AU775833B2

AU775833B2 - A stake surround insert for concrete slabs

Info

Publication number: AU775833B2
Application number: AU36355/00A
Authority: AU
Inventors: Daniel Charles Underwood
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 1997-05-30
Filing date: 2000-05-22
Publication date: 2004-08-19
Anticipated expiration: 2012-11-04
Also published as: AU3635500A

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor(s): Address for Service: DANIEL CHARLES UNDERWOOD DANIEL CHARLES UNDERWOOD

INTELLPRO

Patent Trade Mark Attorneys Level 7, Reserve Bank Building 102 Adelaide Street BRISBANE, QLD, 4000 (GPO Box 1339, BRISBANE, 4001) A STAKE SURROUND INSERT FOR CONCRETE SLABS Invention Title: Details of Associated Provisional Application(s) No(s): Australian Patent Application No. PQ0518 filed 21 May 1999 Parent Invention Details: Application No. 23733/97 Patent No. 714110 The following statement is a full description of this invention, including the best method of performing it known to me: 2 A STAKE SURROUND INSERT FOR CONCRETE SLABS TECHNICAL FIELD OF THE INVENTION THIS INVENTION relates to an insert in concrete structures and in particular concrete structures employing key joints and stakes holding the key joints in operative position prior to pouring the concrete slab.

BACKGROUND TO THE INVENTION The applicant's co-pending patent application No. 23733/97 describes an insert for creating a void using a flexible insert that is fitted to a section of a stake in a concrete slab. The stake is employed to hold lost form work such as a metal St 10 key joint prior to a slab being poured an the insert described in the preferred .embodiment in 23733/97 forms a effectively a complete flexible void extending i from the stake bridging across to the key joint.

i ,The present invention is directed to an improvement or modification in the main invention described in 23733/97 and in particular of the structure for the 15 insert which is suitable for use in circumstances where a complete void is not "-required and in many circumstances the present insert is easier to manufacture Sand simpler to instal.

OUTLINE OF THE INVENTION In one aspect therefore the present invention provides a stake surround used as an insert surrounding a stake supporting lost form work in a concrete slab, the insert having a body able to occupy space around the stake as lost form work in the slab and to deform against the stake in response to slab movement, the surround being elongate and being loll It *l 0 II00 00 0 marginally of greater cross-section than the stake and having stake passage means enabling the stake to be positioned within the stake surround. The surround need not be of uniform cross-section but is typically generally cylindrical.

Typically the surround is a compressible insert adapted to be coupled to surround the stake, the stake being employed with a key joint comprising an elongate panel having a top section, a bottom section and an intermediate section displaced laterally out of the plane of said panel, the junctures between the intermediate section and the other sections have opposed stake holes so that a stake passing through the holes is positioned with an upper end portion of the stake adjacent the top section of the panel, a lower section of the stake adjacent the bottom section of the panel and an intermediate section of the stake C °located adjacent the intermediate section of the panel and on the opposite side S *of the panel, the insert being formed as a cylindrical section of foam material that 15 can be positioned to surround any one, two or all of the upper, lower and intermediate sections of the stake. Preferably the insert is formed with a longitudinally extending resilient stake entry laterally communicating with the stake passage. The insert is preferably made from a expanded foam material that is chosen such that it doesn't compress to much under the concrete pour but merely occupies space but compresses against the stake in response to slab movement to inhibit cracking adjacent to the stake.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention can be more readily understood and be put into practical effect reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:- Figure 1 is a drawing illustrating a key joint supported on stakes.

Figure 2 is a drawing illustrating the key joint with a simple cylindrical insert that can be placed in a position as shown either at the top of the stake, the intermediate section or at the bottom, thus providing some margin for contraction o:g o **of the sections of the slab allowing movement relative to the stake to thereby inhibit cracking of the slab that would otherwise be caused by the stake.

Figure 3 is a profile through a typical insert.

METHOD OF PERFORMANCE Referring to the drawings there is illustrated a metal key joint 10 that can be slid onto a stake 11 having a flattened threaded section that can be rotated S 15 through 900 to lock the stake to the key joint. This enables the height of the key joint to be set in place along a line of stakes 11. The key joint is used as lost form work in a concrete slab.

A c-shaped foam insert 12 can be pushed into position about the stake so that a foam filled void absent concrete is formed about the stake after concrete is poured. This will inhibit cracking due to contraction or other slab movement.

The c-shaped foam insert is illustrated in profile in Figure 3. It will be appreciated that any shape can be used. Also the insert need not be used on all sections of the stake although it is preferred that it is.

