JPH10231674A - Stepladder with expansion construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a function as the length of a bearing leg for a stepladder can be freely and surely adjusted with a sufficient safety mechanism for the stepladder. SOLUTION: A stepladder with expansion construction is constituted of an expansion leg section 2 having a bearing leg 1 and an interlocking groove 2b, a stopper 3 having an interlocking claw 3a interlocking with the interlocking groove 2b, a compression spring 4 pushing the stopper 3, a bottom seat 5 holding the compression spring, handle section, etc., and those members are monolithically bound with a binding bolt 8. The length of the length can be quickly, safely and surely adjusted by the stepladder construction to fix.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for adjusting the height of a supporting leg of a structure such as a stepladder, a ladder or the like, and more specifically, to a case where the structure is to be mounted on uneven or sloping ground having many irregularities. The present invention also relates to a leg length adjusting structure of a supporting leg which can adjust the leg length of the supporting leg and stably hold the structure.

[0002]

2. Description of the Related Art When performing work at a high place in a building such as a house, generally, a structure such as a ladder, a stepladder, and a scaffold is erected on the ground, and an operator rides on top of the structure. We are working on various tasks. As a structure of such a work table for home use, a stepladder formed of a lightweight material such as an aluminum material or a thin steel material is widely used. As a structure of the stepladder, four frame-shaped supporting members are used. It has legs and has a step on the upper end, and many have a mechanism that can be folded freely.

[0003]

The folding stepladder having such a folding structure is not stable until the four legs are installed evenly, so that the work can be performed on the stepladder. The occurrence of an ungrounded portion at a location results in an extremely unstable work situation. For this reason, various structures capable of adjusting the dimensions of the legs along the uneven shape have been developed, and Japanese Utility Model Laid-Open No. 55-119900 shown here is one of them. This will be described in detail with reference to the drawings. As shown in FIG. 3, a slidable pipe (11) formed at a lower portion of a leg is moved to an arbitrary position by a thumb screw (12) and a nut (9). A size adjustment mechanism that can be fixed is proposed. However, it is not possible to work on the stepladder with security by the above-described size adjusting mechanism. That is, the work on the stepladder naturally involves a large external stress, such as vibration or impact, applied to the stepladder. In the fastening structure of the thumb screw bolt (12) and the nut (9), which does not have the slip prevention device of the safety mechanism, There is a risk that the structure may be displaced by the external stress or may fall loose in some cases, and it must be said that the structure has a serious disadvantage. The present invention has been developed in view of such a drawback, and an object of the present invention is to provide a stepladder with a telescoping structure that allows a free adjustment of a leg length of a supporting leg with a sufficient safety mechanism.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a stepladder capable of extending and contracting a leg, and as shown in FIG. 1, a supporting leg (1) having a C-shaped cross section, and the supporting leg (1). A telescopic leg portion (2) having a long hole (2a) provided in the longitudinal direction, which is provided so as to be extendable and retractable, and an engagement groove (2b) cut at equal intervals;
A stopper (3) having an engagement claw (3a) engaged with the engagement groove (2b) and having a tapered portion (3b) in a mounting portion; and a compression spring (4) for applying a pressing force to the stopper (3). ), A bottom seat (5) for pressing the compression spring (4), and a tapered portion (3) of the stopper (3).
b) a handle portion (6) having a tapered portion (6a) meshed with the handle portion (6), and a pedestal (7) and the like taperedly engaged with the handle portion (6).
And a stopper (3), a compression spring (4), a bottom seat (5), a handle portion (6), a base (7), and other members are integrally bound by a binding bolt (8). In these assembled states, the pedestal (7) is restricted in free rotation in order to exert a taper cam action with the handle part (6), and is also united with the binding bolt (8). A binding fastener (represented by a nut here) is provided outside the bottom seat (5).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a stepladder having a telescopic structure as described above, and to a supporting leg (1) for a structure having a lightweight C-shaped cross section as shown in FIGS. The telescopic leg (2) is securely attached and fixed by the engagement between the engaging claw (31) of the stopper (3) and the engaging groove (2b) of the telescopic leg (2). When the handle (41) is turned to an appropriate angle, the taper (6a) interlocking with the handle (41) slides in a cam shape with the taper (3b) of the stopper (3), and the stopper (3) The stopper (3) compresses and deforms the compression spring (4) which is in close contact with the stopper, thereby forcing the stopper (3) to move backward. Then, the engaging claw (3a) of the stopper (3) is disengaged from the engaging groove (2b) of the telescopic leg (2), and the telescopic leg (2) is left free.

