Abstract: A movable backing system enables it to continuously, easily perform full penetration welding along a weld line in a confined space, irrespective of the length, configuration and other factors of a weld zone. A weld backing, which has a backing member disposed on the side facing a workpiece and cooling means disposed inside the weld backing for cooling the backing member, is so supported on a wheeled carriage as to be movable toward the workpiece. The weld backing is provided with follower elements which are always in contact with the underside of the workpiece and which turn following the movement of the workpiece to keep a predetermined gap between the underside of the workpiece and the weld backing so that desired bead thickness can be obtained. The wheeled carriage is moved synchronously with the movement of the welder to continuously perform full penetration welding.

Abstract: A plasma torch, capable of cutting in a dross free state, is made possible by increased energy density of the arc jet. The operation efficiency is not reduced even with a low operating gas flow rate, since the arc jet can be stably maintained in the plasma torch. The torch has a high double arc resistance and excellent durability. This is realized by forming a velocity reduction space N from near a lower end (3b) of the electrode (3) to a nozzle (9) at the front end of the plasma torch (1), the velocity reduction space being used for reducing the axial velocity component of the operating gas which flows along the outer periphery of an electrode (3). The velocity reduction space (N) is cylindrically shaped, and the diameter (Dd) of the cylindrical shape is larger than the diameter (da) of a lower end (3b) of the electrode (3).

Abstract: The thermal load on a transmission clutch, which is generated when a shift between forward and reverse is made, can be reduced and a shock from a speed change can be eliminated. To these ends, as soon as a speed change signal is received (step 150), an all clutch control system (ACC) is actuated to set a target acceleration in terms of the amount of control (steps 152, 154). Then, it is determined whether the speed change involves a shift between forward and reverse (FR speed change) (step 156). If the speed change is found to be the FR speed change, then it is further determined whether the vehicle speed V is larger than a reference value V.sub.O (step 158); if the vehicle speed is larger than the reference value, then the oil pressure for operating a steering brake is read from preestablished map data (step 160), and the steering brake is operated by the oil pressure which has been read (steps 162, 164). After that, the ACC control program goes back to step 156.

Abstract: A transfer press, capable of being easily transported, capable of being adjusted flexibly to changes in specifications, and capable of eliminating the idling of the transfer feeder, has a body (1) which is divided into a bed (2), uprights (3) provided vertically upon the bed, a pair of supporting beams (4) provided upon the uprights and disposed in spaced relationship with each other in a horizontal direction perpendicular to the direction in which a workpiece is fed, and a plurality of pressing units (5) each of which is independently provided for a respective one of a plurality of pressing operations. Each of the pressing units (5) comprises a crown (6) accommodating a slide-driving mechanism (8), and a slide (7). The crowns (6), provided for the individual pressing operations, are removably mounted upon the supporting beams (4). Slide guides (12) for guiding the vertical motion of the slides (7) are also provided on the supporting beams (4).

Abstract: A serial controller in which nodes to which are connected one or plurality of sensors and one or a plurality of actuators are connected in series in the form of a closed loop including a main controller which sends data frame signals including a first special code, a second special code and output data for the actuators. The main controller measures and controls the time interval for sending the data frame signals and selecting a broken-line detection time setting in order to improve the transmission efficiency and to carry out the control in real time.

Abstract: A laser marking apparatus, capable of marking at a high scanning speed, effectively utilizing a laser power, and providing high marking accuracy, irradiates an incident laser beam from a laser beam source onto a marking surface by raster-scanning through a raster scanning system. The raster scanning system includes an X-direction polarizing mirror, a Y-direction polarizing mirror, a field lens, and a mask. A double polarizing prism, which includes a pair of polarizing prisms (13a, 13b) for branching the incident laser beam (1) into twin laser beams, is arranged in series at an intermediate position between the laser beam source (2) and the upstream one of the X-direction polarizing mirror (3) and the Y-direction polarizing mirror (8).

Abstract: A motor grader includes a work implement operating device which permits operation of a plurality of direction control valve with reduced number of operation levers. The motor grader includes a wheeled body for traveling and carrying at least one work implement, at least one operation lever operable in a first direction for electrically generating a first operation command signal and a second direction perpendicular to the first direction for generating a second operation command signal and a mode selector selectable at least between a first mode and a second mode for generating a mode selection signal. A controller receives the first and second operation command signals and the mode selection signal for controlling different motor grader functions depending upon an input combination of the first and second operation command signals and the mode selection signal.

