DEVICE FOR JOINING REINFORCEMENTS

Description

FIELD OF THE INVENTION

[0001] The present invention relates to an apparatus for connecting reinforcement. More particularly, but not exclusively, the present invention relates to an apparatus for connecting reinforcing bar with a threaded coupler. The coupler may be in the form of a threaded connecting device for threaded reinforcing bar to form a mechanical connection as may be used in concrete construction.BACKGROUND OF THE INVENTION

[0002] One form of reinforcing bar used in concrete construction incorporates a continuous coarse external thread. The thread not only acts to form a key between the bar and concrete, it also enables a range of supplementary fittings easily to be applied to the bar by engagement of a mating thread with that of the bar. One such threaded reinforcing bar is marketed under the trademark "ReidBar" by Reid Construction Systems, a division of ITW Australia Pty Ltd, a related entity of the present applicant. The thread on the reinforcing bar is quite coarse and its pitch ranges from 8mm for a bar of 12mm diameter to around 16.5mm for a bar diameter of 32mm.

[0003] Internally threaded fittings for mounting over the end of threaded reinforcing bar for example for coupling lengths of bar in series tend, principally for cost considerations, to be of cast construction, with the internal thread being formed during casting by a sand core. The internal thread formed in this way is not formed to the degree of accuracy which would be expected from a conventionally tapped thread and, moreover, the external thread on the bar itself is not formed to a particularly high degree of accuracy. A consequence of this is that there may not be a particularly tight engagement between the fitting and the bar and some longitudinal movement or free-play can occur between the bar and the fitting.

[0004] Longitudinal free-play of a coupler on a threaded reinforcing bar can have serious consequences and relevant construction standards require that slip be limited and controlled. This can be difficult to achieve given the large tolerances involved in manufacturing coarse threaded bar. While slippage can be avoided by filling the interior of the coupler with an epoxy cement or by mounting a lock nut on the bar to tighten against the end of the coupler, these measures add to the time and cost of installing the coupler to the bar as well as not being accepted as solutions by certain construction authorities. Prior patent document CN104264997A describes a steel bar connection device. Other methods include machining metric threads and swaging sleeves onto the ends of the bar. These are even more time-consuming, complex and expensive due to the extra processes and equipment required. Accordingly, it is desirable to provide a coupler that can accommodate the loose tolerances of the reinforcing bar and minimise slip of the coupler along the reinforcing bar to within the required standard.

[0005] The applicant has also determined that existing methods and devices do not permit installation in some circumstances where rotation of the reinforcing bars is not possible and / or where a gap has to be bridged between the two elements. It has been determined that it would be advantageous for there to be provided a coupler which enables coupling between reinforcing bars where rotation of the reinforcing bars is prevented or at least restricted, and which provides bridging of a gap between the reinforcing bars to be coupled. The applicant has further determined that it would be advantageous to provide an improved coupler for mechanically coupling reinforcing bars and to provide an apparatus for mechanically coupling the coupler to a reinforcing bar.SUMMARY OF THE INVENTION

[0006] In accordance with one aspect of the present invention, there is provided an apparatus for connecting a threaded reinforcing bar to a threaded fitting, the apparatus including a base, a holder for holding the reinforcing bar against rotation relative to the base, and a support for a driving tool for threadedly driving the threaded fitting onto an end portion of the reinforcing bar, wherein the apparatus includes a brace for bracing the support against movement relative to the base. The holder includes a pair of clamp halves, and, each of the clamp halves has an internal threadform for corresponding to external thread of the reinforcing bar.

[0007] Preferably, the brace is arranged for bracing the support against rotation relative to said base during operation of the driving tool whereby torque is used for securing the threaded fitting to the reinforcing bar.

[0008] In a preferred form, a predetermined torque threshold is used for securing the threaded fitting to the reinforcing bar and the brace is arranged for bracing the support against rotation relative to said base during operation of the driving tool at said torque threshold. In one form, the driving tool includes a torque multiplier. More preferably, the driving tool includes a torque multiplier in combination with a motor-driven rotational driver.

