JPH074318Y2 - Telescopic ladder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a telescopic ladder used for work in high places.

(Prior Art) This type of expandable ladder includes a lower ladder 1 and a lower ladder 1 as shown in FIG. 4, FIG. 5 and FIG.
An upper ladder 2 that expands and contracts along the upper and lower sides, an operation rope 3 to be described later that is suspended over both ladders, and a hooking device 4 that engages and holds the upper ladder 2 in a required expansion and contraction position. As a result, the upper ladder 2 rises and extends along the lower ladder 1, and the engaging device 4 moves at the required extension position.
The engaging piece 5 is urged by the spring 6 to engage with the step rail 1a of the lower ladder 1, and holds the upper ladder 2 in the engaging position even if the operation of pulling the operation rope 3 is released. When contracting and lowering the upper ladder 2, the upper rope 2 is lifted from the engaging position until the engaging release piece 6 of the engaging device 4 is positioned higher than the step rail 1a by further pulling on the operation rope 3. By releasing the pulling operation of the operation rope 3, the engagement release piece 6
Since the hooking portion 5a of the hooking piece 5 is closed, the hooking piece 5 contracts and descends without engaging the step rail 1a while the upper ladder 2 is descending, and is engaged with the engaging device 4 at the desired lowering position, or the lowermost end. When the lower end of the upper ladder 2 is engaged with the reinforcing bar 7 provided at the lower end of the lower ladder 1 at the position in advance of the stopper, the upper ladder 2 is held by the lower ladder 1 and further descends. Never.

As described above, the upper ladder 2 is always engaged with the engagement piece 5 of the engagement device 4 or the stopper 7 provided on the lower ladder 1 at the time of the most contraction unless the engagement release piece 6 works.
It is held by the lower ladder 1 so as not to descend further, but on the contrary, when the upper ladder 2 extends along the lower ladder 1, it can freely rise to the maximum extension position. There is nothing to prevent.

(Problems to be solved by the invention) As described above, in the conventional telescopic ladder, since the upper ladder 2 is always held by the lower ladder 1, the lower ladder side must be held when the telescopic ladder is transported. If you accidentally lift the upper ladder side, the upper ladder 2
Is unable to lift the lower ladder 1 because it is free to extend and lower with respect to the lower ladder 1. For this reason, the lower ladder must be gripped and lifted again, and it takes time to transport a long stretchable ladder, and the upper ladder is accidentally lifted, which causes imbalance and falls, resulting in an unexpected accident such as injury. There were things.

Therefore, it is an object of the present invention to propose an extendable ladder in which the upper ladder side is also lifted up integrally with the lower ladder side, and the extension and lowering operation of the upper ladder is not hindered.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention shows a lower ladder 1 and an upper ladder 2 which is engaged with the lower ladder 1 so as to be able to move up and down, as indicated by the reference numerals in the drawings. And an operation rope 3 provided over both ladders, and the operation ladder 3 is used to extend and retract the upper ladder 2 along the lower ladder 1 so that the upper and lower ladders 2 are extended and lowered by a spring 19. Although it is rotatable, it cannot rotate upward from a substantially horizontal state, and when it is in a substantially horizontal state by being urged by the spring 19, its tip portion 13a is an engagement hole provided in the upper ladder 2. A lock lever 13 engaged with 21 or 21 'is pivotally attached to the lower ladder 1, and by pulling the operating rope 3, the tip end portion 13a of the lock lever 13 resists the urging force of the spring 19 and the engaging hole 21
Or the operation rope 3 to escape from 21 'and rotate downward
The upper end of the lock lever 13 is connected to the lock lever 13.

