JPH10169344A - Collapsible stepladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable and simple stepladder in the structure, by fixing treads in parallel to the upper and lower sashes to stride parallelogram link bodies and appropriately erecting the legs and laying the lower sash on a floor face. SOLUTION: Legs 3a, 3b are pivotted to the lower inclined sashes 7a, 7b and a support bar 8 is fitted to the upper end thereof to connect both legs 3a, 3b together. Parallelogram link bodies 2a, 2b are supported by the support bar 8 provided at the upper end of the legs to work the structure as a stepladder. When the axis 9 pivotting the legs 3 to the lower inclined sashes 7, the connection axis of the upper sash 4 and the lower inclined sashes 7, and the apex position of a triangle ABC connecting the support bar 8, are defined, the shape of the parallelogram link bodies is not deformed and the stepladder is kept in a certain inclined angle. The support bar 8 is naturally fitted to the fitting groove of the upper sash 4 by erecting the stepladder in order to keep constant the position of the support bar and prevent the position from shifting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly stable folding stepladder.

[0002]

2. Description of the Related Art In general, a stepladder is used when placing an object at a high place or removing an object at a high place, and a person can work on the stepladder. Therefore, each household often has a stepladder for putting objects in and out of high places. Of course, the stepladder is often used for interior and exterior work in a house, and has a use different from that of a ladder. That is, the stepladder can be opened on both sides 2
It has the legs of a book and can stand alone on a flat place, instead of leaning on it like a ladder.

FIG. 4 is a specific example showing a conventional stepladder. The three treads (a), (b) ... are arranged horizontally at regular intervals, and have four legs (b), (b), (c), (c) and two support members ( D), supported by (d). Legs
(B) and the supporting member (d) are parallel to each other, and the step plates (a), (b),. One leg (c) crosses the leg (b) in an X-shape to raise the stepladder.

Here, a support rod is provided at the upper end of the legs (c) and (c).
(E) is hung, and the tread (a) at the upper end is supported on the support bar (e). That is, the upper step board (a) is horizontally supported by the shaft (f) and the support rod (e) provided on the leg (b), and the lower step boards (a) and (b) D) It is fixed to. A fitting groove is formed in the tread plate (a) at the upper end, and a support rod (e) is fitted in this fitting groove to perform positioning, and each tread plate (a), (b) is horizontally positioned. It is arranged stably.

When the stepladder is folded, the supporting rod
(E) is removed from the fitting groove provided in the upper step board (a), and each step board (a), (b) ... fits in one plane, and the leg (b), the support member ( D) Become parallel. by the way,
The steps (a) and (b) of the stepladder are required to have stability in order for people to be able to stand on them. However, the support bar (e) may not be completely fitted in the fitting groove, and sometimes As a result, the stepladder falls down as soon as it is placed.
In addition, it is only supported by two legs (b) and (c) on one side, and lacks stability when it is placed on the tip of the tread.

[0006]

As described above, the conventional stepladder has the above-mentioned problems. The problems to be solved by the present invention are these problems, and provide a stepladder having high stability, a simple structure, and being easy to carry.

[0007]

The stepladder of the present invention is basically the same as the conventional stepladder, but the shape of the leg is different, and the supporting rod provided at the upper end of the leg is provided to be inclined rearward. And the stepping plate are different in engagement form. That is, the stepladder of the present invention is provided with a parallelogram link body on both sides, and a step board is attached across the parallelogram link body. The tread is mounted parallel to the upper and lower crossings,
If the lower beam is placed on the floor when the legs are standing, the tread is arranged parallel to the floor.

A leg for supporting a ladder formed by attaching a tread plate to the parallelogram link body from the rear is provided. The leg is pivotally supported by a lower inclined beam of the parallel link body. A support bar is attached to the upper end, and the support bar connects both legs. Further, a fitting groove is formed in the upper crosspiece of the link body for fitting the support rod, and the support rod naturally fits into the fitting groove while the stepladder stands upright.