Here, the telescopic leg portion (2) in the free state is adjusted to the required height, and then the handle portion (6) is returned in the opposite direction to the above, and the respective tapered portions are turned. (6a) and (3b) make a return movement to bring the stopper (3) closer to the support leg (1) and the telescopic leg (2), and finally return the stopper (3) by the compression spring (4). The stopper (3) is pressed against the supporting leg (1), and the engaging claw (3a) of the stopper (3) is
Is pressed into the engagement groove (2b). At this time, even if the engaging claw (3a) and the engaging groove (2b) are not at a position where they engage exactly (even if they are slightly displaced), they are brought into pressure contact with each other by the pressing force of the compression spring (4). Therefore, if they are slightly moved due to the vertical load, they can easily be fitted and engaged and securely fixed.

As described above, according to the present invention, the secure fixing is realized by the long holes (2a) and the engagement grooves (2b) provided in the telescopic leg (2) and the engagement claws (3a) of the stopper (3). It is possible to obtain a contradictory action between the detachment preventing action and the simple adjusting action.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to carry out the present invention, in FIGS. 1 and 2, a supporting bolt (8) and a pedestal (7) for binding a supporting leg (1) and a telescopic leg (2) to other parts are used. Presser cover (1
0) is described, and the operation is not specified, but the operation of gripping the support leg (1) and the telescopic leg (2) and the cam operation of the tapered portions (6a) (3b) are smoothed. If action is required, deployment is necessary. A pedestal (7) is provided at the base of the handle (6) as shown in FIG. 2 for the purpose of rotating and fixing the handle (6) to a certain position when adjusting the expansion and contraction of the stepladder. When the tapered portions that mesh with each other are provided, tightening and fixing for restricting the free rotation of the handle portion (6) at a fixed position by the tapered cam action can be achieved, and the height adjustment operation can be further simplified.

As described above, the engagement leg (2b) and the long hole (2a) are cut in the telescopic leg (2), and the long hole (2) is formed.
a) moves the binding bolt (8) up and down, and the engaging groove (2b) functions to adjust and fix the engaging claw (3a) to an arbitrary height by engaging and disengaging the engaging claw (3a). The setting is important, but other than the illustrated groove shape, each may be provided independently, or may be provided in a round hole-like uneven shape.

[0010]

According to the above configuration, the following excellent effects can be obtained. The stepladder with the telescopic structure of the present invention is in pressure contact with each other even if the engaging claw (3a) and the engaging groove (2b), which are fixing means, are not engaged with each other, and when the stepladder receives an excessive load in the vertical direction, it moves slightly. Since it was immediately fitted and engaged and securely fixed, the danger of slipping or loose dropping due to external stresses such as vibration or impact could be completely eliminated. Of course, the height adjustment operation is sufficient with a one-touch operation by turning the handle, which greatly improves workability and operability on site.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional structure not using the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support leg 2 telescopic leg 2 a long hole 2 b engaging groove 3 stopper 3 a engaging claw 3 b taper 4 compression spring 5 bottom seat 6 handle 7 base 8 binding bolt 9 nut 10 holding cover 11 pipe 12 thumbscrew bolt

Claims (2)

[Claims] 1. A support leg having a C-shaped cross section in a stepladder, a ladder, or the like, a long hole provided in the support leg so as to be extendable and provided in a longitudinal direction, and an engagement groove cut at equal intervals. A telescopic leg, a stopper having an engagement claw that engages with the engagement groove and having a tapered portion in a mounting portion, a compression spring that applies a pressing force to the stopper, a bottom seat that presses the compression spring, and the stopper A handle portion having a tapered portion that meshes with the tapered portion, a pedestal or the like that taperly engages with the handle portion, the support leg, the telescopic leg, a stopper, a compression spring, a bottom seat, a handle, A stepladder with a telescopic structure, wherein members such as a pedestal are bound by a binding bolt. 2. A stepladder with a telescopic structure according to claim 1, wherein a presser cover for covering the support leg and the telescopic leg is arranged between the support leg and the pedestal of the handle.