JPS6236953Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pipe stepladder that has the safety and strength to be used at various construction sites, etc., and can be folded and stored in a thin and compact form.

(Prior Art) Conventionally, as this type of pipe stepladder, the one shown in FIG. 1 of Japanese Utility Model Application Publication No. 1985-8500 filed by the present applicant has been used for a long time. Specifically, a top plate is welded and fixed to the upper ends of a pair of left and right pipe legs, the pipe legs are foldably supported using their spindles as fulcrums, and multiple treads are installed horizontally on the pipe legs. It was fixed by welding, and the left and right sides of the tread in the center were pivotally connected by the left and right levers.

Therefore, when the legs of such a stepladder are folded and closed, the legs are simply folded using the support shafts connected to the center portions of the left and right top plates as a fulcrum, which satisfies the need for a thin and compact stepladder when storing or transporting the stepladder. It was something I didn't have.

Therefore, Figures 2 and 5 of Utility Model Publication No. 59-8500
As shown in the figure, of the pair of left and right top plates, the right side is fixed to the back side of the right top plate and the upper end of its pipe leg, and a support plate is provided that extends to the left side of the back side of the left top plate. In addition, a support plate is provided with the left side fixed to the back surface of the left top plate and the upper end of the pipe leg, and a support plate formed on the left side of the back surface of the left top plate, and the pipe leg is attached to the left end of the support plate. We have devised a pipe stepladder with a structure in which the support shaft of the stepladder is inserted and supported, and this has made it possible to make the stepladder thin and compact when storing it or transporting it.

(Problem to be solved by the invention) However, although the pipe stepladder has been improved to have the above-mentioned structure, the actual folding situation is different from that of the Utility Model 59-
As shown in FIG. 4 of the 8500 publication, a gap about the size of one pipe was formed between a pair of left and right pipe legs that were folded in parallel.

Therefore, in the present invention, when the left and right pair of pipe legs are folded and closed, as a pipe stepladder that does not form a gap between them, the upper part of the pipe legs is placed so that the upper part of the pipe legs and the top plate are approximately perpendicular to each other. He devised a stepladder made of pipe with bent sections, thereby improving efficiency by making each stepladder thinner and more compact when storing and transporting the stepladder.

(Embodiment) An embodiment of the present invention will be described with reference to the accompanying drawings. Reference numerals 1 and 2 are a pair of left and right pipe legs, and the pipe legs 1 and 2 are downwardly expanded front legs 1a and 2a.
and hind legs 1b, 2b. 3 and 4 are front legs 1
The footboard has an inverted U-shaped cross section and is welded and fixed between the rear legs 1b and 2b, and is disposed at a position that substantially divides the pipe legs 1 and 2 into four vertically.

Reference numerals 5 and 6 denote a pair of left and right top plates, and the upper ends of the pipe legs 1 and 2 are directly welded and fixed near the center of the back side of the top plates. Reference numeral 7 denotes a support plate whose right base end is welded and fixed to both the front and back sides of the back surface of the right top plate 6 and the upper end of the right pipe leg 2, and which extends toward both the front and back sides of the left side of the left top plate 5; is a support plate formed on both the front and rear sides of the left side of the left top plate 5, with the right side base end welded and fixed to the front and rear sides of the back side of the left top plate 5 and the upper end of the left pipe leg 1. The support plates 7 and 8 are arranged side by side on both front and rear sides of the back surface of the left top plate 5 in an overlapping state.

Reference numeral 9 is a support shaft of the pipe legs 1 and 2, which is located at a position offset to the left end of the overlapping support plates 7 and 8, that is,
A support plate 8 is disposed outside the left pipe leg 1 and is located on both front and rear sides of the left top plate 5, and a support plate extends from both front and rear sides of the right top plate 6 to an outside position of the pipe leg 1. At the left end of 7, attach pipe leg 1,
The support shaft 9 of No. 2 is inserted through and is foldable.

Numerals 10 and 11 are projecting pieces fixed to the front and rear ends of the top plates 5 and 6 in an inverted U-shape, and are used for work scaffolding boards to be constructed on the top plates 5 and 6 of adjacent pipe stepladders. Prevent back and forth movement.

Support pieces 12 and 13 project from the center of the back surfaces of the central tread plates 3 and 4, and are provided closer to the outside of the back surfaces of the tread plates 3 and 4. Among them, one support piece 12
is welded and fixed to the back left inner wall surface of the tread plate 3 of the left pipe leg 1 with its upper end abutting, and the center position of the support piece 12 is twisted approximately 90 degrees (z) to form a downward droop. are doing. Also, the other support piece 1
3 is welded and fixed to the right side of the back surface of the tread plate 4 of the right pipe leg 2, and is formed to hang downward.

