JPH0352794Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is based on the main boom, which has a main hook attached to the tip and is hung at the left and right connecting points that protrude from the left and right positions of the main boom, which is suspended so that it can be rolled up and lowered freely. The base ends of the left and right legs of the multi-stage jib, which is composed of an outer jib having left and right legs at its base end and an inner jib telescopically fitted into the outer jib, are connected to each other to form the main multi-stage jib. A crane equipped with a multi-stage jib configured to be able to rotate around the connection point between an extended position where the tip of the boom extends forward and a folded position where it is folded along the main boom, particularly where the multi-stage jib is extended out. The present invention relates to a crane equipped with a multi-stage jib configured such that the main hook passes through a main hook transition space between the left and right legs when rotating between a folded position and a folded position.

(Prior Art) In a crane equipped with this type of multi-stage jib, when the multi-stage jib is rotated between the extended position and the folded position, the multi-stage jib is moved so that the base end of the inner jib does not interfere with the main hook. The base end portion of the inner jib is configured not to be located within the main hook passage space when the inner jib is in its most contracted state.

As a result, the extension and contraction stroke of the inner jib has become shorter.

(Problem to be solved by the invention) However, in a crane equipped with a conventional multi-stage jib configured as described above, the length of the multi-stage jib at its maximum extension is shortened to the extent that the extension stroke of the inner jib is shortened. Therefore, there was a problem that the working range in which objects could be lifted became smaller.

The object of this invention is to solve the above-mentioned problems and provide a crane equipped with a multi-stage jib that can increase the extension and contraction stroke of the inner jib of the multi-stage jib compared to the conventional crane.

(Means for Solving the Problems) In order to achieve the above-mentioned purpose, the present invention provides a crane equipped with a multi-stage jib such that when the multi-stage jib A is contracted to the maximum, the base end of the inner jib 2 is The inner jib is configured to be located within the main hook transition space, and the base end of the inner jib 2 is located between the outer jib 1 and the inner jib 2 of the multi-stage jib A at an intermediate extended position where it is not located within the main hook transition space. 2 is provided with a fixing means for fixing it.

(Function) The crane equipped with the multi-stage jib of the present invention configured as described above can be operated in a multi-stage manner similar to conventional cranes by fixing the base end of the inner jib 2 at an intermediate extended position that is not located within the main hook passage space. Although the jib A can be rotated between the folded position and the extended position, in the folded position of the multi-stage jib, the inner jib 2 of the multi-stage jib A is rotated so that the base end of the inner jib 2 is attached to the main hook. Since the inner jib 2 can be brought into the most contracted state within the elapsed space, the extension and contraction stroke of the inner jib 2 can be increased accordingly.

(Example) Next, an example of a crane equipped with a multi-stage jib according to the present invention will be described based on FIGS. 1 to 3.

FIG. 1 shows a two-stage telescopic multi-stage jib A, and the multi-stage jib A is composed of an outer jib 1 and an inner jib 2 that is telescopically fitted into the outer jib 1. 3 is a recess formed at the base end of the left and right legs at the base end of the outer jib 1;
are connected to left and right connecting points (pins) 11 that protrude from the left and right positions of the tip of the main boom 10, which will be described later. 4 is a through hole bored at the tip of the outer jib 1. Reference numerals 5, 6, and 7 indicate through holes drilled at the tip, middle, and proximal positions of the inner jib 2, respectively, and these through holes 5, 6, and 7 are overlapped with the through hole 4 to form holes therein. By inserting the connecting pin 8 into
It is designed to be fixed at the most extended position. At the most contracted position of the inner jib 2, that is, at the most contracted position of the multi-stage jib A, the base end of the inner jib 2 is located within the main hook passage space. In addition, through hole 6
In the intermediate extended position where the through hole 4 is connected with the connecting pin 8, the base end of the inner jib 2 is not located within the main hook passage space. The through hole 6, the through hole 4, and the connecting pin 8 constitute a fixing means for fixing the inner jib 2 at an intermediate extended position where the base end of the inner jib 2 is not located in the main hook passage space. 9 is a pulley placed at the tip of the inner jib 2.

