WO2007035989A1

WO2007035989A1 - Improvements to tie device, and apparatus and method for tying said tie device

Info

Publication number: WO2007035989A1
Application number: PCT/AU2006/001413
Authority: WO
Inventors: Cecil Gwilliam Jones
Original assignee: Ironbar Pty Ltd; Jones, Corinne, Gloria
Priority date: 2005-09-27
Filing date: 2006-09-27
Publication date: 2007-04-05

Abstract

A tie device (Fig. 5) and a tying apparatus (Fig. 4), for tying reinforcing bars or mesh, used in the construction industry. The tie device (Fig. 5) includes a pair of arms, and an intermediate portion. Each arm has a hook, which are adapted to be coupled. The intermediate portion is shaped such that it is bowed or substantially convex, which enables positive control of the device during its delivery about the reinforcing rods. A tying apparatus (Fig. 4) is also provided, which delivers the tie device to its required position about the reinforcing rods. The apparatus includes a connecting means operatively attached to a delivering means, such that the delivering means moves the tie device to an intermediate position, and then the delivering means moves the connecting means to thereby interengage and connect the hook means of the tie device. The tying apparatus also includes a twisting means which are adapted to allow the hooks of the tie device to pass on opposite sides of the plates, and, cooperate with the intermediate portion of the tie device and release from the tie device without requiring movement in a reverse direction to that in which the twisting means are twisted.

Description

IMPROVEMENTS TO TIE DEVICE, AND APPARATUS AND METHOD FOR

TYING SAID TIE DEVICE

Background of the Invention The present invention relates to a tie device, to tying apparatus and to methods for tying using said tie device, and in particular, to a tie device and apparatus and method which enables reinforcing bars or mesh, typically used in the construction industry, to be quickly and securely "tied".

In particular, the present invention relates to improvements and/or modifications to a tie device, and to tying apparatus and methods for tying, as outlined in the Applicant's previous Australian Patent Nos. 679198 and 694070, and to corresponding Patents/ Applications ^ in other countries, including US Patent Nos. 5913341 and 6128882. The reference made to these specifications should be taken as incorporating the entire disclosures of those Patent specifications within the present document.

Description of the Prior Art

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that prior art forms part of the common general knowledge in Australia or overseas.

As described in the Applicant's earlier Patents/ Applications, the Applicant has previously developed a tying apparatus for tying a tie device about two or more reinforcing bars, a method for tying a tie device about two or more reinforcing bars to be tied, and a tie device which may be utilised either separately from, or in conjunction with the apparatus and method.

. As shown in Figs. l(a) and l(b), a tie device, generally designated by the numeral

I may be tied about a pair of reinforcing bars 7 and 8. Fig. 1 shows an elevational view of the tie device tied about the reinforcing bars, whilst Fig. l(b) shows a view from the underside thereof. Prior to tying, the tie device, as shown in Figs. 2(a) and 2(b), is basically of U- or V-shaped configuration constructed of a substantially ductile material, such as metal, provided in a thin wire-like formation. Of course, any other suitable material, such as plastics, may be utilised. Basically, the tie device 1 includes a pair of elongate arms 2 and 3, extending from an intermediate portion 4 thereof, in a substantially U- or V-like configuration. Hook means 5 and 6 are provided at each end of each arm 2 and 3 respectively. It will be noted that the tie device depicted in Figs. 2(a) and 2(b) are provided with hook means 5 and 6 each of which are differently shaped, the hook 5 being of two bends, bent back in the same plane as the remainder of the device, whilst the hook 6 has three bends, and extends out of the plane of the remainder of the tie device 1. The purpose for at least one of the hooks extending out of the plane of the remainder of the device 1 , is such that "automatic" engagement of the two hooks may occur upon application of an inward force, as will be described hereinafter. Fig. 2(b), perhaps better illustrates the "out of plane" bending of the hook 6 shown in Fig. 2(a).

