JPH08260860A - Ladder horizontal muntin - Google Patents

Abstract

PURPOSE: To reinforce strength by forming a ladder horizontal muntin of one metal extruded shape material having a plurality of hollow parts which are substantially triangle-shaped in cross section and extending both directions on the whole. CONSTITUTION: A plurality of non-slip projected strips extending in both directions are formed on the top of the horizontal muntin 1 in one piece with a spacing in every direction. Then, a substantially parallelogram-shaped-hollow part 3 extending in both directions is formed at the central part before and behind on the horizontal muntin 1. There are also formed a plurality of hollow parts 4 to 9 whose cross section is substantially triangle-shaped extending in both directions on both sides of the hollow part 3 before and behind. Then, a plurality of horizontal muntins 1 are laid out with a spacing in the longitudinal direction where both ends of the horizontal muntins 1 on both sides are fixed with side timbers, thereby forming a scaffolding ladder. This construction makes it possible to form with a metal extruded shape material having hollow parts 4 to 9 which extend in both directions and shape up a triangle substantially in the longitudinal cross section, thereby enhancing the strength of the ladder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ladder used for scaffolding at a construction site, for example, in which a plurality of parallel side trees are arranged at intervals in the lengthwise direction, and the left and right ends are sideways. It relates to a ladder crosspiece fixed to a tree.

In this specification, the right side of each drawing is
The opposite side is called the rear. Further, the lower side of FIGS. 3 and 6 is referred to as the right, and the opposite side is referred to as the left.
Furthermore, in this specification, the term "aluminum" includes aluminum alloy in addition to pure aluminum.

[0003]

2. Description of the Related Art Conventionally, as a horizontal rail for this type of ladder, a plurality of reinforcing ribs extending in the left-right direction are integrally formed on the lower surface,
An extruded aluminum material having a plurality of anti-slip ridges extending in the left-right direction integrally formed on the upper surface at intervals in the front-rear direction has been used.

[0004]

However, since the conventional cross rail lacks strength, the reinforcing end members made of an aluminum extruded profile having a U-shaped cross section extending in the front-rear direction are welded to the left and right ends thereof. There is a problem that it is necessary to fix them by rivets, screws, etc., and the number of man-hours for that is increased and the work of manufacturing the ladder becomes troublesome.

An object of the present invention is to provide a cross rail for a ladder that solves the above problems.

[0006]

A first cross rail for a ladder according to the present invention is arranged between a pair of parallel side trees at intervals in the lengthwise direction, and both left and right ends are side trees. The ladder cross rail is fixed, and is entirely formed of one metal extruded shape member having a plurality of hollow portions each having a substantially triangular cross section and extending in the left-right direction.

A second ladder cross rail according to the present invention is a plurality of lateral rails for a ladder, which are arranged between a pair of parallel side trees at intervals in the lengthwise direction and whose left and right ends are fixed to the side trees. The crosspiece is formed by arranging a plurality of metal extruded shapes each having a plurality of hollow portions each having a substantially triangular cross-section extending in the left-right direction in the front-rear direction and adjoining adjacent ones. .

In the above-mentioned second cross rail for ladder, an internal expansion groove extending in the left-right direction is formed on one of the surfaces of the adjacent metal extruded shapes to be joined to each other, and an internal expansion groove is formed on the other side. A protrusion may be formed to fit in the groove.

Further, in the second cross rail for the ladder, the length of the metal extruded shape fixed to the side tree in the left-right direction is longer than the length of the other metal extruded shape in the left-right direction. Sometimes.

[0010]

Since the first and second ladder cross rails are formed of the metal extruded shape member having a plurality of hollow portions each having a substantially triangular cross section extending in the left-right direction, the strength thereof is higher than that of the conventional one. And the need for reinforcing end members is eliminated.

In the second ladder cross rail, an internal expansion groove extending in the left-right direction is formed on one of the surfaces of the adjacent metal extruded shapes to be joined to each other, and an internal expansion groove is formed on the other side. If a ridge that fits inside is formed,
Adjacent metal extruded profiles can be slid in the left-right direction so that the ridges can be fitted in the internal expansion grooves, whereby the metal extruded profiles can be joined together.

In the second cross rail for a ladder, if the length of the metal extruded profile fixed to the side tree in the left-right direction is longer than the length of the other metal extruded profiles in the left-right direction, A gap can be formed between the side wood and the metal extruded profile positioned on the front and rear sides of the metal extruded profile fixed to the tree. As a result, it is possible to reduce the bulkiness by stacking a plurality of ladders in the front-rear direction. That is, for example, the front portion of the cross rail of the rear ladder can be fitted between the side trees of the front ladder and overlapped on the cross rail of the front ladder. If the horizontal length of the metal extruded profile fixed to the side tree is not longer than the horizontal length of other metal extruded profiles, separate gap adjustment plates on the side tree and the side rails. It is necessary to intervene between it and the fixed part to the tree.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The same parts and the same parts are denoted by the same reference symbols throughout the drawings.