FIG. 2 shows how the base ends (recesses) 3 of the left and right legs of the base end of the outer jib 1 of the multi-stage jib A are connected to the main boom 10.
The left and right sides of the jib A are connected to connection points (pins) 11, and the multi-stage jib A is shown suspended from the tip of the main boom 10. In FIG. 2, 12 is a swivel base that pivots the base end of the main boom 10, and 13 is a hoisting cylinder that controls the hoisting of the main boom 10. 14 is a main winch that suspends the main hook 15 from the tip of the main boom 10, and 16 is a sub winch that suspends a sub hook (not shown) via a pulley 9 at the tip of the multi-stage jib A. be. Reference numeral 17 is a pulley disposed protruding forward from the tip of the main boom 10, and when the multi-stage jib A is not in use, the rope let out from the sub winch 16 is suspended via the pulley 17. The secondary hook is placed at the end of the rope for cargo handling work. 18
is the base end (recess) 3 of the outer jib 1 and the main boom 10
This is a removable pin that maintains the connection state of the connection point (pin) 11 at the tip. Reference numeral 19 denotes a rope connecting portion disposed at the tip of the outer jib 1 of the multi-stage jib A.

Next, the action will be explained.

When the multi-stage jib A is not in use, it is folded along the main boom 10 and fixed to the main boom 10, but in this state, the multi-stage jib A is kept in the most contracted state. .

When moving the multi-stage jib 2 from the folded position to the extended position where the tip of the main boom 10 is extended forward, first the main hook 15 is moved by the winch 14.
Hoist the main boom 10 until it comes close to or in contact with the tip of the main boom 10, and release the fastening between the multistage jib 1 and the main boom, as well as the left and right leg base ends (recesses) 3 of the base end of the outer boom 1 of the multistage jib A. Connecting points (pins) 11 are engaged and these are connected by detachable pins 19, and the main boom is raised to the state shown in FIG. 2 in which the multi-stage jib 1 is suspended from the tip of the main boom 10. Next, the rope let out from the auxiliary winch 16 passes through the pulleys 17 and 9 in sequence, and its tip is fixed to the rope connection part 19 of the outer jib 1. In this state, the main hook 15 and the base end of the inner jib 2 are in pressure contact, and the multi-stage jib A cannot be rotated any further toward the extended side. Next, when the pin 8 is pulled out from the through holes 4 and 5 and the rope of the auxiliary winch 16 is let out, the inner jib 2 expands due to its own weight. Then, the pin 8 is inserted into the through holes 4 and 6 in a state where the through holes 4 and 6 overlap. FIG. 3 shows this state. When the rope of the auxiliary winch 16 is wound up from the state shown in FIG. 3, the multistage jib A rotates from its extended position in front of the tip of the main boom 10. Next, in this extended state, the main boom 10 is laid down and the outer jib 1 and the tip of the main boom 10 are connected at appropriate positions using a tension bar or a tension rope. In this state, the multi-stage jiff A is put into an appropriate extended state (maximum extended state) and used.

To change the multi-stage jib A from the extended position to the folded position, the above operation may be reversed.

In the above embodiment, the multi-stage jib A has been described as a two-stage telescoping type, but it goes without saying that the multi-stage jib A may be a telescoping type with three or more stages.

(Effects) A crane equipped with a multi-stage jib constructed and operated as described above can make the extension/contraction stroke of the multi-stage jib longer than that of conventional cranes, and the length of the multi-stage jib in its fully extended state can be increased. This has the excellent effect of enlarging the working range.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of an embodiment of a crane equipped with a multi-stage jib according to the present invention, in which Figure 1 is an overall view of the multi-stage jib, and Figures 2 and 3 are illustrations of the crane when the multi-stage jib is extended. It is an explanatory diagram. 15...Main hook, 10...Main boom, 11...
...Connection point, A...Multi-stage jib, 1...Outer jib, 2
...Inner jib, through hole 6, through hole 4 and connecting pin 8
...Fixing means for fixing the inner jib 2 in the intermediate extended position.

Claims (1)

[Scope of Claim for Utility Model Registration] At the left and right connecting points 11 protruding from the left and right positions of the main boom 10, the main boom 10 has a main hook 15 at its tip and can be hoisted up and lowered, and left and right legs are attached at the base end of the main boom 10. A multi-stage jib A consisting of an outer jib 1 with a section and an inner jib 2 telescopically fitted into the outer jib 1.
The base ends of the left and right legs of are connected, respectively, and the multi-stage jib A is centered between the extended position where it is extended to the front of the tip of the main boom 10 and the folded position where it is folded along the main boom 10, with the connection point 11 being the center. In particular, when the multi-stage jib A is rotated between an extended position and a folded position, the main hook 15
is configured such that the multi-stage jib A passes through the main hook transit space between the left and right legs, and the base end of the inner jib 2 passes through the main hook transit space when the multi-stage jib A is contracted to the maximum. and fixing the inner jib 2 between the outer jib 1 and the inner jib 2 of the multi-stage jib A at an intermediate extended position where the base end of the inner jib 2 is not located within the main hook passage space. A crane equipped with a multi-stage jib characterized by the provision of means.