AU2009238356C1

AU2009238356C1 - A Box for Form Work

Info

Publication number: AU2009238356C1
Application number: AU2009238356A
Authority: AU
Inventors: Daniel Charles Underwood
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 2008-11-21
Filing date: 2009-11-23
Publication date: 2017-01-19
Anticipated expiration: 2029-11-23
Also published as: AU2009238356A1; AU2009238356B2

Abstract

A formwork box has a back sheet 10 having an edge 11 and an opposite edge 12, lines of weakness in the form of perforations 13 define a perforated line 14 5 and a perforated line 15 along opposite sides of the sheet 10. The perforations define marginal edge regions 16 and 17. The perforations 13 are about 1mm wide, 25 mm long and separated by a gap of about 5 mm-10mm. The basic function of the perforations is to facilitate folding on-site with minimal tooling so that folding and assembly of the boxes is essentially by hand. This means that the sheets may be 1o transported as flat packs rather than have wasted space by transporting the finished boxes. _______ Jo ol 1 1 1k 0 I I J N N + I Pd Ia o. __ I _ I I I I I I I ol 1 1 I>? 1 1 _ N InN

Description

2009238356 23 Nov 2009 1 P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990

COMPLETE SPECIFICATION FOR A STANDARD PATENT

Name of Applicant: UNDERWOOD COMPANIES HOLDINGS PTY LTD

Actual Inventor(s): Daniel Charles Underwood

Address for Service: INTELLEPRO

Patent & Trade Mark Attorneys Level 7 102 Adelaide Street BRISBANE, QLD, 4000 (GPO Box 1339, BRISBANE, 4001)

Invention Title: Box for Form Work

Details of Associated Provisional Australian Patent Application No 2008906042

The following statement is a full description of this invention, including the best method of performing it known to me: 2009238356 01 Aug 2016 ]|\ft-sw\|mi:rv.mcn\NUJOni>tUJrawxw\|D^B?n„l.dcicx-25/nTOOl6 -2-

BOX FOR FORM WORK THIS INVENTION relates to form work employing tie bars installed in a box used to form a rebate in concrete structures.

In one aspect there is provided a method by which boxed tie bars are made from plural 5 bent bars, a metallic back sheet and a metallic front sheet, the back sheet having a longitudinal axis and opposite longitudinal edges, each edge having a marginal edge region defined by longitudinally extending lines of weakness comprising spaced perforations, the back sheet having longitudinally spaced rebar entry/exit holes located just inboard of the perforations, the front sheet having a longitudinal axis and opposite longitudinal edges, the edges of the front 10 sheet each having a marginal edge region defined by longitudinally extending lines of weakness, typically spaced perforations, the method comprising, folding by hand the front and back sheets about the lines of weakness to form folded sheets of U-shaped profile and having opposed flanges arising from the folding about the lines of weakness; inserting the bent rebars through the entry/exit holes in the back sheet; placing the front sheet over the rebars in the 15 back sheet with the flanges of the sheets overlapping. In this configuration, the sheets form a box which has open ends and it is preferable that the ends be closed by inserting a closure into each end of the box. Typically, the closure at each end comprises a block of polystyrene. Of course extra lines of weakness could be formed in one or both sheets so that the ends are closed by extra flanges. Finally, it is preferable that the entire box be secured closed using 20 some form of fastening. Typically, tape is employed so that the box may be opened to release the rebars.

In another aspect there is provided a box containing bent rebars with a portion of the rebars located inside the box and a portion located outside the box, the box being formed from hand-folded together metallic sheets closed at opposite ends, each sheet having longitudinal 25 folds defined by longitudinally extending lines of weakness, typically, longitudinally extending perforations. Preferably, the portion of the rebars 2009238356 23 Nov 2009 3 located outside the box is a loop and the portion located inside are terminal end sections of the bars that may be bent out after the loops are secured in concrete. In other words the back of the box is lost in concrete and upon removal of the front the bar ends are exposed and these may be manually bent out to a projected position for 5 tying into a slab poured into the rebate.

In order that the present invention may be more readily understood and be put into practical effect reference will having made to the accompanying drawings which illustrate a preferred embodiment and wherein:-

Figure 1 is a plan view of a back sheet prior to folding; 10 Figure 2 is a plan view of a front sheet prior to folding;

Figure 3 is a drawing illustrating the front sheet being folded;

Figure 4 is a drawing illustrating the back sheet being folded and with the rebars located in position;

Figure 5 is a drawing illustrating the assembly of a box; and 15 Figure 6 shows a closed end of a box.

