WO1993004248A1

WO1993004248A1 - Formwork jig

Info

Publication number: WO1993004248A1
Application number: PCT/AU1992/000428
Authority: WO
Inventors: Colin Graham Sattler
Original assignee: Colin Graham Sattler
Priority date: 1991-08-12
Filing date: 1992-08-12
Publication date: 1993-03-04

Abstract

A formwork jig (1) comprising a mounting member (2) and a formwork support member (3) which are interconnected by tie means (4), connections between ends of the tie means (4) and the respective members (2, 3) which connections maintain a mounting surface (6) of the mounting member (2) and a support surface (13) of the support member (3) in substantially parallel planes with said mounting member (2) in overlying relationship with a support surface (13) of the support member (3) and wherein said tie means (4) is linearly extensible and contractible and has associated retaining means (15, 16) to at least hold said mounting and support members (2, 3) in a predetermined spacial relationship and resist forces tending to move said mounting member (2) and said support member (3) apart.

Description

FORMWORK JIG

The present invention relates to means to secure formwork around assembled floor or roof panels to receive concrete and thereby provide a peripheral consolidation ring-beam around the assembly. More particularly the invention provides a jig that greatly simplifies the erection of the formwork. The invention has particular application where the assembled floor or roof panels are made of autoclaved aerated concrete, hereinafter referred to as AAC.

The use of AAC for structural floors, walls, and roofs is growing in popularity in many countries including Australia. AAC offers several advantages over traditional building materials due to its excellent thermal properties, the speed at which such material can be laid because of its light weight and versatility in design.

Although this specification primarily addresses the formation of ring or edge beams for floors, the jig of this invention can also be used for the formation of edge beams adjacent AAC panel roofs of low to moderate slope and one example is hereinafter provided.

AAC floors are usually comprised of interlocking reinforced AAC panels, the size of the panels being typically 6m x 0.6m x 0.2m. In forming such floors, AAC [panels are butted together, joint reinforcement and spacers installed and mortar then poured to seal between adjacent panels. The edges of the panels are adapted to facilitate the foregoing.

Good engineering practice requires a ring beam around the perimeter of the floor to anchor the floor panels and/or maintain them in a consolidated form. The pouring of a ring beam requires suitable formwork including an edgeboard, and, if there is no existing supporting base extending beyond the floor perimeter, a base board.

The usual method of constructing formwork is very time consuming and labour intensive. It is an object of the present invention to provide a means to facilitate the erection of formwork and so substantially reduce the cost, labour and time involved in preparing formwork to receive concrete.

Broadly the invention can be said to comprise a formwork jig comprising a mounting member and a formwork support member which are interconnected by tie means, connections between ends of the tie means and the respective members which connections maintain a mounting surface of the mounting member and a support surface of the support member in substantially parallel planes with said mounting member in overlying relationship with a support surface of the support member and wherein said tie means is linearly extensible and contractible and has associated retaining means to at least hold said mounting and support members in a predetermined spacial relationship and resist forces tending to move said mounting member and said support member apart .

Presently preferred embodiments of the invention will now be described with reference to the accompanying drawings in which:

Fig.l is a perspective view of one form of the formwork jig of the invention,

Fig.2 is a a perspective view of a typical arrangement where the jig of Fig.l is holding a formwork edge and base board adjacent an assembly of AAC panels, Fig.3 is a sectional end view of the arrangement of

Fig.2 showing the panels supported on a steel beam inboard of the panel ends,

Fig. is a view similar to fig.3 where the panels are supported on a wall and thus no base board is required in the formwork,

Fig. 5 is a view similar to Fig.l where the bracing of the jig is different from that of Fig.l

Fig.6 is a side view of a foldable jig according to the invention.

Fig.7 is an alternate form of tie means between the support member and the mounting member of the jig,

Fig.8 is an alternate form of tie means,

Fig.9 is another alternative form of tie means and

Fig.10 is a sectional end view of a jig as would be used to provide a ring beam along the end of an assembly of panels. Referring to Fig.l the jig 1 of the invention comprises a mounting member 2 and a support member 3 joined by tie means 4. The supporting member 2 is shown as being of angle form and this is particularly suitable as it provides strength with light weight. The member 2 has a horizontal flange 5 and a vertical flange 6 and there are holes 7 in the horizontal flange 5 to facilitate the nailing of the mounting member to a support, which will invariably be the panels to be provided" with an edge beam. This can be readily seen from Figs.2 to 4.

