Abstract: A rear wheel suspension for motorcycles which comprises a hydraulic damper of telescope type consisting of telescopic inner and outer tubes and a suspension coil spring positioned in these tubes. In order to stabilize the damping characteristics, and at the same time, to prevent the inner end cross section of the inner tube from fouling the suspension coil spring and thereby causing unsatisfactory operation, abnormal noise and other problems, one part of the suspension coil spring, which is located in the outer tube under the condition where the hydraulic damper is extended to the maximum, is made smaller in pitch diameter than the other part, which is located in the inner tube so that the inside working oil flow due to its expansion or compression may be hardly hindered by the part of the suspension coil spring that is located in the outer tube.

Abstract: A seal mechanism in gear pumps or motors, in which a pair of gears engage, so that at least one side surface of these gears is sealed by a pressure plate movable in the direction of the shaft, the said pressure plate is partitioned by a seal member in the shape of a figure "3" at the back into the low pressure zone and the high pressure zone which lead to the inlet side pressure and the outlet side pressure, respectively, both ends of the said seal member are formed in a loop-like shape, and block members for backup use, movable with respect to the pressure plate, are housed in the loop-like parts, so that the said block members may be pressed toward the low pressure side through the seal member by the liquid pressure which is connected to the high pressure zone during the operation of the gear pump or motor, so that these block members may press the end parts of the seal member to the inner wall surface of the gear bower in the housing and so that no liquid may leak from these parts.

Abstract: At least one pair of intermeshing impeller gears are supported by bearings such as bushings or roller bearings. Liquid drawn through the suction port is forced first to flow perpendicular to the axes of the gears toward one ends of the shafts or trunions thereof and then through a low pressure passage extended in parallel with the axes of the gears and communicated with the pump chamber in opposed relationship with the zone where the teeth of the gears are disengaging. Each bearing is formed with a lubrication or oil groove or passage. One port or end remote from the side face of the gear of the lubrication or oil groove is communicated with the low pressure passage at the closed end thereof or at a position adjacent to the inlet thereof through a passage while the other port or end is communicated through a passage with the low pressure passage at a position between the inlet and closed end thereof.

Abstract: A gear pump or motor wherein at least two pump or gear units are arranged in coaxial relationship and have their axially inwardly extended driven and driving shafts journalled in a common intermediate casing, the driving shafts being splined together with an internally splined sleeve. The inlet port opened in the intermediate casing is communicated through low-pressure passages with the pump chambers of the respective pump or motor units (and with the assembly chamber or pocket formed to accommodate the opposing ends of the axially inwardly extended driving shafts). The diameter of the inlet port is made larger than the size of the sleeve for interconnecting the driving shafts so that the sleeve may be inserted through the inlet opening into the assembly chamber or pocket and interconnect the driving shafts. Thus, in assembly the interconnection between the driving shafts may be much facilitated.

Abstract: A pressure responsive sequence device wherein in order to carry out the pressure responsive sequencing operation in both the meter-in and meter-out flow control modes, between a supply line and a discharge line of a primary actuator is inserted a switching valve which automatically switches, in response to the pressure difference between the supply and discharge lines, to communicate either of them having a lower pressure than the other with a tank through a low pressure relief valve; and a sequencing valve is inserted in a supply line which communicates a pump in a hydraulic power source with a secondary actuator.

Abstract: A pressure-reducing device which incorporates, in a hydraulic actuating system provided with more than one circuit module, a flow rate control valve which is set at a lower flow rate value than the fluid supply rate from the hydraulic source and is installed in the supply side of a circuit module so as to control precisely the maximum working pressure of any of the said circuit modules thereby assuring that the maximum working pressure is at a value lower than the maximum pressure value set by a main relief valve installed in the fluid supply side leading from the hydraulic source. A relief valve is installed in the lower stream of the said flow rate control valve so as to control its maximum working pressure.

Abstract: A gear pump is disclosed wherein the shafts of at least a pair of intermeshing gears are rotatably supported in bushings each with an axially extended lubrication groove formed in the bore of the bushing, one end of the lubrication groove being communicated through a low pressure chamber defined in the inner end face of the bushing with a portion of a suction port located adjacent to the root or dedendum circle of the gear while the other end of the lubrication groove being communicated with the suction port through a hole extended through the bushing or casing or notch formed therein, whereby part of the liquid drawn through the suction port upon rotation of the intermeshing gears is forced into the pressure chamber because of the fact that the liquid drawn into each tooth space of the gear is imparted with the impact speed directed in the radial direction of the tooth space due to the difference between the speed with which the liquid is drawn into the gear pump and the rotational speed of the intermeshing

Abstract: Disclosed is a pressure loaded gear pump wherein two assemblies each consisting of a pair of abutted bushings are axially slidably fitted into a casing on both sides of a pair of intermeshing impeller gears for supporting rotatably the shafts thereof and for sealing the side faces of the gears; and defined on each side of the casing between the pair of abutted bushings and an end plate are a low pressure chamber into which is admitted the hydraulic pressure in a suction opening, a high pressure chamber into which is admitted the hydraulic pressure in a discharge opening and two moderate pressure chambers each of which is communicated with a sector between the suction opening and the pressure transition or gradient sector of the liquid passage from the suction to discharge openings. The effective area of each moderate pressure chamber is equal to or slightly greater than the cross sectional area of the space between the teeth of the gears.

Abstract: The present invention discloses a power-steering pump which may reduce in a very stable manner the flow rate of the hydraulic liquid under pressure to be delivered to a power steering system with increase of the rotational speed of an engine beyond an idling speed and which may easily change the above rate reduction or attenuation characteristic depending upon the types of the automotive vehicles and power steering systems thereof. A flow-control valve which is disposed in parallel with the axis of a pump mechanism is provided with a variable-area orifice which determines the flow rate attenuation characteristic and which is defined by an orifice groove cut through a flange of a partition wall member and an enlarged-diameter portion at the free end of a control rod extended through the partition wall member from the front end of a control spool of the flow-control valve.

Abstract: A front wheel suspension unit for motorcycles, in which the center part of a crank-shaped bent shaft having two parallel axes is taken as the axle, so that buffer effects may be produced against impact inputs in the horizontal direction of movement as well as in the vertical direction, and the wheel is supported, rotating freely around the axis of the said axle, while the other shaft part of the said bent shaft is held at the lower part of the front fork, so that the wheel may be supported while turning freely around the axis of the said shaft part.

Abstract: A fluid control valve, which relates to fluid control valves in which a pilot passage is opened or closed as a pilot flow is detected in the said pilot passage by means of a limit orifice mechanism located at the middle of the flow and a valve spool is switched by the differential pressure produced in the fluid passing the said limit orifice mechanism so as to effect a switch-over between unloaded and loaded states, and incorporates, as the said valve spool, a first valve spool effecting the switching action based on the differential pressure of the fluid passing the limit orifice mechanism and a second valve spool arranged in series with the first valve spool effecting a switching action being effected by the fluid pressure so that a load check function may also be provided.