FIG. 1 shows a first cross rail according to the invention,
2 and 3 show the structure of the main part of a ladder for scaffolding using the cross rail of FIG. Further, FIG. 4 shows a state in which a plurality of ladders are stacked.

In FIG. 1, the ladder cross rail (1) is entirely formed of one hollow aluminum extruded profile having a substantially trapezoidal cross section. On the upper surface of the horizontal rail (1), a plurality of anti-slip ridges (2) extending in the left-right direction are integrally formed at intervals in the front-rear direction. On the horizontal rail (1), there is one hollow part that extends in the left-right direction and is approximately parallelogram-shaped in the center part in the front-rear direction.
The hollow portion (3) is formed, and a plurality of hollow portions (4) to (9) each having a substantially triangular cross-section and extending in the left-right direction are formed on both front and rear sides of the hollow portion (3). In the partition walls (10) and (11) between the substantially parallelogram-shaped hollow portion (3) and the substantially triangular-shaped hollow portions (4) and (7) on the front and rear sides thereof, fixing screw screw holes (12) extending in the left and right directions, respectively. Are formed.

As shown in FIGS. 2 and 3, a ladder for scaffolding
(15) has a plurality of horizontal bars (1) arranged at intervals in the length direction between a pair of left and right aluminum extruded profile side trees (16) which are parallel to each other. The left and right ends of the are fixed to the side tree (16). The side tree (16) has a U-shaped cross section, and is arranged with its opening outward in the left-right direction.

The portions corresponding to the substantially parallelogram-shaped hollow portions (3) at the front and rear central portions at the left and right ends of the horizontal rail (1) are connected to the web portion () of the side tree (16) via the gap adjusting plate (17). 16a), and in this state the web part (16a) and the gap adjusting plate (1
It is fixed to the side tree (16) by screwing a fixing screw (18) which penetrates 7) from the outside into a fixing screw screwing hole (12) of the cross rail (1). Seen from a plane, the gap (1) between the front and rear sides of the cross rail (1) and the side tree (16) is equal to the thickness of the gap adjusting plate (17).
9) exists.

As shown in FIG. 4, when stacking a plurality of ladders (15) in the front-rear direction, the front portion of the horizontal rail (1) of the rear ladder (15) is attached to the front ladder (15). Insert it between the side trees (16) and stack it on the cross rail (1) of the front ladder. As a result, multiple ladders
Stacking (15) in the front-rear direction reduces the volume.

FIG. 5 shows a second cross rail for a ladder according to the present invention, and FIG. 6 shows the structure of a main part of a scaffolding ladder using the cross rail of FIG.

In FIG. 5, the ladder rungs (20) are formed by a plurality of hollow aluminum extruded profile rung members (21), (22) and (23) arranged in the front-rear direction and joined to each other. Has been done. That is, it is composed of a first cross rail constituent member (21) having a substantially parallelogram shape in cross section, and second and third cross rail constituent members (22) (23) arranged in front and rear thereof and having a substantially triangular cross section. . First
The horizontal length of the horizontal cross member (21) is the second and the third.
It is slightly longer than the horizontal length of the horizontal rail constituent members (22) and (23). The first horizontal cross member (21) includes one substantially parallelogram-shaped hollow portion (2
4) is formed, and one hollow portion (25) (26) having a substantially triangular cross section is formed on each of the front and rear sides of the hollow portion (24). Partition walls (27) (28) between the substantially parallelogram-shaped hollow portion (24) and the substantially triangular-shaped hollow portions (25) (26) on the front and rear sides thereof.
Each has a fixing screw threaded hole (12) that extends in the left-right direction.
Are formed. Second and third horizontal rail component members (22) (2
In 3), a plurality of hollow portions (29), (30), (31) and (32) each having a substantially triangular cross-section and formed in the front-rear direction and extending in the left-right direction are formed. Also, the first to third horizontal rail component members (21) (22) (23)
A plurality of anti-slip protrusions (2) each extending in the left-right direction are integrally formed on the upper surface of the with an interval in the front-rear direction.