(Operation) When the telescopic ladder is transported, the pulling operation of the operation rope 3 is naturally not performed and the lock lever 13 pivotally attached to the lower ladder 1 is biased by the spring 19 and is in a substantially horizontal state. Moreover, since it is regulated upward so as not to be rotatable from the horizontal state, when the tip portion 13a of the lock lever 13 is engaged with the engaging hole 21 or 21 'provided in the upper ladder 2, Even if the upper ladder 2 is lifted, the lower ladder 1 is also integrally lifted through the lock lever 13 by engaging with the upper ladder 2, and only the upper ladder 2 is lifted upward or the lower ladder. Only 1 never falls downwards.

On the other hand, when the telescopic ladder is extended, by pulling the operation rope 3, the lock lever 13 connected to the upper end of the rope 3 resists the urging force of the spring 19 and the tip 13
Since the a escapes from the engagement hole 21 or 21 'and rotates downward, the upper ladder 2 is locked by the lock lever 1
3, therefore, the engagement state with the lower ladder 1 is released, so that when the operation loaf 3 is pulled more strongly, the lower ladder 2 is extended and extended by the pulling force of the operation rope 3, and the upper ladder 2 It does not hinder the lifting operation.

(Embodiment) First, the overall structure of the expandable ladder will be described. As shown in FIGS. 4 and 5, of the lower ladder 1 and the upper ladder 2 that moves up and down along the lower ladder 1, near the upper and lower ends of the lower ladder 1. Brackets 9 and 10 projecting to the upper ladder side are fixedly attached to the upper side, and pulleys 11 and 12 are axially attached to the respective brackets. Further, the upper end side bracket 9 has a lock lever which is a lock mechanism of a main part of the present invention.
13 are pivotally attached. A pair of intermediate pulleys 14 and 15 are vertically attached to the upper and lower intermediate positions of the upper ladder 2.

The upper end of the operating rope 3 is connected to the lock lever 13, and the rope 3 is connected to the upper middle pulley 14 of the upper ladder 2, the upper pulley 11 of the lower ladder 1, the lower pulley 12 of the same, and the lower middle of the upper ladder 2. The lower end portion of the operation rope 3 is connected to the lower end bracket 10 of the lower ladder 1 by sequentially winding the pulleys 15.

FIG. 6 shows another embodiment of the present invention, which is a lower ladder 1
Bracket 9 protruding toward the upper ladder only near the upper end of the
And a pulley 11 is pivotally attached to the upper end of the upper ladder 2.
The operation rope 3 whose upper end is connected to the lock lever 13 is sequentially wound from the upper ladder side pulley 14 to the lower ladder side pulley 11 to hang down the lower end side thereof, and the lower end portion is put in place. May be attached.

Further, the detailed structure of the lock lever 13 will be described with reference to FIGS. 1 and 2, by using a pivot 11a for pivotally attaching a pulley 11 to an upper end side bracket 9 projecting from the lower ladder 1 to the upper ladder 2 side. A lock casing (17) is fixed to the bracket (9), and a lock lever (13) is pivotally attached to the casing (17) by a pivot shaft (18) so as to be rotatable in a direction orthogonal to the pulley (11). Although it is constantly urged upward by the provided helical spring 19, the lock lever 13 hits the lower edge 20 of the bracket 9 or the lock casing 17 from a position where the lock lever 13 is in a substantially horizontal state as shown in the drawing, Since it does not rotate upward, the lock lever 13 is always urged by the spring 19 to project in a substantially horizontal state and its tip 13a is provided on the upper ladder 2 unless another external force is applied. It is engaged with the engaging hole 21. It has become the jar. The upper end of the operating rope 3 is pivotally connected to the middle of the lock lever 13 via a connecting link 22 as appropriate.

The step rail 2b fixed to the side pillar 2a of the upper ladder 2 has a hollow tubular shape, and the step rail end portion 23 is open to the side surface of the side pillar. It may be used as the hole 21, or the side column 2a may be provided with the hole 25 and used as the engaging hole 21 '.