[0009] Preferably, the reinforcement bar is for reinforcing concrete.

[0010] The reinforcement bar is externally threaded. The threaded fitting is internally threaded corresponding to an external thread of the reinforcement bar. Even more preferably, the threaded fitting has an internal stop for abutment against an end of the reinforcing bar.

[0011] The predetermined torque threshold may be used to achieve a specified slip threshold between the threaded fitting and the reinforcing bar.

[0012] Preferably, the brace has a plurality of bracing parts for bracing the support against movement relative to the base. More preferably, the brace has a pair of opposed bracing parts for bracing the support against movement relative to the base. Even more preferably, each of the bracing parts extends substantially perpendicular to an axis of the reinforcing bar.

[0013] Preferably, the support is arranged to be slidable relative to the base in a direction parallel to an axis of the reinforcing bar. More preferably, the base includes a pair of rails along which the support is slidable.

[0014] It is preferred that the reinforcing bar has opposed flat surfaces and the holder is arranged to engage with said flat surfaces to hold the reinforcing bar against rotation relative to the base.

[0015] Preferably, the clamp halves are interchangeable to accommodate reinforcing bars of different sizes.

[0016] The clamp halves may be hingedly movable between an open condition, in which the reinforcing bar is able to be inserted or removed, and a closed condition, in which the reinforcing bar is held between the clamp halves.

[0017] Preferably, the holder includes a biased clip for locking the clamp halves in the closed condition. More preferably, the holder includes a latch with spring mechanism having an over centre design, so that the latch is able to selectively move the biased clip between an operable configuration and a non-operable configuration. Even more preferably, the apparatus includes at least one tightening member for increasing clamping force of the holder on the reinforcing bar.

[0018] In one form, the base is anchored to a structure.

[0019] In accordance with another aspect of the present invention, there is provided a method of connecting a threaded fitting to a reinforcing bar, including the steps of: providing an apparatus as described above; placing the reinforcing bar in the holder for holding the reinforcing bar against rotation relative to the base; using the support to support a driving tool against movement relative to the base; and using the driving tool to apply torque to the threaded fitting over an end of the reinforcing bar to a threshold torque to secure the threaded fitting to the reinforcing bar.

[0020] Preferably, the method further includes the step of removing the reinforcing bar, with the threaded fitting connected, from the holder.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention is further described by way of non-limiting example only with reference to the accompanying drawings, in which: Figure 1 shows an upper perspective view of an apparatus for connecting a threaded fitting to reinforcement bar in accordance with an example of the present invention; Figure 2 shows a side view of the apparatus; Figure 3 shows an end view of the apparatus; Figure 4 shows a side perspective view of a holder of the apparatus in an open condition, showing detail of an upper half clamping portion; Figure 5 shows an upper perspective view of the holder in the open condition, showing detail of a lower half clamping portion; Figure 6 shows a rear perspective view of a support of the apparatus with a driving tool mounted therein; Figure 7 shows a front perspective view of the driving tool mounted in the support of the apparatus; Figure 8shows an upper perspective view of the holder shown in a closed condition; Figure 9 shows an upper perspective view of the holder shown in an open condition; Figure 10 shows an end perspective view of the holder shown in the closed condition, with detail of a latch and spring mechanism having an over centre arrangement; Figure 11 shows an end view of the latch shown in an operational configuration; Figure 12 shows an end view of the latch shown in a non-operational configuration; Figure 13 shows an upper perspective view of the holder of the apparatus shown in the closed condition, with upper detail of a screw threaded fastener for applying a clamping force; Figure 14 shows an upper perspective view of the holder of the apparatus shown in the closed condition, with a screw and Cam action quick release to apply clamping force; and Figure 15 shows an upper perspective view of the apparatus in combination with a reinforcing bar and threaded fitting, prior to insertion of the reinforcing bar into the holder. DETAILED DESCRIPTION