Therefore, a swing arm is attached to the upper crosspiece of the parallelogram link so that the support rod is guided to the fitting groove. The swing arm has a groove at the tip, and has the fitting groove at the same position as the groove. Therefore, the support bar slides and fits into the groove of the swing arm, and at the same time, fits into the fitting groove of the upper rail. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010]

FIG. 1 is an embodiment showing a stepladder according to the present invention. 1 is a tread plate, 2 is a parallelogram link, 3 is a leg, and the parallelogram link 2 is an upper beam 4 and a lower beam 5,
It is a parallelogram connecting the upper inclined bar 6 and the lower inclined bar 7, and the upper and lower bars 4, 5 and the upper and lower inclined bars 6, 7 can be deformed while being kept parallel to each other. Then, parallelogram link bodies 2a and 2b are provided side by side at fixed intervals,
During this time, the treads 1a, 1b and 1c are attached.

The treads 1a, 1b, 1c are respectively
, The front and rear ends of which are pivotally supported by the upper inclined bar 6 and the lower inclined bar 7, respectively, the upper step plate 1a is provided at the same height as the upper bars 4a and 4b, and the other step plates 1b and 1c are fixed. Installed at intervals. Therefore, the parallelogram link members 2a, 2b are connected via the treads 1a, 1b, 1c, and are inclined with the deformation of the parallelogram link members 2a, 2b, and are simultaneously folded.

By the way, the two parallelogram link bodies 2a, 2a
Steps 1a, 1b, and 1c are attached between b to form a ladder. However, since the ladder alone falls down, the ladder is provided with legs 3a and 3b that incline rearward. The legs 3a and 3b are pivotally supported by the lower inclined bars 7a and 7b, and a support rod 8 is attached to the upper end, and the support rod 8 connects the legs 3a and 3b to each other. The parallelogram links 2a and 2b are supported by support rods 8 provided at the upper ends of the legs, and can function as stepladders.

If the position of the shaft 9 that supports the leg 3 on the lower inclined bar 7, the connecting axis of the upper bar 4 and the lower inclined bar 7, and the apex of the triangle ABC connecting the support rod 8 is determined, The shape of the parallelogram link body 2 does not collapse, and the ladder is maintained at a constant inclination angle. Therefore, it is necessary that the stepladder determines the position of the support bar so as not to change, and the stepladder of the present invention naturally supports the support bar 8 on the upper beam 4 by standing up. It fits in the fitting groove.

FIG. 2 shows the details of the swing arm 11 attached to the upper rail 4.
And can be slid between the swing arm 11. A fitting groove 13 is formed on the lower edge 12 of the upper rail 4, and the support rod 8 is fitted into the fitting groove 13.
The support rod 8 is positioned. The support rod 8 slides along the lower edge 12 and, when the stepladder is folded,
When the ladder and the leg 3 are opened and the stepladder is raised, the ladder and the leg 3 are fitted into the fitting groove 13.

The swing arm 11 can swing by being pivotally supported by a shaft 10 connecting the lower inclined bar 7 as shown in FIG. However, a long hole 15 is formed at the tip of the swing arm, and the swing range is regulated by a pin 16 fixed to the upper rail 4. Since the groove 17 is formed at the end of the swing arm, the supporting rod 8 that slides is positioned by fitting into the groove 17. FIG. 2A shows that when the stepladder is to be erected, the support rod 8 is located in the middle of the lower edge 12.
(B) shows a case where the stepladder is completely erected and the support rod 8 is fitted into the fitting groove 13.

When raising a folded stepladder,
The support rod 8 at the upper end of the leg moves from the base point 14 along the lower edge 12 of the upper rail 4. In this case, the swinging arm 11 is not restricted by the elongated hole 15 and the pin 16 formed at the tip end, and does not rotate and drop. The sliding support rod 8 fits into the groove 17. The groove 17 is provided at a position where the support rod 8 sliding along the lower edge 12 can be fitted.

