JPS6223907Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a locking device used to extend the mast by pulling up the inner mast in a telescopic mast in which an inner mast is slidably provided inside an outer mast.

Conventionally, telescopes are extendable and easy to transport, and have been widely used in service machine rigs for oil drilling and the like. The above mast is usually shown in Figure 1a.
As shown in FIG. 1, a pair of telescope-shaped masts 1 are provided in parallel, and their upper parts are connected by a connecting member 2. When extending the mast 1, the inner mast 4, which is slidably fitted to the outer mast 3, is pulled up, and the support member 6 As shown in Figure 1c, from the state of solid line A to the state of double-dashed line B,
The lower end 4a of the inner mast 4 is supported. In this case, in order to stably support the inner mast 4, three supporting members 6 are required as shown in FIG. 1b. Therefore, a total of six hydraulic cylinders 5, three each, are attached to the upper outer periphery of the outer mast 3. The large number of hydraulic cylinders complicates piping, valve operation, etc., and increases costs. Furthermore, six hydraulic cylinders 5 must be operated simultaneously, making it difficult to synchronize them. In addition, the support member 6 has various disadvantages such as being unstable because it supports a cantilever.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention aims to provide a locking device with a simple structure that can support an inner mast through the operation of a single hydraulic cylinder.

Next, the present invention will be explained with reference to the drawings.

2 to 7 show an embodiment of the locking device according to the present invention, and reference numeral 11 in the figures indicates a mast. The mast 11 shown in FIG.
The structure is the same as that in FIG. 1 except for the locking device shown in FIGS. On the upper outer periphery of the outer mast 3 of the mast 11, as shown in FIGS. 6 and 7, a pair of semicircular locking members 12, 12 are located horizontally along the outer periphery and extend half way around the outer periphery. It is provided. The opposing base ends 12a, 12a of these locking members 12, 12 are each rotatably attached to a bracket 13 attached to the outer mast 3 by vertical pins 14, respectively. Further, locking members 15 projecting rightward are attached to the other opposing ends 12b of the locking member 12, respectively.
At the tips of these locking members 15, there is a shaft 1 in the left and right direction.
6a is fixed, and rollers 16 are rotatably attached to the ends thereof. Further, the rollers 16 of the locking member 15 are respectively fitted into V-shaped holes 17a provided on the surface of the lock plate cam 17 shown in FIG. In addition, the above lock plate cam 1
7 is attached to the tip of a rod 18a of a hydraulic cylinder 18 fixed to the outside of the outer mast 3, and is adapted to be driven in the vertical direction. Due to this vertical drive, the roller 16 rotates along the V-shaped groove 17a, and the locking member 1
The ends 12b, 12b of 2 can be opened and closed.

Further, a stopper 19 is attached to the center of each of the locking members 12. This stopper 19 is inserted into the through hole 20 formed in the outer mast 3, and as the end portion 12b is opened and closed by the operation of the lock plate cam 17,
It is adapted to enter and exit the through hole 20.

Note that 21 in the figure is a receiving plate for reinforcing the through hole of the outer mast.

Next, a method of operating the locking device constructed as described above will be explained.

(1) The inner mast 4 is stored inside the outer mast 3, and the shortened mast 11 is transported and installed at a predetermined location. (2) The inner mast 4 is connected to the inner mast 4 by a rope or a hydraulic cylinder (both not shown) arranged between the telescopic masts 1 installed in parallel.
, and the lower end 4a is inserted into the through hole 2 of the outer mast 3.
Make it above 0. (3) Hydraulic cylinder 18
is operated to shorten the cylinder rod 18a, and the lock plate cam 17 is pulled up vertically and moved from the position indicated by the two-dot chain line in FIGS. 3 and 4 to the position indicated by the solid line. As a result, the roller 16 moves along the V-shaped groove 17a, and the distance between the end portions 12b of the locking member 15 narrows, and the state shown in FIG. 6 changes from the state shown in FIG. 7.
The stopper 19 is projected inside the outer mast 3. 4 Move the inner mast 4 downward and lower the lower end 4a.
The mast 11 is extended by abutting against the stopper 19.

When shortening the mast 11, the inner mast 4 is accommodated within the outer mast 3 by performing the operation in the reverse order as described above, and the mast 11 can be easily shortened.

As described above, the locking device according to the present invention allows the stoppers provided on both sides of the outer mast to protrude into the inside of the outer mast by operating two hydraulic cylinders and simply moving the lock plate cam up and down. Because it can be forced or withdrawn,
It is easy to extend and shorten the mast, and the lower end of the inner mast hits the stopper and is supported by the receiving plate to handle the large load placed on the top of the inner mast, ensuring reliable support and easy operation. It has many advantages such as being easy to use.

[Brief explanation of the drawing]

Fig. 1a is a front view of the mast with a conventional locking device installed, and Fig. 1b is the - of Fig. 1a.
1c is a cross-sectional view of FIG. 1b, FIG. 2 is a front view of the mast with a locking device according to the present invention installed, and FIG. 3 is a detailed view of part A in FIG. 2. , FIG. 4 is a front view of the lock plate cam, FIG. 5 is a sectional view taken along the - arrow in FIG. 3, FIGS. 6 and 7 are sectional views taken along the - arrow in FIG. 7 shows a state in which the stopper is inserted, and FIG. 7 shows a state in which the stopper is removed. 1...Telescope mast, 2...Connecting member, 3...Outer mast, 4...Inner mast,
4a... Lower end of the inner mast, 5... Hydraulic cylinder, 6... Support member, 11... Mast, 12...
Locking member, 12a...one end, 12b
...Other end, 13...Bracket, 14...
Vertical pin, 15... Locking member, 16... Roller, 16a... Shaft, 17... Lock plate cam, 1
7a...H-shaped groove, 18...Hydraulic cylinder, 18
a...Cylinder rod, 19...Stopper, 20
...Through hole in outer mast, 21...Receiver plate.

Claims (1)

[Scope of utility model registration request] A telescopic mast having an inner mast slidably fitted inside an outer mast, comprising: a pair of locking members provided horizontally along the upper outer peripheral surface of the outer mast, each half-circling the outer circumference; a pin for attaching opposing proximal ends of the locking member to the outer mast so as to be rotatable in the horizontal direction;
A hydraulic cylinder is attached to the outer circumferential surface of the outer mast and opens and closes the opposite ends of the locking members; A locking device for a telescopic mast, comprising a stopper that enters and exits from a through hole provided in the mast.