[0022] As can be seen in Figures 1 to 15 of the drawings, there is provided an apparatus 10 for connecting reinforcing bar 12 (see Figure 15) to a threaded fitting 14. The apparatus 10 includes a base 16, a holder 18 for holding the reinforcing bar 12 against rotation relative to the base 16, and a support 20 for a driving tool 22 for threadedly driving the threaded fitting 14 onto an end portion of the reinforcing bar 12. The apparatus 10 includes a brace 24 for bracing the support 20 against movement relative to the base 16. The holder 18 acts as an anti-rotational system for restraining against rotation of the reinforcing bar 12 as the threaded fitting 14 is threaded onto the reinforcing bar 12.

[0023] Advantageously, the apparatus 10 facilitates connection of the threaded fitting 14 to the reinforcing bar 12 without modification of the reinforcing bar 12 (for example, modification by machining the reinforcing bar 12 to have a metric thread). Also advantageous is that the apparatus 10 may be portable.

[0024] The brace 24 is arranged for bracing the support 20 against rotation relative to the base 16 during operation of the driving tool 22 whereby torque is used for securing the threaded fitting 14 to the reinforcing bar 12.

[0025] In the example shown in the drawings, a predetermined torque threshold is used for securing the threaded fitting 14 to the reinforcing bar 12 and the brace 24 is arranged for bracing the support 20 against rotation relative to the base 16 during operation of the driving tool 22 at the torque threshold. The torque threshold may be relatively high, possibly in the region of 1500Nm (by way of example only).

[0026] With reference to Figure 1, the driving tool 22 may include a torque multiplier 26. In particular, as shown, the driving tool 22 may include a torque multiplier 26 in combination with a motor-driven rotational driver 28. The applicant has determined that this form of driving tool 22 may be beneficial through achieving consistent torque, as opposed to an impact driver which the applicant has determined to have inconsistent torque.

[0027] The reinforcing bar 12 may be of the kind used for reinforcing concrete and is externally threaded, as shown in Figure 15. The threaded fitting 14 is internally threaded corresponding to an external thread 30 of the reinforcing bar 12. The threaded fitting 14 may have an internal stop for abutment against an end of the reinforcing bar 12, to facilitate application of a high torque by the apparatus 10 to the threaded fitting 14 upon the reinforcing bar 12 so as to achieve a desired secure fitment with minimal slip in accordance with a required specification. The threaded fitting 14 may also be provided with a frangible driving nut 32 to indicate to an operator when the desired torque threshold has been achieved. As an alternative to the frangible driving nut, the desired torque threshold may be achieved by way of a torque measuring tool.

[0028] The predetermined torque threshold may be used to achieve a specified slip threshold between the threaded fitting 14 and the reinforcing bar 12.

[0029] The brace 24 may have a plurality of bracing parts 34 for bracing the support 20 against movement relative to the base 16. In particular, the brace 24 may have a pair of opposed bracing parts 34 for bracing the support 20 against movement relative to the base 16. With reference to figure 15, each of the bracing parts 34 extends substantially perpendicularly to an axis of the reinforcing bar 12 so as to provide lever arms to prevent rotation, twisting and / or deflection of the support 20 relative to the base 16. The pair of bracing parts 34 act as opposite arms against a bending moment to assist in achieving the set torque and quality of installation. As the support 20 is on rails 36, this facilitates optimal axial location of the socket 44 for engagement with the threaded fitting 14. It will be appreciated by those skilled in the art that there may be alternatives to the driving tool 22 such as, for example, manual driving of the threaded fitting 14.

[0030] The support 20 is arranged to be slidable relative to the base 16 in a direction parallel to an axis of the reinforcing bar 12. In the example shown in Figure 1, the base 16 includes a pair of rails 36 along which the support 20 is slidable.

[0031] As shown in Figure 15, the reinforcing bar 12 has opposed flat surfaces 38 (top and bottom) and the holder 18 is arranged to engage with said flat surfaces 38 to hold the reinforcing bar 12 against rotation relative to the base 16.

