Background Art Construction of reinforced concrete structures usually involves preparing a formwork in the desired shape, laying appropriate steel reinforcement, and subsequently pouring concrete into the form work such that it encases the steel reinforcement. Once the concrete has set, the formwork is removed. The size of the concrete structure being constructed may require reinforcing of lengths greater than the length of the individual steel reinforcement available for use. Otherwise, the reinforcing may be required to change direction such as where a floor is to meets a wall or column or the like. In such instances, it is necessary to connect two or more pieces of steel reinforcement together in order to obtain the desired strength properties in the finished structure. In order to connect two or more pieces of reinforcing steel together, it has been common practice to lay the steel reinforcement such that the ends of two pieces or steel reinforcement overlap to a certain extent. The overlapped ends are then tied together using tie wire. This task is laborious, back breaking and relatively slow. The tying of steel reinforcement together compromises occupational health and safety on a building site and also slows down the construction process.

Steel reinforcement must be joined end to end in some instances where space is a problem such as the vertical reinforcement in columns. Overlapping bar is not suitable or needs to be deformed in order to be able to be used. In WO03/062552 by the present applicant there is described a particular application in respect of joining floor reinforcing to wall reinforcing and including forming the wall reinforcing into loops that extend into a formed void in the wall casting into which the floor edge is to be cast. A floor reinforcing bar is provided with a connector secured to one end, the connector having a head including a channel which enables the head to hook over the staple of wall reinforcing projecting into the void. By this means the floor reinforcing bar is in tensile connection with the wall reinforcing as required to maintain optimum strength of the reinforced concrete in the region of the wall/floor junction. However, this

arrangement requires special treatment of the wall reinforcing and is not amenable to general application to reinforcement connection.

Summary of the Invention It is an object of the invention to provide a connector for reinforcement which overcomes or at least ameliorates one or more of the above mentioned disadvantages.

In one aspect, the present invention resides broadly in a connector for reinforcement and including a pair of members, at least one of which is adapted to be secured in tensile relation to the end of a reinforcing bar, the members having complementary coupling portions selected to interengage by relative movement transverse the direction of said tensile relation and resist removal from each other by relative movement in the direction of said tensile relation.

The connector may further include retaining means for retaining the coupling portions in the coupling position. The retaining means suitably is movable between a position where separation of the coupling portions is possible to a retaining position where the coupling portions are retained in the coupled position. The retaining means may comprise a movable sleeve that fits over a portion of both members when in the retaining position. The movable sleeve may be slidable or movable by rotation over a thread. Where slidable, the retaining means may be frictionally engaged to hold in a selected position. Other retaining means may also be used in the present invention.

The respective coupling portions may be configured as complementary hooks. The hooks may each include a transverse, undercut receiving channel bounded by an outer Np, whereby interengagement with a like channel is lip to lip. The hook is suitably configured such that when the hook of a like-shaped coupling portion is brought into a coupling position, the receiving channel of one hook receives the lip or outer rim of the other hook and the lip or outer rim of the one hook is received in the receiving channel of the other hook. The hook may be configured such that the side wall(s) of the bodies of the first and second members are in general alignment when in the engaged position. This provides a tidy appearance and facilitates placement of the retaining means in the retaining position. Most suitably, a rear side of the hook forms an extension of a side wall or

walls of the body whereby the side wall(s) of the bodies of the first and second members are in general alignment when in the coupled position.

The complementary coupling portions may be interengaged by one of the members further including a cavity for receiving a part of the other member, the cavity extending from an end of the first member into the first member and being shaped such that the part of the second member is placed in the cavity by transverse movement of the first member relative to the part of the second member and the part of the second member resists removal from the cavity by relative longitudinal movement between the first member and the second member. The second of the pair of members may also be arranged to receive an end of a length of reinforcement. In this fashion, the connector can be used to connect together two pieces of reinforcement. Each member may include a cavity for receiving and retaining the end of a length of reinforcement. The cavity may include an internal thread so that it can be thread ably connected to a thread, ribs or like formations on the outer surface of the reinforcement. Alternatively, the end of the reinforcement may be tightly received in the cavity such that the end of the reinforcement is retained in the cavity by a friction fit. As further alternatives, the cavity may be arranged as described for the cavity in our co-pending international patent publication WO03/062552, the entire contents of which are herein incorporated herein by reference.

