JPH0126879Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stopper device used for a telescoping ladder.

Generally, this type of ladder is as shown in Figure 1, with the lower ladder 1
An upper ladder 2, which is relatively telescopically connected to the upper ladder, is operated by a rope 3, thereby making it possible to adjust the length of the entire ladder. Although not clearly shown, a rotary locking mechanism 4 having a pawl or a hook surface is provided at the bottom of the ladder, and the mechanism 4 prevents the upper ladder 2 from descending after adjusting the length. It's becoming like that. The lock mechanism 4 is, for example,
57-165586 as a conventional structure.
However, the locking mechanism 4 is designed so that the locked state is released when the rope 3 is pulled, that is, when the upper ladder 2 in the locked position is pulled up, in order to enable the extension and contraction of the ladder. There are problems like this. In other words, when a worker applies a force in the extension direction to the upper ladder 2 in order to move the ladder from a roof, etc., the locked state is released, and the upper ladder 2 does not fall down due to the frictional force of each part. It may hold its position. Therefore, if a worker steps on the upper ladder 2 in such an unstable state, the ladder will contract under the worker's weight, and there is a risk that the worker will fall.

In order to solve the above-mentioned problems, the present invention includes a manually operated stopper for preventing the upper ladder from rising, in addition to the general locking mechanism, and is constructed as follows.

In other words, in the ladder to which the present invention is applied, the upper ladder and the lower ladder are connected so that they can be relatively expanded and contracted, and the expansion and contraction operation rope is hung on a pulley at the top of the lower ladder, and one end of the rope is connected to the lower part of the upper ladder. The lower ladder is provided with a locking mechanism whose operating state switches between a locked state that prevents descent and a released state that allows the upper ladder to descend, and the locking mechanism is released from the locked state when the upper ladder rises. The state is configured to switch to a state.

In the present invention, in such a ladder, a mounting part for the stopper is provided on one of the upper ladder and the lower ladder, a support member is attached to the mounting part, and the stopper is supported by the support member. The stopper is configured to be movable on the support member between an engagement position in which it engages with the other of the upper ladder and the lower ladder and a disengaged position in which it does not engage, and in the engagement position, a fixed position and a non-fixed position. It is configured to be movable between positions. Further, a spring is provided which biases the stopper in the engagement position toward the fixed position.
A movement prevention part that prevents the stopper from moving from the engagement position to the disengagement position in the fixed position is formed by a concave-convex fitting part provided on the stopper and the mounting part, and in the engagement position, the stopper moves against the upper ladder relative to the lower ladder. The relative rise in

According to this configuration, when the stopper is moved from the disengaged position to the engaged position by manual operation, the stopper is moved to the fixed position by the action of the spring, and is held at that position by the action of the movement prevention part. Therefore, until the stopper is operated again,
The stopper remains in a position where it prevents the upper ladder from rising, ie, where it prevents the locking mechanism from being released.

In order to return the stopper to the release position, the stopper may be manually moved from the fixed position to the non-fixed position against the elasticity of the spring, and then moved from the engaged position to the released position in the non-fixed position.

Next, embodiments will be described with reference to the drawings.

First, the basic structure of a ladder will be explained with reference to FIG.
Lower ladder 1 and upper ladder 2 each have a pair of vertical members 5, 5.
and 6, 6, and a large number of step bars 7 and 8, and the vertical bars 5, 6 are connected to each other so as to be slidable in the longitudinal direction. A pulley 10 is attached to a step 7 at the upper end of the lower ladder 1 via a bracket. The rope 3 is hung on a pulley 10, and one end is connected to a tread 8 at the bottom of the upper ladder 2. A lever-shaped rotating part (not shown) of the lock mechanism 4 is rotatably connected to the lower part of both vertical members 6 of the upper ladder 2, and is configured so that it can be engaged with the rung 7 of the lower ladder 1 from above. It's summery.

2, which is an enlarged perspective partial view of the − cross section of FIG.
As shown in the figure, the vertical members 5 and 6 are made of, for example, an extruded aluminum section having a substantially I-shaped cross section, and the inner surfaces (surfaces on the treadle side) of the webs 9 and 10 are each provided with a A pair of protrusions 11 and 12 are integrally provided.

In the above-mentioned ladder, a stopper 15 is provided at the upper part of the vertical member 5 of the lower ladder 1 in the embodiment of the present invention. The stopper 15 is, for example, a bent molded product of a steel plate, and integrally includes a support portion 17 supported by a bolt 16 and a locking portion 18 projecting upward from the end of the step 8 of the upper ladder 2. In the state in which the locking mechanism 4 shown in FIG. 1 is engaged with the step 7, the locking portion 18 is in contact with or close to the step 8.

As shown in FIG. 3, which is a partial cross-sectional view of FIG. The middle part in the width direction (both protrusions 1
A nut 23 is tightened on a small diameter portion 21 that abuts on the web 9 (the portion between 1 and 11) and passes through a hole in the web 9. The lever support part 17 has a box shape that opens upward and inward (to the right in FIG. 3), and a large diameter part 22 and a bolt head 25 are housed inside. In the illustrated state, the support portion 17 is unrotatably fitted between the protrusions 11, 11, and the wall portion 26 on the nut 23 side is in contact with the web 9. The wall portion 26 is provided with a hole that is slidably fitted into the large diameter portion 22, and a compression coil spring 28 is provided between the peripheral edge of the hole and the bolt head 25.