[0032] Figure 2 shows a side view of the apparatus 10 and Figure 3 shows an end view from an end of the apparatus at which the holder 18 is located. The driving tool 22 may be provided with a socket 44 engaging with the frangible driving nut 32 so as to apply torque to same.

[0033] With reference to Figures 3 to 5, in the example shown, the holder 18 includes a pair of clamp halves 42, and may also include a top plate 44 to facilitate application of clamping force. Each of the clamp halves 42 depicted has an internal threadform 46 corresponding to the external thread 30 of the reinforcing bar 12. The clamp halves 42 may be interchangeable with other clamp halves of different size / configuration to accommodate reinforcing bars of different sizes.

[0034] The clamp halves 42 may be hingedly movable between an open condition (as shown in Figures 4 and 5), in which the reinforcing bar 12 is able to be inserted or removed, and a closed condition (as shown in Figure 10), in which the reinforcing bar 12 is able to be rotatably held between the clamp halves 42.

[0035] Figures 6 and 7 show detail of the driving tool 22 supported by the support 20. The support 20 may be provided with radial teeth, and the torque multiplier 26 may be provided with corresponding radial teeth so as to be held securely against rotation relative to the support 20.

[0036] Figure 8 shows the holder 18 in the closed condition and Figure 9 shows the holder 18 in the open condition. A shield 54 may be provided as part of the apparatus 10 for safety, particularly in view of the high torque being applied, to protect the operator.

[0037] The holder 18 of the depicted example includes a biased clip 48 for locking the clamp halves 42 in the closed condition. More specifically, as shown in Figures 3 to 5, the holder 18 includes a latch 50 with spring 52 mechanism having an over centre design, so that the latch 50 is able to selectively move the biased clip 48 between an operable configuration (Figure 11) and a non-operable configuration (Figure 12). With reference to Figure 10, the apparatus 10 may include at least one tightening member 56 for increasing clamping force of the holder 18 on the reinforcing bar 12. The tightening member 56 may be in the form of a screw and cam action quick release for applying clamping force and for locking the top plate 44 in place. Alternatively, hydraulic force may be used for acting on the top jaw through either an external hydraulic press or a fitted hydraulic cylinder. The base may be anchored securely to a structure, such as a bench for floor surface. In particular, the apparatus can be fixed to a bench or trolley through the six mounting holes located in the base 16.

[0038] As will be appreciated from the above, the present invention provides a method of connecting a threaded fitting 14 to a reinforcing bar 12, including the steps of: providing an apparatus 10 including a base 16, a holder 18 and a support 20; placing the reinforcing bar 12 in the holder 18 for holding the reinforcing bar 12 against rotation relative to the base 16; using the support 20 to support a driving tool 22 against movement relative to the base 16; and using the driving tool 22 to apply torque to the threaded fitting 14 over an end of the reinforcing bar 12 to a threshold torque to secure the threaded fitting 14 to the reinforcing bar 12.

[0039] The method may further include the step of removing the reinforcing bar 12, with the threaded fitting 14 connected, from the holder 18.Example

[0040] Accordingly, as will be appreciated from the above, the applicant has developed a vice or holding fixture for a new coupling system to join reinforcing bar reinforcement within concrete structures, allowing continuous reinforcement between concrete elements.

[0041] The coupling system relies on screen together each coupler half onto the reinforcing bar and applying a set torque to ensure the performance of the system. To aid the installation and ensure that the reinforcing bar is held firmly and safely when the torque is applied, the applicant has developed a vice / fixture to assist operators with this procedure.

[0042] The core function of the product is to firmly hold the reinforcing bar (which may be in the form of externally threaded reinforcing bar marketed under the branding ReidBar) when torque is applied via a coupler or fitting being screwed on to the reinforcing bar. This ensures when the torque is applied, force is not lost through the relative movement of the reinforcing bar and / or the bar rotates suddenly creating an unsafe condition when installing the coupler or fitting.