In the disclosure of WO03/062552, the member includes a cavity for receiving an end of a length of reinforcement. Preferably the body is formed from a plurality of parts which may be secured to or held relative to one another and which collectively form the cavity mentioned above. Reinforcement often has ribs or formations on its outer surface and the interior face of the cavity may be provided by the body have complementary formations for receiving the formations on the length of reinforcement. This assists in attaching the length of reinforcement relative to the body. The body may be formed from two parts or halves which may be secured to one another to capture an end of the reinforcement between them. An inner end of the cavity may be enlarged relative to the remainder of the cavity in the body. This ensures that the cavity may readily be able to receive an end of a length of reinforcement even if the free end of the length is deformed. Deformation often occurs when a desired length of

reinforcement is cut from a longer length of such material. Where the body is formed of two parts they may be held to each other by one or more connecting members. The connecting member may be a collar. The connecting members may consist of studs projecting from one of the parts of the body and the other part of the body may have corresponding apertures for receiving the studs. Free ends of the studs may be deformed to lock the body parts to one another and may function like rivets. If desired that body part with the apertures may be provided with recesses for receiving the deformed ends of the studs. Alternatively, the studs may be relatively short and serve to locate one part relative to the other part and a retainer such as a collar may hold the parts relative to each other.

In another aspect, the present invention provides a connector for reinforcement including a member having a body for receiving and retaining an end of a length of reinforcement and a coupling portion for coupling with a like- shaped coupling portion of another member, wherein the coupling portion of the member is brought into a coupling position with a like-shaped coupling portion of another member by relative transverse movement and the coupling portions resist removal from each other by relative longitudinal movement, the connector further including retaining means for retaining the coupling portion in the coupling position with the coupling portion of another member. In the construction of concrete multi-level buildings, the walls are first cast.

In casting the wall structure, formwork is assembled and the wall reinforcing is located in the formwork. At the future position of floors and like intersecting structures, a void forming channel is secured to the formwork, the void providing a recess in the finished wall into which will be cast the edge of the floor or other intersecting structure. A typical void forming channel or "reinforcing box" may be that known by the trade name "REBOX".

The void former may include reinforcing tie bars that may be tied off to the wall reinforcing or may have apertures adapted to receive wall reinforcing bent well into the plane of the future floor or other intersecting structure. The tie bars or reinforcing are bent along the void forming channel to permit positioning of the open face of the channel against the wall forming formwork. The void forming channel will usually be sealed at both ends and may be capped across the open face to seal the void forming channel against the formwork. In this way concrete is

prohibited from entering the channel when the wall is formed.

After the wall is poured and set, the formwork is removed to expose the void and the reinforcing bent along it. The formwork for the floor is established in position, the reinforcing is bent back out into the plane of the floor and the floor reinforcing is tied off to it.

The bending out of the reinforcement delays the reinforcing of the floor or other intersecting structure since this cannot be placed until the steel reinforcement within the void has been manually deployed. This manual deployment of the reinforcement within the void may cause the reinforcing bar to assume an 'S' shape that cannot be manually straightened and in practice is not straitened. This 'S' shape means that the tied off reinforcement is not disposed as a tensile member in the region of the floor edge, reducing the strength of the steel reinforced concrete. The manual deformation of the reinforcement within the void may lead to serious lower back strain and long term repetitive strain injury. While embedding threaded inserts in a cast wall structure may permit the tying of floor reinforcing by intermediate booker tie bars, this is made difficult because of possible burring of the end of the threaded reinforcement, by contamination of the internal cavity of the threaded insert by concrete fines or by difficult access to the threaded insert because of other steel reinforcement in close proximity to the threaded insert.