In use, the hook may be used to tie a pair of reinforcing bars 7 and 8, as depicted in Figs. 2(c) and 2(d). Once the hook is appropriately positioned around the objects to be tied, the hook portions 5 and 6 are moved in the direction of arrows 9 as shown in Fig. 2(c), such that they "overlap". Then, upon subsequent release of the force, and due to the resilient nature of the material used in the construction of the tie device, the arms 2 and 3, together with their respective hooks 5 and 6, move outwardly in the direction of arrows 10 as shown in Fig. 2(d). In such a position, they therefore remain interengaged in the connected position. The hooks are shaped such as to not thereafter release from such interconnected position, and the tie is twisted such that it is securely fastened about the reinforcing rods as shown in Figs. l(a) and l(b).

It will therefore be appreciated that the method of tying the tie device 1 about two or more bars 7 and 8 to be tied, includes the steps of, firstly provided a tie device 1 about the reinforcing bars to be tied such that the hooks 5 and 6 are provided onto opposed sides of the bars 7 and 8, secondly, interengaging and connecting the hook means 5 and 6, and finally, twisting the intermediate portion 4 of the tie device 1 to effect a tightening of the tie device 1 about the objects 7 and 8.

To achieve this purpose, the Applicant has also hereinbefore invented a tying apparatus for tying the tie device 1 about the reinforcing bars 7 and 8, disclosed in the Patent documents hereinbefore referenced. Such an apparatus is shown in Fig. 3, which is primarily mechanical in operation. Other embodiments are shown in the Applicant's above referenced Patent applications, including an electro-mechanical version and an electrical version. It will be appreciated that any combination of mechanical, hydraulic, pneumatic, electrical and/or electromechanical, or otherwise, device may be alternatively- used to implement the tying operation.

Basically, the tying apparatus for tying a tie device about one or more objects to be tied, includes a delivering means, to deliver the tie device 1 to a tying position, substantially about the bars, such that the hooks 5 and 6 are provided on opposed sides of the bars 7 and 8, a connecting means, to effect interengaging and connection of the hook portions 5 and 6 of the tie device 1 , and, a twisting means, to twist and thereby tighten the tie device about the object, such that the resultant tied tie device 1 should therefore appear as shown in Fig. 1.

As shown in Fig. 3, which describes the mechanical embodiment of the Applicant's previous invention, a stack of tie devices 1 is provided within the magazine 11. The machine is placed diagonally and approximately centrally across the bars 7 and 8 with the saddles 13 resting on the top bar 7 and the coupler guide housing 14 straddling the bars 7 and 8.

The handles of the machine 15 are pressed down to move the top frame 16 and the bottom frame 17 in a downwards position. The shear blade or guillotine 12 connected to the bottom frame 17 shears the front tie device 1 from the stack thereof in the magazine 11 and delivers it to the couplers 18. The shear blade or guillotine 12 stops at this position being released from the bottom frame 17 by the engage-release catch 19. At this same position, the coupler pivots 18a are engaged by the coupler drive plates 20 also connected to the bottom frame 17. As the handles continue to be pressed down, the couplers are driven down with the tie device now secured in the couplers. Relative positions of the coupler pivots 18a and 18b in the coupler guides control movement of the couplers, to position the tie device 1 around the bars 7 and 8 and bring the hooks together for coupling with the top of the loop formed resting on the twist rods 21. The downward movement of the handles 15 is stopped at this position.

This downward movement of the handles brings the top frame 16 into contact with screw shaft 22 through the drive rod 23 connected to the top frame and the arm 24 connected to the screw shaft 22. The top frame 16 is released from the bottom frame 17 by a finger control 25. The handles are continued to be pressed down to move the top frame down to the bottom frame. The screw shaft is driven down through the screw nut 26 which rotates. The screw nut, which is connected to the drive gear 27 rotates the drive gear and in turn the twist gear 28, its hollow shaft 80 and the twist rods 21 which are connected to the hollow shaft. The twist rods 21 twist the tie device 1 to form the tie. The screw shaft moves down against a spring and is locked down by a catch. With the tie device twisted and the twist rods now held firmly in the top loop that has been formed, the handles are pulled up so that the top and bottom frames are returned to their original positions.