Referring to the drawings and initially to Figures 1 and 2 there is illustrated a back sheet 10 having an edge 11 and an opposite edge 12, lines of weakness in the form of perforations 13 define a perforated line 14 and a perforated line 15 along opposite sides of the sheet 10. The perforations define marginal edge regions 16 2 0 and 17. The perforations 13 are about 1mm wide, 25 mm long and separated by a gap of about 5 mm-10mm. The basic function of the perforations is to facilitate folding on-site with minimal tooling so that folding and assembly of the boxes is essentially by hand. This means that the sheets may be transported as flat packs rather than have wasted space by transporting the finished boxes. 25 The sheet material used in the front and back sheets is galvanized steel sheeting of about Ά mm thick so that the marginal regions 16 and 17 may be folded Ι!ΐ«^»»ίΙΐηΛ'!Χ'Ι;'ϊ : -4- 2009238356 20 Sep 2016 manuallv along the perforations lines to form flanges set at right angles to the plane oi toe .sheet.

The back sheet 10 has spaced holes 18 set .In pairs so that U-shaped rebars may be inserted through the holes, The back sheet is typically dimpled (not shows} 5 in order to improve tne adhesion of concrete to the back sheet. A irooi sheet 19 is aoout tne same Uee as tne bav:\ vu.ct 5 and has similar perforations 13 so that marginal edge regions 20 and 21 may be folded into flanges, also manually.

Referring to Figure 3 the front sheet 19 is illustrated with its flanges 22 and 23 folded to form a U-shaped sheet. Likewise. Figure 4 shows the back sheet 11) with to its hanges 2-1 and 2a folded in position to form a U-shaped sheet. Rebars 26 have been inserted through the holes I B 10 into the position shown hi Figure 4. The rebars have their ends bent at about 90 degrees to the loop so that the ends locate inside the finished box with the loops protruding at about 90 degrees. I he rebars 26 have their free ends located inside the back sheet and wherein i a tne hack sneer and front sheet are inverted from the positions illustrated in Figure 3 and Figure 4, they may be assembled as shown in Figure 5 by placing the front sheet over the hack sheet and closing the ends 15 by inserting blocks 27 and 28 of polystyrene into the ends. Finally, tape is applied along the overlapping flanges and around the ends to dose and seal the box. Once the box ss instated in concrete the 20 front remains accessible so that it may be removed to expose the ends ot the rebars. A bar bending tool is then used to straighten the rebars which are then used as tie ears into the next slab. 20 Whilst die above has been given by way of illustrative example of the present invention many variations and modifications thereto will be apparent to those skilled 25 in the art. without departing from the broad ambit and scope of the invention as herein set out in the following claims.

Throughout this specification and the claims which follow, unless the context requires otherwise. 25 the word ’’comprise", and variations such as "comprises" and ’’comprising”, will be understood to imply the inclusion of a stated integer or step of group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from ill or to any matter which is known, is not, and should not be taken as an acknowledgment-or 30 admission or any form of suggestion that that prior publication (or information derived from it} ot* known matter forms part of the common general knowledge in the field of endeavour to which this specification relates..

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method by which boxed tie bars are made from plural bent bars, a metallic back sheet and a metallic front sheet, the back sheet having a longitudinal axis and opposite longitudinal edges, each edge having a marginal edge region defined by longitudinally extending lines of weakness comprising spaced perforations, the back sheet having longitudinally spaced rebar entry/exit holes located just inboard of the perforations, the front sheet having a longitudinal axis and opposite longitudinal edges, the edges of the front sheet each having a marginal edge region defined by longitudinally extending lines of weakness comprising spaced perforations, the method comprising, folding by hand the front and back sheets about the lines of weakness to form folded sheets of U-shaped profile and having opposed flanges arising from the folding about the lines of weakness; inserting the bent rebars through the entry/exit holes in the back sheet; placing the front sheet over the rebars in the back sheet with the flanges of the sheets overlapping.
2. The method according to claim 1 wherein the sheets form a box which has open ends and the ends are closed by inserting a closure into each end of the box.
3. A box containing bent rebars with a portion of the rebars located inside the box and a portion located outside the box, the box being formed from hand-folded together metallic sheets closed at opposite ends, each sheet having longitudinal folds defined by longitudinally extending lines of weakness comprising longitudinally extending perforations.