JPH0619759Y2 - Double ladder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention This invention relates to a double ladder.

2. Description of the Related Art Conventionally, as a double ladder, a lower ladder, an upper ladder slidably connected after the lower ladder, an upper ladder elevating rope across the two ladders, and a pair of upper pillars of the upper ladder. An engaging claw that is attached to a predetermined position on the inner surface of the lower part so as to be swingable downward, is biased by a spring in the direction of the lower ladder, and has a recess on the lower surface that fits into the step rail of the lower ladder; It is known that the lower end portion is formed so as to be swingably attached to the upper ladder and is constituted by a locking prevention piece that hits a step rail of the lower ladder from above and closes the concave portion (Japanese Utility Model Publication No. 62-21680).

However, the above-mentioned double ladder has the following problems. That is, the locking claws are locked to the stepped rails at the required positions on the lower ladder, the upper ladder is fixed, the double ladder extended to the desired length is erected and raised to the roof, and then the worker sits on the roof. When trying to change the standing position of the ladder by holding the upper ladder from
Since only the upper ladder is pulled up, it is difficult to change the standing position. Not only that, once the upper ladder has been pulled up and the locking block has passed above the stepped rail that was in the locked state, the upper ladder drops by its own weight when you release your hand. To work, there is a danger that the ladder will fall all at once and the ladder will fall.

Therefore, as a double ladder that solves the above problems, the upper ladder is slidably connected to the rear side of the lower ladder configured with the parent pillar having the concave groove on the outer surface, and the upper ladder is The lifting rope is hung on the pulley arranged so that the part is exposed and the pulley provided on the bracket that is attached to the main pillar of the upper ladder and extends toward the lower ladder. By the shaft pin on the main pillar and the guide pin fitted in the arc-shaped long hole formed in the bracket,
It was proposed that the shaft pin is tiltably mounted, and the upper end of the bracket is pressed against the inner surface of the front wall of the main pillar of the lower ladder when tilted (actually 63-2).
8800).

According to the above-mentioned proposed double ladder, when the upper ladder is pulled up from the roof, the bracket tilts about the shaft pin as a fulcrum, the guide pin comes into contact with the rear end of the long hole, and the upper end of the bracket is attached to the main pillar. It presses against the inner surface of the front wall, and this pressure contact prevents only the upper ladder from being pulled up from the lower ladder, and the upper ladder can be lifted with the lower ladder, and even if the upper ladder is released, Since the brake is applied to the upper ladder via the bracket in the stopped state, the upper ladder does not drop at once by its own weight, and the lowering of the upper ladder is reliably prevented by the locking claws.

Problems to be Solved by the Invention However, the following problems remain in the above proposed double ladder. That is, if the rope exposed on the front surface of the main pillar of the lower ladder is pulled down, the guide pins come into contact with the front end of the long hole so that the pair of upper and lower sheaves of the bracket remain parallel to the sheaves of the support pillars and Since a gap is secured between the inner surface of the main pillar and the front wall, the upper ladder can be slid back to its original position. Since the corners of the upper end of the bracket bite into the inner surface of the front wall of the main pillar, the bracket may not easily return to its original shape even if the rope is pulled down. On the other hand, when the upper ladder is pulled up from the roof, the load of the lower ladder is suddenly applied to the bracket, so that the guide pin cannot move smoothly in the long hole and the bracket does not tilt securely. There may be a slight gap between the inner surface and the inner surface, which may cause no pressure contact.

The purpose of this invention is a double ladder in which there is no such concern as described above, the standing position of the double ladder can be changed from the top of the roof, and there is no problem of dropping the upper ladder when the upper ladder is released. To provide.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a lower ladder,
An upper ladder slidably connected after the lower ladder, an upper ladder lifting rope spanned between the two ladders, and a pair of parent pillars of the upper ladder that are attached to the lower inner surface of a pair of lower pillars so that they can swing downward A locking claw that is biased by a spring in the direction of the lower ladder and has a recess on the lower surface that fits into the step of the lower ladder, and is swingably mounted near the upper ladder of the lower end of the locking claw. In a double ladder consisting of a locking blocking piece that hits the step of the lower ladder from above to close the recess, it is pivotally attached to the upper position of the locking claw on the inner surface of at least one of the pair of main pillars of the upper ladder. And an upper ladder pull upper arm that is rotatably attached so as to project between the upper and lower adjacent ladders of the lower ladder, and an upper ladder pull in a state of protruding between the vertically adjacent ladders. Between the protrusion that receives the upper stop arm and the step rails that are vertically adjacent to each other The projection that receives the upper ladder pull-up stop arm when it is not extended and the projection that sandwiches the upper ladder pull-up stop arm sandwiches the projection and the upper ladder pull-up stop arm has some resistance. The inner surface of the main pillar of the lower ladder is provided with a protrusion that can be crossed, but when the upper ladder in the locked state is pulled up, the lock blocking piece that opens the recess can close the recess when descending. By the time the projecting upper ladder pull-up stop arm hits the pedestal directly above.