At the end of this upward travel, the catch holding down the screw shaft is automatically released. The screw shaft moves up to reverse the direction of rotation of the screw nut and in turn the twist rods which spin the twist rods clear of the tie device allowing the machine to be removed. The twist shaft, hollow shaft and twist rods are returned to their original positions ready to receive the next tie device and the procedure is repeated.

Whilst the tie device, tying apparatus and method as hereinbefore described have significant advantages over the prior art, the Applicant/Inventor has identified some improvements and modifications which can be made thereto which provide significant advantages thereover.

Summary of the Invention

The present invention seeks to provide improvements and modifications to the tie device useful for tying about reinforcing bars, and which may be readily tied either by conventional manual methods or by an 'automated' tying apparatus.

The present invention also seeks to provide improvements and modifications to the tying apparatus which is hereinbefore referenced and described in the Applicant's previous Patents/Applications.

In one broad form, the present invention provides a tie device for tying at least two reinforcing bars together, the tie device being constructed of substantially ductile material, the tie device including: a first elongated arm and a second elongated arm, the first elongated arm having a first free end and the second elongated arm having a second free end; an intermediate portion coupled between the pair of elongated arms to form a tie plane and one of a substantially U- and V-shaped configuration; and a means for fastening comprising a first hook means and a second hook means, the first hook means coupled to the first free end and the second hook means coupled to the second free end so that the first hook means and the second hook means face each other, wherein at least one of the hook means includes one or more bends shaped to at least partially extend out of the tie plane, the first hook means having at least two bends and the second hook means having at least two bends, the first hook means and the second hook means being adapted to move together and interengage upon application of an inward force to at least one elongated arm, and, upon subsequent release of the inward force, the first hook means remains securely interengaged with the second hook means to form a connection, and further wherein at least the intermediate portion is adapted to be twisted such that the connection deforms about the at least two reinforcing bars so as to increase the security of the interengagement of the connection as at least the intermediate portion is twisted; characterised in that, said intermediate portion is shaped such that it is substantially convex.

In a further broad form, the present invention provides a tying apparatus for tying a tie device about two or more reinforcing bars, said tie device being substantially U- or V- shaped having an intermediate portion and hook means at end portions thereof, said tying apparatus including: delivering means, to deliver said tie device to a tying position substantially about said bars, such that said hook means are provided beyond the opposed side of said bars; connecting means to interengage and connect said hook means; and, twisting means to twist said intermediate portion of said tie device and thereby 10 tighten said tie device about said object(s); characterised in that, said connecting means are operatively attached to said delivering means, such that as said delivering means moves said tie device to an intermediate position, said delivering means moves said connecting means and thereby interengages and connects said hook means of said tie device, said connecting means thereafter being biased to return to its starting position as said delivering means returns to its initial position.

Preferably, said delivering means includes a roller and said connecting means, includes a cam, whereby said roller abuts said cam to operate said connecting means.

In yet further broad form, the present invention provides a tying apparatus for tying a tie device about two or more reinforcing bars, said tie device being substantially

U- or V-shaped having an intermediate portion and hook means at end portions thereof, said tying apparatus including: delivering means, to deliver said tie device to a tying position substantially about said bars, such that said hook means are provided beyond the opposed side of said bars; connecting means to interengage and connect said hook means; and, twisting means to twist said intermediate portion of said tie device and thereby tighten said tie device about said object(s); characterised in that, said twisting means is in the form of at least one pair of horizontally mounted twist plates or at least one pair of vertically mounted twist plates having different bevelled surfaces thereon, adapted to allow said hook means to pass on opposite sides of said plates, and further being adapted to cooperate with said intermediate portion of said tie device and release from said tie device without requiring movement in a reverse direction to that in which said twisting means are twisted.

