AU746561B2 - A dowel alignment device - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: Details of Associated Provisional Application(s) No(s): 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 Dowel Alignment Device" Australian Patent Application No. P08787 filed 26 August 1997 and Australian Patent Application No. PP1007 filed 18 December 1997 The following statement is a full description of this invention, including the best method of performing it known to me: 2 A DOWEL ALIGNMENT DEVICE TECHNICAL FIELD THIS INVENTION relates to a dowel alignment device for use in the construction of concrete slabs of the type employing key joints to separate sections of the slab.

BACKGROUND ART During the construction of concrete slabs key joints are employed between sections of the slabs. Key joints usually employ holes and metal dowels passing through the holes and projecting into each of the adjacent slabs. During 10 preparation for pouring the concrete slab it is desirable to keep dowels aligned o:ooe o at 90' to the key joint. Present dowel aligners are prone to move during pouring of the slab. Typical dowel aligners comprise a plastic jacket screwed to the key joint adjacent each hole so that a dowel can be slid into the jacket and project ::from the opposite side of the key joint.

Since these dowel aligners are secured in place by screws at the point of contact then there is a risk that the dowel aligner will itself become misaligned.

Also the use of screw fasteners is time consuming and it would be desirable to provide a dowel aligner that did not require fasteners and avoided the problems of the prior art.

OUTLINE OF THE INVENTION In one aspect therefore the present invention resides in a key joint assembly, the assembly comprising a key joint having spaced dowel holes and a dowel projecting from each hole, a dowel aligner fitted to each dowel, the aligner having a stake attachment means and a stake passing through the stake attachment 3 means and driven into the ground adjacent the key joint in order to hold the dowel aligner in pre-determined aligned position. Preferably the dowel aligner is secured in the hole in the key joint.

Preferably the dowel aligner includes internal projections that cause the dowel to be aligned within the dowel aligner and spaced from the walls of the dowel aligner.

Preferably the dowel aligner includes hand insertable clip means or other hand insertable means enabling the dowel aligner to be secured in the hole in the key joint using a hand insertable action. Typically the hand insertable action can 10 be a sliding action or a twist and turn or bayonet type action.

.ooooi In one preferred embodiment the dowel aligner is made from a base section and a cap section hinged to the base section, the stake attachment means comprising two parts, the first part thereof being carried by the cap section and second part being carried by the base section so that when the cap section is 15 clipped to the base section the two parts of the stake attachment means align.

In a further embodiment the dowel aligner does not clip into the hole in S"the key joint but rather is an end cap for the dowel.

Preferably the assembly includes a locking means such as a wedge or other suitable means holding the stake in a fixed position relative to the aligner.

BRIEF DESCRIPTION OF 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:- 4 Figure 1 is a perspective drawing illustrating a key joint positioned with dowel aligners and dowels in place; Figure 2 illustrates the use of a stake to hold the dowel aligner in position; Figure 3 is a drawing from the opposite side showing the dowel aligner clipped into the key joint; Figure 4 is a drawing illustrating the dowel aligner according to a preferred form of the present invention; Figures 5, 6 and 7 illustrate a twist action method for securing a dowel aligner to the key joint; and S 10 Figures 8 and 9 illustrate an alternative embodiment where the aligner is S- not connected to the key joint.

*METHOD OF PERFORMANCE Referring to the drawings and initially to Figure 1 there is illustrated a key *-joint assembly 10 comprising a key joint 11 and a plurality of hollow dowel aligners 12 clipped into holes 13 in the key joint and held in place by stakes 14.

*Stakes 15 hold the key joint in position in the usual way. Dowels 16 can be seen S"projecting from the opposite side of the key joint. It will be appreciated that the dowels 16 slide back into the dowel aligners 12.

The position of the stake is illustrated in Figure 2 and as can be seen the dowel aligner 12 comprises a top cap section 17 and a base section 18. The stake attachment means is in the form of a pair of mating rings 19 and 20 on the cap section 17 and the base 18 respectively.