In WO03/062552 by the present applicant has proposed eliminating the bending of reinforcing into and out of the void by configuring the reinforcing in the void as continuous loops in the void space presenting as staples on the bottom of the void. A floor reinforcing bar is provided with a connector secured to one end, the connector having a head including a channel which enables the head to hook over the staple of wall reinforcing projecting into the void. By this means the floor reinforcing bar is in tensile connection with the wall reinforcing as required to maintain optimum strength of the reinforced concrete in the region of the wall/floor junction. However, this arrangement requires special treatment of the wall reinforcing to provide the necessary staple portions in the void. As such it means that commercial products such as REBOX having starter bars that extend through the floor of the void forming channel cannot be used.

Accordingly in a further aspect this invention resides broadly in a

reinforcing connector including a pair of members, one of which is adapted to be secured in tensile relation to the end of a reinforcing bar, the other of which is adapted to be secured to a structure, the members having complementary coupling portions selected to interengage by relative movement transverse the direction of said tensile relation and resist removal from each other by relative movement in the direction of said tensile relation.

The complementary coupling portions may be interengaged as described above including by one of the members further including a cavity for receiving a part of the other member, the cavity extending from an end of the first member into the first member and being shaped such that the part of the second member is placed in the cavity by transverse movement of the first member relative to the part of the second member and the part of the second member resists removal from the cavity by relative longitudinal movement between the first member and the second member. The cavity may extend from an opening in the end of the first member and a portion of the second member extends into or through the opening in the end of the first member when the first and second members are connected to each other. The second member may be adapted to be secured to a structure by being embedded in the structure. For example, the second member may include a shank portion adapted to be embedded in a first formed part of a structure and be configured to resist pulling out under tensile loads. The embedding may be by casting in of the second member in the case of newly formed structures. Alternatively, the second member may be formed as a masonry anchor such as an expanding bolt of the style of DYNABOLT ^® . The second member may be adapted to receive an end of another length of reinforcement, or be adapted to be secured to reinforcing by tying.

One or more of the members adapted to be secured to a structure may be mounted by their respective coupling portions in a void forming body attached to formwork before casting of a first part of a structure whereby, after curing of the first part, removal of the void forming body leaves said coupling portions exposed. The cavity in the first member may be suitably shaped such that it includes an opening in the end of the first member and an opening in a side of the first member. Most suitably, the opening in the side of the first member may be

contiguous with the opening in the end of the first member. The cavity may also extend inwardly from the end of the first member such that an inner part of the cavity is larger than the opening in the end of the first member. In this fashion, the cavity may receive a complementarily-shaped part of the second member by relative transverse movement between the first and the second members but removal of the second member from the cavity by relative longitudinal movement is resisted by virtue of the opening of the cavity in the end of the first member being smaller than the part of the second member that fits into the enlarged part of the cavity. In one embodiment, the first member comprises a body for receiving and retaining an end of the length of reinforcement, preferably with the cavity for receiving the part of the second member being positioned towards an opposite end of the body.

In an embodiment of the present invention, the cavity includes an inner part having an enlarged diameter relative to the size of the opening in the end of the body, wherein the end wall of the body surrounding the opening and the enlarged diameter portion of the cavity define a shoulder. In this embodiment, it is further preferred that the second member includes a shank portion of a diameter that fits into the opening in the end of the body, and the second member further includes an end portion of larger diameter that fits into the enlarged diameter portion of the cavity.

In some embodiments, the second member is adapted to be fixed in or to a wall. Preferably, the second member is adapted to be fixed in a wall by placing the second member into a wall cavity defined by form work, pouring concrete into the wall cavity defined by the formwork and allowing the concrete to set. In such embodiments, it is advantageous to provide the second member with a shape that assists in retaining the second member within the concrete. For example, the second member may be provided with an enlarged end, or it may be provided with an open ring or other apertures that enable the concrete to mechanically key with the second member. The second member may also be provided with suitable protrusions or projections in order to make it more difficult to remove the second member from the concrete wall structure. In a yet further aspect this invention resides broadly in a method of forming a