Abstract: A working tool unit of a construction machine, which excels in transportability and is capable of smoothly carrying out diversified types of work in a wide range, is disclosed. Therefore, the working tool unit according to the present invention includes: a first boom (31a) rockably mounted on a turning frame of a vehicle body; a second boom (3b) mounted to be rockable on the first boom; an arm (32) mounted to be rockable on the second boom; a working tool such as a bucket (33) mounted on said arm; a first boom cylinder (35) mounted on the turning frame (21) and the second boom to rock the second boom; a second boom cylinder (36) mounted on the second boom and the first boom to rock the second boom; and an arm cylinder (37) mounted on the second boom and the arm to rock the arm.

Abstract: A vehicle body levelling device for a working vehicle having outriggers 5 provided at the front and rear of a self-propelled lower running body 1 for stabilizing the vehicle body while in service wherein the inclinations of the vehicle body in the front to rear and left to right directions thereof are detected by means of a front to rear inclination detector 13 and a left to right inclination detector 14, respectively, and the lengths of the front, rear, left and right outrigger arms 6 are detected by outrigger length detectors 18 so as to calculate by a controller 10 required amount of extension of piston rods of the left and right jack cylinders 7 provided on the front and rear outriggers 5, and wherein a control valve 15 provided on each of the jack cylinders is controlled in accordance with results of the calculation, whereby the vehicle body can be levelled in a short period of time even on an inclined place.

Abstract: When objects of crushing are clogged between a bottom plate and a crusher, a locking of the bottom plate that may ensue is automatically released in a self-propelled crushing machine. The machine comprises a feeder hydraulic motor (54) for reciprocating the bottom plate of a hopper and a feeder valve (50) for supplying a first port (54a) and a second port (54b) of the feeder hydraulic motor (54) with a pressurized discharged fluid from a hydraulic pump. The feeder valve (50) takes a first position (B) upon a first solenoid (55) thereof being electrically energized and takes a second position (C) upon a second solenoid (56) thereof being electrically energized. a keep relay (59) electrically energizes the first solenoid (55) and the second solenoid (56) by passing an electric current through each of them, and a first pressure switch (57) and a second pressure switch (58) are turned on when a pressure of the first port (54a) and a pressure of the second port (54b) exceeds a set pressure, respectively.

Abstract: A door opening of an operator cab for a construction machine is enlarged so that protrusion of the door beyond a turning radius can be avoided when the door is fully opened and so that the operator cab can have a wide indoor space. Therefore, a side wall (2a) of the operator cab (2) at an opposite side to a boom of a working-machine installed on a swivel base (1) is formed to have an outer convex surface, including the door; rails (4, 5 and 6) are provided on the side wall (2a) of the operator cab (2); the door (3) is provided with rollers (7, 8 and 9) which are always engaged with the rails to slide the door for easy opening and closing operation, and the position of the door (3) when the door is locked fully open is set to be within a range of turning radius (R) of the swivel base (1) along the outer surface of side wall (2a) of the operator cab (2).

Abstract: An apparatus controls a pressure in a cylinder chamber of a hydraulic pump-motor. The cylinder chamber is formed by fitting a piston in a cylinder bore of a rotatable cylinder block, and the cylinder block is rotated so that ports going to the cylinder chambers are alternatively opened to a high pressure port and a lower pressure port that are both formed in a valve plate. The apparatus includes a first switching port formed at a top dead point side of the valve plate, the first switching port being communicated with a tank through a first open-close valve. A second switching port is formed at a bottom dead point of the valve plate, the second switching port being communicated with the high pressure port through a second open-close valve.

Abstract: A lock-up clutch by way of which input/output shafts of a torque converter are operatively connected to each other is connected to an electronic type pressure control valve. During speed changing in a transmission, the problem of interruption of torque transmission can be solved by turning off the lock-up clutch at the time when filling of one of the speed changing clutches to be next brought into an operatively engaged state with hydraulic oil is completed. Hydraulic pressure (P.sub.t) in the torque converter is exerted on the back 100 pressure portion of a piston of the lock-up clutch while hydraulic pressure (P.sub.t) in the torque converter is exerted on the proportional solenoid side of the pressure control valve, making it possible to reduce the initial hydraulic pressure. During speed changing, the lock-up clutch is not fully released from the engaged state but maintains its operative state at low pressure, causing shock from shifting the lock-up state to be reduced.

