NZ567876A

NZ567876A - Ferrule chair

Info

Publication number: NZ567876A
Application number: NZ56787608A
Authority: NZ
Inventors: Andrew Emden O'loughlin; Brendan Andersen
Original assignee: Itw Construction Systems Austr
Priority date: 2007-05-24
Filing date: 2008-05-02
Publication date: 2009-08-28
Also published as: AU2008201842B2; AU2008201842A1

Abstract

A ferrule chair for supporting an internally threaded ferrule to be incorporated into a concrete component during casting to provide a fixing point in the cast component is disclosed. The ferrule may be a star foot ferrule or a straight ferrule. The chair has a support surface for the foot of a star foot ferrule and also has means to locate and support a transverse reinforcing bar (16) that extends through the lower portion of a straight ferrule.

Description

<div class="application article clearfix" id="description"> NEW ZEALAND *10055652804* PATENTS ACT 1953 COMPLETE SPECIFICATION 5 6 7 8 7 6 After Australian Provisional Application No. 2007902771 filed 24 May 2007 Davies Collison Cave Reference: 30532017 APPLICANTS) ITW Construction Systems Australia Pty Ltd 3 Chester Street, Oakleigh, Victoria 3166, Australia An Australian company My/Our contact address is: My/Our address for service is: DAVIES COLLISON CAVE DAVIES COLLISON CAVE 1 Nicholson Street c/- James & Wells G.P.O. Box 4387QQ Level 9, James & Wells Tower Melbourne 3000 56 Cawley Street Victoria, AUSTRALIA Private Bag 11907 Telephone: 61 3 9254 2777 DX CP 34005 Facsimile 61 3 9254 2770 Ellerslie Auckland Email: mail@davies.com.au NEW ZEALAND INVENTION TITLE: Ferrule chair We/I, ITW Construction Systems Australia Pty Ltd hereby declare the invention for which we pray that a patent be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: intellectual property OFFICE OF N.2, 12 MAY 2008 RECEIVED P:\REC\NZ\Docs\3G5320I7 120.doc- 29/4^08 P:\0PER\ftSH\3tlS12712-CAP.<toc.24V»4/2«>8 -la- 567 8 7 6 FERRULE CHAIR The present invention relates to a chair for an internally threaded ferrule to be incorporated into a concrete component during casting to provide a fixing point in the cast component. 5 Internally threaded ferrules for incorporation into a concrete component during casting are produced in a variety of different forms. In one form the ferrule is of constant external cross-section (either circular or hexagonal) throughout its length, a so-called straight ferrule. In another form, the ferrule is enlarged diameter at its lower end to form a foot by 10 which the ferrule can be supported. In one version of a ferrule with foot, the foot is divided into four angularly spaced segments and this is sometimes known as a star foot ferrule. A straight ferrule and star foot ferrule are shown in Figure 1 and the foot segments of the star foot ferrule are designated 2 in that figure. In each case the ferrule has at its lower end portion a transverse passage to receive reinforcing bar by which the ferrule is 15 tied into other reinforcement of the concrete component. The present invention relates particularly to a support chair which can be used selectively with a straight ferrule or star foot ferrule. 20 According to the present invention, there is provided a ferrule chair for supporting selectively a star foot ferrule or a straight ferrule, the chair having a support surface for the foot of a star foot ferrule, the chair having means for locating and supporting a transverse reinforcing bar extending through the lower portion of a straight ferrule whereby to provide support for the ferrule and for locating a transverse reinforcing bar extending 25 through the lower end portion of a star foot ferrule. In a preferred embodiment of the invention, the support surface for the star foot ferrule is configured to permit the lower end portion of a straight ferrule to lie beneath the level of the support surface. 30 In a preferred embodiment of the invention, the support surface for the star foot ferrule is P:\0PER\RSH\30512712-CAP.doc-24/04/2(H)8 -2- of ring-shaped form which, when the chair is used with a straight ferrule will surround the lower end portion of the ferrule. An annular array of fins extends upwardly from the support surface to locate externally the upper part of a ferrule within the chair. 5 In the preferred embodiment, the means for locating and supporting the transverse reinforcing bar of a straight ferrule and for locating a transverse reinforcing bar of a star foot ferrule comprises a pair of diametrically opposed slots within an annular structure surrounding the array of fins. Preferably, the annular structure has a further pair of diametrically opposed slots for locating and supporting the transverse reinforcing bar of a 10 straight ferrule at a different height to that achieved when using the first pair of slots. Preferably, the slots are configured to grip onto reinforcing bar of profiled form whereby to prevent the bar from sliding out of the ferrule. Preferably the chair is supplied with a set of extension feet for application to legs of the 15 chair. The extension feet are such that they can serve, selectively, to increase the height of the chair or to locate the chair relative to a casting bed by engagement of a lower stem of each foot in a hole drilled into the bed. Extension feet of this type also have applicability to other types of ferrule chair. 20 Accordingly, in accordance with a further aspect of the invention there is provided an extension foot for application to the leg of a ferrule chair, a plurality of such feet serving, selectively, to increase the height of the chair or to locate the chair relative to a casting bed by engagement of a lower stem of each foot in a hole drilled into the bed. 25 An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 2 is a side view of a ferrule chair in accordance with the preferred embodiment of the invention; 30 Figure 3 is a side view looking at right angles to that of Figure 2; Figure 4 is a plan view of the chair; P:\OPER\RSH\305I2712-C APdoc-24/ft4/2<Xm -3 - Figure 5 is a perspective view of the chair; Figure 6 is a perspective view showing the ferrule chair supporting a straight ferrule at a lower height within the chair; Figure 7 is a perspective view similar to Figure 6 but showing the ferrule supported 5 at an increased height; Figure 8 is a perspective view of an extension/locating foot; Figure 9 is a side view of the extension/locating foot; and Figure 10 is an enlarged view showing how the extension/locating foot is applied to the lower end portion of a leg of the chair. 