AU2007100211A4

AU2007100211A4 - Coupler

Info

Publication number: AU2007100211A4
Application number: AU2007100211A
Authority: AU
Inventors: Robert Urquhart Connell
Original assignee: ITW Australia Pty Ltd
Current assignee: ITW Australia Pty Ltd
Priority date: 2007-03-09
Filing date: 2007-03-09
Publication date: 2007-04-05
Anticipated expiration: 2015-03-09

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT Name of Applicant: Actual Inventor: Address for Service: Invention Title: ITW Construction Products Australia Pty Ltd of 3 Chester Street, Oakleigh, Victoria 3166, Australia.

Robert Urquhart Connell DAVIES COLLISON CAVE, Patent Attorneys, of 1 Nicholson Street, Melbourne, Victoria 3000, Australia "Coupler" The following statement is a full description of this invention, including the best method of performing it known to us: Q:\OPER\RSH\Jan 07 June 07\30187205-68.doc 9/3/07 P \OPERUSI3SO 187251-1dnnov d.c-2 2(X)7 -1-

COUPLER

The present invention relates to a coupler for use with reinforcing bar for concrete components.

Reinforcing bar for incorporation into a concrete component conventionally comprises projections raised from the surface of the bar to provide a keyed connection between the bar and the concrete. In some versions the projections are formed to act as a helical thread, usually a discontinuous thread, which has benefit in the installation of the bar; for example a threaded coupler can be used to connect lengths of the bar in end to end relation, or the bar can act as a bolt which can be clamped using nuts applied to the bar. A version of a reinforcing bar with a thread form on its outer surface is sold by a division of the present applicants under the trade mark "Reidbar". The thread form on reinforcing bars is a non-standard thread form and will typically be a coarse thread having a thread pitch of between 9mm and approximately 15mm depending on the diameter of the bar and therefore a special range of threaded couplers and other fittings is needed for this purpose.

The present applicants have determined that it is desirable in some situations for the reinforcing bar to carry a fixing point for engagement with a standard screw thread, usually a standard metric thread for coupling to a bolt or threaded rod with a standard thread. This may arise, for example, in circumstances where the cast concrete component is to have a fixing point for a fitting subject to a cyclic loading.

According to the present invention there is provided a coupler for coupling threaded reinforcing bar to a component having a standard thread form, the coupler being of tubular form and of cast construction, the coupler having a first internal thread to mate with that of the reinforcing bar, the first thread being accessible from one end of the coupler, and the coupler having a second internal thread accessible from the opposite end of the coupler, the second thread being axially aligned with the first thread and being a standard thread, wherein the standard thread is formed by tapping into a blank cylindrical surface formed within the coupler during casting.

P \OPERXRSHO3I18720 -innov dc-2A)32007 -2- An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a coupler in accordance with the invention; Figure 2 shows the coupler in axial section.

There is shown in the drawings, a coupler in accordance with the preferred embodiment of the invention for use with reinforcing bar having a thread form. The coupler is of generally tubular form and of cast construction, for example of a suitable iron alloy or steel. Its outer surface is of hexagonal form over a substantial part of its length to permit tightening of the coupler by means of a wrench. Internally, the coupler has a first thread 2 extending from one end of the coupler to approximately midway along the length of the coupler. The first thread 2 has a thread form which corresponds to that of the reinforcing bar with which the coupler is to be used whereby that end portion of the coupler can be screwed onto the reinforcing bar. As the thread form provided on reinforcing bars has a large pitch such as previously discussed and is a coarse thread, the corresponding thread 2 can readily be formed by casting when the coupler is cast. The first thread 2 extends as far as a central flange 4 which acts as a stop for the outer end of the reinforcing bar. The part of the tubular passage extending from the other end of the coupler to the other side of the central flange 4 is cast with a plain or blank cylindrical surface co-axial with the first thread 2, and after casting a standard thread 6, usually a metric thread, is tapped into the plain surface.

In use, the coupler is applied to the reinforcing bar prior to casting of the concrete by screwing the coupler tightly onto the bar, the opposite end of the coupler lying in a position such that it will open onto the surface of the component being cast, a removable cap or plug being placed over the open end of the coupler to prevent entry of concrete during casting. Accordingly in the completed cast concrete component, the part of the coupler incorporating the standard metric (or other) thread will open onto the surface of the component for engagement with a threaded rod or bolt for mounting another component.

That threaded connection will be achieved by using threaded fittings with a standard thread P \OPERIRSHOU187205-.ino, doc.2A)3f2007 -3and which has the capacity to handle cyclic loading. This provides a significantly better performance in this regard than could be achieved if the threaded reinforcing bar were to extend to the outside of the cast concrete component to provide a direct threaded mounting point as its coarse thread of large pitch does not cope well with cyclic loading. It is however to be noted that although the coupler itself is connected to the reinforcing bar by the coarse thread of large pitch, as the coupler and reinforcing bar are embedded within the concrete the embedment ensures appropriate resistance of the internal connection to the cyclic loading.

In practice, the coupler will be produced in a range of diameters to couple with a range of reinforcing bar diameters for coupling to a metric (or other standard) thread of generally similar diameter.

Claims

2. A coupler according to claim 1, wherein the first thread is formed during the casting of the coupler.
3. A concrete component having a coupler according to claim 1 or claim 2 installed to a threaded reinforcing bar of the component by engagement of the bar with the first thread of the coupler, the opposite end of the coupler opening onto an outer surface of the concrete component.
4. A coupler substantially as hereinbefore described with reference to the accompanying drawings.