The present invention relates to a process of producing a boom part from a sheet metal blank, in particular a process of producing a boom part having a bearing seat, in which the starting material is merely formed by bending. Thus, the production process is simplified. In addition, the present invention relates to a process of producing a boom that is closed at both ends by joining two boom parts produced by means of the process of the present invention. Furthermore, the present invention comprises boom parts and booms which are produced by means of one of the processes according to the present invention.

The present invention relates to a process of producing a boom part from a sheet metal blank, in particular a process of producing a boom part having a bearing seat, in which the starting material is merely formed by bending. Thus, the production process is simplified. In addition, the present invention relates to a process of producing a boom that is closed at both ends by joining two boom parts produced by means of the process of the present invention. Furthermore, the present invention comprises boom parts and booms which are produced by means of one of the processes according to the present invention.

A hydraulic system includes: a boom cylinder to move a boom; a working tool cylinder to move a working tool attached to the boom; a boom control valve to control the boom cylinder; a working tool control valve to control the working tool cylinder; a horizontal control valve having: an activating position to allow a horizontalizing operation of the working tool; and a stopping position to stop the horizontalizing operation; and a controller device having: a first information obtaining portion to obtain permission and non-permission to the horizontalizing operation; a second information obtaining portion to obtain at least one of upward operation and upward movement of the boom; and a horizontal controller to set the horizontal control valve to the stopping position when the first information obtaining portion obtains the non-permission and the second information obtaining portion obtains one of the upward operation and the upward movement.

A hydraulic system includes: a boom cylinder to move a boom; a working tool cylinder to move a working tool attached to the boom; a boom control valve to control the boom cylinder; a working tool control valve to control the working tool cylinder; a horizontal control valve having: an activating position to allow a horizontalizing operation of the working tool; and a stopping position to stop the horizontalizing operation; and a controller device having: a first information obtaining portion to obtain permission and non-permission to the horizontalizing operation; a second information obtaining portion to obtain at least one of upward operation and upward movement of the boom; and a horizontal controller to set the horizontal control valve to the stopping position when the first information obtaining portion obtains the non-permission and the second information obtaining portion obtains one of the upward operation and the upward movement.

A hydraulic excavator includes a computer-aided construction controller for performing machine control to operate a front work implement based on detected results from posture sensors and predetermined conditions. The computer-aided construction controller has a calibration posture storing section that stores at least one predetermined calibration posture of the front work implement for calibrating the posture sensors, and a calibration posture controlling section that carries out the machine control to inactivate the hydraulic actuators if detection target values of the posture sensors in the calibration posture and the detected results from the posture sensors are equal to each other. The time required for calibration can thus be shortened by increasing the operability for adjusting a calibration posture.

A hydraulic excavator includes a computer-aided construction controller for performing machine control to operate a front work implement based on detected results from posture sensors and predetermined conditions. The computer-aided construction controller has a calibration posture storing section that stores at least one predetermined calibration posture of the front work implement for calibrating the posture sensors, and a calibration posture controlling section that carries out the machine control to inactivate the hydraulic actuators if detection target values of the posture sensors in the calibration posture and the detected results from the posture sensors are equal to each other. The time required for calibration can thus be shortened by increasing the operability for adjusting a calibration posture.

A skid steer loader includes a chassis frame, a cab, a main beam, and a bucket. The chassis frame is assembled with a walking system to form a movable chassis of the skid steer loader, and a power system of the skid steer loader is assembled to a tail portion of the chassis frame. The cab is arranged on a front portion of the chassis frame in an. overturning manner, and the cab is horizontally placed on the chassis frame when a telescopic support rod is in a retracted state and overturns forward when the telescopic support rod is in an extended state. A tail end of the main beam is movably hinged to the tail portion of the chassis frame by a four-bar linkage mechanism, the bucket is assembled to a front end of the main beam.

A skid steer loader includes a chassis frame, a cab, a main beam, and a bucket. The chassis frame is assembled with a walking system to form a movable chassis of the skid steer loader, and a power system of the skid steer loader is assembled to a tail portion of the chassis frame. The cab is arranged on a front portion of the chassis frame in an. overturning manner, and the cab is horizontally placed on the chassis frame when a telescopic support rod is in a retracted state and overturns forward when the telescopic support rod is in an extended state. A tail end of the main beam is movably hinged to the tail portion of the chassis frame by a four-bar linkage mechanism, the bucket is assembled to a front end of the main beam.

A liquid pumping vehicle has: a frame; a platform rotatably mounted on the frame; an articulated boom mounted on the platform; a liquid pump mounted on the boom; and, an engine mounted on the platform, so that a rotation axis of the platform is between the boom and the engine and so that a first turning moment created on a first moment arm relative to the rotation axis by weight of the engine and other components on an engine-side of the platform is balanced under operational conditions of the pumping vehicle by a second turning moment created on a second moment arm relative to the rotation axis by weight of the boom and other components on a boom-side of the platform. The vehicle is better balanced for greater stability when in use for pumping a liquid, e.g., liquid manure.

A compact utility loader compact utility loader comprising a frame, and a loader arm configured to support an attachment. The compact utility loader additionally comprises a first link pivotably secured to the frame, a second link pivotably secured to the frame, and an actuator configured to raise and lower the loader arm. The actuator is not simultaneously secured to both the frame and the loader arm.