Brief Description of the Drawings

The present invention will become more fully understood from the following detailed description of preferred but non-limiting embodiments thereof, described in connection with the accompanying drawings, wherein:

Fig. 1 illustrates, in Figs. l(a) and l(b) thereof, elevational and underside views of a tie device tied about reinforcing bars;

Fig. 2, in Figs. 2(a), 2(b), 2(c) and 2(d) thereof, illustrate the Applicant's prior art arrangement of a tie device, Fig. 2(a) illustrating an elevational view of the tie device prior to use, Fig. 2(b) illustrating an underside view of the device of Fig. 2(a), Fig. 2(c) illustrating the interengaging of the hooks of the tie device as it is positioned about the objects to be tied, and, Fig. 2(d) illustrating a subsequent position of the tie device as it is positioned about the objects to the tied; Fig. 3 illustrates the Applicant's prior art mechanical implementation of a tying apparatus, used for tying the tie device about the objects to be tied;

Fig. 4 illustrates an improved and modified version of the tying apparatus in accordance with the present invention, Fig. 4(a) illustrating an isometric view of the apparatus, Fig. 4(b) illustrating a diagrammatic view of the gear arrangement of the apparatus shown in Fig. 4(a), Fig. 4(c) illustrating an elevational view of the improved apparatus with the couplers in the open position, whilst Fig. 4(d) illustrates an elevational view of the improved apparatus with the couplers in the closed position;

Fig. 5 illustrates details of an improved or modified version of a tie device, Figs. 5(a) and 5(b) showing the improved or modified version of the tie device in the disengaged and engaged positions, respectively;

Fig. 6 shows, for comparison purposes, the prior art tie device, in Figs. 6(a) and 30 6Qo);

Fig.7 illustrates an alternative embodiment of the improved tie device in accordance with the present invention; Fig. 8 illustrates, in Figs. 8(a), 8(b), 8(c) and 8(d), an improved "horizontally mounted" twisting means;

Fig. 9, in Figs.9(a), 9(b), 9(c) and 9(d), describe details of an improved "vertically 5 mounted" twisting means in accordance with the present invention; and,

Fig. 10 shows in Figs. 10(a) to 10(e), three dimensional representations of an alternatively preferred embodiment, showing the coupler and the twist cylinders, and showing how the ends of the tie device are engaged and the tie device is twisted about the reinforcing bars.

Detailed Description of Preferred Embodiments Throughout the drawings, like numerals will be used to identify similar features, except where expressly otherwise indicated.

Both the original and improved apparatus have a delivering means and interengaging means for the supply and engagement of the hooks of the tie device on the opposed sides of the reinforcing bars.

In the case or the Applicant's original apparatus, the hooks of the tie device are spread apart during their delivery, to provide the required clearance to the bars, then brought together under the bars for engagement. This means that the width of the device can be less than the diameter of the hollow shaft through which it travels, providing savings in packaging and transport of the device to the construction site. It also results in an overall reduction in the size of the apparatus, at least in relation to the twist mechanism. To achieve this, the coupler mechanism is relatively complex and thereby presents drawbacks in its manufacture.

The couplers, have two core functions, firstly as part of the delivery means and, secondly, as the interengagement means. In the modified apparatus in accordance with the present invention, the couplers' sole function is as an interengagement means. The diameter of the twist gear hollow shaft is made so that it is delivered through the hollow shaft en route to the bars. The disadvantages of the relatively larger tie device are more than offset by the simplicity of the manufacture of the couplers and is a significant improvement in the apparatus.

The Applicant's original coupler mechanism, is such as shown in Fig. 3, whilst the improved mechanism is shown in Fig. 4. In Fig. 4(a) is shown, the DC motor 211, the carrier arm 212, the roller 205 fixed to the carrier arm, and the cam 204 engaged by the roller. A block 215 which forms part of the carrier arm, and the top of the delivery blade 201 fixed to this block. The Acme screw shaft 206 on which the carrier arm travels, is also shown.