Abstract: A plasma torch can produce a uniform and intense swirl in the operating gas, and as a result further stabilize the output of the plasma jet, which results in good cutting quality, so as to extend the life of consumables or the like. This is achieved when jet ports (3) from which operating gas G is ejected are positioned such that in a transverse cross-section (2A) of a swirler (50) including the jet ports (3), a relationship between a diameter D of a swirler chamber and a minimum distance (d) from a line (2b), which is tangent to the diameter D of the swirler chamber and parallel to a projected line (3c) of an axis (3b) of the jet hole (3a), to the side end (2c), of the side of the jet port (3) adjacent to the tangential line (2b), is represented by 0<d/D.ltoreq.0.03.

Abstract: A geared steering system, which is capable of actuating rightside and leftside driving mechanisms to ensure efficient operation of a crawler vehicle, has a geared steering device (30) and a control system. The geared steering device (30) has one power input shaft (31), leftside and rightside steering brakes (38L, 38R) and leftside and rightside direct-coupled clutches (36, 44), one turn clutch (46), three planet gear trains (40, 43, 48), leftside and rightside power output shafts (32L, 32R) coupled to leftside and rightside steering brake hubs (34L, 34R), and a hydraulic turning motor (83) coupled to the turn clutch (46) with gears.

Abstract: A three-dimensional image measuring device which comprises a light source; a plane image forming unit for forming a plane image in a space in its depth direction on the basis of light emitted from the light source; a scanning unit for moving and scanning the plane image formed by the plane image forming unit in its depth direction; an object to be measured disposed in the space,where the plane image is formed; a light receiving unit for measuring strength of light scattered on a surface of the object as the plane image is moved and scanned and; a distance measuring unit for measuring the distance to the Object on the basis of the output of the light receiving unit, whereby a three-dimensional image with least reduced invisible area is easily and accurately measured in a short time without using the principle of triangulation.

Abstract: In a four-wheel drive traveling system for a tipper, an output side of an engine is connected to rear wheels via a power transmission, at least one variable hydraulic motor for driving the front wheels and a hydraulic pump driven by the engine are provided, and the variable hydraulic pump and the variable hydraulic motor are connected into a closed circuit. The system includes arrangements for controlling displacement of the variable hydraulic pump, for detecting slippage of the rear wheels, for setting a discharge pressure of the hydraulic pump between a high pressure and a low pressure, and for controlling the displacement of the variable hydraulic pump so that the discharge pressure is a low pressure while slippage is not caused for the rear wheels and so that the discharge pressure is a high pressure while slippage is caused for the rear wheels.

Abstract: A load control unit for a bulldozer, comprising an actual tractive force detector for detecting the actual tractive force of a vehicle body; target tractive force setting switch for setting a target tractive force for an automatic blade control mode in dozing operation; and blade controller for controlling a blade to be lifted or lowered such that if there is a difference between the actual tractive force detected by the actual tractive force detector and the target tractive force set by the target tractive force setting switch when digging is started with the automatic blade control mode in dozing operation, the actual tractive force gradually comes closer to the target tractive force.

Abstract: The present invention provides a spacious operation cabin of a construction machine which has a large opening for a door, and which prevents the door from jutting out of the turning radius of the cabin when the door is opened. The outer side (2a) of the operation cabin (2) opposite to a working equipment boom installed on a turntable (1) is formed into an outwardly curved arc including the door (3), and the door (3) is adapted to be freely slidable with rails and rollers which are appropriately positioned. The position of the door (3) when it is opened is controlled to be within the turning radius (R) of the turntable.

Abstract: An apparatus for guiding the traveling of a moving body along a predetermined traveling path with a high degree of accuracy by accurately and reliably determining a corrected position and a corrected traveling direction of the moving body. A moving distance of the moving body between points of reception of light beams is obtained by a counter, and a CPU calculates a corrected position of the moving body by using an angle formed by the projecting directions of the light beams, the position of installation of a reflecting mirror, and an estimated traveling direction obtained on the basis of an output of a rate gyro. A corrected traveling direction is then calculated by using the corrected position thus calculated. The corrected position is calculated by using the traveling direction thus estimatively calculated.