JPH041189Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multistage telescopic boom having a boom that is extended and contracted by a rope that is linked to the expansion and contraction of the boom by the expansion and contraction of a cylinder device.

[Conventional technology]

Here are three examples of conventionally used multi-stage telescopic booms.
Figure 8 shows the stage telescopic boom.

The cylinder device 1 is pivoted by a pin 13 to the base end of a first boom 6 whose rod end is a proximal boom, and the rod end of the cylinder is supported on the base end of a second boom 7 which is an intermediate boom. It is pivotally connected via a member. A pair of rope devices is usually provided on the left and right sides of the boom shaft, but for convenience of explanation below, in principle, one side of the rope device will be explained. The second boom 7 is provided with an extension sheave 10 on the third boom 8 side, which is the front end boom, and a contraction sheave 14 on the first boom side. and the second boom installed on the third boom 8.
An extension rope 17 is passed around the extension sheave 10 between the first attachment part 5 provided on the first boom 6 and the second attachment part 15 provided on the third boom 8. A shrinking rope 18 is stretched between the sections 16 and wrapped around the shrinking sheave 14.
9,9 is Kaidrola.

[The problem that the idea aims to solve]

Therefore, conventionally, two ropes, the extension rope 17 and the contraction rope 18, are used, so if the rope becomes loose, for example, the length must be adjusted for each of the two ropes. It was time-consuming.

The present invention is intended to solve the above-mentioned problems of the prior art, and aims to provide a multi-stage telescopic boom that allows the tension of the rope to be easily adjusted.

[Means to solve the problem]

The present invention includes a proximal boom, an intermediate boom, and a distal boom that are combined to be extendable and retractable, and the intermediate boom is extended and contracted by a cylinder device provided between the proximal boom and the proximal boom. In the boom, an extension sheave and a retraction sheave are provided near a distal end and a proximal end of the intermediate boom, respectively, and the distal boom is rotatable relative to the distal boom. a rope winding member held by the rope winding member; and a fixing device that allows the rope winding member to be selected between a rotatable state and a fixed state relative to the distal end side boom;
a first member fixed relatively to the proximal boom;
The rope fastened to the fastening part is passed around the extension sheave, then wrapped around the rope winding member, and further passed around the contraction sheave, so that the rope is fixed relative to the proximal boom. This is a multi-stage telescopic boom characterized by being attached to a fixed second attachment part.

[Effect]

The multi-stage telescopic boom of the present invention includes a rope wrapping member held rotatably relative to the tip boom on the tip side boom, and a rope wrapping member held relatively to the tip boom. A fixing device that can be selected between a rotatable state and a fixed state is provided, and the rope fixed to the first fastening part fixed relative to the proximal boom is hung on the extension sheave. After turning the rope, it was wrapped around the rope winding member, further wrapped around the retraction sheave, and secured to the second attachment part fixed relatively to the proximal boom, so that the extension sheave side or When either rope on the contraction sheave side becomes loose, if the rope wrapping member is made rotatable by a fixing device, the rope wrapping member will rotate due to the difference in tension between the ropes on both sides. The tension of the ropes on both sides is equalized, and the boom on the tip end can be reliably extended and contracted by the ropes.

〔Example〕

An embodiment of the present invention will be described using FIGS. 1 to 7.

Note that the same reference numerals as in FIG. 8 represent the same members.

Near the proximal end of the second boom 7, contraction sheaves 11 and 12 are provided in two stages vertically, and a third
The boom 8 has a drum 2 as a rope wrapping member.
After fixing one end to the first fixing part 4, the rope 3 is wound around the extension sheave 10 for half a turn, then wrapped around the drum 2 two to three times, and then wrapped around the contraction sheave 11, 12. After applying 1/4 rotation to
The other end is fixed to a second fastening part 5 provided at the tip of the first boom 6, and the boom is tensioned.

The contraction sheaves 11 and 12 are rotatably supported and attached to the side plate of the second boom 7,
The cylinder of the cylinder device 1 is supported by a support shaft of a contraction sheave 12 via a support member, and is pivotally attached to a side plate of the second boom 7.

The drum 2 is provided on the third boom 8 so as to be rotatable relative to the third boom 8, but the drum 2 is fixed at any rotational position with respect to the third boom 8,
In order to prevent relative rotation, a fixing device is provided which allows the drum 2 to be placed in a rotatable state and in a fixed state. In this embodiment, the drum 2 and the pair of drums 2 are mounted on a support shaft 19 mounted between both side plates on the base end side of the third boom 8.
It is rotatably supported via 0. In addition, in order to fix the drum 2 with a fixing device, the drum 2 is attached to a support shaft 19.
A pin 21 parallel to the third boom 8 is provided with one end protruding toward the center of the third boom 8 and fixed to the drum side plate. The fixing device is as shown in Figures 5 and 6.
A meshing member 22 having a tooth groove parallel to the support shaft 19 is fixed to the outside of the ceiling plate of the third boom 8 by welding or the like, a meshing portion that meshes with the meshing member 22 is provided at one end, and the other end is connected to the pins 21, 21. connected boat 2
3. Bolts 24 and nuts 25 are used to fix the engaging member 22 and the board 23. board 23
The end of the side connected to the pins 21, 21 has tongue pieces hanging vertically on both sides, and each tongue piece has a long hole having a width approximately the same as the outer diameter of the pin 21 and long in a direction perpendicular to the board 23. 26 is bored, and a pin 21 is inserted into the elongated hole 26 to connect them. A long hole 27 for a bolt 24, which is long in the direction perpendicular to the tooth groove, is bored in the end of the board 23 on the meshing part side, and the nut 25 is inserted inside the third boom 8 on the back side of the meshing member 22. Two pieces are fixed at appropriate intervals.