The double ladder according to the present invention is composed of a lower ladder, an upper ladder slidably connected to the lower ladder, an upper ladder lifting rope extending between both ladders, and a lower portion of a pair of upper pillars of the upper ladder. The locking claw, which is attached to the inner side surface at a predetermined position so as to be swingable downward, is biased in the direction of the lower ladder by a spring, and has a recess on the lower surface, which is fitted to the step rail of the lower ladder, and the locking claw. A lock prevention piece that is swingably attached to the lower end near the upper ladder and hits the step of the lower ladder from above to close the recess, and a locking claw on the inner surface of at least one of the parent pillars of the upper ladder. Between the upper ladder upper stop arm pivotally attached to the upper position of the upper ladder and rotatably mounted so as to project from the main pillar to the vertically adjacent step rails of the lower ladder and the vertically adjacent step rails. The protrusion that receives the upper ladder pull-up stop arm in the protruding state, and the upper and lower A protrusion that receives the upper ladder pull-up stop arm that does not project between the adjacent cross rails, and an upper ladder pull-up stop arm that is provided so as to face the protrusion with the upper ladder pull-up stop arm sandwiched between them. Since there is some resistance on the inside surface of the main pillar of the lower ladder, there is some resistance, but if the ladder pull-up stop arm is received by the projection beyond the projection, it can be lifted by the rope operation. There is no difference from the conventional art in that the ladder can be freely moved up and down, and the upper ladder can be fixed to the lower ladder by locking the locking claws to a predetermined step to set the double ladder to a desired length.

Also, when the upper ladder in the locked state (see FIG. 5) is pulled up, the upper ladder pull-up stop arm is stopped until the locking block that opens the recess can close the recess when descending. Is designed to hit the ridge directly above (see Fig. 6), so when changing the standing position of the ladder from above the roof, turn the upper ladder pull-up stop arm by hand and make a predetermined adjacency If it is made to protrude between the steps, when the upper ladder is pulled up, the stop arm hits the step of the lower ladder directly above it from below, so that the lower ladder is pulled up together with the upper ladder. Then, after changing the ladder to the desired position, when the hand is released from the upper ladder, the locking claws are immediately locked to the step rail immediately below the ladder, and the upper ladder is fixed to the lower ladder at that position.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

The double ladder shown in FIGS. 1 to 6 is a lower ladder.
(1) and the upper ladder slidably connected after the lower ladder (1)
(2) and the upper ladder lifting rope (1
3) and a pair of main pillars (5) of the upper ladder (2) are attached to the lower inner side of the upper pillars at predetermined positions so as to be swingable downward, and are urged by a spring (18) in the direction of the lower ladder, and are attached to the lower surface. A locking claw (14) having a recess (14a) that fits into the step (4) of the ladder (1), and a lower end of the locking claw (14) swingably mounted near the upper ladder and Locking stop piece (16) that hits the step (4) of the lower ladder (1) from above to close the recess (14a) and the locking claw on the inner surface of the left main pillar (5) of the upper ladder (2). An upper ladder pulling stop which is pivotally attached to a position above (14) and is rotatably mounted so as to project from the main pillar (5) between the vertically adjacent step rails (4) of the lower ladder (1). ·arm
(20) and a protrusion (23) provided on the inner surface of the same pillar (5) and receiving the upper ladder pulling up stop arm (20), and the upper ladder (2) in the locked state. When pulling up, recess (14a)
Make sure that the upper ladder pull-up stop arm (20) hits the step rail (4) directly above by the time the locking prevention piece (16) that is opening is ready to close the recess (14a) when descending. Has been done.

The pair of main pillars (3) of the lower ladder (1) has a U-shaped cross section with the open side facing inward, and the pair of main pillars (5) to which the step (6) of the upper ladder (2) is crossed. ) Has a U-shaped cross section with the open side facing outward, and the front wall of the latter overlaps the front side of the rear wall of the former, so that the upper ladder (2) slides after the lower ladder (1). It is movably connected.

