NZ242482A

NZ242482A - Joint for co-axial tubes: swaged narrowed end seating within belled increased end: scaffold units or platforms with such components

Info

Publication number: NZ242482A
Application number: NZ242482A
Authority: NZ
Inventors: Christopher Binyon
Original assignee: Adwin Products Pty Ltd
Priority date: 1991-04-26
Filing date: 1992-04-24
Publication date: 1994-11-25
Also published as: EP0581825A1; EP0581825A4; CA2109200A1; ATE145959T1; WO1992019870A1; EP0581825B1; DE69215670D1; ZA922968B

Abstract

A work platform and scaffolding unit are disclosed. The work platform is made up of a number of scaffolding units assembled in various configurations. Each scaffolding unit has two posts (1) and at least two cross bars (2). The posts have a belled lower end (6) and a swaged top (5) which fit together to provide the assembly. Rigidity is obtained by two spaced apart points of contact in the joints.

Description

Zklyiz Priorixy Date(s): . 1 ' 1 ' i . • • » i • i • # i • » « i » n , Complete Specification Filed: Claps: J1*-, Jk;. s^o/ TTi.Vs.j&Tl ks>;.. F.ifcBfciiwa Publication Date: P.O. Journal, No: . eaTT5 9 JUL 1992 "i Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION IMPROVEMENTS IN SCAFFOLD ARRANGEMENTS WE, ADWIN PRODUCTS PTY LTD., an Australian company of 129 Glen Osmond Road, Eastwood, South Australia, AUSTRALIA hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: (followed by page la) r 242482 IMPROVEMENTS IN SCAFFOLD ARRANGEMENTS This invention relates to scaffolding arrangements and more particularly to scaffolding arrangements which can be assembled to make work platforms constructed of a number of scaffolding units.

Scaffolding arrangements are very important in all facets of building construction. They can be used on the outside buildings for instance for bricklayers and painters and also can be used inside buildings for plasterboard fixers, ceiling painters and the like. To be useful for building constructions however scaffolding units must be light and easy to transport 1 0 easy to assemble and when assembled be sufficiently strong for their required purpose.

There have been proposed scaffolding units made from aluminium tubing but these can be very expensive and have to be of a heavy construction because of the physical characteristics of aluminium.

It would be convenient to be able to construct a scaffolding unit from thin walled steel tubing but such an arrangement has problems with assembly of a structure with such tubing.

This invention proposes a scaffolding unit and a work platform made up of scaffolding units which is economic to construct and is sufficiently strong and 2 0 sturdy for building work.

A further problem exists with the use of thin walled steel tubing in the construction of scaffolding units in that thin walled steel tubing is made by rolling a strip of tubing and forming it by welding into a tube. Such a method of construction can give an inaccurate diameter and a weld line inside the 25 tube.

This invention proposes a method by which these problems can be overcome.

In one form therefore although this may not necessarily be the only or - \r o broadest form the invention is said to reside in a scaffolding unit comprising /'* two vertical posts and at least two horizontal cross bars, the cross bars being M £\\ MjuuwJ (followed by page 2) 242482 * ?4P? t w r ^ " ' o 2 rigidly fastened at their respective ends to respective posts each post being hollow and cylindrical and having an upper end swaged into a reduced diameter and a lower end belled out to an increased diameter such that the swaged upper end fits into a corresponding belled end of an adjacent 5 scaffolding unit, the post and bars being constructed from thin walled steel tubing.

It will be seen that by this method of construction there is provided a scaffolding unit which can be used assembled with a number of similar scaffolding units to provide a work platform. 1 0 Preferably, the work platform may further include a locking bar including saddles at each end adapted to fit over the cross bars of parallel spaced apart scaffolding units.

In a preferred embodiment the swaged end and a belled end of each scaffolding unit may each extend for approximately 10% of the length of the 1 5 vertical posts.

The important feature of such a scaffolding unit is to be able to get rigid joints between adjacent scaffolding units and this is done by swaging one end of the thin walled steel tubing of the post and belling the other end so that the two fit accurately together. Preferably the length of the swaged portion is equal to 2 0 the length of the belled portion on each post such that the lower end of the vertical post bears against an external shoulder of the swaged portion of a connected post and the upper end of the vertical post bears against an internal shoulder of the belled portion of a connected post whereby to provide rigidity to the work platform. 2 5 This form of construction with two points of contact on adjacent connected posts spaced apart vertically at the joining point gives particularly good bracing to the work platform structure comprised of a plurality of scaffolding units.

In one preferred embodiment, the thin walled steel tube may have an outer 3 0 diameter of 44.5mm with a 1.6mm wall of thickness. The swaged ends may be reduced to 41.4mm in diameter and the internal diameter of the belled portion may be increased from 41.3mm to 42.4mm. This allows 1 mm of free ■■A juuw'y 242482 3 play for ease of assembly and disassembly.

A typical scaffolding unit may have a height of 550mm and an overall width of 730,1090 or 1590mm. The length of the swaged and belled portions may be 50mm. This gives a modular system in which different sizes may be joined together to give different configurations.

It may be particularly noted that by belling the lower end of each of the posts the problem with the welded join of the thin walled steel tubing will be overcome as this will be pushed out during the belling process to provide an even internal diameter for the swaged end of the posts. 1 0 This then generally describes the invention but to assist with understanding the invention reference will now be made to the accompanying drawings which show a preferred embodiment of the invention.

In the drawings: FIG. 1 shows a side view of a scaffolding unit according to this 15 invention, FIG. 2 shows a cross sectional view of one post of a scaffolding unit according to this invention, FIG. 3 shows a cross sectional detail of the joining of two posts, and FIG. 4 shows a work platform assembled using scaffolding units of 20 the present invention.