The engaging member 22 and the board 23 are provided so that when the boom is extended, the engaging portion side of the board 23 is completely exposed and is in a position where it can be easily operated and adjusted from the outside.

As the first fastening part 4 or the second fastening part 5,
Equalizers such as lever type equalizers, fixed semicircular equalizers, equalizer sheaves, etc. can be used.

Note that the first fastening part 4 or the second fastening part 5,
Preferably, the latter is provided with a take-up for tensioning the rope 3 used when attaching or replacing the rope. Note that, regardless of whether an equalizer or take-up is used, it is preferable to use a spring in the second fastening part 5 so that a predetermined tension is always applied to the rope so that the rope 3 wound around the drum 2 does not loosen. .

Thus, by wrapping the rope 3 around the drum 2 for at least one turn, preferably two to three times, and tensioning it between the fastening parts 4 and 5, the rope 3 can be fastened to the drum 2 by friction. At this time, since the drum 2 is fixed via the board 23 with bolts 24, the tension of the rope 3 can be reliably transmitted to the third boom 8. Therefore, when the cylinder device 1 is extended, the second boom 7 is extended, and the extension action of the second boom 7 causes the rope 3 from the first attachment part 4 to the drum 2 to act as an extension rope. The third boom 8 is extended, changing from the contracted state shown in FIG. 1 to the extended state shown in FIG. 2. When the cylinder device 1 is retracted from the state shown in Fig. 2, even if the boom is horizontal or the tip is lowered, the retracting action of the second boom 7 causes the rope 3 from the second attachment part 5 to the drum 2 to be retracted. Acting as a rope, the third boom 8 is retracted, and the first
It becomes the contracted state as shown in the figure.

If either the extension rope or the contraction rope becomes loose, the boom is leveled and extended to expose the tip of the board 23 to the outside. Then, remove the bolt 24, lift up the tip of the board 23 slightly to disengage it from the engaging member 22, and remove the drum 23.
is in a rotatable state. At this time, since the drum 2 is in a rotatable state, it rotates without resistance in response to the imbalance in the tension of the rope 3, and settles at a rotation position where the rope 3 is under an even tension over its entire length. In response to this rotation of the drum 2, the board 23 is moved by the pin 21, and the engagement position with the engagement member 22 changes. At that changed position, the board 23 is moved to the engaging member 2.
2 and secure with bolts 24.

Although the explanation has been given above using a three-stage telescopic boom, the present invention can also be applied to a multi-stage telescopic boom having four or more stages.

[Effect of idea]

The multi-stage telescopic boom of the present invention includes a rope wrapping member held rotatably relative to the tip boom on the tip side boom, and a rope wrapping member held relatively to the tip boom. A fixing device that can be selected between a rotatable state and a fixed state is provided, and the rope fixed to the first fastening part fixed relative to the proximal boom is hung on the extension sheave. After turning, the rope winding member was wound around the rope winding member, and then around the shrinking sheave, and the rope winding member was fastened to the second fastening portion fixed relatively to the proximal boom. By releasing the fixation and making it rotatable, the imbalance in tension between the ropes on the extension side and the contraction side is corrected at the same time, and the boom can be stably extended and contracted by the rope. Thus, for example, if the rope becomes loose, it can be tensioned very quickly and easily.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention, and FIG.
FIG. 2 shows a cross-sectional front view taken along the line of FIG. 4, with FIG. 1 showing the state when contracted and FIG. 2 showing the state when being expanded. Figure 3 is a cross-sectional side view taken from Figure 2, and Figure 4 is a cross-sectional side view of Figure 2.
Fig. 5 is a cross-sectional side view taken along the line in Fig. 4, Fig. 6 is a front view taken along the line sectional view shown in Fig. 5, and Fig. 7 is a front view taken along the line sectional view shown in Fig. 2.
The line cross-sectional side view, FIG. 8, is a diagram corresponding to FIG. 1 of the conventional example. DESCRIPTION OF SYMBOLS 1... Cylinder device, 2... Drum, 3... Rope, 4... First fastening part, 5... Second fastening part, 6... First boom, 7... Second boom, 8...
...Third boom, 9...Guide roller, 10...Extension sheave, 11...Contraction sheave, 12...Contraction sheave, 13...Pin, 14...Contraction sheave, 15...First Fastening part, 16... Second fastening part, 17... Extension rope, 18... Contraction rope, 19... Support shaft, 20... Bearing, 21... Pin, 22... Engaging member, 23...Board, 24...
...Bolt, 25...Nut, 26...Elongated hole, 27
...Long hole.

Claims (1)

[Scope of utility model registration request] The multistage telescopic boom includes a proximal boom, an intermediate boom, and a distal end boom that are combined so as to be extendable and retractable, and the intermediate boom is extendable and retractable by a cylinder device provided between the proximal boom and the proximal boom. An extension sheave and a contraction sheave are arranged near the distal end and the proximal end of the intermediate boom, respectively, and the distal boom is rotatably held relative to the distal boom. a rope winding member; and a fixing device that allows the rope winding member to be selected between a rotatable state and a fixed state relative to the distal end boom; The rope fastened to the first fastening part that is relatively fixed to the first fastening part is wrapped around the elongating sheave, then wrapped around the rope wrapping member, and then wrapped around the shrinking sheave, so that the proximal end A multi-stage telescopic boom, characterized in that it is fixed to a second fastening part that is fixed relatively to a side boom.