JPH0988465A - Folding stepladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a safe folding stepladder wherein there is no fear of missing of worker's step when the worker goes up and down the stepladder and the worker stands on the top end to work in the stepladder. SOLUTION: A stepladder is so constituted that a leg body 3 is combined with a folding staircase formed of a parallelogram link body, a platform 1a provided to the upper end of the folding staircase 5 and a platform 1b on the upper end of the leg body are connected to each other in a foldable manner and, at the same time, an expansible leg 4 is provided downward of the leg body 3. An expansible bearing member 10 is built from the front end of an upper link of the folding staircase 5 to the lower end of the leg body, and a lock device for locking a lower vertical link 9 and the bearing member 10 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly stable folding stepladder.

[0002]

2. Description of the Related Art A stepladder is generally used for placing an object at a high place or removing an object at a high place, and a person works on the stepladder. Therefore, each household often has a stepladder for putting objects in and out of high places. Of course, the stepladder is often used for interior and exterior work in a house, and has a use different from that of a ladder. That is, the stepladder has two legs that can be opened on both sides, and can stand up independently if it is a flat place, rather than leaning up like a ladder.

FIG. 5 shows a commonly used stepladder. The two legs (a) and (a) spread downward,
It has an inverted V shape, and the upper ends of the legs (a) and (a) are bases.
It is swingably connected to (b). The leg (a) has two vertical rails (c), (c) horizontally mounted with treads (d), (d) .... Therefore, it is possible to put the foot on these treads (d), (d) ... to raise them to an appropriate height, but the tread (d) of this type of stepladder is a thin bar material, and therefore In addition, it lacks stability due to lack of foot support, and may fall off the foot or sometimes during work. In addition, it lacks stability even in a standing state.

On the other hand, the stepladder, as is clear from the figure,
Since it is symmetrical about the neutral axis passing through (b), the position of the base (b) will be displaced by the distance L from the position of the lower end of the leg (a), for example. This misalignment may be inconvenient depending on the intended use, and it cannot be used in contact with the wall surface. Also, since the table (b) is small, there is a danger in working on it, and when changing the work place, it is impossible to move the body while it remains on the stepladder. That is, it is necessary to once descend from the stepladder and move the stepladder itself to an appropriate place.

[0005]

As described above, the conventional stepladder has the above-mentioned problems. The problems to be solved by the present invention are these problems, the base at the upper end is large and highly stable, and it is possible to move to some extent while being mounted on the base, and it is dangerous even when lifting a heavy object. Without
Also, one leg stands up almost vertically, providing a stepladder that can stand up against the wall surface because there is no distance from the stand.

[0006]

The stepladder of the present invention is not an inverted V shape as in the prior art, but a trapezoid in which one leg is substantially vertical. One leg is inclined to form a folding staircase in which a foot plate is attached to the leg. The side pieces that make up this folding staircase are parallelogram-shaped link bodies.The upper link and the lower link are parallel to the floor surface, and the upper vertical link and the lower vertical link connect both ends of the upper and lower links. There is. The base is attached between the left and right upper links, and the other step plate is axially mounted between the upper vertical link and the lower vertical link so as to be parallel to the base.

The width of the footboard is the distance between the parallelogram links on both sides, and the depth is the distance when the upper vertical link and the lower vertical link are vertically erected. Therefore, the depth is larger than that of the conventional stepboard of the stepladder, and it is stable without stepping on the foot. The upper and lower vertical links have a slope of stairs inclined at an appropriate angle, and are equipped with a lock device for fixing this angle.

Another link is flexibly connected to the left and right upper links to which the foldable stairs stand is attached,
A platform is also attached to the link. The legs are connected to the rear end of the base so that the legs can be bent with respect to the links, but the bending direction of the rear base is a direction in which both bases are convex, and the legs are concave. do not do. In addition, a supporting member is hung between the upper link tip of the folding staircase and the lower end portion of the leg body, and both bases, the leg body and the supporting member form a triangle.