Horizontal upper and lower support members extending to the upper ladder (2) side near the upper end and slightly above the lower end of the outer surface of the right main pillar (3) of the lower ladder (1).
(7) and (9) are fixed, and the vertical support members (7) and (9) support the vertical pulleys (8) and (10). A vertical support member (11) is fixed at a position slightly above the lower end of the outer surface of the upper ladder (2), and a pair of upper and lower intermediate pulleys (12A) and (12B) are supported by this. The upper end of the rope (13) is attached to the upper support member (7), and the upper middle pulley (12A), the upper pulley (8), the lower pulley (10), and the lower middle pulley (13B) are successively swung around to form the lower end. Are attached to the lower support member (9).

As shown in FIG. 2, the locking claw (14) has a triangular shape having a top on the front side, and a base (14b) protruding upward has an upper ladder.
The pin is housed in a hollow rocking control member (17) fixed to the inner surface of the left main pillar (5) of (2) and whose lower end is open.
In the normal state, the front surface of the base portion (14b) abuts against the rear surface of the front wall of the rocking control member (17) by the spring (18), so that the concave portion of the locking claw (14) is suspended. (14a) is just a step
(4) It protrudes diagonally to the lower front so that it can fit in. The front side of the locking claw (14) has its upper half portion inclined forward and downward and its lower half portion inclined rearward and downward so as to reduce resistance when the upper ladder (2) moves up and down. The recessed portion (14a) is present above the rear lower inclined side.

The locking block (16) is a flat straight line that gradually becomes thinner toward the tip. Recessed claw (14) recess (14a)
At the rear corner of the opening of the, there is formed an inverted L-shaped step (14c) when viewed from the side where the front and the bottom are opened, and the base (16a) of the locking block (16) is formed here. Stacked and pivoted with pins (19). When the locking block (16) closes the recess (14a), the tip of the locking block (16) is on the extension line of the front lower slope of the locking claw (14), as shown by the two-dot chain line in FIG. Also, one side edge of the same is located on the extension line of the downwardly inclined portion.

As shown in FIG. 3 and FIG. 4, the upper ladder pull-up stop arm (20) is an L-shaped round bar when viewed from the front, and its base (20a) is crushed from both sides. A circular bulging boss (21a) formed in the center of a vertically long rectangular support plate (21), which is flat and has four corners riveted to the inner surface of the main pillar (5), is rotated. It is pivoted with rivets (22) with a slight clearance as possible. On the support plate (21),
Around the boss (21a), a circular bulge (21
b) is formed, and the pin that becomes the protrusion (23) that horizontally receives the upper ladder pulling up stop arm (20) and the stop that is rotated by 270 ° from the protruding state and is in the hanging state -The pins that serve as the protrusions (25) for receiving the arms (20) are fixed to each other so as to project inward. Circular bulge (2
In 1b), the protrusions (24) (26) bulged in a hemisphere shape are spaced apart by the diameter of the stop arm (20) so as to face the protrusions (23) (25). Is provided. Convex part (2
4) The height of (26) is slightly higher than the height of the boss (21a),
The stop arm (20) can rotate over these with some resistance, but when it is horizontal or drooping, it is caught between the protrusions (23) (25) and the protrusions (24) (26). Each state is held so that it does not rotate naturally.

5 and 6 show that when the upper ladder (2) in the locked state is pulled up, the lock blocking piece (16) that opens the recess (14a) can close the recess (14a) when descending. It shows a state in which the upper ladder pull-up stop arm (20) hits the step rail (4) directly above by the time the state is reached.

7 and 8 show modifications of the upper ladder pull-up stop arm, the protrusion, and the like. That is, the upper ladder pull-up stop arm (30) in the figure is made of an L-shaped plate when viewed from the front, and its base (30a) is vertically long with four corners riveted to the inner surface of the main pillar (5). A rivet (32) is pivotally attached to a circular bulging boss portion (31a) formed in the center of a rectangular support plate (31) with a slight gap so as to be rotatable. The support plate (31) has a cut-and-raised portion which becomes a protrusion (33) for horizontally receiving the upper ladder pull-up stop arm (30), and 270 ° from the protruding state.
The stop arm (3
The cut-and-raised parts that serve as the projections (35) for receiving 0) are provided so as to project inward. These cut-and-raised parts have a 1/4 spherical shape in which the receiving surface is straight when viewed from the side. Support plate (31)
The stop arm (30) so that it faces the protrusion (35).
The protrusions (3
4) is provided. The height of the convex portion (34) is slightly higher than the height of the boss portion (31a), and although the stop arm (30) has some resistance, it can rotate beyond this, but when it is in the hanging state, the protrusion The state is held by being sandwiched between (35) and the convex portion (34) so that it does not rotate naturally.