Now looking more closely at the drawings it will be seen that a scaffolding unit as shown in Fig. 1 comprises vertical posts 1 and horizontal cross bars 2. The cross bars 2 are welded to the vertical posts 1 by welding at 3. Preferably the ends of the cross bars are flattened to facilitate welding to the cylindrical posts.

O,.

./ ^ 'Vv A *\\ ^.9 JUlflWy As can be seen in more detail in Fig. 2 the post 1 comprises a thin walled 4 steel tubing with a swaged upper end generally shown as 5 and a belled lower end generally shown as 6. The swaged upper end 5 has a region 7 of reduced diameter which fits into a region 8 of the belled portion of increased 2 diameter.

Between the swaged portion 7 and the main portion of the post 1 is an external shoulder 9 and between the belled out portion 8 and the main portion of the post 1 is an internal shoulder 10.

When a post of one scaffolding unit assembled onto the post of another scaffolding unit the upper end 11 of the swaged end bears against the shoulder 10 and the lower end 12 of the belled end bears against the shoulder 9. This provides two vertically spaced apart contact points for the join between adjacent posts of an assembly of scaffolding units into a work 10 platform which arrangement provides particular rigidity.

It will be noted from Fig. 3 that the upper end 11 of the post has a substantially squared edge which vail lock into the bevel 10 between the belled portion and the post when a connection is made. Similarly the lower end 12 of the ■ post has a substantially squared edge which will lock into the bevel 9 15 between the swaged portion and the post when a connection is made. These two substantially squared edges iocking into the bevels provide a joint which grips but which is easy to release when necessary.

As can be seen in Fig. 4 a work platform construction may comprise pairs of scaffolding units 20 joined together to provide a vertical construction in this 20 case four scaffolding units high. There may be placed planks 21 on the cross bars to provide a work platform and to maintain the top of the work platform rigid and to put side rails there may be a locking bar 22 extending between parallel spaced apart cross bars 23.

Overall by this invention it will be seen there is provided a scaffolding unit 25 which is relatively simple to construct but can be used to provide a rigid structure for making a work platform for building construction and the like.

Claims

WHAT WE CLAIM IS:

1. A work platform comprising an assembly of a plurality of scaffolding units, each scaffolding unit comprising two vertical posts and at least two horizontal cross bars, the posts and bars being constructed from thin walled cylindrical steel tubing, the cross bars being rigidly fastened at their respective ends to the respective posts intermediate the ends of the posts, an upper portion of each post terminating in a swaged portion of reduced diameter with an external shoulder merging the swaged portion and an intermediate portion of the post and a lower end of each post terminating in a belled portion of increased diameter with an internal shoulder merging the belled portion and the intermediate portion of the post, wherein a joint between adjacent coaxial posts is provided by the swaged portion of the first post connecting into the belled portion of the second post, characterised by the swaged portion being equal in length to the belled portion such that in forming the joint the end of the belled portion bears against the external shoulder and the end of the swaged portion bears against the internal shoulder to provide longitudinally spaced apart contact points in the joint to give rigidity to the joint and to the work platform and at least one plank extending between horizontally adjacent cross bars of parallel spaced apart scaffolding units to provide the work platform.

2. A work platform as in Claim 1 wherein the swaged portion and the belled portion of each scaffolding unit each extend for approximately 10% of the length of the vertical posts.

3. A work platform as in Claim 1 wherein the work platform further includes a locking bar having saddles at each end thereof adapted to fit over the cross bars of parallel spaced apart scaffolding units.

4. A work platform substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.

5. A scaffolding unit for use in the assembly of a work platform, the scaffolding unit comprising two vertical posts and at least two horizontal cross bars, the posts and bars being constructed from thin walled cylindrical steel tubing, the cross bars being rigidly fastened at their respective ends to the respective posts intermediate the ends of the posts, an upper portion of eac post terminating in a swaged portion of reduced diameter with an external ^ shoulder merging the swaged portion and an intermediate portion of the post and a lower end of each post terminating in a belled portion of increased diameter with an internal shoulder merging the belled portion and the intermediate portion of the post, wherein a joint between coaxial adjacent posts in a work platform assembly can be provided by connecting the swaged portion of the first post into the belled portion of the second post, characterised by the swaged portion being equal in length to the belled portion such that in forming the joint the end of the belled portion will bear against the external shoulder and end of the swaged portion will bear against the internal shoulder to provide longitudinally spaced apart contact points in the joint to give rigidity to the joint and to a work platform assembled using the joint.

6. A scaffolding unit as in Claim 5 wherein the swaged portion and the belled portion of each post each extend for approximately 10% of the length of the vertical post.

7. A scaffolding unit as in Claim 5 wherein the posts have an outer diameter of 44.5 mm and a 1.6 mm wall thickness and the swaged portions are reduced to a diameter of 41.4 mm and the internal diameter of the belled portions are increased to 42.4 mm.

8. A scaffolding unit substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings. 9 A joint between first and second coaxial posts, each post constructed from hollow, cylindrical, thin walled tube, the first post having an end terminating in a swaged portion of reduced diameter with an external shoulder merging the swaged portion and an intermediate portion of the first post and the second post having an end terminating in a belled portion of increased diameter with an internal shoulder merging the belled portion and an intermediate portion of the second post, wherein the joint is provided by the swaged portion of the first post connecting into the belled portion of the second post, characterised by the swaged portion of the first post being equal in length to the belled portion of the second post such that in forming the joint the end of the belled portion of the second post bears against the external shoulder of the first post and the end of the swaged portion of the first post bears against the internal shoulder of the second post to provide longitudin spaced apart contact points in the joint to give rigidity to the joint. 7 — ■ *. "f 10 A joint between first and second posts substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings. ADWIN PRODUCTS PTY LTD By their attorneys qfrf SON & CAREY