JPH0324797Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of application of the invention) This invention is useful when workers climb ladders to work at relatively high places, such as when caring for garden trees, working in orchards, or gardens. This invention relates to a so-called self-supporting ladder that can also be used as a stepladder, in which the ladder itself is supported in a self-supporting manner because there is no place to lean the ladder against.

(Prior art) As a self-supporting ladder that can also be used as a stepladder,
There is a prior art disclosed in No. 11576. In this prior art, a main ladder and a secondary ladder are rotatably connected to each other by a pivot part at the upper end, and both ladders stand opposite each other in an A shape with the upper end pivot part as a fulcrum to form a stepladder. can be made into a long ladder by extending in a straight line with respect to the main ladder, and in order to make this long ladder independent, a pair of support legs are installed in the middle of the main ladder so that they can freely rotate not only back and forth but also left and right. It is connected in a way that cannot be separated.

(Problem that the invention attempts to solve) With this conventional technology, since the pair of support legs are attached to the main ladder side of both the master and subordinate ladders, the subordinate ladder cannot be extended in a straight line with respect to the main ladder. When a long ladder is made to stand on its own with a pair of support legs attached to the main ladder side, there is no support on the secondary ladder side, so work at high places is performed by climbing on the secondary ladder side. This is a fatal drawback for long ladders, which are originally used for working at heights.

In addition, according to this prior art, the pair of support legs for making the long ladder independent are pivotally connected to the main ladder so that they can rotate not only back and forth but also left and right, so that the opposing angles of the two support legs are There is no regulation to keep it constant, and it becomes unstable and dangerous when used.

Furthermore, according to this prior art, since the pair of support legs are irremovably pivotally connected to the main ladder, both support legs become bulky when being transported, stored, or used as a stepladder. It gets in the way and is inconvenient to handle.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a stable self-supporting ladder that can also be used as a stepladder, which eliminates the above-mentioned drawbacks of the prior art.

(Means for Solving the Problems) In order to solve the above problems, the present invention pivots the main ladder 1 and the secondary ladder 2 by a pivot joint 3 at the upper end, and both ladders 1 , 2 stand oppositely in an A shape with the pivot part 3 as a fulcrum to form a stepladder 4, and the secondary ladder 2 can be extended linearly with respect to the main ladder 1 to form a long ladder 5. In the middle part of the secondary ladder 2, a pair of support legs 6 and 7 extending in an approximately figure eight shape and extending at fixed opposite angles are provided so as to be rotatable back and forth with respect to the secondary ladder 2. It adopts a structure in which it is pivotally connected in a detachable manner.

(Function) When extending the secondary ladder 2 linearly with respect to the main ladder to make it a long ladder and making it independent by a pair of support legs, the middle of the secondary ladder which is the upper ladder of both the main and subordinate ladders. A pair of support legs are pivotally attached to the lower part of the ladder, so when working at heights by climbing onto the side of the secondary ladder, the ladder is supported by the pair of support legs, making it possible to work at heights safely. can.

The pair of support legs are pivoted to the secondary ladder so that they widen in an approximately figure-eight shape and their facing angles are fixed. To stably stand a long ladder on its own by three-point support with a pair of support legs whose facing distance does not change.

When transporting or storing the ladder, or when using it as a stepladder, the pair of support legs are removed from the ladder so that the ladder does not become bulky and does not get in the way of use.

(Example) As is well known, FIG. 1 shows the state in which the main ladder 1 and the secondary ladder 2 are used as a stepladder 4. A hinge 8 is attached to the upper end of the main ladder 1 and the secondary ladder 2, and the hinge 8 is rotated by the pivot 3. The main and subordinate ladders 1 and 2 are movably pivoted, and by engaging the engagement fitting 9 pivotally supported on the main ladder 1 with the engagement pin 10 protruding from the subordinate ladder 2, both the master and subordinate ladders 1 and 2 are turned into a substantially A shape. It is kept and used. Both of these ladders 1 and 2 have the same substantially vertically elongated trapezoidal shape, and the tread 1
1 and side pillars 12, 12 on both sides thereof, and it is well known that the treadle 11 is formed wider toward the lower stage.

