JP2007100375A - Simple trestle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple trestle which includes a plurality of rungs, is lightweight to carry, stable, and can be erected even if an obstacle is present on a rear side thereof. <P>SOLUTION: According to the structure of the simple trestle, an almost L-shaped frame 1 has brackets 6, 6, ... secured to both inclined supports 4, 4, at predetermined intervals, and the rungs 2, 2, ... horizontally attached thereto via the brackets 6, 6, .... Both the inclined supports 4, 4 are concavely connected together at an upper portion 5. Then the frame 1 is continuously extended via the inclined supports 4, 4 and the corner portions 9, 9 to form horizontal leg portions 3, 3 each having leg ends 10a, 10b, ... at both ends thereof. Further the leg portions have casters 11, 11 attached thereto at locations near the leg ends 10b, 10b on the side of the corner portions, respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a simple stepladder that is light and easy to carry and that stands up stably.

  When placing an object at a high place or removing an object at a high place, a stepladder is generally used, and a person works on the stepladder. In addition, at least one leg is stored in each household, such as when a stepladder is generally used when performing a cleaning operation in a high place that is out of reach. Of course, ladders are often used in addition to stepladders as a means of going up to high places, but if working at high places, the stepladder is more stable than ladders, and its utility value is high.

  By the way, there are various types of stepladders, but basically it has a multi-step tread board, and it can be put on the tread board so that it can go up to a high place, and when it goes up on the tread board The support structure is stable so that it will not fall over. FIG. 5 is a general stepladder that has been widely used in the past. The two legs (b) and (b) spread downward and form an inverted V shape, and the legs (b) and (b) are swung by a base (b) provided at the upper end thereof. Connected freely.

  Each leg (A), (A) has two vertical bars (C), (C) mounted with treads (D), (D) ... horizontally. Therefore, these footboards (d), (d) can be raised to an appropriate height by putting their feet on them, but the stepping board (d) attached to this type of stepladder is a thin bar. For this reason, there is less support for the foot and lacks stability, and the foot may be stepped off or sometimes dropped during work. Even in an upright state, stability is often lacking.

  On the other hand, as is clear from the figure, the stepladder is symmetrical with respect to the neutral axis passing through the base (b), so the position of the base (b) is, for example, the lower end of the leg (b). It will be displaced by a distance L from the position. This misalignment may be inconvenient depending on the intended use and cannot be used in contact with the wall surface. In addition, there is a problem that the table (b) is small and it is dangerous to work on it.

  The applicant has previously filed a patent application regarding “folding stepladder” (Japanese Patent Laid-Open Nos. 9-21285 and 10-169344). “Folding stepladder” according to Japanese Patent Application Laid-Open No. 9-21285 is a combination of a folding staircase composed of a parallelogram link body and a leg body having a base at the upper end thereof. And the upper ends of the legs are connected to each other so that they can be bent at the same height, and extendable legs are attached to the legs.

  A "foldable stepladder" according to Japanese Patent Application Laid-Open No. 10-169344 is composed of a ladder having a plurality of footboards attached between parallel parallel link bodies on both sides, and a leg that supports the ladder, and an upper end support bar of the leg Is fitted into a fitting groove formed on the lower edge of the upper rail by an arm provided on the upper rail so as to be swingable.

These folding stepladders are convenient in that they can be folded when stored, but the structure is complicated and sturdy by providing the folding mechanism, and the weight is relatively heavy. Further, when the foldable stepladder is erected by the presence of the leg body at the rear side, there are many cases where it becomes an obstacle as in the case of the stepladder shown in FIG.
"Folding stepladder" according to JP-A-9-21285 "Folding stepladder" according to JP-A-10-169344

  Thus, the conventional stepladder has the above-mentioned problems. The problem to be solved by the present invention is this problem, and provides a simple stepladder that is light and easy to carry, and can stand up stably without obstruction even if there is an obstacle behind it.

  The simplified stepladder according to the present invention has a substantially L-shaped frame shape when viewed from the side thereof, and has leg portions and inclined columns. This frame is provided on both the left and right sides, and is connected at the upper part, and the upper part is curved into a smooth convex shape. A plurality of treads are hung on both inclined struts whose upper part is tilted rearward and attached horizontally, and the treads can be lifted with their feet.

  Legs are attached to both ends of the leg part to support an inclined column with a tread plate attached thereto, and a caster is provided close to the front leg. Moreover, both leg parts are extended to both sides so that the back side may spread. The simplified stepladder of the present invention having a substantially L-shaped frame has a large space between the leg and the inclined column, and has a smoothly curved corner between the leg and the inclined column. ing. Here, the corner portion is reinforced as necessary.

  The simplified stepladder of the present invention has a plurality of treads attached to both inclined struts of an approximately L-shaped frame, and has both leg portions extending rearward. Therefore, the stepladder is stable, and can be raised to the upper step board to work with peace of mind. However, the upper part of the frame has a convex curved shape in order to prevent the foot from being put on.

  On the other hand, since the frame of the stepladder is generally L-shaped, if there is an obstacle behind it, the obstacle can enter the space formed behind it. It becomes possible to stand a stepladder without becoming. Further, since the leg portion is expanded rearward in the outward direction, the standing stepladder is stabilized and a plurality of stepladders can be stacked and stored.