Fig. 4(b) shows the DC motor 211 driving the drive gear 218 through its drive shaft 219. This gear drives the delivery gear 220 to which is fixed the Acme screw shaft 206. Rotation of the gear in one direction moves the carrier arm down the shaft and rotation in the opposite direction, moves the arm up. The drive shaft is also connected to the twist drive gear 221 through a commercially available one way bearing 222. The twist drive gear is connected to the twist gear 223. The hollow shaft 224 is also shown. The bearing is arranged so that the twist gear is stationary during the delivery cycle and rotates during the twist cycle. In Fig. 4(c), the shear blade 201, is shown above the tie 202, in the magazine. The couplers 203, fixed to the cams 204, are in the open position. Fig. 4(d) shows the couplers closed, with the tie delivered around the bars and the hooks engaged. The shear blade controls the vertical travel and the couplers the lateral travel to engage the hooks. The couplers are closed by the action of the rollers 205, on the cams. The rollers are connected to the shear blade via carrier arms 206 and move down and up with the shear blade. The couplers are returned to the open position by the springs 207.

Fig. 8 shows the tie being delivered through the hollow shaft 8, to horizontally mounted twisting means.

The couplers simply push on the legs of the tie to bring the hooks to the engage position. There are no moving parts within the couplers as is the case with the Applicant's original apparatus.

With the tie device twisted around the bars, the apparatus becomes tied to the bars by the tie device at the twist means. This is the case with both the original apparatus and the improved apparatus. The twisting means of the original apparatus, that is, the twist rods, are released from the tie device by reversing their rotation. This requires an additional reversal of the DC motor, adding to the tying cycle time and providing a need for a control system such as a microprocessor.

In the Applicant's improved apparatus, the twisting means, the twist plates 208, in

Fig. 8, are ramped down. Twisting of the tie causes the tie to change shape from a loop to a "figure 8" shape. If the top of the tie is prevented from moving down, the bottom of the tie must move up, which brings the hooks up against the bottom bar and allows the tie to tighten around the bars as it is further twisted. There is a downward pressure on the twist plates. However, this pressure only exists while the tie is being twisted. The top of the tie must remain on the twist plates for twisting to take place, so that it will not slide down the ramps while it is being twisted. When twisting stops, that is, when the tie is completed, there is no pressure on the tie by the plates and the tool can be lifted clear, with the top of the tie sliding down the ramps. This eliminates the need for the additional motor reversal, reducing the cycle time and simplifying the control system. This is a significant improvement in the operation of the tying mechanism.

Fig. 9(a) shows the vertical mounted plates in plan view. They are offset a small angle in the same clockwise direction from the centre line of the twist cylinder. The offset is in this direction to match the twist rotation.

Fig. 9(b) shows a side view of the plates (twist cylinder not shown). They are beveled on the surfaces opposite the bend. For the plates to capture the top section of the tie device and twist it, the hooks must pass on opposite sides of the plates. For all positions of the plates, other than when they are in the path of the tie, they will pass, without interference, on opposite sides. When the plates are in the path of the hooks, there are two possible occurrences:

The first possible occurrence is as follows. The bend of the right hand hook, as drawn, contacts the beveled surface of the right hand plate. The stiffness of the wire causes the cylinder to rotate as the hook runs down the surface. The bevel is on the outside bend of the plate, so that the cylinder will be made to rotate clockwise, which moves the left hand plate out of the path of the left hand hook and allows it to pass on the correct side of the plate for twisting. The right hand plate, as drawn, is higher than the left hand plate, which ensures that the tie will contact this plate first (Fig. 9(b)).