10 As shown in Figures 2 to 7, a ferrule chair in the form of a one-piece plastics moulding has a base structure comprising an array of legs 4 by which the chair is supported on a casting bed or casting surface. In the embodiment shown, the legs 4 axe of a T cross-section although other cross-sections may alternatively be used, for example the leg may be of 15 circular cross-section of tubular form. However a leg of T-section is preferred over a tubular leg as it uses less plastics, is easy to produce, but nevertheless provides the requisite strength. The base structure carries upper structure by which the ferrule is located and supported. The upper structure comprises an array of four angularly spaced upstanding fins 6, the inner surfaces of which are at a diameter corresponding to that of the 20 ferrule so that it is held in an upright manner by the fins. The fms 6 extend upwardly from a ring-shaped base 8 (see Figures 4 and 5) which acts as a support on which can rest the spaced segments 2 of the foot portion of a star foot ferrule, with the base of the fins 6 lying in the gaps between the adjacent segments. When used with a straight ferrule, the base 8 does not provide a supporting function, this being provided instead by co-operation 25 between its transverse reinforcing bar and the chair as will be described. The array of fms 6 is surrounded in its lower part by an outer wall 10 of annular form. This outer wall 10 is provided with two pairs of diametrically opposed slots 12, 14 for cooperation with the transverse reinforcing bar passing through the base portion of the 30 ferrule, the two pairs of slots being offset through 90°. It is preferred that the slots of each pair are of slightly undersized in relation to standard reinforcing bar of profiled (deformed) P:\OPER\RSH\30512712-CAP.doc-24/04/200a -4- form so that when the ferrule with its transverse reinforcing bar 16 (see Figures 6 and 7) is pushed downwardly into the chair, the sides of the slots will grip onto the bar to prevent it from sliding out of the ferrule. Accordingly it is not necessary to tie the bar to the chair or ferrule as is normally required to ensure it remains in the correct position for tying to the 5 reinforcement. The first pair of slots 12 is intended for use when the ferrule is a star foot ferrule positioned in the chair with its foot portion resting on the ring-shaped base 8, The first pair of slots 12 is also intended for use when the ferrule is a straight ferrule and in that case its transverse bar 16 will rest on the base of the slots to provide the necessary support at the required height; in this condition the lower end of the ferrule will lie suspended 10 within the interior of the base 8. The second pair of slots 14 is positioned at a greater height than the first pair and is also intended for use with the straight ferrule whereby the transverse bar 16 of the ferrule can alternatively be engaged with the second pair of slots and thereby the straight ferrule can be set at a selected one of two different heights within the chair. 15 The chair may be produced in a range of different leg heights to suit a range of different depths or thicknesses of component being cast, panels for example. For the T-sectioned legs shown the preferred embodiment, the main stem of the T-section tapers to a small foot 20 to provide a small contact area in engagement with the casting bed and thereby 20 minimum exposure on the under surface of the cast component. The transverse stem of the T-section also tapers to a small foot 22 which is above the level of the foot 20 and at right angles thereto. The overall height of the chair can be reduced by cutting off the lower feet 20 whereby the feet 22 then engage the casting bed. 25 An increase in the overall height of the chair can be achieved by application of an extension foot 24 (see Figures 8 to 10) which slidably mounts onto the lower end portion of each leg. For this purpose the foot 24 is shaped with opposed channels 26 which receive the opposed flanges of the T-section leg. The extension foot is slid onto the leg 4 from its lower end until lateral shoulders 28 at the base of the tapered foot 22 (see Figures 30 6 and 7) engage against a stop 30 in the base of each channel 26 in the fully engaged position. When the extension foot is engaged with the leg it is retained on the leg at a P:\OPER\RSH\30512712-CAP,doc-24/04/2008 -5- predetennined height and cannot move further upwards along the leg. To extend the height of the chair, an extension foot 24 will be applied to each of the four legs of the chair. 5 The extension feet 24 can also act as locator feet to accurately locate the chair on the casting bed. In this regard when accurate location is required, it is common practice to locate chairs with tubular legs by drilling into the casting bed through the interior of the legs and then inserting locating dowels. The T-section legs which are used in the preferred embodiment do not permit this location technique. Location, if required, is effected 10 instead by the use of a pair of the extension feet 24 applied to one diametrically opposed pair of legs. It will be seen that the downwardly projecting stem 32 of the foot 24 steps downwardly to a reduced diameter section 32a at a position level with the lower end edge of the foot 20. For location purposes a hole is drilled into the casting bed of a diameter to accept the reduced diameter lower end section 32a of the stem whereby the step 32b at the 15 upper end of the section 32a will rest on the surface of the casting bed level with the lower edge of the foot 20 as shown in Figure 10. Although as shown the stem 32 of the extension foot is of a cruciform cross-section it may alternatively be of other cross-section, circular for example. A single size of extension foot can be produced for all chair sizes within the range. The extension foot shown in Figures 8 and 9 has applicability to any 20 form of ferrule chair with legs of T-section, and it will be understood that extension feet of the general type described can be designed to fit onto legs of other than T-section. The embodiment has been described by way of example only and modifications are possible within the scope of the invention. </div>