reinforced concrete structure including the steps of: providing a formwork for a first concrete structure; providing a reinforcing connector including a pair of members, one of which is adapted to be secured in tensile relation to the end of a reinforcing bar, the other of which is adapted to be secured to said first portion, the members having complementary coupling portions selected to interengage by relative movement transverse the direction of said tensile relation and resist removal from each other by relative movement in the direction of said tensile relation; mounting said other portion by its coupling portion in a void forming body attached to said formwork; pouring concrete into said formwork and curing to form said first concrete structure and to embed and retain a portion of said other member in said concrete; removing said formwork and said void forming body to expose the coupling portion of said other member; installing the one said member to the end of a reinforcing bar; interengaging said complementary coupling portions; incorporating said _. reinforcing bar into the reinforcing of a second reinforced concrete structure to be formed up to the first concrete structure; and pouring and curing said second reinforced concrete structure.

The first structure is itself preferably a reinforced concrete structure. The other member may be formed up with or secured to the reinforcing of the first concrete structure.

Brief Description of the Drawings

Figure 1 is an isometric view of a connector in accordance with an embodiment of the present invention. In Figure 1 , the connector is shown in an unconnected position;

Figure 2 is an elevation of Figure 1 ; Figure 3 is a sectional view taken of line A-A in Figure 2;

Figure 4 is an isometric view of the connector shown in Figure 1 , but in the connected position;

Figure 5 is an elevation of Figure 4;

Figure 6 is a cross-sectional view taken along line A-A of Figure 5;

Figure 7 is an isometric view of a holder and rebate former for use with the connector with the present invention;

Figure 8 is an elevation of another embodiment of the connector in accordance with the present invention;

Figure 9 is an end elevation of a connector in accordance with the present invention;

Figure 10 is an isometric view of the connector of Figure 9;

Figure 11 is a side elevation of the connector of Figures 9 and 10; Figure 12 is a front elevation of the connector of Figure 11 ; and

Figures 13 to 16 show use of connectors in accordance with the present invention

Detailed Description of the Drawings

It will be appreciated that the attached drawings show embodiments of the present invention. It is to be understood that these drawings are provided for illustrative purposes only and that the invention should not be considered to be restricted to the features shown in the drawings.

The connector 10 shown in Figures 1 to 6 comprises a first member 12 and a second member 14. The first member 12 comprises a body 16 having a cavity 18 for receiving the end of a reinforcing bar 20. This is most clearly shown in Figures 3 and 6. Cavity 18 receives and securely retains the end of reinforcing bar 20. For example, cavity 18 may be provided with a threaded portion or with protrusions to couple with thread 22 formed on bar 20. Alternatively, cavity 18 may be sized such that the end of reinforcing bar 20 is received in cavity 18 in a tight friction fit to thereby securely retain the reinforcing bar 20 in cavity 18.

The other end of body 16 is provided with a second cavity 24. Second cavity 24 extends from an opening 26 located in the end 28 of body 16. As best shown in Figure 2, cavity 24 extends inwardly from opening 26 via cavity region 30 and thereafter cavity 24 opens into enlarged portion 32. The end wall 34 of body 16 provides a shoulder 36 that defines the outer extent of enlarged portion 32 of cavity 24.

As best shown in Figures 1 and 2, opening 26 extends from the end 28 of body 16 into an opening 38 in the sidewall of body 16. Thus, cavity 24 is partly

defined by opening 26 in the end 28 of body 16 and opening 38 in the sidewall of the body 16.

The second member 14 comprises a body 40. One end of body 40 is formed with an enlarged portion 42 that is formed with or connected to a shank portion 44 having a diameter that is smaller than the diameter of enlarged portion 42. Shoulder 46 is defined between the enlarged portion 42 and the shank portion 44. A further enlarged portion 48 is provided on body 40 to assist in locating the second member 14 relative to the first member 12 when it is desired to connect the two members together. It will also be seen that the body 40 has a second end that is provided with an enlarged tapered portion 50. Enlarged tapered portion 50 is provided to increase the pullout resistance of body 40 when body 40 is embedded in concrete.

