Hoists, platforms and davits are described as well as methods of securing same to telecommunication and other towers. The hoists, platforms and davits may be secured to the towers on a temporary basis using clamps. The clamps may include brackets and cables. The cables may be attached to the brackets, may wrap around the outer surface/perimeter of the tower pole/leg and may use tension to keep the bracket in place.

The invention relates to a method of weathervaning a work machine in out-of-operation mode, in particular of weathervaning a revolving crane/revolving tower crane or a concrete spreader mast, wherein the work machine comprises at least one slewing part that is rotatable about a substantially vertical axis by means of a slewing gear, and wherein in a first step one or more wind data are measured by means of a measurement system arranged at the work machine; an optimum position of the slewing part is determined for an optimum weathervaning in dependence on the detected wind data; and the slewing gear drive is subsequently correspondingly actuated to bring the slewing part into the determined position.

The invention relates to a method of weathervaning a work machine in out-of-operation mode, in particular of weathervaning a revolving crane/revolving tower crane or a concrete spreader mast, wherein the work machine comprises at least one slewing part that is rotatable about a substantially vertical axis by means of a slewing gear, and wherein in a first step one or more wind data are measured by means of a measurement system arranged at the work machine; an optimum position of the slewing part is determined for an optimum weathervaning in dependence on the detected wind data; and the slewing gear drive is subsequently correspondingly actuated to bring the slewing part into the determined position.

A control system for a work machine having an upper frame rotatably mounted to a lower frame includes a controller configured to limit a maximum speed of the machine when a rotation angle between the upper frame and the lower frame exceeds a first predetermined value.

A mobile crane is configured so that a boom is raised by a derrick cylinder in response to a raise signal output from a derrick lever and the derrick cylinder is stopped in response to the derrick angle of the boom reaching the maximum angle γ corresponding to the hoisted-down length of a rope.

A mobile crane is configured so that a boom is raised by a derrick cylinder in response to a raise signal output from a derrick lever and the derrick cylinder is stopped in response to the derrick angle of the boom reaching the maximum angle γ corresponding to the hoisted-down length of a rope.

The invention relates to a system for monitoring wind influences on a working machine, in particular a mobile crane or crawler crane, comprising at least one detection unit that is arranged on the working machine and by means of which a current wind speed can be detected, a recording unit that is configured to receive, to store, and to transmit data of the detection unit during and outside the operation of the working machine, a controller of the working machine that is configured to determine a current working machine state, an external processing unit that is configured to directly or indirectly receive and process data from the detection unit relating to an current wind speed and data from the controller, and an output device that is configured to receive data from the external processing unit. The controller and/or the external processing unit is/are configured here to determine a limit value for a wind speed in dependence on the current working machine state. The output device is further configured to output a warning on a reaching and/or exceeding and/or impending reaching of the limit value by the current wind speed. The invention further relates to a working machine having components of the system in accordance with the invention.

Various hoisting systems with anti-two-block sensing devices are provided. In one embodiment, an apparatus includes a crane having a hoisting line and an anti-two-block sensing device installed about the hoisting line. The anti-two-block sensing device includes an upper chandelier, a lower trigger assembly suspended from the upper chandelier, and a detector positioned to detect movement of the lower trigger assembly with respect to the upper chandelier. The lower trigger assembly can include two plates each having a hoisting line aperture and a slot that allows transverse installation of the plate about the hoisting line. Further, the two plates can be positioned such that their slots are offset from one another and the plates cooperate to fully surround the hoisting line. Additional systems, devices, and methods are also disclosed.

Various hoisting systems with anti-two-block sensing devices are provided. In one embodiment, an apparatus includes a hoisting system having a hoisting line, a sleeve positioned on the hoisting line, and an anti-two-block sensing device installed about the hoisting line so as to allow the hoisting line to move through the anti-two-block sensing device. The anti-two-block sensing device includes a detector positioned to detect a sleeve component when the sleeve is present within the anti-two-block sensing device. Additional systems, devices, and methods are also disclosed.

A height adjustment assistance device includes an initial state determination part for determining whether a suspended cargo has been lifted from a ground at a start of lifting work, a height detection part for detecting a height of a counterweight from the ground, a storage part for storing an initial height, a calculation part for calculating a target value for correcting the height of the counterweight from the ground based on the initial height and a post-work height, a notification part for notifying an operator of information regarding the target value, and a length adjustment device for adjusting a length of a hanging member by operating in a manner to change the length of the hanging member extending from a tip of a mast to the counterweight.