Reference numerals 14 and 15 refer to a pair of left and right connecting rods that are linked between the left and right support pieces 12 and 13, of which the left side of the left rod 14 is connected to the lower end of the support piece 12 by a support shaft 16 such as a bolt or pin. A pivot is installed in the through hole, and the right rod 15
The right side of the left rod 14 and the left side of the right rod 15 are connected to a support shaft 18 such as a bolt, nut or shaft pin.
It can be folded in half and connected freely.

Reference numeral 19 denotes a stopper member for preventing the opening of the left rod 14 and the right rod 15, which is formed at a connecting portion approximately in the center of the left rod 14 and the right rod 15;
As shown in FIGS. 7 and 7, there is a U-shaped plate portion 19b with protruding flanges 19a bent at both upper and lower ends, and a cylindrical tube portion 19c fixed to the plate surface of the plate portion 19b.
The cylindrical portion 19 of the stopper member 19
The support shafts 18 of the connecting rods 14 and 15 are connected to the plate part 1 from c.
9b through hole 19d, left rod 14 right side through hole 14
a, The right rod 15 is fixedly supported by sequentially passing through the through hole 15a on the left side.

Reference numeral 20 denotes a coil spring installed inside the cylindrical portion 19c, which is wound and supported around the support shaft 18 between the head of the support shaft 18 and the plate surface of the plate portion 19b. With this, the overhanging flange portion 19a of the stopper member 19,
It is biased and supported so that it can be engaged with and detached from the upper and lower ends of the right side of the left rod 14 and the left side of the right rod 15. 21 is a cap fitted onto the lower end of the pipe legs 1 and 2.

In addition, 5a and 6a are top plate covers made of synthetic resin, rubber, etc. that are supported on the top plates 5 and 6, and 3a and 4a are tread plates made of synthetic resin, rubber, etc. that are supported on the tread plates 3 and 4. As a cover, these top plate covers 5a,
6a and the tread covers 3a, 4a are crowned as necessary, but this prevents foreign matter such as mortar, concrete, etc., from falling from above and sticking to the tops 5, 6 and the top surfaces of the treads 3, 4. This is useful in eliminating the need for dropping operations. At that time, if the top cover 5a, 6a and the tread cover 3a, 4a are made of rubber, remove them and rub off any foreign matter stuck to the covers, or if they are made of synthetic resin, This makes it convenient to remove and replace the cover with foreign objects stuck to it.

(Means for Solving the Problems) In order to solve the problems of the present invention in the pipe stepladder having the overall structure as described above, first, the upper parts of the pipe legs 1 and 2, that is, the front legs 1a and 2a The upper parts of the rear legs 1b and 2b are bent in opposite directions, for example, as shown in FIG.
When using the pipe legs 1 and 2, the upper parts of the pipe legs 1 and 2 are bent so as to be in a substantially parallel state, and the lower parts thereof are formed in a downwardly expanding shape, and as shown in FIG. 2, when the legs are folded and closed, the upper portions of these legs are expanded upward, and the lower portions are closely supported in a substantially parallel manner and folded.

In other words, by bending and fixedly supporting the upper parts of the pipe legs 1 and 2 so that the upper parts of the pipe legs 1 and 2 and the top plates 5 and 6 are substantially orthogonal (x), They devised ways to achieve their intended purpose.

At that time, the tread plate 3 installed horizontally on the pipe legs 1 and 2,
The pipe legs 4 are made of a material having a width that extends inwardly from the pipe legs 1 and 2. Therefore, cutouts y are formed at the inner corners of both the front and rear ends of the footboards 3 and 4 as shown in FIG.
One of the support pieces 12 and 13 is approximately 90
The pipe legs 1 and 2 are twisted by a degree z, so that the left and right pipe legs 1 and 2 are folded into a substantially tight state as shown in FIG.

(Function) Therefore, when folding the stepladder according to the present invention in the open leg state as shown in FIG.
When the cylindrical portion 19c of 9 is pulled toward this side against the biasing force of the coil spring 20, the overhanging flange portion 19a that has been engaged with the right side of the left rod 14 and the left side of the right rod 15 to prevent them from opening is released. When the right rod 15 is stretched by at least the thickness of the left side of the right rod 15, the engagement between the overhanging flange 19a and the left side of the right rod 15 is released.