In use of the connector 10 shown in Figures 1 to 6, second member 14 is placed in a desired position in concrete form work and concrete poured into the 15 form work. It is desirable that the second member 14 is embedded in the concrete such that an underside 52 of enlarged portion 48 is located at an outer surface of the concrete, with enlarged tapered portion 50 being fully embedded in the concrete. Most suitably, the second member 14 is positioned in the formwork such that the enlarged portion 42 and shank portion 44 extends out of the concrete but in a rebate formed in the concrete. This is especially useful when the connector 10 of the present invention is used to connect the reinforcement of a floor section to a cast wall section.

In order to connect the second member 14 to the first member 12, first member 12 is positioned such that opening 38 in the sidewall of body 16 is located adjacent to enlarged portion 42 and shank portion 44 of second member 14. The first member 12 is then moved transversely relative to second member 14 until the enlarged portion 42 and shank portion 44 of second member 14 are received in cavity 24. As best shown in Figures 5 and 6, enlarged portion 42 rests in enlarged portion 32 of cavity 24 whilst shank portion 44 of second member 14 rests in and extends through opening 26 of cavity 24. It will also be seen that shoulder 46 contacts shoulder 36 to thereby prevent separation of the first member 12 and second member 14 by relative longitudinal movement.

Once the reinforcing bars 20 of a floor section are connected to the first

elements 14 embedded in the concrete of a wall, and appropriate formwork formed for the floor section, concrete can be poured and allowed to set to form the floor section.

In order to position the second members 14 in the formwork required for a wall section, it is desirable to mount the second members 14 in an appropriate rebate forming piece that is incorporated into the formwork. An example of a suitable rebate forming piece is shown in Figure 7. The apparatus of Figure 7 comprises a body 60 made from a suitable material, such as a foam material or wood. The body 60 includes a plurality of holes 62, 64, 66, etc. which are sized to receive the enlarged portion 42 and shank 44 of second member 14. It will be appreciated that the body 60 forms a rebate in the concrete after the concrete has been poured into the form work and that the embedded second members 14 have shank portion 44 and enlarged portion 42 extending out of the concrete in the rebate area. Figure 8 shows an alternative embodiment of the second member 14 shown in Figures 1 to 6. The embodiment shown in Figure 8 is particularly useful for connecting one length of reinforcement to another length of reinforcement.

The second member shown in Figure 8 comprises a body 70 having a similar enlarged portion 42, shank portion 44 and further enlarged portion 48 as the second member 14 shown in Figures 1 to 6. However, the body 70 shown in Figure 8 differs from the second member 14 shown in Figures 1 to 6 by virtue of it including a cavity 72 having an opening 74 at one end of the body 70. Cavity 72 is adapted to receive and securely retain an end of a reinforcing bar 76. In this regard, cavity 72 may be similar to cavity 18 as shown in Figures 1 to 6. It will be appreciated that one end 78 of body 70 is essentially identical in structure to the corresponding end of second member 14 shown in Figures 1 to 6. Therefore, separate reinforcement can be easily and quickly connected together.

Those skilled in the art will appreciate that the present invention may be subject to variations and modifications. For example, the cavities for receiving the end of the reinforcement may be formed from two or more parts that can be joined together, as described in our corresponding international patent publication WO03/062552. Similarly, the first member and second member may be made integrally by casting or by machining, or they may be made from separate pieces

connected together.

With reference to the embodiment of Figures 9 to 12, a connector 110 in accordance with an embodiment of the present invention includes a body 112. Body 112 is suitably made from a metal material, such as mild steel. As best shown in Figures 10 to 12, body 112 includes a cavity 114 for receiving and securely retaining an end of a reinforcing bar. Cavity 114 includes a tapered upper end 116 which facilitates insertion of a reinforcing bar into the cavity 114 and an internal thread 118 for threadably receiving an external thread or ribs formed on the reinforcing bar. The body 112 also includes a coupling portion 120. Coupling portion 120 is formed as a hook and is used to engage with a like shaped coupling portion on another connector. The coupling portion 120 includes a generally U-shaped receiving channel 122 that extends across the body in a transverse direction (see Figure 12). Receiving channel 122 has an outer rim 124 configured such that a shoulder 126 is defined between the bottom of receiving channel 122 and outer rim 124.