As can clearly be seen in Figure 3 and also in Figure 4 the dowel aligner 12 includes a hand insertable clip action portion at 20 that enables the dowel aligner to be clipped into the openings 13. In this regard the clip portion includes a tapered nose section 21 and a shoulder 22 and a slot 23 to the width of the thickness of the key joint material so that the leading portion 21 is resiliently closed as the dowel aligner clips into place.

It will be appreciated that the present invention allows for easy hand insertable clip action of the dowel aligner into the key joint and subsequent installation and support utilising a stake so that there is quick and easy assembly of the key joint assembly. The dowels can then be easily slid into place as •req u i red.

S 10 Also in relation to Figure 4 it will be seen that the interior of the dowel .:ooo: S.0 aligner includes projections 24 thereby providing when the dowel 16 is in place voids at 25 and these projections 24 are sufficiently flexible that slight movement *oo of the dowel can occur within the dowel aligner to compensate for expansion and contraction and relative movement of the slabs of either side of the key joint 11.

"0 0 15 Referring now to Figure 5, 6 and 7 there is illustrated a key joint 26 having a hole 27, measuring 24.5mm by 24mm. The dowel aligner 32 has a C-shaped groove 33, and due to the .5mm difference in dimension the groove can be aligned in the direction shown in Figure 6 and the dowel aligner rotated to lock it in position.

Figures 8 and 9 illustrate a further embodiment where the aligner forms a short cap 34. A wedge 35 can be used to secure the stake relative to the aligner by provision of a small gap near the stake. The wedge can be used in the previous embodiments as well.

6 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 invention as defined in the accompanying claims.

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Claims (11)

1. A key joint assembly, the assembly comprising a key joint having spaced dowel holes and a dowel projecting from each hole, a dowel aligner fitted to each dowel, the aligner having a stake attachment means and a stake passing through the stake attachment means and driven into the ground adjacent the key joint in order to hold the dowel aligner in pre-determined aligned position.

2. A key joint assembly according to claim 1 wherein the dowel aligner is secured in the hole in the key joint.

3. A key joint according to claim 1 or claim 2 wherein the dowel aligner 10 includes wall and internal projections that cause the dowel to be aligned within S•the dowel aligner and spaced from the walls of the dowel aligner.

4. A key joint assembly according to any one of the preceding claims where the dowel aligner includes hand insertable means enabling the dowel aligner to be secured in the hole in the key joint using a hand insertable action.

5. A key joint assembly according to claim 4 wherein the hand insertable •••action is a sliding action or a twist and turn or bayonet type action.

6. A key joint assembly according to any one of the preceding claims wherein the dowel aligner is made from a base section and a cap section hinged to the base section, the stake attachment means comprising two parts, the first part thereof being carried by the cap section and a second part being carried by the base section so that when the cap section is clipped to the base section the two parts of the stake attachment means align. 8

7. A dowel aligner comprising a body adapted to receive a dowel in a concrete construction, the body having stake receiving means to enable the aligner to be held in operative position by a stake.

8. A dowel aligner according to claim 7 wherein the dowel aligner includes wall and internal projections that cause the dowel to be aligned within the dowel aligner and spaced from the walls of the dowel aligner.

9. A dowel aligner according to claim 7 or claim 8 wherein the dowel aligner includes hand insertable means enabling the dowel aligner to be secured in the hole in the key joint using a hand insertable action.

10. A dowel aligner according to claim 7, claim 8 or claim 9 wherein the S• dowel aligner is made from a base section and a cap section hinged to the base section, the stake attachment means comprising two parts, the first part thereof being carried by the cap section and a second part being carried by the base section so that when the cap section is clipped to the base section the two parts of the stake attachment means align.

11. A dowel aligner substantially as described with reference to the accompanying drawings. DATED this Twenty-Sixth day of August 1998 DANIEL CHARLES UNDERWOOD By his Patent Attorneys INTELLPRO