Abstract: A movable type ladder device for a work vehicle includes a ladder main body, a drive mechanism, and an up-and-down lock mechanism. The ladder main body has first and second end portions in a longitudinal direction thereof with the first end portion being rotatably supported with respect to the vehicle body. The drive mechanism is configured to move the ladder main body between a boarding posture and a retracted posture by rotating the ladder main body at an angle of 90 degrees. The up-and-down lock mechanism is configured to restrict the ladder main body set in the retracted posture from moving in an up-and-down direction. The rotational center axis is disposed perpendicularly to the longitudinal direction of the ladder main body set in the boarding posture in a front view, and perpendicularly to the longitudinal direction of the ladder main body set in the retracted posture in a plan view.

Abstract: A movable type ladder device for a work vehicle includes a ladder main body, a drive mechanism, and an up-and-down lock mechanism. The ladder main body has first and second end portions in a longitudinal direction thereof with the first end portion being rotatably supported with respect to the vehicle body. The drive mechanism is configured to move the ladder main body between a boarding posture and a retracted posture by rotating the ladder main body at an angle of 90 degrees. The up-and-down lock mechanism is configured to restrict the ladder main body set in the retracted posture from moving in an up-and-down direction. The rotational center axis is disposed perpendicularly to the longitudinal direction of the ladder main body set in the boarding posture in a front view, and perpendicularly to the longitudinal direction of the ladder main body set in the retracted posture in a plan view.

Abstract: An attachment coupler includes a first arm and a second arm, each including a U-shaped portion, and upper portions of the first and second arms being swingably connected by a swing shaft, and an expansion-contraction tool which opens and closes the first and second arms around the swing shaft as a fulcrum. A locking member provided with a cam and a hook provided with a cam follower are rotatably provided on the second arm. A state in which a free end of the hook is removed from an opening of the U-shaped portion is maintained by engagement of the cam and the cam follower during contraction of the expansion-contraction tool. The cam follower is driven by the cam along with rotation of the locking member during expansion of the expansion-contraction tool, thereby causing the free end of the hook to advance toward the opening of the U-shaped portion.

Abstract: An attachment coupler includes a first arm and a second arm, each including a U-shaped portion, and upper portions of the first and second arms being swingably connected by a swing shaft, and an expansion-contraction tool which opens and closes the first and second arms around the swing shaft as a fulcrum. A locking member provided with a cam and a hook provided with a cam follower are rotatably provided on the second arm. A state in which a free end of the hook is removed from an opening of the U-shaped portion is maintained by engagement of the cam and the cam follower during contraction of the expansion-contraction tool. The cam follower is driven by the cam along with rotation of the locking member during expansion of the expansion-contraction tool, thereby causing the free end of the hook to advance toward the opening of the U-shaped portion.

Abstract: A safety device for a device for fastening an attachment such as a bucket to the leading end of the arm of a power shovel is disclosed. Even if negligence and erroneous operation occur in combination, the attachment can be prevented from dropping from the arm end. To this end, mounting pins provided for the attachment are inserted into a pair of receiving recess portions which are arranged such that their openings face each other or their backs face each other and this inserted condition is maintained by hydraulic power. The fastening device includes: engagement metal fittings retractably attached in the vicinity of the receiving recess portions and having projections that are projectable into the openings of the recess portions; and lock members for engaging the engagement metal fittings, with their projections projecting into the openings.

Abstract: The present invention relates to a machine tool maintenance system, which evaluates and controls the static and/or dynamic characteristics by operating the machine, whereby the static and/or dynamic characteristics of the machine tool 20 can be evaluated and controlled at a user side, and in addition, preventive measures can be taken based on the obtained results of evaluations.