In the present invention, bearings 13 are mounted on both side pillars 12, 12 at or above the lowermost step 11a of the subordinate ladder 2 of the main and subordinate ladders 1, 2.
13 is fixed with screws etc., and the axis 1 is attached to this.
4 is rotatably supported parallel to the step 11, and a pair of short rods 15, 16 are fixedly corresponded to the pivot 14 in a substantially figure-eight shape by means such as welding. It is installed protrudingly. Therefore, the pair of short rods 15 and 16 are formed in a substantially figure-eight shape so as to be able to freely rotate together with the pivot 14 in a state corresponding to a required angle.

As shown in FIG. 3, tubular support legs 6 and 7 are fitted into the pair of short rods 15 and 16, respectively, and nut-shaped nuts welded to the support legs 6 and 7 are fitted to the pair of short rods 15 and 16, respectively. The female threaded portion 17 and the presser bolt 18 screwed into this are attached, and the presser bolt 1 is attached when fitted.
8 is pressed against the short rods 15, 16 to prevent them from coming apart, but the presser bolt 18 may not be provided as will be described later.

Adjustment legs 19 are fitted to the lower parts of the support legs 6 and 7, and adjustment holes 20 are provided through the adjustment legs 19 at appropriate intervals in the longitudinal direction, and mounting holes 2 are provided in the support legs 6 and 7.
By inserting a support pin 22 across the support legs 6 and 1, the overall length of the support legs 6 and 7 can be adjusted. In addition, 23 is a well-known ground plate pivotally supported by the adjustment leg 19. Further, in FIG. 2, reference numeral 24 denotes a support leg distance maintaining strap detachably suspended between one side post 12 and the support leg 7 via a hook 25.

As shown in FIG. 1, when the stepladder 4 is used as a well-known stepladder 4, the supporting legs 6 and 7 are separated from the short rods 15 and 16 of the subsidiary ladder 2. In this state, as shown in the figure, the short rods 15 and 16 do not protrude much from the side columns 12 and 12 on both sides, so the overall size is not bulky and there is no problem in use.

As shown in FIG. 2, in order to extend the secondary ladder 2 linearly with respect to the main ladder 1 and use it as a long ladder 5, and to make it independent, a pair of support legs 6,
7 are fitted into the short rods 15 and 16, respectively, and both support legs 6 and 7 are extended forward from the secondary ladder 2 using the pivot 14 as a fulcrum, and the support legs 6 and 7 are fitted in accordance with the inclination angle of the long ladder 5.
It is only necessary to adjust the adjusting legs 19, 19 of No. 7 to ground it. In this manner, by providing the pair of support legs 6 and 7 on the secondary ladder 2 side, which is the higher side of both the master and slave ladders, it is possible to stably stand up on its own as a long ladder, making it possible to work at heights. In order to stably stand on its own as a longer ladder, it is preferable to pivot the supporting legs 6 and 7 as close as possible to the upper end of the secondary ladder 2, as shown in the figure. In this case, in order for the long ladder 5 to be supported at three points by the main ladder 1 and the pair of support legs 6 and 7 and to stand up stably, it is necessary to
The mounting angle of the pair of short rods 15, 16 is determined so that _{the opposing distance 2 between} the support legs 6, 7 is 3 to 5 times, preferably 4 to 5 times the width of the opposing distance 1 between the support legs 6, 7. It is preferable to do so. Note that when the long ladder 5 stands on its own, the short rods 15 and 16 and the tubular support legs 6 and 7 externally fitted thereon are pressed against each other by their own weight and do not physically separate, so the above-mentioned presser foot Although it is not necessary to provide the bolt 18, it is better to provide the bolt in order to prevent separation during short-distance movement.

