A vehicle crane having a boom that can be luffed between a storage position and a working position within a vertical luffing plane by at least two luffing cylinders The luffing cylinders that lie opposite one another on the luffing plane, enclosing a spread angle between their longitudinal axes in the working position, and the luffing cylinders acting on the boom outside its ends. The longitudinal axis, projected onto the luffing plane, of one luffing cylinder and a vertical direction extending within the luffing plane enclose an angle of inclination there between when the boom is in the storage position to achieve a compact design, particularly when the boom is in the storage position.

A fall protection device configured to retain and prevent the fall of a connecting pin used for an end-to-end assembly of two frame elements of a structure, the fall protection device includes a clamping collar having at least one internal groove, configurable between an open position capable of authorizing the insertion of an enlarged head of the connecting pin, and at least one closed position capable of locking the enlarged head inside the internal groove. The device further includes a lock cooperating with the clamping collar to lock the clamping collar in the closed position and a mooring link anchored on the clamping collar to moor the device on a fixed element.

A fall protection device configured to retain and prevent the fall of a connecting pin used for an end-to-end assembly of two frame elements of a structure, the fall protection device includes a clamping collar having at least one internal groove, configurable between an open position capable of authorizing the insertion of an enlarged head of the connecting pin, and at least one closed position capable of locking the enlarged head inside the internal groove. The device further includes a lock cooperating with the clamping collar to lock the clamping collar in the closed position and a mooring link anchored on the clamping collar to moor the device on a fixed element.

In a lower travelling body of a mobile crane, each of a right front coupling member and a right rear coupling member is arranged to change a relative position to one or both of a right crawler frame and a car body in order to reduce dimensions of the lower travelling body when it is transported. Each of a left front coupling member and a left rear coupling member is arranged to change a relative position to one or both of a left crawler frame and the car body in order to reduce dimensions of the lower travelling body when it is transported.

The invention relates to a tread device for walking on a crawler carrier of a work machine having a caterpillar drive, wherein the tread device has a holder that can be installed at the crane, in particular at the crawler carrier, at which at least one tread surface is provided, characterized in that the tread surface lies on the upwardly disposed surface of a crawler chain of the caterpillar drive in the state installed at the work machine and the lower side of the tread surface comprises at least one sliding element to ensure a sliding or rolling relative movement between the crawler chain and the tread surface.

The present invention relates to a process for the automatic movement of the boom system of a crane, in particular a mobile crane, with at least two boom elements. The process includes the following steps: measuring of at least one control parameter and in particular automatic actuation of at least one drive of the boom system depending on the measured control parameter.

The present invention relates to a process for the automatic movement of the boom system of a crane, in particular a mobile crane, with at least two boom elements. The process includes the following steps: measuring of at least one control parameter and in particular automatic actuation of at least one drive of the boom system depending on the measured control parameter.

The present disclosure relates to a method for operating a crane with a traversable undercarriage, an uppercarriage rotatably mounted on the same with luffing main boom and derrick boom arranged thereon, wherein an auxiliary crane with telescopic boom as derrick ballast is connected with the crane and via the telescopic boom of the auxiliary crane the derrick ballast radius is adjusted. According to the present disclosure, a suspended ballast is lifted in addition to the auxiliary crane provided as derrick ballast for erecting the main boom, wherein first the auxiliary crane is lifted, before the suspended ballast is lifted, when necessary. The present disclosure also relates to a crane for carrying out the method.

The present disclosure relates to a method for operating a crane with a traversable undercarriage, an uppercarriage rotatably mounted on the same with luffing main boom and derrick boom arranged thereon, wherein an auxiliary crane with telescopic boom as derrick ballast is connected with the crane and via the telescopic boom of the auxiliary crane the derrick ballast radius is adjusted. According to the present disclosure, a suspended ballast is lifted in addition to the auxiliary crane provided as derrick ballast for erecting the main boom, wherein first the auxiliary crane is lifted, before the suspended ballast is lifted, when necessary. The present disclosure also relates to a crane for carrying out the method.

A track hitching structure is for a wheeled crane and the wheeled crane, and includes a vehicle frame and a connecting cross beam. The first end of the connecting cross beam is connected with a track. The second end of the connecting cross beam is connected with the vehicle frame. The second end of the connecting cross beam is higher than the first end of the connecting cross beam. The vehicle frame is connected with the track by the connecting cross beam with one high end and one low end, so the long-distance force transfer from the track to the race of the vehicle frame can be handled, then the shortcomings of tedious structure, large size, large weight and the like of the connecting device caused by a horizontal connecting cross beam are avoided, and the reliability and the working performance of the entire crane are improved.