The above-mentioned triangular shape does not change regardless of how the slope of the folding staircase changes, and tension is applied to the support member by the load acting on the upper surface of the base, and the legs connected to the rear base. I can't fall down. Further, a lock device is provided to fasten the lower vertical link of the folding stair and the supporting member in order to fix the gradient of the folding stair at a predetermined angle. In addition, the leg length can be adjusted according to the slope of the folding stairs. Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an embodiment showing a stepladder of the present invention and shows an overall external view. As is apparent from the figure, the base 1 at the upper end is large and the area of the footboard 2 is large as compared with the conventional stepladder. Therefore, the stepladder is safe and stable without stepping off. The leg on one side constitutes a foldable staircase, the two treads 2, 2 are parallel to the base 1a, and the other leg 3 extends substantially vertically downward from the base 1b, Flexible legs 4 and 4 are attached below. Of course, it does not have a footboard. The platform 1b has the same height as the platform 1a of the folding stairs 5 and is connected so as to be folded together.

If only the left slanted leg in the figure is taken, it is a foldable staircase 5, the side part of which is composed of parallelogram links, and the footboards 2, 2 are placed between the parallelogram links. Also, the base 1a is attached. The step plates 2 and 2 are mounted so that they can be moved in accordance with the deformation of the parallelogram link body. This parallelogram link body is composed of an upper link 6a, a lower link 7, an upper vertical link 8 and a lower vertical link 9, and the upper vertical link 8 and the lower vertical link 9 are connected to both ends of the upper and lower links 6,7. I am configuring.
The upper link 6a and the lower link 7 are always parallel and horizontal, and the upper vertical link 8 and the lower vertical link 9 are also parallel to each other and are inclined at a predetermined angle.

The treads 2, 2 are the upper and lower links 6,
Edges of side ends are fixed to the upper vertical link 8 and the lower vertical link 9 so as to be parallel to 7. Therefore, no matter how the parallelogram link body has any shape, as long as the lower link 7 is in contact with the floor surface, the treads 2, 2 are always horizontal and do not affect the inclination angle of the folding stairs 5.

By the way, the folding angle of the folding stairs 5 can be freely adjusted and can be fixed at a predetermined gradient. That is, the supporting members 10 and 10 are obliquely attached to both sides of the stepladder, the upper end thereof is connected to the front end of the upper link 6a, and the lower end thereof is connected to the lower end of the leg body 3. And this support member 1
0 is expandable and contractible, but it is regulated so as not to extend further when the stepladder as shown in FIG.

FIG. 2 is a side view of the stepladder of the present invention. When the stepladder is erected, a triangle ABC is formed, and the shape of the triangle ABC does not collapse. That is, the side AB is the base 1
The lengths are the lengths of the upper links 6a and 6b to which a and 1b are attached, the side BC is the length of the leg body 3, and the side AC is the length of the support member 10 fully extended. Since the lengths of the three sides are fixed, the shape of the triangle ABC is fixed.
Here, the load P due to a person resting on the table 1a, 1b
Is applied, the support member 10 is tensioned and does not contract. Since the leg 3 is slightly inclined,
The load P acts as a force that pushes the lower end of the leg body 3 outward.

The bases 1a and 1b are connected via a shaft 11. The shaft 11 is located below the base 1a, and the upper link 6b to which the base 1b is attached is The both ends 1a, 1b are not bent by the load P by contacting the end surface of the upper link 6a of the base 1a. By defining the triangle ABC in this manner, the legs 3 connected to the platform 1a, 1b and the upper link 1b are stabilized.

However, the inclination angle of the folding staircase 5 is not fixed, and the upper vertical link 8 and the lower vertical link 9 are A-shaped.
It can be swung about the point and the axis 11. Therefore, in order to fix the inclination angle of the folding stairs 5, the lower vertical link 9 is fixed to the support member 10. FIG. 3 shows this locking device, and the lower vertical link 9
A lock pin 12 is attached to the lock pin 12, and the lock pin 12 can be engaged with a hole formed in the support member 10 by being operated by a lever 13.