  FIG. 1 shows an embodiment of a simplified stepladder according to the present invention. In the figure, 1 is a frame, 2, 2... Are treads, and the frame 1 is manufactured by bending one pipe and has legs 3, 3 and inclined columns 4, 4. The upper portions 5 of the columns 4 and 4 are curved and connected in a convex shape. The two inclined struts 4, 4 are parallel to each other at a predetermined interval, and the tread plates 2, 2,.

  Brackets 6 and 6 are screwed to the inclined columns 4 and 4, and the tread plate 2 is horizontally attached to the brackets 6 and 6. The two inclined struts 4 and 4 are connected at the upper part 5, but the overall strength and rigidity are increased by attaching the footboards 2, 2... Via the brackets 6,. The strength of. The bracket 6 is substantially L-shaped, and both ends of the base portion 7 are fixed to the inclined support column 4 with screws, and the tread plate 2 is screwed to an arm 8 extending horizontally from the base portion 7. Here, it is considered that the upper portion 5 of the frame 1 is formed in a smooth convex shape so that the upper portion 5 is not stepped on.

  The stepping plates 2, 2... Of the stepladder shown in the figure are provided at a height of 250 mm, 500 mm, and 750 mm from the floor surface, and constitute a relatively compact simple stepladder. Of course, the height dimension of the treads 2, 2... Is only one specific example. The two leg portions 3 and 3 are continuous with the inclined support columns 4 and 4 and are provided with smoothly curved corner portions 9 and 9 to extend horizontally. Moreover, as shown in the plan view of FIG. 2, the distance between the legs 3 and 3 is inclined so as to widen the rear side.

  The stepladder has two horizontal leg portions 3 and 3 extending rearward outward so that the inclined columns 4 and 4 to which a plurality of footboards 2 are attached do not fall down. Here, since the load acting on the tread plate 2 acts as a bending moment on the curved corner portions 9 and 9 connecting the inclined support columns 4 and 4 and the leg portions 3 and 3, the corner portions 9 and 9 are subjected to the moment. Reinforced to withstand.

  Of course, if the pipes that make up the frame 1 are made thicker or pipes made of a material with high tensile strength are used, no special reinforcement is required, but a pipe made of a relatively thin aluminum alloy as a stepladder that is convenient to carry. If this is used, the corner portions 9 and 9 need to be reinforced. The reinforcing method is not limited because there are various methods. For example, a strong frame 1 can be configured by fitting a thin pipe inside the corner portions 9 and 9 and bending the frame 1 in this state. It becomes possible.

  When the legs a, 1010b,... Are attached to both ends of the horizontally extending legs 3, 3, and the stepladder is rattled due to unevenness on the floor surface, the legs 10b on the corners 9, 9 side, It can also be set as the structure which can adjust the height of 10b. In addition, casters 11 and 11 are attached close to the legs 10b and 10b. The relationship between the caster 11 and the leg 10b is as shown in FIG.

  Therefore, when the stepladder stands up, both legs 3 and 3 are supported by the legs 10a, 10b,. However, if the upper part 5 of the frame 1 is lifted with a hand, the rear of the leg parts 3 and 3 rises and inclines, and the casters 11 and 11 come into contact with the floor surface. Therefore, it is possible to move by rolling the casters 11 and 11 without lifting the entire stepladder.

  By the way, since the stepladder of the present invention is a form in which the step plates 2, 2,... Are attached to the inclined posts 4, 4 of the schematic frame, a large space 12 is formed between the horizontally extending legs 3, 3. Has been. Therefore, even when there is an obstacle at the position of the space 12, the stepladder can be erected without any trouble.

  FIG. 4 shows a state in which the three legs are stacked and stored, but both leg portions 3 and 3 are widened so that the rear portion becomes larger. 3 and 3 can be inserted and overlapped. As shown in FIG. 2, the leg portions 3 and 3 of the stepladder shown in the embodiment extend obliquely outward and rearward, but the leg portion 3 is configured to expand outward by forming a step at the intermediate portion. , 3 can also be used.

The Example which shows the simple type stepladder which concerns on this invention. The top view of the simplified stepladder of this invention. The side view of the simple type stepladder of this invention. When the simple stepladders are stacked and stored. Conventional general stepladder.

Explanation of symbols

1 Frame 2 Footboard 3 Leg 4 Inclined Strut 5 Upper 6 Bracket 7 Base 8 Arm 9 Corner
10 legs
11 casters
12 space

Claims (3)

In a stepladder having a plurality of footboards, the stepladder has a frame that is generally L-shaped and includes two inclined struts and two legs, and both inclined struts with the upper part tilted rearward are The bracket is fixed at a predetermined interval and the tread board is horizontally mounted through the bracket. The upper portions of both inclined struts are continuously curved in a convex shape, and are continuous with both inclined struts and the corners in between. The legs provided horizontally extend with the rear side extended outward, and legs are provided at both ends of the legs, and casters are attached close to the legs on the corner side, and the lower ends of the casters are slightly lower than the legs. A simple stepladder characterized by its height. The simple stepladder according to claim 1, wherein the frame is manufactured by bending a single continuous pipe. The simplified stepladder according to claim 1 or 2, wherein a thin pipe or a metal core is fitted inside a corner portion formed between the inclined support column and the leg portion of the frame for reinforcement.

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