A portable apparatus, and methods to operate the apparatus, comprising a base that securely engages with a tire, a motor support structure, an electric motor coupled to an electrical power source, a pulley system, one or more attachment devices, and an electrical motor control device utilized to raise and lower a windshield (or other component) from a vehicle.

A rotating tower crane for erecting a wind turbine, having a tower and a tower substructure, which is connected to the tower and is intended for supporting the tower, wherein the tower substructure has a supporting cross frame, which has three or more, preferably four, legs, extending from the tower. It is proposed that each leg has fastened on it, on the ground side, a load-distributor plate, which is not connected to the foundation, wherein the load-distributor plates together form the ballast of the tower.

A rotary crane including a vertical axis; an jib that extends from the vertical axis; a drive for rotating the jib about the vertical axis; a condition monitoring which determines wind loading, namely internal force variables, tensions, strains, transverse forces, tilting and torsion torques of the rotary crane; and a computing unit which computes a preferred direction for locking the jib from the wind loading. The invention also relates to a method for orienting the rotary crane. In order to improve the orientation of the jib of a shut down rotary crane it is proposed that the rotary crane includes measuring elements for capturing local measuring local values of the wind loading.

A motor assembly includes a three-phase asynchronous machine equipped with three stator phases, a capacitor assembly to establish self-excited generator operation of the asynchronous machine, a load resistor assembly to establish resistive load for self-excited generator operation of the asynchronous machine, and a load resistor switch which is arranged to connect the load resistor assembly to the stator phases. The load resistor assembly is asymmetrical.

A jib crane, having a low-weight boom with a proximate end, a distal end, a top, a bottom, and a first length between the proximate and distal ends. A high-strength brace extends along the top of the boom from the proximate end by a second length. The boom is mountable to a support structure by way of the brace. The second length may be less than the first length and the brace is attached to the top of the boom and to a pivoting bracket, which is pivotably mounted to the support structure.

In some embodiments, a davit arm system comprises a davit body arranged to engage a support and an arm supported by the davit body. The arm is moveable along a length of the davit body. In some embodiments, a bearing is oriented between said arm and said davit body. In some embodiments, a bearing a polymer sleeve. In some embodiments, a bearing comprises rollers. In some embodiments, a bearing comprises ball transfer bearings. In some embodiments, a bearing excludes moving parts.

This disclosure provides a system and method for limiting a swing angle of a jib crane, the jib crane having a jib rotatably mounted to a mast. The device can have a collar having a collar height and a collar width, the collar being configured to be fit to the mast at a stop height. The device can also have one or more stopping tabs enagagable with the collar and configured to be positioned on the collar at one or more points about a circumference of the mast. The stop height can place the one or more stopping tabs in a position coincident with the jib to interfere with the swing angle of the jib. The method can use the device to limit the angle through which the jibe crane can swing unimpeded.

The present invention relates to a crane tower comprising a crane tower base, which has a crane tower or a crane tower element fixed thereto and from which the crane tower extends upwards, and a tension element for bracing the crane tower 1 on the crane tower base. The tension element has one of its two ends connected to the crane tower base and its respective other end connected to the crane tower or to a coupling element that is connected to the crane tower. The crane tower is characterized in that the tension element extends outside of the crane tower. It is thus possible to reduce the dimensions of the crane tower without causing any change of bending resistance or to increase the bending resistance on the basis of the same dimensions.

The present invention relates to a crane tower comprising a crane tower base, which has a crane tower or a crane tower element fixed thereto and from which the crane tower extends upwards, and a tension element for bracing the crane tower 1 on the crane tower base. The tension element has one of its two ends connected to the crane tower base and its respective other end connected to the crane tower or to a coupling element that is connected to the crane tower. The crane tower is characterized in that the tension element extends outside of the crane tower. It is thus possible to reduce the dimensions of the crane tower without causing any change of bending resistance or to increase the bending resistance on the basis of the same dimensions.

The invention relates to a crane, in particular a rotary tower crane, comprising a crane boom, from which a load hook can be raised and lowered via a hoist cable, and an electric power supply on the load hook and/or an optionally provided trolley which can be moved on the crane boom. According to the invention, the electric power is directly generated at the location where it is required, and in the process kinetic energy present at said location is converted into power. According to the invention, the electric power supply comprises a generator which is arranged on the load hook and/or on the trolley and which can be driven by a deflecting and/or running pulley and/or a cable running around the deflecting pulley.