Furthermore, by pivoting the support legs 6 and 7 not to the upper end of the secondary ladder 2 when used as a long ladder 5, but to the upper midway part thereof, the upper part of the secondary ladder 2 can be used as a kind of handrail. will play a role.

Figure 4 shows a state in which the long ladder 5 is used by extending over a high place A such as a high-rise building.
A long ladder, which is a long object, is supported by grounding both support legs 6 and 7 pivoted to the ground in an almost vertical state,
It is possible to prevent the occurrence of deflection and damage to the pivot joint.

(Effects) According to the present invention, since it is only necessary to provide a pair of support legs on the secondary ladder side of both the master and subordinate ladders, a self-supporting ladder can be manufactured using a normal stepladder, and manufacturing costs can be reduced. can be reduced.

According to the present invention, the pair of support legs are provided on the long ladder in an approximately figure-eight shape, and the opposite angles to each other are fixed, so that the support legs do not wobble during use and can be fixed at the so-called three points. The support allows the long ladder to stand on its own in a stable manner.

According to the present invention, when the secondary ladder is extended linearly with respect to the main ladder and used as a long ladder,
A pair of support legs are pivotally connected to the upper sub-ladder, and it is supported by these legs, allowing it to be built into a very tall self-supporting ladder, allowing it to be used at high places, which was previously impossible. This makes it possible to perform the following tasks.

According to the present invention, the pair of support legs are removably pivoted to the long ladder, so when transporting or storing the support legs, or when using it as a stepladder, both support legs can be detached from the long ladder. It is not bulky, does not get in the way of use, and is advantageous in handling.

According to the embodiment of the present invention, both support legs are pivotally attached to the upper middle part of the long ladder, so that the upper part of the long ladder functions as a kind of handrail during use, making it easy to use.

According to the embodiment of the present invention, since the length of the pair of support legs is adjustable, it can be easily adapted to cases where the ground surface is uneven or when used as a free-standing ladder. .

According to the embodiment of the present invention, the distance between the pair of supporting legs pivoted thereon is set to be 3 to 5 times, preferably 4 to 5 times, the width between the pillars on both sides of the long ladder. The so-called three-point support function can be effectively exhibited, and the long ladder can be made to stand on its own in a more stable manner.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention.
The figure is a perspective view when used as a stepladder, FIG. 2 is a perspective view when used as a self-supporting ladder, FIG. 3 is a vertical sectional side view of the main part, and FIG. 4 is a side view showing an example of the state of use. 1... Main ladder, 2... Secondary ladder, 3... Pivot part,
4...Stepladder, 5...Long ladder, 6,7...Support legs,
15, 16...Short rod, 19...Adjustable leg.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A main ladder and a secondary ladder are pivotally connected at a pivot part at the upper end thereof, and both ladders are stood on opposing legs in an A shape with the pivot part as a fulcrum, so that the ladder can be used as a stepladder. At the same time, in a stepladder that can be made into a long ladder by extending the secondary ladder in a straight line with respect to the main ladder, there is a stepladder in the middle of the secondary ladder that expands in an approximately figure-eight shape and has opposite angles to each other. A self-supporting ladder in which a pair of fixedly extending support legs are pivotally connected to a subordinate ladder so as to be rotatable back and forth and detachable. 2. A self-supporting ladder that can also be used as a stepladder as set forth in claim 1 of the utility model registration claim, in which both support legs are pivotally attached to the upper middle part of a secondary ladder when used as a long ladder. 3. A self-supporting ladder that can also be used as a stepladder as set forth in claim 1 or 2 of the utility model registration claim, wherein the pair of support legs are provided so that their lengths can be freely adjusted. 4. The distance between the side columns at the ground contact part of the main ladder is 3.
A self-supporting ladder that can also be used as a stepladder according to claim 1, 2, or 3, which is formed to be 5 times larger, preferably 4 to 5 times larger.