Then, push down the stopper member 19 to fold the connecting rods 14 and 15 downward in half, and fold one of the pipe legs 1 and 2 into the other pipe legs 1 and 2.
pull it to the side.

Then, the left and right pipe legs 1 and 2 are compactly folded into a substantially parallel state in close contact with each other, as shown in FIG. The upper end portion is folded upwardly into an expanded shape.

At that time, the connecting rods 14 and 15 are folded downward in half and stored without being exposed between the parallel pipe legs 1 and 2, but when the lower part of the pipe legs 1 and 2 is expanded again, the connecting rods 14 and 15 are folded downward and stored. When the rods 14 and 15 are in a straight line from side to side, the overhanging flange 19a of the stopper member 19 is moved toward the right rod 1 by the biasing force of the coil spring 20.
5. It is engaged and supported by both the upper and lower ends of the left side, and is prevented from opening.

(Effect of the invention) As described above, the present invention fixes the top plates 5 and 6 to the upper parts of the left and right pair of pipe legs 1 and 2, and connects the support shaft 9 of the pipe legs 1 and 2 to the top of one of the pipe legs 1. In a pipe stepladder provided on the outside, a plurality of steps 3, 4 are fixed to the pipe legs 1, 2, and a pair of left and right connecting rods 14, 15 are linked between the left and right steps 3, 4. , the pipe legs 1 and 2 are arranged so that the upper parts of the pipe legs 1 and 2 and the top plates 5 and 6 are substantially perpendicular to each other.
The upper part is curved, and when the legs are opened, the pipe leg 1,
The upper part of the pipe legs 1 and 2 is substantially parallel, and when the legs are closed, the upper parts of the pipe legs 1 and 2 are expanded upward, and the lower part of the pipe legs 1 and 2 is folded into a substantially tight state. Therefore, this type of pipe stepladder can be made even thinner and more compact when the legs are folded and closed. At that time, since the width of the tread plate placed horizontally on the pipe leg is formed by a width that extends inward from the pipe leg, the inner corners at both front and rear ends of the tread plate are cut off and formed.
By shifting the positions of the left and right footboards so that they are at different levels, it is possible to fold the left and right pipe legs into a substantially tight state.

Therefore, when storing pipe stepladders, which are used in large quantities at various construction sites, etc., and transporting them from site to site, the stepladders themselves do not take up much space.
Compared to conventional stepladders, you can load a larger amount,
The usefulness of being able to store items efficiently brings about various practical effects, such as being extremely useful.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal front view showing the pipe stepladder in its folded state, Fig. 2 is a longitudinal front view showing its use state;
Figure 3 is a right side view, Figure 4 is an enlarged view of the top plate, Figure 5 is an exploded perspective view of the left and right connecting rods, and Figure 6 is an exploded perspective view of the left and right connecting rods.
The figure is an enlarged view showing the folded state of the continuous rod part.
The figure is a longitudinal sectional side view of the stopper member. Code list, 1, 2... Pipe leg, 3, 4... Step board, 5, 6... Top plate, 7, 8... Support plate, 9...
Pipe leg support shaft, 10, 11... protrusion, 12, 1
3... Support piece, 14, 15... Continuous rod, 16, 1
7, 18... Support shaft of continuous rod, 19... Stopper member, 19a... Overhanging flange part, 19b... Plate part, 1
9c...Cylinder part, 20...Coil spring, 21...Cap.

Claims (1)

[Scope of claims for utility model registration] (1) A top plate 5,
6 is fixed, the support shaft 9 of the pipe legs 1 and 2 is provided on the outside of one of the pipe legs 1, and a plurality of steps 3 and 4 are fixed to the pipe legs 1 and 2, and the left and right steps 3, A pair of left and right connecting rods 14, 1 between 4
In the pipe stepladder formed by linking the pipe legs 1 and 2, the upper parts of the pipe legs 1 and 2 and the top plates 5 and 6
The upper parts of the pipe legs 1 and 2 are curved so that the
A pipe characterized in that its upper part is substantially parallel, and when the legs are closed, the upper parts of pipe legs 1 and 2 are expanded upward, and their lower parts are folded into a substantially tight state. Made of stepladder. (2) In the pipe stepladder described in claim 1 of the utility model registration claim, the treads 3 and 4 are replaced by the pipe legs 1 and 4.
2, and protrudes from the inside of the tread plate 3, 4.
A pipe stepladder made by cutting off the inside corners of both the front and rear ends.