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).

The present invention relates to a method for weathervaning of a crane which has a boom which can rotate about a vertical axis, a slewing gear motor and a slewing gear service brake for securing the boom in a rotational position with a securing torque in the crane mode, wherein in the case of a crane which has been out-of-operation, the boom is braked against rotation with an out-of-operation mode braking torque which is less than said securing torque in the crane mode. In this respect, the invention also relates to such a crane itself, in particular in the form of a revolving tower crane. In accordance with the invention, the out-of-operation mode braking torque is kept at least approximately constant over the range of the speed of rotation and over the range of the angle of rotation of the boom.

A Building Element Lift Enhancer is described. The Building Element Lift Enhancer provides for the movement and precise placement of building elements such as blocks or sheet products by one worker. The Building Element Lift Enhancer senses the force applied by a user to the building element and converts that user applied force to mechanically assisted force from the Building Element Lift Enhancer, allowing the user to precisely move and handle large, heavy or bulky building elements by direct interaction with the building element.

A watercraft may include a crane for lifting loads. The crane may include a tower and a boom that is rotatble with respect to the tower. The tower may be positioned inside the outer contour of the watercraft so as to minimize the profile of the watercraft on radar. The watercraft may include a superstructure within which the tower may be disposed. The superstructure may include planar outer walls that are obtuse relative to a horizontal plane. A rotary bearing may be utilized to connect the boom to the tower and permit the boom to rotate relative to the tower. Further, when the boom is in a rest position, a lower edge of the boom may be positioned 10 cm or less above the crane deck.

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.

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.

An electric motorization system includes a motorized unit equipped with a motor provided with a rotor and stator assembly including several coils, and a frequency converter which is electrically powered by a power supply. The frequency converter is controlled by a monitoring/control unit for turning on the motor in a variable speed operating mode, or for turning off the motor. The electric motorization also includes a measurement system suitable for measuring at least one condensation parameter which is representative of a condensation of the water contained in an ambient air, and the monitoring/control unit is configured to, depending on said condensation parameter, control the frequency converter during the turning off of the motor so that a preheating electric current flows through the coils to activate a preheating of the motor when it is turned off.

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.

A jib crane that includes an open column having a first end and a second end opposite to the first end that is adapted to operably engage with a ground surface. The jib crane also includes at least one interior space collectively defined by the open column between the first end and the second end. The jib crane also includes a crane beam operably engaged with the open column at the second end of the open column. The jib crane also includes a bearing assembly operably engaged with the crane beam and the open column, and the bearing assembly has at least one bearing positioned inside of the at least one interior space defined by the open column.

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.