[0043] Other key functions of the product include: Can accommodate all sizes of ReidBar, RB12, RBA16, RB20, RBA20, RB25, RB32. Designed for use with a torque multiplier, includes support for the torque multiplier. Clamping load can be applied via an incorporated mechanical method or additional hydraulic or pneumatic unit. System is modular and can incorporate elements to automate parts of the process or all of the process.

[0044] To help the Vice / Fixture perform the functions outlined, it incorporates a number of unique features including: ReidBar thread detail in vice / fixture to securely hold ReidBar. Detail holds the minor diameter, major diameter and across the flats of the ReidBar to ensure a firm hold when clamped. Detail may also just hold on the flats and the major diameter. Can hold all sizes of Reidbar, RB12, RBA16, RB20, RBA20, RB25, RB32. Design will utilize interchangeable jaws to hold specific ReidBar size. Jaws feature specific Reidbar profile to securely hold Reidbar. Support for powered torque multiplier through different slide fixtures. Support for manual torque multiplier through different slide fixtures. Support mounted on 'rails' to allow the torque multiplier to move in and away from coupler being tightened while also taking the torque multiplier reaction force. Allows sufficient torque to be applied to break shear nut on coupler to indicate correct tightening torque. Reduces operator fatigue and improves safety. Includes detail to indicated correct positioning of bar within vice / fixture. Flip open design allows quick install and removal of ReidBar in the vice. Quick release spring loaded latch 50 allows quick securing of the top piece of the vice fixture. Latch 50 and spring 52 mechanism features over centre design to allow the latch to be quickly released for removal of the finished bar assembly.

[0045] With reference to Figure 13, the apparatus 10 provides a mechanical method to apply the clamping force to the vice by either one or a combination of the following: Screw thread, preferably trapezoidal screw thread acting on the top plate and top jaw. Threaded lever clamps acting on the top plate and top jaw Screw and cam action quick release to apply clamping force and lock top plate in place Hydraulic force acting on the top jaw through either an external hydraulic press or a fitted hydraulic cylinder

[0046] The example of the invention shown in the drawings also provides a method of assembly using the fixture, as follows: 1. Cut corresponding ReidBar to be joined square. 2. Hand thread coupler half onto ReidBar until it bottoms in the base of the coupler. 3. Ensure correct size jaws and socket are fitted for the corresponding ReidBar being used. 4. Fit ReidBar and coupler into vice / fixture. 5. Close top of vice and ensure latch has secured. 6. Wind each lever clamp or screw thread down to apply force on the top jaw of the vice. 7. Move torque multiplier and socket on to coupler and apply torque until shear nut is removed. 8. Move torque multiplier and socket away from coupler assembly. 9. Unwind each lever clamp or screw thread to release compression on ReidBar. 10. Open latch to release the top piece of the vice. 11. Open vice and remove coupler bar assembly.

[0047] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

[0048] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.List of features:

[0049] 10Apparatus 12Reinforcing bar 14Threaded fitting 16Base 18Holder 20Support 22Driving tool 24Brace 26Torque multiplier 28Motor-driven rotational driver 30External thread 32Frangible driving nut 34Bracing parts 36Rails 38Opposed flat surfaces 40Socket 42Clamp halves 44Top plate 46Internal threadform 48Biased clip 50Latch 52Spring 54Shield 56Tightening member

Claims

1. An apparatus (10) for connecting a threaded reinforcing bar (12) to a threaded fitting (14), the apparatus including: a base (16); a holder (18) for holding the reinforcing bar against rotation relative to the base, the holder including a pair of clamp halves (42); a support (20) for a driving tool (22) for threadedly driving the threaded fitting onto an end portion of the reinforcing bar; and a brace (24) for bracing the support against movement relative to the base, characterized in that each of the clamp halves (42) has an internal threadform (46) for corresponding to an external thread of the reinforcing bar (12).