A plurality of holes are provided in the support member 10 at regular intervals, the tips of the lock pins 12 are fitted into the holes to fix the lower vertical link 9, and the inclination angle of the folding stairs 5 is fixed. . The lock pin 12 is connected to the lever 13, and when the lever 13 is operated, the lock pin 12 retracts and is removed from the hole of the support member 10. A coil spring 14 is attached so that the lock pin 12 does not come out of the hole, and the spring force of the coil spring 14 is urged.

Legs 4 are attached to the leg body 3 so that they can be expanded and contracted, and the base 1b is adjusted so as to be horizontal with the base 1a. A lock device similar to that shown in FIG. 3 is provided at the lower end of the leg 3, and lock pins are fitted and fixed in holes formed at equal intervals in the leg 4.

FIG. 4 shows a case where the stepladder of the present invention is folded. As shown in the figure, the lock device for fixing the inclination angle of the foldable staircase 5 is released, and the vertical link 8,
9 is squeezed to approach it, the table 1b is bent at the axis 11, and the leg 3 is swung about the point B as an axis to be parallel to the table 1b. . The folded stepladder is in the form of a single plate, which does not hinder storage. As described above, in the stepladder of the present invention, the pedestal is connected to the folding staircase and the legs are attached to the pedestal, and the following effects can be obtained.

[0020]

The stepladder of the present invention is provided with a folding staircase, and this staircase is a parallelogrammatic link body to which a large footboard is attached. The foldable staircase can be adjusted in its inclination freely, and since two pedestals of the same size as the footboard are provided at the upper end, the area is large and when the work is carried on the upper end. It is convenient for
On the other hand, since the stepladder can be folded into a single plate by folding the stairs and the legs, it is easy to carry and store, and the leg on the rear side of the stepladder is perpendicular to the base. Because of this, it can be placed so that it contacts without leaving a space on the wall of the room.

[Brief description of drawings]

FIG. 1 is an example showing a stepladder of the present invention.

FIG. 2 is a side view of the stepladder of the present invention.

FIG. 3 is a locking device for fixing the inclination angle of the folding stairs.

FIG. 4 shows the stepladder folded.

FIG. 5 A conventional stepladder.

[Explanation of reference symbols] 1 unit 2 Footboard 3 Legs 4 Legs 5 Folding stairs 6 Upper link 7 Lower link 8 Upper vertical link 9 Lower vertical link 10 Supporting member 11 Axis 12 Lock pin 13 Lever 14 Coil spring

Claims (2)

[Claims] 1. A stepladder comprising a foldable staircase and a leg body having a base at its upper end, wherein the foldable staircase is formed by connecting an upper link, a lower link, an upper vertical link, and a lower vertical link to parallel four sides. A parallel link body is constructed, and the parallelogram link bodies are arranged side by side at regular intervals, and a foot plate is axially attached to the upper vertical link and the lower vertical link in parallel with the upper and lower links, and between the upper links. A base is attached to each leg, and another upper link is flexibly connected to both upper ends of one leg, and a table is attached between both upper links so that the height is the same as that of the foldable stairs. The links are connected so that they can be bent, and the legs are attached to the legs so that they can expand and contract, and a supporting member that allows the legs to extend and contract from the top link tip of the folding staircase is suspended. Folding stair tilt angle Folding stepladder, which is equipped with a locking device for fixing the lower vertical link and the supporting member to fix the 2. The lower vertical link as the locking device is provided with a lock pin that is moved in and out by operating a lever, and one supporting member is formed with a plurality of holes at equal intervals, and the lock pin is fitted into the hole. The foldable stepladder according to claim 1, wherein the foldable stepladder is formed.