The invention relates to a crane, in particular a rotary tower crane, comprising a lifting cable configured to run out from a crane boom and comprises a load receiving component, drive devices configured to move multiple crane elements and displace the load receiving component, a controller configured to control the drive devices such that the load receiving apparatus is displaced along a movement path, and a pendulum damping device configured to dampen pendulum movements of the load receiving apparatus and/or of the lifting cable. The pendulum damping device comprises a pendulum sensor system configured to detect pendulum movements of at least one of the lifting cable and the load receiving component and a regulator module comprising a closed control loop configured to influence the actuation of the drive devices depending on a pendulum sensor system signal returned to the control loop.

A tower crane configured to fold and unfold between a working configuration and a transport configuration includes a boom hinged in rotation relative to a mast about a main axis of rotation. The tower crane includes a rear retainer fastened to a frame supporting the mast and to a stanchion. The stanchion extends the boom rearwardly of the main axis of rotation and is displaceable relative to the boom between a working position and a transport position. The tower crane further includes a lifting cable connected to a winding device exerting, on the lifting cable, a tension force applied on stanchion by a return system configured to cooperate with the lifting cable, so as to cause displacement of said stanchion from the working position to the transport position.

A tower crane configured to fold and unfold between a working configuration and a transport configuration includes a boom hinged in rotation relative to a mast about a main axis of rotation. The tower crane includes a rear retainer fastened to a frame supporting the mast and to a stanchion. The stanchion extends the boom rearwardly of the main axis of rotation and is displaceable relative to the boom between a working position and a transport position. The tower crane further includes a lifting cable connected to a winding device exerting, on the lifting cable, a tension force applied on stanchion by a return system configured to cooperate with the lifting cable, so as to cause displacement of said stanchion from the working position to the transport position.

Techniques facilitating increased operational reliability for jib cranes are provided. In one example, a jib crane can comprise a mast, a shaft mechanism, and a rod. The mast can extend vertically from a base structure. The shaft mechanism can be disposed within the mast. The rod can be coupled to a boom arm and can be disposed within the shaft mechanism. Rotation of the rod can facilitate continuous rotation of the boom arm about a longitudinal axis of the rod with respect to the base structure.

Implementations of cranes may include a first telescoping boom and a second telescoping boom coupled within the first telescoping boom. The second telescoping boom may be entirely within the first telescoping boom when the second telescoping boom is in a fully extended position.

A portable derrick system for use in hoisting and lowering loads at a plurality of job sites, comprising, in combination: a boom subassembly, a boom head subassembly, a mast support subassembly, a mast head subassembly, a load-carrying line, a winch capable of cooperating with said line, power means for driving the winch, means for pivoting the boom assembly, means for controlling said pivoting means, the foregoing elements of the invention capable of being transported by humans to elevated positions such as, without limitation, rooftops and terraces, and wherein the aforementioned are capable of repeated assembly and disassembly at a plurality of job sites and serving to facilitate the elimination of the need for a street-level crane.

This defining method comprises the steps of: —simulating a crane comprising: i) a boom made up of elements and ii) a lifting member that is able to move along the boom, —selecting several elements to be tested, maximum stresses, and several ranges along the boom, and —carrying out the following analysis steps of: •choosing a theoretical load, •calculating stresses brought about by the theoretical load in each element to be tested, •comparing these stresses with maximum stresses, •increasing or decreasing the theoretical load depending on whether stresses are less than or greater than the maximum stresses, •repeating the calculating step and the comparison step and the step of increasing or decreasing until the maximum theoretical load is found, and •recording i) the range and ii) the maximum theoretical load.

This defining method comprises the steps of: —simulating a crane comprising: i) a boom made up of elements and ii) a lifting member that is able to move along the boom, —selecting several elements to be tested, maximum stresses, and several ranges along the boom, and —carrying out the following analysis steps of: •choosing a theoretical load, •calculating stresses brought about by the theoretical load in each element to be tested, •comparing these stresses with maximum stresses, •increasing or decreasing the theoretical load depending on whether stresses are less than or greater than the maximum stresses, •repeating the calculating step and the comparison step and the step of increasing or decreasing until the maximum theoretical load is found, and •recording i) the range and ii) the maximum theoretical load.

The invention relates to a hoist mechanism (20) intended primarily, but not exclusively, for moving a motor driven wheelchair or scooter into and/or out of the load carrying space of a vehicle. The hoist mechanism (20) comprises a lifting arm having, at least in part, a generally U-shaped cross section, and an actuator (28). A mounting point (56) for the actuator (28) is provided within the generally U-shaped cross section. The invention also relates to a stepless adjustment system suitable for use in such a hoist mechanism (20). The adjustment system comprises an inner section (34) received within an outer section (24) in a telescoping arrangement. The outer section (24) comprises first and second body portions (44A, 44B) provided with features for engaging corresponding features (48A, 48B) provided on the inner section (34).

The present invention relates to a crane, in particular in the form of a revolving tower crane, having a jib (3) and a counter-jib (4), which are articulated on a jib articulation piece (8), wherein the jib (3) comprises an outer jib part (3a), which is articulated on an inner jib part (3i) in a hinged manner and is held by a guy (10). According to the invention, the inner jib part (3i) is in the form of a cantilever, which is fastened to the jib articulation piece (8) in a flexurally rigid manner and held, wherein the outer jib part (3a) is articulated on the cantilever in a hinged manner and is held by the guy (10).