An arrangement in a boom system, specifically in a forest machine, includes at least two interlinked boom parts and at least one power transmission connected to the boom parts for moving the boom parts in relation to each other and the environment. The boom part includes an elongated body with a hollow structure and at least one set of joints intersected by turning axles for attaching the boom part to an adjacent structure, and at least one set of attachments for attaching an actuator controlling the boom system to the body, whereby at least one boom part is formed as a uniform, hollow piece made of fluid material. The cross-section of the body is made to cinch toward the midpoint of the body.

An improved knuckle boom crane apparatus provides a supportive base and a frame attached to the base, the frame including a cabin with an interior. A prime mover is supported upon the frame. A main boom is pivotally attached to the frame at a first boom end portion, the main boom having a second end portion. A jib boom is provided having first and second end portions, the jib boom first end portion being pivotally attached to the main boom second end portion, the jib boom second end portion being a free end portion. A main block is attached to the main boom and depending from the main boom second end portion. An auxiliary block is attached to the jib boom and depending from the jib boom second end portion. A main block parking area is provided next to the connection of main boom and jib boom that enables the main block to be parked when using the auxiliary block of the jib boom. The parking area enables the jib boom auxiliary block to lift a selected package without dismantling of the main block. The jib boom articulates relative to the main boom with a specially configured rack gear and pinion gear arrangement or interface.

An improved knuckle boom crane apparatus provides a supportive base and a frame attached to the base, the frame including a cabin with an interior. A prime mover is supported upon the frame. A main boom is pivotally attached to the frame at a first boom end portion, the main boom having a second end portion. A jib boom is provided having first and second end portions, the jib boom first end portion being pivotally attached to the main boom second end portion, the jib boom second end portion being a free end portion. A main block is attached to the main boom and depending from the main boom second end portion. An auxiliary block is attached to the jib boom and depending from the jib boom second end portion. A main block parking area is provided next to the connection of main boom and jib boom that enables the main block to be parked when using the auxiliary block of the jib boom. The parking area enables the jib boom auxiliary block to lift a selected package without dismantling of the main block. The jib boom articulates relative to the main boom with a specially configured rack gear and pinion gear arrangement or interface.

The present disclosure discloses an operating method of a wind power jib of a crane and a crane, and relates to the field of engineering machinery. The method includes the following steps: rotatably connecting a main boom and a wind power jib; overturning the wind power jib to a first preset position by using a traction means of the crane; contacting a cushioning member with the wind power jib provided at the first preset position; further drawing the wind power jib to overturn to a second preset position; releasing the traction means, such that the wind power jib overturns automatically under the effect of self gravity and a cushioning member until the wind power jib is overturned in position.

The present disclosure discloses an operating method of a wind power jib of a crane and a crane, and relates to the field of engineering machinery. The method includes the following steps: rotatably connecting a main boom and a wind power jib; overturning the wind power jib to a first preset position by using a traction means of the crane; contacting a cushioning member with the wind power jib provided at the first preset position; further drawing the wind power jib to overturn to a second preset position; releasing the traction means, such that the wind power jib overturns automatically under the effect of self gravity and a cushioning member until the wind power jib is overturned in position.

A pin puller is mounted between first and second connectors, preferably connectors on a lift crane, each of the connectors having a hole there though. The pin puller includes: a) first and second support frame members; b) a first pin with a first end located in the hole of the first connector and a second end inside the first support frame member; c) a second pin with a first end located in the hole of the second connector and a second end inside the second support frame member; d) at least one linear actuator connected to the first and second pins; and e) a length adjustment device between the first and second support frame members, with its length adjusted so as to force the first support frame member into contact with the first connector and the second support frame member into contact with the second connector.

A pin puller is mounted between first and second connectors, preferably connectors on a lift crane, each of the connectors having a hole there though. The pin puller includes: a) first and second support frame members; b) a first pin with a first end located in the hole of the first connector and a second end inside the first support frame member; c) a second pin with a first end located in the hole of the second connector and a second end inside the second support frame member; d) at least one linear actuator connected to the first and second pins; and e) a length adjustment device between the first and second support frame members, with its length adjusted so as to force the first support frame member into contact with the first connector and the second support frame member into contact with the second connector.

An articulated boom includes a plurality of boom segments connected together via articulated joints. At least one of the boom segments includes a welded structure providing a box profile in which an upper flange and a lower flange are connected together by lateral web plates. At least one of the web plates, the upper flange, and the lower flange includes at least one reinforcing distortion.

An articulated boom includes a plurality of boom segments connected together via articulated joints. At least one of the boom segments includes a welded structure providing a box profile in which an upper flange and a lower flange are connected together by lateral web plates. At least one of the web plates, the upper flange, and the lower flange includes at least one reinforcing distortion.

The present disclosure relates to a foldable truss boom section, a truss boom and a crane. The foldable truss boom section includes: two chords that do not intersect with each other; at least two slideways fixedly disposed on each of the two chords, wherein each of the at least two slideways has at least two slideway fixing points; and at least two long web members connecting the two chords, wherein each of the at least two long web members has at least one sliding end which is slidable along the slideway and connected to the slideway at one of the at least two slideway fixing points, so that a cross-section state of the truss boom section is changeable.