As best seen in Figures 10 and 11 , the rear side 128 of the hook portion of coupling portion 120 is provided as a continuation of the sidewall of body 112.

The connection of two pieces of reinforcement using two connectors as shown in Figures 9 to 12 will now be described with reference to Figures 13 to 16. As can be seen from Figure 13, a first reinforcing bar 130 is joined to a first connector 132. Similarly, a second reinforcing bar 134 is securely connected to a second connector 136. Connectors 132 and 136 are identical to the connector 110 shown in Figures 9 to 12. However, connector 132 shown in Figure 13 also has a slidable retaining sleeve 138 fitted over the outer surface thereof. The slidable retaining sleeve 138 is provided with a retained spring portion 139 adapted to frictionally engage the body of connector 132 in order to hold the retaining sleeve in a selected position on the connector 132.

As shown in Figure 14, in order to connect the first connector 132 to the second connector 136, the connectors are placed close to each other. The connectors are then moved together by relative transverse movement such that the hook portion 140 of first connector 132 couples with or engages with hook portion 142 of second connector 136. In this regard, the receiving channel 144 of

connector 132 receives the outer rim 146 of second connector 136. Similarly, the receiving channel 148 of second connector 136 receives the outer rim 150 of first connector 132. This is best shown in Figure 15.

In Figure 15, the retaining sleeve 138 is still positioned in a position that allows the first and second connectors to be separated from each other. Thus, the coupling portions are coupled with each other but can still be separated from each other, if desired. It will be appreciated that the first and second connectors, as shown in the position of Figure 15, can be removed from each other by relative transverse movement of the first and second connectors (either by moving one of the connectors upwardly relative to the other, or by moving one of the connectors sideways relative to the other). However, the connectors resist separation by longitudinal movement due to interaction between the respective receiving channels and outer rims of the receiving channels.

In order to securely hold the first connector 132 and second connector 136 together, the slidable retaining sleeve 138 is moved from the position shown in Figure 15 to the position shown in Figure 16. In the position shown in Figure 16, the slidable retaining sleeve extends over part of the body of first connector 132, over part of the body of second connector 136 and over the hook portions of both first connector 132 and second connector 136. The connector of the present invention allows for simple and rapid connection of lengths of reinforcement. It is not necessary to undertake a laborious tying process to connect adjacent pieces of reinforcement. Moreover, connection of the reinforcement involves using essentially two identical connectors. This means that manufacture of the connectors is simplified because a plurality of identical connector parts can be manufactured, rather than having to manufacture two different connector parts for connecting to each other. Furthermore, use of the connector on site is also simplified because the operator does not have to choose between differently shaped connector pieces. Rather, the operator may be provided with a large supply of identical connector pieces and simply use any of the pieces as they are removed from the supply. Alternatively, connectors can be placed on to the ends of the reinforcement at the site of manufacture of the reinforcement for delivery to a building site. As all the connectors are identical, there are no concerns about the reinforcement being laid

out in a manner such that adjacent connectors will not connect together.

Those skilled in the art will appreciate that the connector of the present invention may be susceptible to other variations. For example, the retaining means need not be a slidable sleeve. Any other retaining means will also fall within the scope of the present invention. Further, the attached Figures 13 to 16 show the use of two connectors but with only a single retaining sleeve being used. For ease of manufacture and use, it may be desirable to provide each connector with a slidable sleeve or other retaining means so that each connector selected by an operator from a supply of connectors will have a retaining means. Those skilled in the art will further appreciate that the present invention may be susceptible to variations and modifications other than those specifically described. It is to be understood that the present invention encompasses all such variations and modifications that fall within the spirit and scope of the invention defined in the claims appended hereto.