A mobile crane includes a main body and extendable axles, which are selectively re-positioned relative to the main body through strategically positioned apertures. The axles may be automatically locked to the main body in a desired one of the multiple positions without operator intervention. The axles one or more tapered ends for connecting to side frames, which may support crawler tracks. The tapered ends of the axles extend through openings located in the frames such that they are removably connected to an outside or exterior portion of the frames relative to the main body.

A mobile crane includes a main body and extendable axles, which are selectively re-positioned relative to the main body through strategically positioned apertures. The axles may be automatically locked to the main body in a desired one of the multiple positions without operator intervention. The axles one or more tapered ends for connecting to side frames, which may support crawler tracks. The tapered ends of the axles extend through openings located in the frames such that they are removably connected to an outside or exterior portion of the frames relative to the main body.

Provided is a working vehicle capable of efficiently cooling an engine, a torque converter oil and a hydraulic oil. There are provided an engine 11, a torque converter 12, a hydraulic working device 15 to be operated by a hydraulic oil 31, a radiator 16 for radiating heat of engine cooling water 32 for cooling the engine 11, an oil cooler 17 for radiating heat of the hydraulic oil 31, and a heat exchanger 19 for performing a heat exchange between a torque converter oil 33 to be used for the torque converter 12 and the hydraulic oil 31. The torque converter oil 33 is heat exchanged with the hydraulic oil 31. Therefore, heat of the torque converter oil 33 is radiated by the oil cooler 17 through the hydraulic oil 31. Also in a running operation, the heat can be radiated by both of the radiator 16 and the oil cooler 17, and the engine 11, the torque converter oil 33 and the hydraulic oil 31 can be cooled efficiently.

Provided is a working vehicle capable of efficiently cooling an engine, a torque converter oil and a hydraulic oil. There are provided an engine 11, a torque converter 12, a hydraulic working device 15 to be operated by a hydraulic oil 31, a radiator 16 for radiating heat of engine cooling water 32 for cooling the engine 11, an oil cooler 17 for radiating heat of the hydraulic oil 31, and a heat exchanger 19 for performing a heat exchange between a torque converter oil 33 to be used for the torque converter 12 and the hydraulic oil 31. The torque converter oil 33 is heat exchanged with the hydraulic oil 31. Therefore, heat of the torque converter oil 33 is radiated by the oil cooler 17 through the hydraulic oil 31. Also in a running operation, the heat can be radiated by both of the radiator 16 and the oil cooler 17, and the engine 11, the torque converter oil 33 and the hydraulic oil 31 can be cooled efficiently.

The present invention relates to a telescopic device of single-cylinder latch type and a crane. The telescopic device of single-cylinder latch type is applied to a telescopic boom system and includes: a telescopic cylinder, for driving telescopic boom sections of the telescopic boom system to execute a telescopic action relative to a basic boom section; double boom pin structures, arranged on both sides of the tails of the telescopic boom sections to lock and unlock the telescopic boom sections; an boom pin pulling and plugging mechanism, arranged on the cylinder barrel of the telescopic cylinder to execute pulling and plugging operations on the double boom pin structures; and a cylinder pin structure and a cylinder pin cylinder, both arranged on the cylinder barrel of the telescopic cylinder and to lock and unlock the cylinder barrel of the telescopic cylinder and the telescopic boom sections. In the present invention, the double boom pin structures are arranged on both sides of the tails of the telescopic boom sections, compared with the existing upper boom pin solution, the double boom pin structures in the present invention are arranged on both sides of the telescopic boom sections, so that the stress is more uniform compared with a structure which is singly arranged on the upper side of a telescopic boom, and the influence of flexural deformation of a telescopic boom on the position of a pin hole and the stress of an boom pin is reduced.

Provided is a construction method for a fully prefabricated multi-story concrete plant, the construction method may achieve full coverage of a hoisting operation of the large beam and column prefabricated components of a floor by employing a single intelligent hoisting robot, an angle change of the track devices, an angle change of a moving device, and a self-lifting device. It is not necessary to arrange a transition track at the turn of the installation route, which saves space and installation cost, and overcomes the disadvantage of high cost caused by the traditional prefabricated construction mode of multi-story concrete plant, which needs to arrange a plurality of large hoisting equipment. It may achieve the mechanization and intelligence of the whole construction process of the fully prefabricated multi-story concrete plant.

A cylinder retraction system causes a crawler side frame hoisting hydraulic cylinder, swingably suspended on a ventral surface side of a lower boom, to swing between a retracted attitude, in which the hydraulic cylinder is set along a ventral surface of the lower boom, and an operating attitude, in which the hydraulic cylinder is oriented along a vertical direction. As the rod of the hydraulic cylinder, currently having the operating attitude, is contracted by a predetermined extent, the rod front end of the hydraulic cylinder is guided by the guiding portion until the hydraulic cylinder takes on the retracted attitude. As the hydraulic cylinder, currently having the retracted attitude, is extended by a predetermined extent, engagement between the rod front end of the hydraulic cylinder and the guiding portion is released so as to allow the hydraulic cylinder to take on the operating attitude.

A cylinder retraction system causes a crawler side frame hoisting hydraulic cylinder, swingably suspended on a ventral surface side of a lower boom, to swing between a retracted attitude, in which the hydraulic cylinder is set along a ventral surface of the lower boom, and an operating attitude, in which the hydraulic cylinder is oriented along a vertical direction. As the rod of the hydraulic cylinder, currently having the operating attitude, is contracted by a predetermined extent, the rod front end of the hydraulic cylinder is guided by the guiding portion until the hydraulic cylinder takes on the retracted attitude. As the hydraulic cylinder, currently having the retracted attitude, is extended by a predetermined extent, engagement between the rod front end of the hydraulic cylinder and the guiding portion is released so as to allow the hydraulic cylinder to take on the operating attitude.

A control system for a lifting device and a lifting device comprising the same are disclosed. The control system includes a control unit comprising a processor with a memory communicatively coupled to the processor and having computer readable and executable instructions. A battery is electrically coupled to the control unit in addition to at least one indicator. The processor executes the computer readable and executable instructions to: determine an operating characteristic of the lifting device and an operating time of the lifting device as the lifting device is actuated; determine an accumulated load-time parameter for the lifting device based on the operating characteristic and the operating time; store the accumulated load-time parameter in the memory of the lift control system; compare the accumulated load-time parameter to a service constant; and provide an indication the indicator that a lift structural component requires service based on the comparison.

The invention relates to a construction machine having a mast and a lifting element which can be moved up and down along the mast with a hoist rope. The hoist rope can be activated by means of two rope winches. At least one first rope winch is designed as a free fall winch, wherein the hoist rope can be lowered in free fall. To lower the hoist rope a controller is provided, with which the first rope winch, which is designed as a free fall winch, can be switched into a free fall mode. Meanwhile, a second rope winch is operated in force-locking manner.