Next, the method of use of this embodiment will be described. When the operation portion 3a of the operation rope 3 shown in FIG. 4 or 6 is pulled, the lock lever 13 is moved to the first position by the pulling force and the load of the upper ladder 2. As shown in FIG. 3, the tip portion 13a of the spring 19 (FIG. 1) resists the biasing force of the spring 19 and comes out of the engaging hole 21 and rotates downward. As a result, there is nothing to prevent the upper ladder 2 from going up and down, so that the upper ladder 2 can be stretched and raised by pulling the operating rope 3 more strongly, and contracted and lowered by releasing the pulling force of the operating rope 3. Then, at the desired expansion / contraction position, the engaging device 4 described above is used as usual.
However, it is engaged and held by the stopper 7 which is a reinforcing bar at the most contracted position.

When the pulling force of the operation rope 3 is released at the desired engagement position of the upper ladder 2, the lock lever 13 is urged by the spring 19 and protrudes in a substantially horizontal state, and its tip portion 13a is engaged with the engaging hole 21 or 21 '. Will be engaged in.

Because of this, the upper ladder 2 is used to carry the telescopic ladder.
Even if the side is lifted, the lock lever 13 engages with the engagement hole 21 of the upper ladder 2 as shown by the chain line in FIG. 1, and even if the lock lever 13 receives an upward biasing force from the upper ladder 2. Since it is prevented from rotating upward from the horizontally projected position, the lifting force for the upper ladder 2 is the lock lever.
It directly engages the lower ladder 2 via 13, so that the upper ladder 2 can be lifted together with the lower ladder 1.

(Effect) According to the present invention, when carrying the telescopic ladder, it is possible to integrally lift both the lower and upper ladders by grasping and lifting them, so that the carrying work can be carried out easily and easily. It can be carried out and is safe because the upper ladder does not extend even if it is laid down sideways during transportation. Further, unlike the conventional case, since the upper ladder side is lifted, the balance is not lost, and there is no possibility of falling and causing an unexpected accident such as an injury, so that it can be used stably.

Further, according to the present invention, since it is only necessary to interpose a lock lever between the operation rope and the lower ladder, the structure is simple and the manufacturing cost is low. It can be used smoothly and easily because it only needs to be pulled and opened.

Particularly, according to the present invention, when the telescopic ladder is carried by the upper ladder, the lock lever of the lower ladder is engaged with the engaging hole of the upper ladder to prevent the lower ladder from moving. Therefore, the movement of the lower ladder can be surely prevented as compared with the case where the movement of the lower ladder is prevented by a brake structure utilizing sliding friction caused by a spring force.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of the present invention, and FIG.
Fig. 1 is a view taken along the line II-II in Fig. 1, Fig. 3 is a vertical cross-sectional view of a main portion of the operation rope in a state of pulling downward, Fig. 4 is a side view of the entire telescopic ladder in a folded state, and Fig. 5 The figure is the same front view,
FIG. 6 is a side view similar to FIG. 4 of the other embodiment, and FIG. 7 is a longitudinal sectional view of the same extended state. 1 ... Lower ladder, 2 ... Upper ladder, 3 ... Operation rope,
13 ... Lock lever, 19 ... Spring, 21,21 '... Engagement hole, 24 ... Step end face opening, 25 ... Hole.

Claims (1)

[Scope of utility model registration request] 1. A lower ladder, an upper ladder engaged with the lower ladder so as to be able to move up and down, and an operation rope provided over both ladders. By operating the operation rope, the upper ladder expands and contracts along the lower ladder. In the telescopic ladder that is made to be able to be rotated by being biased by the spring,
When the upper lever cannot be rotated upward from the substantially horizontal state and is in the substantially horizontal state by being biased by the spring, the lock lever whose tip end engages with the engaging hole provided in the upper ladder is attached to the lower ladder. The upper end of the operation rope is connected to the lock lever so that the tip end of the lock lever is pivotally attached and pulls the operation rope against the biasing force of the spring so that the tip of the lock lever comes out of the engagement hole and rotates downward. Stretchable ladder.