The support rod 8 fitted in the groove 17 must be fitted in the fitting groove 13 of the upper rail 4, and if the tread plate 1 is pressed from above, it will fit in the fitting groove 13. Can be done. That is, when the support bar 8 is fitted into the groove 17 of the swing arm 11, the tread plate 1 is not completely horizontal, and the lower beam 5 of the parallelogram link 2 to which the tread plate 1 is attached is in contact with the floor surface. If the treadle 1 is pressed for that purpose, the support rod 8 is fitted into the fitting groove 13.

As shown in FIG. 2B, when the support rod 8 is fitted in the fitting groove 8, the support rod 8 is positioned, and the stepladder stands upright. And the support rod 8
By fitting into the groove 17 of the swing arm, the swing arm 11 cannot be rotated and dropped, so that the support rod 8 cannot be detached from the fitting groove 13. Conversely, when the stepladder is folded, the support bar 8 is disengaged from the fitting groove by lifting the front side edge of the treadle 1. If the support bar 8 is slid to the position of the base point 14, a ladder made of a parallelogram link is used. Is folded.

FIG. 3 shows a state where the stepladder of the present invention is folded. If you fold the stepladder like this,
The upper beam 4 and the lower beam 5 are fitted in a straight line with the lower beam 7, and at the same time, the leg 3 is folded along the side of each beam. A caster is attached to the tip of the lower rail, so that the caster can be rolled and carried without being completely lifted when being carried. However, this caster is provided at a position where there is no obstacle when the stepladder is raised, so that the stability of the stepladder is not impaired. As described above, the stepladder of the present invention is mounted on and supported by a ladder having a parallelogram link, a swing arm is provided on the upper beam, and a support bar provided on the upper end of the leg is supported by the upper bar. It is designed to fit naturally into the fitting groove of the crosspiece, and the following effects can be obtained.

[0020]

The stepladder of the present invention is provided with a foldable ladder. This ladder is provided with a large stepping plate attached to a parallelogram link body, and is safe without stepping off when going up and down. The ladder made of the parallelogram link body stands up with the lower crosspiece of a predetermined length placed on the floor, so that the stepladder is stabilized. Then, the leg supporting the ladder is provided with a support rod at an upper end, and the support rod naturally extends into a fitting groove formed in the upper crosspiece of the parallelogram link body. Moreover, the swing arm is attached so that once it is fitted, it does not come off by itself. On the other hand, because a caster is attached to the lower cross,
Carrying a stepladder is convenient.

[Brief description of the drawings]

FIG. 1 is an embodiment showing a stepladder according to the present invention.

FIG. 2 shows a swing arm attached to an upper crosspiece of a parallelogram link body.

FIG. 3 shows a stepladder folded.

FIG. 4 is a conventional stepladder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tread plate 2 Parallelogram link 3 Leg 4 Upper beam 5 Lower beam 6 Upper inclined beam 7 Lower inclined beam 8 Support bar 9 Axis 10 Axis 11 Swing arm 12 Lower edge 13 Fitting groove 14 Base point 15 Slot 16 Pin 17 grooves

Claims (2)

[Claims] 1. A parallelogram link body formed by connecting an upper beam and a lower beam which are parallel to each other, and an upper inclined beam and a lower inclined beam to each other, are disposed on both sides. Construct a ladder with a tread plate attached in parallel with the upper and lower beams, and attach legs to the lower inclined beam, provide a support bar at the upper end and connect both legs, and A swing arm that can swing in a range is provided, a groove is provided at an end of the swing arm, and a fitting groove is formed at a lower edge of the upper crosspiece to which a support rod is fitted. Folding stepladder. 2. A parallelogram link body formed by connecting an upper crosspiece and a lower crosspiece which are parallel to each other, and an upper inclined crosspiece and a lower inclined crosspiece to each other, are disposed on both sides, and between the two parallel quadrilateral link bodies. Construct a ladder with a tread plate attached in parallel with the upper and lower beams, and attach legs to the lower inclined beam, provide a support bar at the upper end and connect both legs, and It has a swing arm that can swing in a range, a groove is provided at the end of the swing arm, and a fitting groove is formed on the lower edge of the upper crossbar to which a support rod is fitted. A foldable stepladder that is equipped with casters at the tip of the crosspiece.