1. field of invention
The invention relates to a coarse belt crane with a wheel neck.
2. Description of the prior art
Fig. 3 shows an exemplary version of a conventional crane.
Referring to fig. 3, the crane shown is a rough area crane, and includes a relatively low fluid body 1, an upper bull head 2 that continues the relatively low fluid body 1, and a telescopic prosperity device 3 is installed as a bull head that moves up and down around a prosperity pin 3 on the upper bull head 2.
The upper bull-nose-shaped body 2 includes a main frame 2- 1 and a winch frame 2b, and when the rear end of the main frame 2 moves in a bull-nose shape, the end telescopic boom 3 (boom foot) is partially unfolded by a boom foot pin 3- 1. At the same time, a pair of winch drums 4 and 5 are operated in a state of being shifted in the front-rear direction in the winch frame 2b, and a pair of guide pulleys 6 and 7 guide the thick rope R 1.. 1 and the Draw from the drums 4 and 5.
As mentioned above, it is necessary to use an extended boom for this kind of wheel neck extension to increase the operational capacity, but due to the extension range of the boom 3, when the wheel crane involves public roads, it is restricted by rules, and the boom length cannot be very long. Therefore, it may be more appropriate to play, and the production method of Shengshi Length 3 is that the longer the better. Under the restriction of law, a prosperity foot is erected, that is, a prosperity foot pin 3 is pointed to the upper bull nose body 3, and the position of the bull nose member is as far back as possible. However, in this example, there are the following problems.