In the above embodiment, the upper ladder pull-up stop arm is attached only to the left main post side, but it may be attached to the right main post side or even to the main post. Of course, a projection or the like for receiving this is provided corresponding to the mounting position of the stop arm.

Effect of the Invention According to the double ladder of the present invention, the upper ladder pulling up stop arm in a state where it does not project between the vertically adjacent stepped bars of the lower ladder is received by one of the projections and faces the projection. Since it is sandwiched between the convex parts provided like
The non-protruding state of the upper ladder pull-up stop arm is easily and reliably maintained. Then, in this state, the upper ladder can be freely moved up and down by operating the rope, and the upper claw is fixed to the lower ladder by locking the locking claw to a predetermined step, so that the double ladder having a desired length can be obtained. Can be formed with a ladder.

On the other hand, when changing the standing position of the ladder from the top of the roof, simply by rotating the upper ladder pull-up stop arm over the convex portion, the stop arm is received by the other protrusion, It will be in a state of protruding between the step rails that are vertically adjacent to each other on the lower ladder. And if you lift the upper ladder in this state,
As a result of the stop arm striking the step ladder of the upper ladder just above from below, the lower ladder is pulled up together with the upper ladder. After that, when the ladder is lowered at a desired leaning position, the locking claws are locked to the step rails directly below it, and the upper ladder is fixed to the lower ladder at that position without dropping.

In summary, in the case of the double ladder of the present invention, the position where the ladder is leaned can be easily and reliably changed only by rotating the upper ladder pull-up stop arm.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is an overall perspective view of a double ladder, Fig. 2 is a vertical enlarged sectional view showing a locking claw portion, and Fig. 3 is an upper ladder pulling up stop arm. FIG. 4 is an enlarged vertical sectional view showing a portion, FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 3, and FIGS. 5 and 6 show the recess when the upper ladder in the locked state is pulled up. The upper ladder pull-up stop
FIG. 5 is a partial vertical sectional view showing a state in which the arm is in contact with the step rail directly above, and FIG.
The figure shows the state during pulling. FIG. 7 is a vertical sectional view corresponding to FIG. 3 showing a modified example of the upper ladder pulling up stop arm and projections, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG. (1)… Lower ladder, (2)… Upper ladder, (4)… Lower ladder, (5)…
Parent ladder of upper ladder, (13) ... upper ladder lifting rope, (14) ... locking claw, (14a) ... recess, (16) ... locking block, (18) ... spring, (2
0) (30)… Upper ladder pull up stop arm, (23) (33)… Protrusion.

Claims (1)

[Scope of utility model registration request] 1. A lower ladder (1), an upper ladder (2) slidably connected after the lower ladder (1), and an upper ladder lifting rope spanned by both ladders (1) (2). (13) and a pair of parent pillars (5) of the upper ladder (2) are attached to the lower inner surfaces of the upper pillars at predetermined positions so as to be swingable downward, and are urged toward the lower ladder by springs (18) and are attached to the lower surface. The locking claw (14) with a recess (14a) that fits into the step (4) of the lower ladder (1) and the lower end of the locking claw (14) are swingably mounted near the upper ladder. In addition, in a double ladder consisting of a locking block (16) that hits the step (4) of the lower ladder (1) from above and closes the recess (14a), a pair of parent pillars (5) of the upper ladder (2) ) Is pivoted at a position above at least one of the engaging claws (14) and pivots so as to project from the main pillar (5) between the vertically adjacent step rails (4) of the lower ladder (1). Between the upper ladder pull-up stop arm (20) (30), which is freely installed, and the step rails (4) that are vertically adjacent to each other. On top of the state that issued the ladder pulling stop arm (20) (30)
The protrusions (23) and (33) for receiving the above and the step rails that are vertically adjacent to each other.
(4) Insert the upper ladder pull-up stop arm (20) (30) and the projection (25) (35) that receives the upper ladder pull-up stop arm (20) (30) that is not protruding between them. It is installed to face the protrusions (25) (35) and the upper ladder pull-up stop arm (2
0) (30) has some resistance but it can be overhanged (26) (34)
And the inner side of the main pillar (5) of the lower ladder (1), and when the upper ladder (2) in the locked state is pulled up, the recess (14a) is opened to prevent the locking block (16). Of the upper ladder pull-up stop arm (2
A double ladder characterized in that (0) (30) is designed to hit the step rail (4) directly above.