Internal enlarged grooves (33) (34) extending in the left-right direction are formed on the rear surface of the second horizontal rail member (22) and the front surface of the third horizontal rail member (23). First crosspiece component
The ridges (35) (36) extending in the left-right direction, which are fitted into the internal expansion grooves (33) (34), are integrally formed on both front and rear surfaces of the (21). Then, the first horizontal rail component member (21) and the second and third
By sliding the horizontal rail constituent members (22) and (23) in the left-right direction and fitting the ridges (35) and (36) into the internal expansion grooves (33) and (34), these horizontal rail constituent members are formed. (21) (22) (23) are connected. At this time, the left and right end portions of the first horizontal rail component member (21) project more than the left and right end portions of the second and third horizontal rail component members (22) and (23).

As shown in FIG. 6, the left and right ends of the first horizontal rail constituting member (21) of the horizontal rail (20) are brought into contact with the web portion (16a) of the side tree (16), and in this state. It is fixed to the side tree (16) by screwing a fixing screw (18) penetrating the web portion (16a) from the outside into a fixing screw screwing hole (12) of the first horizontal cross member (21). Seen from a plane, between the left and right ends of the second and third horizontal rail component members (22) and (23) of the horizontal rail (20) and the side tree (16),
The first horizontal rail component member (21) is the second and third horizontal rail component member (2).
2) There is a gap (19) protruding from (23). In this case, stacking a plurality of ladders in the front-rear direction is performed in the same manner as shown in FIG. 4, and as a result, stacking a plurality of ladders in the front-rear direction is less likely to occur.

[0023]

According to the two cross rails for a ladder of the present invention,
As described above, the strength is increased as compared with the conventional one, and the reinforcing end member is not necessary, so that the labor for fixing the reinforcing end member to the cross rail can be saved and the manufacturing work of the entire ladder can be simplified.

In addition, in the second cross rail for the ladder, an internal expansion groove extending in the left-right direction is formed on one of the surfaces of the adjacent metal extruded shapes which are joined to each other, and the other inside thereof is internally formed. When the convex strip that fits in the enlarged groove is formed, the metal extruded shape members can be connected to each other as described above, so that the work of connecting the metal extruded shape members can be simplified.

Furthermore, in the second cross rail for a ladder, if the length of the metal extruded shape fixed to the side tree in the left-right direction is longer than the length of the other metal extruded shape in the left-right direction. ,
As described above, the plurality of ladders can be stacked in the front-rear direction to reduce the bulkiness. Moreover, it is not necessary to separately provide the gap adjusting plate between the side tree and the portion of the cross rail fixed to the side tree, and the number of parts of the entire ladder is reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view showing a first cross rail for a ladder according to the present invention.

FIG. 2 is a partially enlarged side view of a ladder using the first cross rail for a ladder according to the present invention.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a side view showing a state in which a plurality of ladders are stacked.

FIG. 5 is a cross-sectional perspective view showing a second cross rail for a ladder according to the present invention.

FIG. 6 is a partial enlarged side view of a ladder using the second horizontal rail for the ladder according to the present invention.

[Explanation of symbols]

 (1) Cross rail for ladder (4) Hollow part with a substantially triangular cross section (5) Hollow part with a substantially triangular cross section (6) Hollow part with a substantially triangular cross section (7) Hollow part with a substantially triangular cross section (8) Hollow part with a substantially triangular cross-section (9) Hollow part with a substantially triangular cross-section (20) Ladder rung (21) 1st rung component (metal extrusion) (22) 2nd rung component (metal) (Extruded profile) (23) Third crosspiece member (extruded metal) (25) Hollow part with a substantially triangular cross section (26) Hollow part with a substantially triangular cross section (29) Hollow part with a substantially triangular cross section ( 30) Hollow part with a substantially triangular cross section (31) Hollow part with a substantially triangular cross section (32) Hollow part with a substantially triangular cross section

Claims (4)

[Claims] 1. A ladder crosspiece having a plurality of parallel side trees arranged at intervals in the lengthwise direction and having both left and right ends fixed to the side tree. A cross rail for a ladder, which is formed of one metal extruded profile having a plurality of hollow portions each having a substantially triangular cross-section and extending in a vertical direction. 2. A ladder rung having a plurality of parallel side trees arranged at intervals in the lengthwise direction and having both left and right ends fixed to the side trees, the plurality of lateral cross bars extending in the left and right directions. 2. A ladder rung formed by arranging a plurality of extruded metal members each having a hollow portion having a substantially triangular cross section in the front-rear direction and connecting adjacent ones to each other. 3. An internal expansion groove extending in the left-right direction is formed on any one of the surfaces of adjacent metal extruded shapes that are joined to each other, and a ridge that fits inside the internal expansion groove is formed on the other side. The cross rail for a ladder according to claim 2, which is formed. 4. The cross rail for a ladder according to claim 2, wherein the length of the metal extruded profile fixed to the side tree in the left-right direction is longer than the length of the other metal extruded profiles in the left-right direction.