, and Sn with or without one or more of Al, Ni, W, Cr, In, and Nb, is disclosed.