Abstract: A flow rate control valve device for controlling and then supplying fluid under pressure to an actuator such as an hydraulic cylinder or the like which includes a valve body having a drain port kept at a low pressure and a main spool slidably mounted in the valve body to connect or disconnect the drain port with a pressure chamber. Notch grooves are formed on an outer peripheral surface of the main spool. A spring is interposed between the valve body and the main spool to urge the spool to a valve body seat. A pushing device is provided for pushing the main spool against the resilient force of the spring.

Abstract: It is an object of this invention to provide a transfer feeder wherein lift levers are pivoted to vertically move upstream and downstream lift beams through connecting rods and lift mechanisms to change their heights, and cross bars extend between transfer bars and are adapted to adjust the level of a workpiece to a plurality of different levels. The transfer feeder comprises a first feed height adjustment mechanism (25) disposed between the lift levers (22) and the connecting rods (28) to simultaneously change the height of the upstream lift beams (7.sub.1) and the downstream lift beams (7.sub.2) to respective levels, and a second feed height adjustment mechanism (30) disposed between the lift mechanisms (8) for the upstream lift beams (7.sub.1) and the lift mechanisms (8) for the downstream lift beams (7.sub.2) to change the height of the upstream lift beams relative to the upstream lift beams.

Abstract: A fully hydraulic steering system for a vehicle having a front frame and a rear frame coupled to each other by an articulating pin, the steering system coupling a steering unit operated by a wheel to steering cylinders, for turning the vehicle body. The steering system comprises: a sensor to detect a turning angle of the steering wheel; a sensor to detect an articulating angle of the vehicle body; a controller to compare outputs from these two sensors to drive a wheel position correcting solenoid valve according to the difference between the outputs; a pilot-type diverting valve to allow wheel position correcting oil to branch from a switch pump circuit to the wheel position correcting solenoid valve; and a safety valve to close a drain port of the pilot type diverting valve only when the driver performs steering with the wheel so that the pilot-type diverting valve feeds correcting oil to the wheel position correcting solenoid valve.

Abstract: A steering wheel position compensator of a fully hydraulic steering device for working vehicle, etc.

Abstract: A method of preventing a wheel loader from slipping, aiming at reducing the amount of slip of the loader during excavating operation using it, and preventing the decline in operational efficiency due to the slip. The method of preventing a wheel loader from slipping comprises the steps of detecting the occurrence of slip in accordance with the difference in the number of revolutions between a pair of left and right drive wheels and the change thereof, and controlling the clutch pressure so that the clutch is put in half-clutch condition upon detection of the occurrence of slip.

Abstract: A method of controlling speed changes in a hydraulically actuated type multiple-stage speed change gear, which renders it possible to prevent the occurrence of "shift hunting" without impairing the acceleration characteristics of the vehicle and also reduce the magnitude of shocks which occur at the time of speed changes even in case hydraulic clutches of small capacity are used. According to this method of controlling speed changes, a controller (30) is used to conduct speed changes when conditions for speed changes, i.e., upshift/downshift are satisfied, and in cases where a downshift is made after an upshift and an upshift is made after a downshift, speed changes are conducted after the lapse of a long speed change inhibiting time, and in other cases than the aforementioned, speed changes are conducted after the lapse of a short speed change inhibiting time.

Abstract: A working machine equipped with a boom, an arm and a bucket and is mounted on a construction vehicle, the working machine being capable of being folded compactly at rest. The working machine is easily brought into an operating position without any special apparatus. The boom is divided into two portions that allow it to be folded compactly. The two boom portions are pivotally attached to each other and the first of the two boom portions is pivotally attached to the chassis of the machine. The boom portions work in cooperation with at least one hydraulic cylinder to move between operative and inoperative positions. A retaining device, which can be in the form of another hydraulic cylinder or pins, is used to hold the boom portions in position with respect to each other.

Abstract: The evaluation of the signal transmission performance of an optical communication apparatus used when communication for control purposes is made using optical communication in general industrial machines such as presses. An electric current having a magnitude in a predetermined range is fed stepwise to a light emitting element (33) of a transmission optical link (3), a frame signal which includes an electric current value code indicative of the magnitude of the electric current fed to light emitting element (33) is simultaneously delivered to a receiver (20) through optical fiber (5) from a transmitter (10).

Abstract: A welding start position detecting apparatus for a welding robot in which a first reference voltage and a second reference voltage having different voltage levels are set as comparison reference voltages in which, during a preset time period after start of searching operation, a voltage for detection of the welding start position is compared with the first reference voltage having a higher sensitivity and, when the welding start position detecting voltage comes across a level of the first reference voltage, the first reference voltage is switched to the second reference voltage having a lower sensitivity for comparing operation of the welding start position detecting voltage with the second reference voltage to thereby enable the detection of the welding start position on a base material even when an impedance around a welding torch changes.