Next, the function and operation method will be explained. In the state shown in Figures 2 and 3 when the stopper is tilted to the use side, the stopper 15
does not rotate, so if the upper ladder 2 attempts to move upward, the locking portion 18 engages with the step 8 to prevent such movement. Therefore, even if the worker holds the upper ladder 2 from the roof and moves the entire ladder,
The upper ladder 2 will not rise above the length of the lower ladder 1 to become unlocked, and the locking mechanism 4 (FIG. 1) will not become disengaged.

The stopper 15 is removed as follows when the worker descends the ladder. That is, when the stopper 15 is pulled in the direction of arrow A (direction away from the nut 23) as shown in FIG.
In this state, turn the stopper 15 upward as shown by arrow B and hold it between the protrusions 11, 11, and move the locking part 18 to the treadle 8.
Evacuate from above. When the stopper 15 is removed in this way, the upper ladder 2 can be raised by operating the rope 3 (FIG. 1) from the ground, or the upper ladder 2 can be lowered after being raised a little.

The disengaged stopper 15 can be returned to its original locked state when the worker ascends the ladder. To do this, simply turn the stopper 15 by 90 degrees and return the locking portion 18 to above the treadle 8. Then, due to the elasticity of the spring 28 shown in FIG.
1 and 11 and becomes unrotatable.

As explained above, according to the present invention, the support member (bolt 1
6), and moves the stopper 15 on the support member 16 between an engagement position (the position shown in FIG. 2) in which it engages with the upper ladder 2 and a disengaged position in which it does not engage. configured so that it is possible, and
In the engaged position, it is configured to be movable between a fixed position (FIG. 3) and an unfixed position (FIG. 4). When the lock mechanism 4 is in the locked state, the stopper 15 is held at the fixed position (engaged position) by the action of the spring 28 and the concave-convex fitting part, and the relative rise of the upper ladder 2 is prevented. It's getting old.

Therefore, the lock mechanism 4 will not come off when the ladder is moved from a roof or the like, and the safety of the ladder can be improved.

The present invention can also be embodied as shown in FIGS. 5 and 6. In this embodiment, the bolt 16a is fitted into a hole in the web 9 so as to be slidable in its longitudinal direction, and the bolt head 25a is fitted into the support part 17. The nut 23 is separated from the web 9, and a compression coil spring 28a is compressed between the nut 23 and the web 9 via a washer. In the state shown in FIG. 5, the support portion 17 is fitted between the protrusions 11, 11 in a non-rotatable manner due to the action of the spring 28a. From this state, the stopper 15 can be made rotatable by pushing the tip of the bolt 16a in the direction of arrow A to remove the support part 17 from between the protrusions 11, 11, as shown in FIG.

The present invention can also be embodied as shown in FIG. FIG. 7 shows an embodiment in which the web 9 is not provided with the protrusion 11 (FIG. 5), and in this case, an annular rotation preventing member 35 is welded to the inner surface of the web 9 around the bolt 16b. ing. The annular end surface of the member 35 on the stopper 15 side is provided with ratchet teeth 36 as shown in FIG. 8, and the stopper 15 is also provided with pawls 37 that can mesh with the ratchet teeth 36 as shown in FIG. The installation structure of the spring 28b and nut 23 in FIG. 7 is the same as that in FIG. 5. Even in the structure shown in FIG. 7, by moving the stopper 15 in the direction of arrow A, the claw 3
7 from the ratchet teeth 36 and remove the stopper 15.
can be made rotatable. In addition, in the structure shown in FIG. 7, when moving the stopper 15 in the direction of arrow A, the tip of the bolt 16b may be pushed or the stopper 15 may be pulled. It has the advantage that it can be done from either.

In addition, in any of the embodiments, the stopper 1
5 can be provided only on one side of the ladder, or on both sides. It is also possible to attach a stopper to the upper ladder 2 and fit it into the treadle 7 of the lower ladder 1 from below.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view of an embodiment of the present invention, Fig. 2 is an enlarged partial perspective view of the cross-section of Fig.
4 is a sectional view of the stopper in a rotatable state, FIGS. 5 and 6 are sectional views showing another embodiment in different states, and FIG. 7 is a sectional view of yet another embodiment. The sectional view, FIG. 8, is a perspective view of the locking member of FIG. 7. DESCRIPTION OF SYMBOLS 1... Lower ladder, 2... Upper ladder, 3... Rope for telescopic operation, 4... Lock mechanism, 5... Vertical member (attachment part), 10... Pulley, 15... Stopper, 16
...Bolt, 28...Spring.

Claims (1)

[Scope of utility model registration request] The upper ladder and the lower ladder are connected in a relatively expandable and retractable manner, and a telescopic operating rope is hung over a pulley at the top of the lower ladder, and one end of the rope is connected to the lower part of the upper ladder to prevent the upper ladder from descending. A ladder is provided with a locking mechanism whose operating state is switched between a released state that allows descent, and the locking mechanism is configured such that the operating state is switched from the locked state to the released state as the upper ladder ascends. A mounting part for the stopper is provided on one side of the lower ladder, a support member is attached to the mounting part, the stopper is supported by the support member, and the stopper is placed on the support member,
configured to be movable between an engagement position where it engages with the other of the upper ladder and the lower ladder and a detached position where it does not engage, and movable between a fixed position and a non-fixed position in the engagement position, A concave-convex fit in which a spring is provided to urge the stopper in the engaged position toward the fixed position, and a movement prevention part is provided in the stopper and the mounting part to prevent the stopper from moving from the engaged position to the disengaged position in the fixed position. 1. A stopper device for a ladder, characterized in that the stopper is formed by a mating portion and prevents the upper ladder from rising relative to the lower ladder in the engaged position.