The tie means 4 is linearly extensible and contractible and is preferably of the telescopic form where one element slides within another, however this is not essential as will be explained later with reference to Fig.7. As illustrated in Fig.l the tie means 4 comprises a first (outer) tubular component 8 fixed at 9 to the underface of the flange 5 of the mounting member 2. The joint is a right angle joint however this is not essential as will be explained later with reference to Fig.10. The other component 11 of the tie means 4 is likewise tubular and is fixed at right angles at 12 to the support member 3, again tubular, and it is to be noted that the joint is, at right angles to the axis of the tie means but is offset relative to the length of the member 3 thereby providing a long and a short leg 13 and 14 respectively.

The tie means also included a threaded rod 16 with a nut which bears on the upper face of the horizontal flange 5 of the mounting member 2. There is a head 17 (which may be another nut) which is on the other end of the rod 15 and bears on the underface of the support member 3.

It is to be noted that there is a gusset plate 16 between the overhang portion 19 of the mounting member 2 and the tie means portion 8 to maintain a required angle between the plane of the supporting member 2 and the tie means portion 6.

In a use situation, see Figs.2 to 4, the mounting member will be fixed in a suitable manner to a panel as by masonry nails through the holes 7, with the tie means 4 spaced from the end of the panels 20 by a distance which will depend upon the width of the edge beam to be formed. In Fig.3, the panel 20 is supported on a metal beam 21 inboard of the end of the panel 20 and so an edge board 22 and a base board 23 are required. In this configuration the long leg 13 of the support member 3 extends under the panel 20 and the base board 23 is disposed between the underface of the panel 20 and the upper face of the leg 13 and the height of the edge board 22 is such that when the tie means 4 is caused to contract it will ideally clamp the board 22,23 between the members 2 and 5 and the base board 23 against the underface of the panel 10.

The edge beam will have a wide head part as a result of the upper edge recess 24 of the panel 20 and a depth determined by the thickness of the panel 20. Prior to the pouring of concrete to form the edge beam suitable reinforcing 25 is supported in place in the channel indicated 26 to be filled with concrete.

In the arrangement of Fig.4 the panels 20 are stopped short of the edge of a support wall 27 and the support member is reversed to present the short leg 14, which has a length equal to the thickness of the edge board 22 of the formwork. The end of the leg 14 abuts the wall 27 and there is thus formed a channel 26 the same as is provided with the Fig.3 arrangement.

The jig 1 of Fig.5 is much the same as that shown in Fig.l except that the triangular gusset 18 is replaced by a single brace member 28.

Fig.6 illustrated an arrangement where the tie means portion 8 is hingedly connected at 29 to the support member 2 allowing the assembly to be folded up for storage or the like. The brace 28 is pivotally connected at 30 to the tie means portion 8 and there is an eye 31 on the overhang 19 of the mounting member 2 for engagement by the end 32 of the brace 28 which is suitably adapted for such connection.

The tie means as described is of square tubular section with one component 11 telescopically slidable in the other component 8. This has the advantage that the support member can be rotated easily and accurately through 180 degrees. Fig.7 illustrates an extensible and contractible member 33 comprised of two nested angle members 34 and 35 which would be respectively fixed at their free ends to the mounting member 2 and the support member 3. The member 35 is provided with slots and clamping screws mounted in the member 35 can be used to fix the length of the assembly 33. This is a functional alternative to the arrangement of Fig.l in so far as allowing extension and contraction of the tie means. However, the Fig.7 arrangement would require two supporting members, one with a long leg and one with a short leg because the arrangement of Fig.7 is not readily reversible as is the supporting member of Fig.l. This is ^no-t necessarily a major drawback as it is often the case that a jig will be designed for a particular manner of usage, say for the use of Fig.3 or Fig.4, and thus reversability is not a requirement.

Fig. 8 illustrated an alternative to the tie means of Fig.l and its operation can be readily seen from the drawing.

Fig.9 illustrated an arrangement where the component 11 of Fig.l is a solid element and the rod 15 is fixed to it by threading, or welding or in some other manner. Such an arrangement would have particular relevance to a jig for roof edge beams.