Abstract: In order to safely transport a building material to its mounting area of a building body and to temporarily hold the same until it is firmly mounted on the mounting area on the building site, according to the present invention, there is provided, an apparatus for transporting/mounting a building material including a self-propelled vehicle body provided with a steering/driving device, the vehicle body assuming a substantially L-shaped form constructed of an upright main body and a pair of lower frames which are parallelly spaced apart from each other and horizontally extend from opposite sides of a lower portion of the main body; an elevator unit movably mounted on a vertical side portion of the main body so as to be vertically movable along the vertical side portion of the main body; a first frame horizontally extending forward from a vertical side of the elevator unit, the first frame having its base end mounted on the elevator unit so as to be horizontally movable in a horizontal plane; a second frame slida

Abstract: A controlling apparatus for use in a balanced work or cargo handling system which aims at detecting the weight of the work or cargo suspended accurately even if a drift occurs in an acceleration detector due to changes in ambient temperature to thereby enable a stable work or cargo raising and lowering operation to be achieved. The controlling apparatus comprises an acceleration correcting arithmetic unit (23) adapted to output the difference between an averaged acceleration signal (Va.phi.) obtained by averaging the drifted acceleration signals (Va) transmitted by an acceleration; detector (8) during a predetermined period of time and the drifted acceleration signal (Va), as a corrected acceleration signal (Va') to a command arithmetic unit (17) and a load storage and arithmetic unit (22) when the absolute value (.vertline.Va.vertline.) of the drifted speed signal (Va) is less than a preset value (.epsilon.a) and the absolute value (.vertline.V.vertline.

Abstract: This invention provides a hydraulic circuit system capable of reducing the flow rate distribution error in supplying pressurized fluid from a single hydraulic pump into a plurality of hydraulic actuators, and also supplying pressurized fluid quickly. The circuit is simplified to reduce manufacturing costs.

Abstract: A tapping function is imparted to a microjoint separation apparatus in order to obtain uniform cycle time and to improve productivity. The apparatus includes: grips (6) for moving a workpiece (2) in the X-axial direction of the main body (1) of the apparatus; a hammer (30) and a tapping unit (40) provided on the main body (1) and movable in a Y-axial direction perpendicular to the X-axial direction; an NC device (35) for positioning tapping point and hammering point of the workpiece (2) by moving the grips (6), the hammer (30) and the tapping unit (40) in X-Y axial directions; and cradles (31, 32) for selectively supporting a lower portion of the workpiece (2) during the hammering operation and the tapping operation.

Abstract: As a melt of a raw material SrLaGaO.sub.4 is used as shown by the following formula and a monocrystal is obtained by Czochralski pulling method.Sr.sub.x La.sub.y Ga.sub.z O.sub.wwherez.gtoreq.x, y.gtoreq.x and 0.28.ltoreq.x.ltoreq.0.325x+y+z=1w=(2x+3y+3z)/2Preferably, the melt of raw material is formed while rotating the raw material. It is also advantageous to form a SrLaGaO.sub.4 monocrystal in an atmosphere containing decreased quantities of H.sub.2 O vapor and CO.sub.2 by Czochralski pulling method.

Abstract: A method for automatically changing the speed of a dump truck for use as a construction vehicle which is capable of improving the fuel cost by utilizing the engine output effectively and efficiently, improving the durability of the power transmission system and giving the driver a comfortable ride. According to this automatic speed change method, a desired, optimum speed stage which meets the loading condition of the dump truck and/or the engine output condition can be selected by using controllers each having a built-in computer.

Abstract: A hydraulic-controlled electronic governor employed in a fuel injection system is provided with a proportional pressure-reducing solenoid valve (10) capable of conducting a self-regulation of an input hydraulic pressure supplied from a hydraulic pressure source (30). Such pressure-reducing solenoid valve (10) is connected with a control rack (25) for controlling an amount of fuel injection, while interposed between the hydraulic pressure source (30) and a pressure input chamber (28) of a power piston/cylinder mechanism (22) for controlling the control rack (25), so that the input hydraulic force acting on one side of the piston (24) of the power piston/cylinder mechanism (22) balances the resilient force of a return spring (27) acting on the other side of such piston (24) so as to control the control rack (25) in its position.

Abstract: A pressure control system in which a pressure in a back pressure chamber of a flow control valve is controlled according to a throttle opening of a pilot valve to locate stationary the valve body of the flow control valve at a position corresponding to the throttle opening of the pilot valve. In the system, a fixed throttle is provided in an oil passage extended to the back pressure chamber of the flow control valve, thereby applying a dampering action to the valve body.

Abstract: A pressure control system in which a pressure in a back pressure chamber of a flow control valve is controlled according to a throttle opening of a pilot valve to locate stationary the valve body of the flow control valve at a position corresponding to the throttle opening of the pilot valve. In the system, a fixed throttle is provided in an oil passage extended to the back pressure chamber of the flow control valve, thereby applying a dampering action to the valve body.

Abstract: A hydraulic pilot valve unit constructed with an aim of controlling the flow rate of fluid under pressure in proportion to the stroke of the operating lever, irrespective of the speed of operation of the lever, and adapted for use in supply of pilot fluid under pressure by a pilot fluid actuated type changeover valve or the like arranged to be actuated for switch-over by pilot fluid under pressure. This hydraulic pilot valve unit includes valve spools 23 each being slidably movable between a first position where the pilot fluid under pressure supplied by a pilot pressurized fluid supply pump (27) is allowed to flow into outlet ports (26) formed in the valve body (1), and a second position where the outlet ports are allowed to communicate with a reservoir port (30) formed for drainage purposes.

Abstract: A managing system for a construction vehicle which has for its object to enable management of the vehicle relating to pre-operation checking, maintenance and summary of work load, etc to be conducted easily and quickly. This managing system comprises a vehicle control monitor (7) for inputting and recording information necessary for management of the vehicle from a plurality of information sources, a non-contact type recording card (27) for recording the information recorded in the vehicle control monitor (7), a card reader/writer (40) for reading out the information recorded in the recording card (27), and a printer (42) and a personal computer (43) for compiling management ledgers and displaying data on the basis of the information read out by the card reader/writer.