2. An apparatus (10) as claimed in claim 1, wherein said brace (24) is arranged for bracing the support (20) against rotation relative to said base (16) during operation of the driving tool (22) whereby torque is used for securing the threaded fitting (14) to the reinforcing bar (12).

3. An apparatus (10) as claimed in claim 1 or claim 2, wherein a predetermined torque threshold is used for securing the threaded fitting (14) to the reinforcing bar (12) and the brace (24) is arranged for bracing the support (20) against rotation relative to said base (16) during operation of the driving tool (22) at said torque threshold.

4. An apparatus (10) as claimed in any one of claims 1 to 3, wherein the driving tool (22) includes a torque multiplier (26) and optionally wherein the driving tool includes a torque multiplier in combination with a motor-driven rotational driver (28).

5. An apparatus (10) as claimed in any one of claims 1 to 4, wherein the reinforcement bar (12) is for reinforcing concrete.

6. An apparatus (10) as claimed in any one of claims 1 to 5, wherein the reinforcement bar (12) is externally threaded and optionally wherein the threaded fitting (14) is internally threaded corresponding to an external thread of the reinforcement bar and optionally wherein the threaded fitting has an internal stop for abutment against an end of the reinforcing bar.

7. An apparatus (10) as claimed in claim 3, wherein said predetermined torque threshold is used to achieve a specified slip threshold between the threaded fitting (14) and the reinforcing bar (12).

8. An apparatus (10) as claimed in any one of claims 1 to 7, wherein the brace (24) has a plurality of bracing parts (34) for bracing the support (20) against movement relative to the base (16) and optionally wherein the brace has a pair of opposed bracing parts for bracing the support against movement relative to the base and optionally wherein each of the bracing parts extends substantially perpendicular to an axis of the reinforcing bar (12).

9. An apparatus (10) as claimed in any one of claims 1 to 8, wherein the support (20) is arranged to be slidable relative to the base (16) in a direction parallel to an axis of the reinforcing bar (12) and optionally wherein the base includes a pair of rails (36) along which the support is slidable.

10. An apparatus (10) as claimed in any one of claims 1 to 9, wherein the reinforcing bar (12) has opposed flat surfaces (38) and the holder (18) is arranged to engage with said flat surfaces to hold the reinforcing bar against rotation relative to the base (16).

11. An apparatus (10) as claimed in claim 1, wherein the clamp halves (42) are interchangeable to accommodate reinforcing bars (12) of different sizes.

12. An apparatus (10) as claimed in claim 1 or claim 11, wherein the clamp halves (42) are hingedly movable between an open condition, in which the reinforcing bar (12) is able to be inserted or removed, and a closed condition, in which the reinforcing bar is held between the clamp halves.

13. An apparatus (10) as claimed in claim 12, wherein the holder (18) includes a biased clip (48) for locking the clamp halves (42) in the closed condition.

14. An apparatus (10) as claimed in claim 13, wherein the holder (18) includes a latch (50) with spring mechanism (52) having an over centre design, so that the latch is able to selectively move the biased clip (48) between an operable configuration and a non-operable configuration.

15. An apparatus (10) as claimed in any one of claims 12 to 14, including at least one tightening member (56) for increasing clamping force of the holder (18) on the reinforcing bar (12).

16. An apparatus (10) as claimed in any one of claims 1 to 15, wherein the base (16) is anchored to a structure.

17. A method of connecting a threaded fitting (14) to a threaded reinforcing bar (12), including the steps of: - providing an apparatus (10) as claimed in any one of claims 1 to 16; - placing the reinforcing bar in the holder for holding the reinforcing bar against rotation relative to the base; - using the support to support a driving tool (22) against movement relative to the base; and - using the driving tool to apply torque to the threaded fitting over an end of the reinforcing bar to a threshold torque to secure the threaded fitting to the reinforcing bar.

18. A method as claimed in claim 17, further including the step of: - removing the reinforcing bar (12), with the threaded fitting (14) connected, from the holder (18).