Abstract: A hook device includes a central shaft which extends in a first direction, and a first locking portion and a second locking portion which are disposed such that the central shaft is interposed therebetween, in a second direction orthogonal to the first direction. The first locking portion and the second locking portion are connected to the central shaft in a state where the first locking portion and the second locking portion are not rotatable independently around an axis extending in the first direction and are rotatable around an axis extending in a third direction different from the first direction and the second direction.

Abstract: A crane includes: a boom; a jib; a front post that is swingably attached to a tip end side of the boom; a rear post that is swingably attached to the tip end side of the boom; a post-side pendant member, with one end of the post-side pendant member being attached to a tip end of the rear post; a boom-side pendant member, with one end of the boom-side pendant member being attached to another end of the post-side pendant member, and another end of the boom-side pendant member being attached to the boom; and a post driving device having a link mechanism that rotates the rear post in a range including a position at which the rear post is swung down to the front post side and a position at which the rear post is swung down to the boom side, while the boom is held down in a horizontal position.

Abstract: A crane includes: a boom; a jib; a front post that is swingably attached to a tip end side of the boom; a rear post that is swingably attached to the tip end side of the boom; a post-side pendant member, with one end of the post-side pendant member being attached to a tip end of the rear post; a boom-side pendant member, with one end of the boom-side pendant member being attached to another end of the post-side pendant member, and another end of the boom-side pendant member being attached to the boom; and a post driving device having a link mechanism that rotates the rear post in a range including a position at which the rear post is swung down to the front post side and a position at which the rear post is swung down to the boom side, while the boom is held down in a horizontal position.

Abstract: A counterweight suspension device includes a pair of suspension cylinders that suspends a counterweight and that are hung from first and second hanging points provided separately in a left and right direction at a top end of a rear mast. A coupling member couples cylinder rod ends of the pair with each other. A lifting member lifts the counterweight. First and second connection points of the counterweight are connected with each of the cylinder rod ends, with the first and the second connection points provided separately in the left and right direction on the counterweight for attaching the lifting member to the counterweight. A first communication circuit is provided through which rod chambers of the suspension cylinders communicate with each other. A second communication circuit is provided through which bottom chambers of the suspension cylinders communicate with each other.

Abstract: A rotating superstructure includes: a front block on which a power unit that includes a prime mover; and a rear block on which a unit for raising and lowering a boom that includes a winch, a, and an arm. And the rotating superstructure is configured to be split into the front block and the rear block.

Abstract: A counterweight suspension device includes: a pair of suspension cylinders that suspends a counterweight, and that are hung from a first and a second hanging points provided separately in a left and right direction at a top end of a rear mast; a coupling member that couples cylinder rod ends of the pair of suspension cylinders with each other; a lifting member for lifting the counterweight, that connects a first and a second connection points of the counterweight with each of the cylinder rod ends of the pair of suspension cylinders, with the first and the second connection points provided separately in the left and right direction on the counterweight for attaching the lifting member to the counterweight; a first communication circuit through which rod chambers of the pair of suspension cylinders communicate with each other; and a second communication circuit through which bottom chambers of the pair of suspension cylinders communicate with each other.

Abstract: A rotating superstructure includes: a front block on which a power unit that includes a prime mover; and a rear block on which a unit for raising and lowering a boom that includes a winch, a, and an arm. And the rotating superstructure is configured to be split into the front block and the rear block.

Abstract: A durable door opening/closing mechanism that does not require a large space for opening and closing operation such that a door and a main body such as a cab, can be freely designed. To achieve this, the door is supported by links coupled to the cab by joints. One end of the door is guided along the side of the cab by a guide rail. When a rail support begins moving along the side of the cab while being guided by the guide rail, a couple of forces, causing the door to rotate, act on the joints at both ends of the links. The other end of the door is swung out of the cab towards the outside by the couple of forces.

Abstract: The present invention aims at providing a durable door opening/closing mechanism that does not require a large space for opening and closing operation and that a door and main body can be freely designed. To achieve this, a door is supported by links coupled to a cab by joints. One end of the door is guided along the side of the cab by a guide rail. When a rail support begins moving along the side of the cab while being guided by the guide rail, a couple of forces, causing the door to rotate, act on the joints at the both ends of the links. The other end of the door is swung out of the cab toward outside by the couple of forces, and the track is regulated into an arc form by the rod.