Whilst the above has been given by way of illustrative example of the present invention many variations and modifications thereto will be apparent to those skilled in the art without departing from the broad ambit and scope of the o" invention as set out in the appended claims.

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Claims

1. A stake surround used as an insert surrounding a stake supporting lost form work in a concrete slab, the insert having a body able to occupy space around the stake as lost form work in the slab and to deform against the stake in response to slab movement, the surround being elongate and being marginally of greater cross-section than the stake and having stake passage means enabling the stake to be positioned within the stake surround.

2. A stake surround according to claim 1 wherein the lost form work includes a key joint comprising an elongate panel having a top section, a bottom section 10 and an intermediate section displaced laterally out of the plane of said panel, the 0.b junctures between the intermediate section and the top and bottom sections having opposed stake holes so that a stake passing through the opposed holes o is positioned with an upper end portion of the stake adjacent the top section of the panel and on one side of the panel, a lower section of the stake adjacent the So. 15 bottom section of the panel on the same said one side of the panel and an -intermediate section of the stake located adjacent the intermediate section of the Y panel and on a side of the panel opposite said one side of the panel, the insert e• 0: being formed as a section of material positioned to surround the upper section of the stake.

3. A stake surround according to claim 1 wherein the lost form work includes a key joint comprising an elongate panel having a top section, a bottom section and an intermediate section displaced laterally out of the plane of said panel, the junctures between the intermediate section and the top and bottom sections C* eC C* eC e C C. CC e Ce CC.. CC CC *C CCCC *e e CC eC C C CC C* C C C CC C .C *e C CC C CC eC CC C CU eC *C CC CC junctures between the intermediate section and the top and bottom sections having opposed stake holes so that a stake passing through the opposed holes is positioned with an upper end portion of the stake adjacent the top section of the panel and on one side of the panel, a lower section of the stake adjacent the bottom section of the panel on the same said one side of the panel and an intermediate section of the stake located adjacent the intermediate section of the panel and on a side of the panel opposite said one side of the panel, the insert being formed as a section of material positioned to surround the lower section of the stake.

4. A stake surround according to claim 1 wherein the lost form work includes a key joint comprising an elongate panel having a top section, a bottom section and an intermediate section displaced laterally out of the plane of said panel, the junctures between the intermediate section and the top and bottom sections o: .having opposed stake holes so that a stake passing through the opposed holes S° 15 is positioned with an upper end portion of the stake adjacent the top section of the panel and on one side of the panel, a lower section of the stake adjacent the bottom section of the panel on the same said one side of the panel and an intermediate section of the stake located adjacent the intermediate section of the panel and on a side of the panel opposite said one side of the panel, the insert being formed as a section of material positioned to surround the intermediate section of the stake. A stake surround according to claim 1 wherein the lost form work includes a key joint comprising an elongate panel having a top section, a bottom section and an intermediate section displaced laterally out of the plane of said panel, the junctures between the intermediate section and the top and bottom sections having opposed stake holes so that a stake passing through the opposed holes is positioned with an upper end portion of the stake adjacent the top section of the panel and on one side of the panel, a lower section of the stake adjacent the bottom section of the panel on the same said one side of the panel and an e. intermediate section of the stake located adjacent the intermediate section of the panel and on a side of the panel opposite said one side of the panel, the insert being formed as separate sections positioned to surround the upper, lower and intermediate sections of the stake.

6. A stake surround according to claim 1 wherein the lost form work includes a key joint comprising an elongate panel having a top section, a bottom section and an intermediate section displaced laterally out of the plane of said panel, the junctures between the intermediate section and the top and bottom sections having opposed stake holes so that a stake passing through the opposed holes is positioned with an upper end portion of the stake adjacent the top section of the panel and on one side of the panel, a lower section of the stake adjacent the bottom section of the panel on the same said one side of the panel and an intermediate section of the stake located adjacent the intermediate section of the panel and on a side of the panel opposite said one side of the panel, the insert being formed as separate sections of material positioned to surround any two of the upper, lower or intermediate sections of the stake. 9

8. A stake surround according to claim 1 wherein the surround has a longitudinally extending resilient stake entry communicating laterally with the stake passage.

9. A stake surround according to claim 1 wherein the surround is generally C-shaped in cross-section. A stake surround according to claim 1 wherein the surround is of uniform cross-section and generally cylindrical in shape having a longitudinally extending resilient stake entry communicating laterally with the stake passage.

11. A stake surround substantially as described with reference to the accompanying drawings. DATED this 29th day of August 2002 DANIEL CHARLES UNDERWOOD By his Patent Attorneys INTELLPRO