JPS6129915Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a stepladder that can be used stably even when there is a difference in height due to a simple structure in which the legs can be rotated.

Conventional stepladders have two ladders connected to each other so that the legs can be opened and closed, and the opening and closing of the legs are fixed depending on the degree of opening and closing of the legs. In some cases, it was unstable and posed a danger. For this reason, the inventors of the present invention first
16394 (Utility Application No. 16394-89143), which provided a stable stepladder even on scaffolding with height differences, this invention used a rotating rivet joint and a rotating bolt joint at the connection part of the two ladders. , since it uses movable rivet joints for curved parts, etc., the structure is not only complicated, but also the height must be adjusted at the connecting part of the two ladders that serve as work platforms, and moreover, it is twisted in three dimensions. There is a limit in location when the opening of the stepladder and the height of the ground used as a foothold are significant.
In addition, the horizontal beam used as a step stool for work was unstable and could not be called a sufficiently stable stepladder.

As a result of further research based on the above technology, the inventors of the present invention took into account that people must move on the work platform at the top of the stepladder, and created a stable system by moving the legs of the ladder without moving the work step. The idea was to create a stepladder, and for this purpose, we focused on the fact that no matter how high or low the scaffold is, the three legs of the stepladder always land on the ground, and the remaining one is floating in the air.
To provide a stable simple stepladder by rotating this floating free leg and fixing the position according to the height of the scaffold.

The present invention has been achieved with the above-mentioned objectives, and its gist is that a platform plate serving as a work platform is provided at the top of two ladders, and each leg is connected by a connecting device between the tops. In a stepladder which is connected so as to be openable and closable and whose legs can be fixed with a holder depending on the opening/closing angle of the legs, one of the two ladders is divided into two parts: a connecting upper part and a rotating leg part. death,
The two legs of the ladder that is not provided with the pivoting legs and the one leg that is provided with the pivoting legs are fixed to the scaffold by a support provided between the two members, and the fixation is performed. The remaining leg of the rotating leg can be rotated and positioned using the leg of the rotating leg as an axis without moving the aforementioned mounting plate, and the four legs can be fixed according to the height of the scaffold. It is located on a stepladder.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings as follows. Reference numerals 1 and 1' are two ladders each having a required number of steps 2 and 2' whose lower portions are slightly open, and connecting plates 3, 3' and 4, between the opposing legs between the upper parts of each ladder. Connectors 7 and 7' are provided in which the legs are openably and closably connected by pins 5 and 6, respectively. This connector is not necessarily limited to one that can be opened and closed using a connecting plate and a pin, and may be anything that can open and close the legs, such as a hinge. Further, at the upper part of the ladders 1, 1', mounting plates 8, 8' are provided which serve as work platforms for placing people and the like. Furthermore, the ladders 1 and 1' are composed of legs a and b and legs c and d. Furthermore, each leg can be fixed by a holder 17 depending on the opening/closing angle of the leg. The holder 17 includes a holding rod 10 pivotally mounted by a pin 9 provided on the upper part of one of the opposing legs, and a plurality of adjustment grooves 11 provided in the holding rod 10 for fixing the legs according to the opening/closing angle. and a pin 12 provided on the top of the other opposing leg that engages the groove 11.

Therefore, in the present invention, the middle of either of the two ladders is divided into the connecting upper part A and the rotating leg part B, and the lower center of the connecting upper part A and the upper center of the rotating leg part B are connected to the bolt and nut 14. The rotary leg portion B is pivotally supported by a support 15 consisting of a support member 15, and is provided so as to be rotatable left and right. Furthermore, a sliding fixture 16 is provided on the connecting upper part A and the rotating leg part B, which are divided parts of the ladder, to be fixed or divided by sliding on the legs. to separate the connecting upper part A and the rotating leg part B, making the rotating leg part B rotatable (the first
(Fig.), when used as a ladder, the two ladders 1 and 1' are extended in a straight line, and the fixing 16 is slidably fixed at the split point, making the rotating leg unrotatable (the Figure 2). In addition, 18 is the non-slip rubber of the stepladder.

To explain the usage of the present invention with the above configuration, first, as shown in Figure 3 A, in order for the stepladder to stand on any high or low scaffold (for example, if d is a high scaffold), the rotating legs must be Legs a and b without a pivot leg and one leg d with a pivot leg.
Three of the legs will touch the ground in any case, but the remaining leg of c will float. In this case, by using the support 15, the rotating leg B is rotated around the fixed leg d of the rotating leg B, and c is extended to a grounding point further forward than usual, and the four legs a, b, and c are rotated. and d can be grounded and fixed. In addition, Figure 3 (b) shows a case where leg c is on a high platform and leg d is floating, but in this case as well, initially legs a, b and c are on the ground, but leg d is brought forward. If it touches the ground, the four legs a, b, c
and d can all be grounded and fixed. Similarly, in FIGS. 3C and 3, each leg a or b is a high scaffold, but in this case, the four legs of the stepladder are Legs a, b, c, and d can be stably erected. In this case, the axis of rotation is not leg b or a, but one of legs a, b and c or d is forcibly grounded, and the remaining low footing leg d
Or c will come forward.

In addition, to use the present invention as a ladder, remove the holding rod 10 of the holder 17, open the ladders 1, 1' linearly, and then slide the fixture 16 to separate the connecting upper part A and the rotating legs. By fixing the pivoting legs unrotatably at the dividing points of part B, a stable ladder can be formed in a straight line.

As mentioned above, the present invention has a simple structure and utilizes the fact that no matter how high or low the footing is, three of the four legs of the stepladder are always in contact with the ground, and the remaining one is floating. It is easy to handle because the legs of the book can be rotated to position them forward and backward, thereby stabilizing all the legs. In addition, in this invention, one of the two ladders is divided into two parts, the connecting upper part and the rotating leg, so that only the rotating leg can be used without moving the connecting upper part or the work platform. Since all four legs can be fixed by rotating back and forth, it is not only easy to position the legs, but also avoids the risk of the mounting plate, which serves as a work platform, moving during work. .

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of the stepladder of the present invention, Fig. 2 is a plan view of the main parts when the present invention is used as a ladder, and Fig. 3 A, B, C, and D show the height and low aspects of the scaffold. FIG. 3 is a separate diagram illustrating the state of use of the present invention. 1, 1'...Ladder, 7...Connector, 15...Support, 16...Fixing tool, 17...Holder, A...
Upper part of the connection, B...Rotating leg.

Claims (1)

[Scope of utility model registration request] A mounting plate that serves as a work step is provided at the top of the two ladders, and a connecting tool between the upper parts connects each leg so that it can be opened and closed, and the legs can be fixed with a holder depending on the opening and closing angle of the legs. In the stepladder made of The two legs of the ladder on the one side and the one leg on the side with the rotating leg part are fixed to the scaffold, and the above-mentioned mounting plate can be rotated around the fixed leg of the rotating leg part without moving. This stepladder is characterized in that the remaining one leg of the movable leg section is rotated to determine its position, and the four legs can be fixed according to the height of the scaffold.