Fig.10 is an illustration of how the jig of the invention can be constructed to facilitate the support of formwork on sloping roof forming panels. The panels are inclined and supported on a wall (or a beam if desired) as indicated generally 39. The ends of the panels 38 are provided with recesses 24 as previously described but are general at right angles to the plane of the panel and are thus angled to the horizontal. The outer edge of the ring beam along the edge of the roof is however required to be in a plane at right angles to the horizontal.

The tie means in the jig of Fig.10 is fixed to the mounting member 2 and the support member 3 at an angle corresponding to the angle of the panel 38 to the horizontal. The mounting member is 'nailed' to the panel 38 as before, the support member extends under the panel 38 as before and the side and base boards are clamped as before.

It is to be noted that the formwork side board 22 has its edges machined at an angle to the plane of the board 22 to suit the angle of the roof and so the edges will bear flat against the engaged faces of the mounting and support members 2 and 3. As an alternative the edges can be left ¹square' and a tapered packing piece can be interposed between the edges of the board 22 and the members 2 and 3. For security a nail can be driven through a hole in the flange 5 of the member 2 into the edge of the board 22. As will be understood jigs 1 are spaced at regular intervals along the ends of a floor assembly or a roof assembly to accommodate the long side and bottom boards 22, 23 needed to construct the formwork for the edge beam.

The foregoing are examples of the invention and are not to be considered as limiting the scope of the invention. The concept as herein disclosed is capable of being put into effect in many ways. For example, the mounting member 2 can be made of material other than angle steel, the supporting member can be made of material other than square tube as illustrated in the drawings, the threaded drawbar can be replaced by other force applying means (such as a lever acting on a head on the member 15) with an associated wedge/collet arrangement to grip the drawbar surface with teeth or in the form of a split nut to engage the threads on the draw bar.

There can also be features added, such as a socket indicated 41 on the tie components 8 to provide sockets for ends of posts of a safety fence required by some safety regulations.

Claims

I CLAIM :

1. A formwork jig comprising a mounting member and a formwork support member which are interconnected by tie means, connections between ends of the tie means and the respective members which connections maintain a mounting surface of the mounting member and a support surface of the support member in substantially parallel planes with said mounting member in overlying relationship with a support surface of the support member and wherein said tie means is linearly extensible and contractible and has associated retaining means to at least hold said mounting and support members in a predetermined spacial relationship and resist forces tending to move said mounting member and said support member apart.

2. A formwork jig as claimed in claim 1 wherein said tie means is also capable of adjusting the distance between said mounting means and said supporting means.

3. A formwork jig as claimed in claim 1 or claim 2 wherein said tie means comprising a tubular component and another component connected to the respective members with said other component telescopically slidably mounted in the tubular component and said retaining means comprises a drawbar and tensioning means to apply a tension force to said drawbar which tensioning means when applied will draw the components with their associated members towards each other and when released will permit the components with the associated members to move apart.

4. A formwork jig as claimed in claim 3 wherein the said components are both tubular and the drawbar extends through the tie means and has portions which project beyond both members and wherein the tensioning means comprises fitments on said drawbar portions and at least one of said fitments is threaded on an associated drawbar port . allow the members to be drawn together and retain the members in a predetermined spacial relationship.

5. A formwork jig as claimed in claim 3 or claim 4 wherein the tubular component connected to said mounting member is the outer of said tubular components and said mounting member has elements which extend in opposite directions beyond the tie means with one of the elements .overlying the support member and the other element connected by a brace to the outer of said tubular components to resist spreading movement between the support member and the mounting member when said maintaining means is activated to draw said mounting member and said supporting member towards each other.

6. A formwork jig as claimed in any one of claims 3 to 5 where the tubular member has a bore which is multi-sided and said other component is telescopically slidable therein and is similarly externally configured thereby to substantially prevent rotational movement between said components and maintain said mounting member in overlying relationship with a support surface of the support member.

7. A formwork jig as claimed in any one of claims 1 to 6 wherein the mounting member and the support member are elongated and the distance from the tie means to a free end of the mounting member greatly exceeds the distance from the tie means to a free end of the support member and the mounting member is adapted to facilitate the mounting of the mounting member through its mounting surface to a jig support.

8. A formwork jig as claimed in any one of claims 1 to 7 wherein the tie means has an axis of extension and contraction which lies at right angles to the planes occupied by said mounting and the supporting members.

9. A formwork jig as claimed in claim any one of claims 1 to 8 wherein the support member includes more than one leg radiating from the tie means and each leg has a support surface and the legs are of different length.