Claims

<div class="application article clearfix printTableText" id="claims"> P:\OPER\RSH\305127i 2-CAP.doc-24/04/2008 -6- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A ferrule chair for supporting selectively a star foot ferrule or a straight ferrule, the chair having a support surface for the foot of a star foot ferrule, the chair having means for 5 locating and supporting a transverse reinforcing bar extending through the lower portion of a straight ferrule whereby to provide support for the ferrule and for locating a transverse reinforcing bar extending through the lower end portion of a star foot ferrule.

2. A chair according to claim 1, wherein the support surface for the star foot ferrule is 10 configured to permit the lower end portion of a straight ferrule to lie beneath the level of the support surface.

3. A chair according to claim 2, wherein the support surface for the star foot ferrule is of ring-shaped form which, when the chair is used with a straight ferrule, will surround the 15 lower end portion of the ferrule.

4. A chair according to any one of claims 1 to 3 having an annular array of fms extending upwardly from the support surface to locate externally the upper part of a ferrule within the chair. 20

5. A chair according to claim 4, wherein the means for locating and supporting the transverse reinforcing bar of a straight ferrule and for locating a transverse reinforcing bar of a star foot ferrule comprises a pair of diametrically opposed slots within an annular structure surrounding the array of fins. 25

6. A chair according to claim 5, wherein the annular structure has a further pair of diametrically opposed slots for locating and supporting the transverse reinforcing bar of a straight ferrule at a different height to that achieved when using the first pair of slots. 30

7. A chair according to claim 5 or claim 6, wherein the slots are configured to grip onto reinforcing bar of profiled form whereby to prevent the bar from sliding out of the P;\QPER\RSH\30512712-NZclaims,doc-22/08/2<X>8 -7- ferrule.

8. A chair according to any one of claims 1 to 7 in combination with a set of extension feet for selective application to legs of the chair, wherein the extension feet are such that 5 they can serve, selectively, to increase the height of the chair or to locate the chair relative to a casting bed by engagement of a lower stem of each foot in a hole drilled into the bed,

9. A chair according to claim 8, wherein each extension foot has an upwardly-opening socket to receive slidably the lower end portion of the leg, and the lower stem of each foot 10 is stepped down to a reduced diameter portion engageable with the hole drilled into the bed with the shoulder of the step resting on the surface of the bed.

10. A ferrule chair for supporting selectively a star foot ferrule or a straight ferrule, the chair having a support surface for the foot of a star foot ferrule so that the ferrule is 15 supported in the chair at a predetermined height, fins arranged in an annular array to locate externally the upper part of a star foot ferrule or straight ferrule, and slots in structure arranged externally of the fins for locating a transverse reinforcing bar extending through the lower end portion of a star foot ferrule or straight ferrule, with the slots providing support for the transverse bar of a straight ferrule whereby that ferrule is supported in the 20 chair at a predetermined height. IPONZ 27 AUG 2008 i P\OPER\RSW3OS12712-NZclaim8.dcc-22/0a/20fi8 -8-

11. A ferrule chair substantially as hereinbefore described with reference to the accompanying drawings. 1ponz 27 AUG 2008 </div>