The second possible occurrence is as follows. The tops of beveled plates are directly in line with the tie, as shown in Fig. 9(c). In this case, the right hand hook, as drawn, either passes down the outside bend surface or the inside bend surface. The actual surface cannot be predicted. In the former case, the cylinder will be made to rotate as hereinbefore described. In the other case, with the right hand hook moving down the inside surface, the front of the left hand hook, being offset from the plate, will direct the hook down the inside surface of its plate. This will again place the hooks on opposite sides of the plates, required for twisting.

Fig. 10 illustrates three dimensional views of an alternatively preferred embodiment of the present invention, detailing the couplers and twist cylinder, and showing how the ends of the tie device are engaged and then twisted about the reinforcing bars. The modification from the embodiment hereinbefore described is that this embodiment has two pairs of twist plates. This simply reduces the rotation of the device that can occur before the plates "pick up" the tie to twist it. The two pair twist plates perform in exactly the same way as described for one pair. Fig. 10(a) is an isometric drawing showing the hooks moving down the bevelled surface of the higher plate to deflect the plates and allow the hooks to pass on opposite sides of the opposing plates. Fig. 10(b) shows the hooks engaged under the bars with the top of the tie just above the horizontal section of the twist plates, which is the position of the tie prior to twisting. Fig. 10(c) shows the tie in the engaged position viewed from above. Fig. 10(a) shows the tie twisted around the bars, viewed from above. Fig. 10(d) shows the tie twisted around the bars.

Both the Applicant's original and improved tie devices are substantially V- or U- shaped, with hooks at each end of the arms, which interengage, and, an intermediate section, which is twisted.

The tie device is delivered in each case by a shear blade, with the bottom of the blade pushing down on the intermediate section. If the top of the tie device is level, as shown in Fig. 6(a), it will bow upwards when the legs are pushed towards each other, as shown in Fig. 6(b). The shear blade, therefore, bears only on the top part of the curved section. This was the case with the original tie in the Applicant's previous Patents/ Applications.

However, if the intermediate section of the tie device is shaped such as is shown in

Fig. 5, and is matched by the shape of the bottom of the shear blade, this bowing effect is reduced or eliminated, which results in a more positive control of the tie device during its delivery. This is a substantial improvement to the tie device in its apparatus in the apparatus.

Alternative shapes of the top of the tie are shown in Fig. 7. Other shapes could be 20 devised, which would produce the same result.

It will therefore be appreciated by a person skilled in the art that these improvements and modifications provide advantages over the Applicant's earlier tie device and apparatus for tying. It will be appreciated that further modifications and improvements may be envisaged from a reading of the description herein provided. All such additional variations and modifications should also be considered to fall within the scope of the invention as herein after claimed.

Claims

Claims:

1. A tie device for tying at least two reinforcing bars together, the tie device being constructed of substantially ductile material, the tie device including: a first elongated arm and a second elongated arm, the first elongated arm having a first free end and the second elongated arm having a second free end; an intermediate portion coupled between the pair of elongated arms to form a tie plane and one of a substantially U- and V-shaped configuration; and a means for fastening comprising a first hook means and a second hook means, the first hook means coupled to the first free end and the second hook means coupled to the second free end so that the first hook means and the second hook means face each other, wherein at least one of the hook means includes one or more bends shaped to at least partially extend out of the tie plane, the first hook means having at least two bends and the second hook means having at least two bends, the first hook means and the second hook means being adapted to move together and interengage upon application of an inward force to at least one elongated arm, and, upon subsequent release of the inward force, the first hook means remains securely interengaged with the second hook means to form a connection, and further wherein at least the intermediate portion is adapted to be twisted such that the connection deforms about the at least two reinforcing bars so as to increase the security of the interengagement of the connection as at least the intermediate portion is twisted; characterised in that, said intermediate portion is shaped such that it is substantially bowed or convex.

2. The tie device of claim 1 wherein the plurality of bends extend out of the tie plane along a coil path.

3. A tie for connecting reinforcing bars, the tie comprising: an intermediate portion having a first end and a second end; a first elongated arm coupled to the first end of the intermediate portion; a second elongated arm coupled to the second end of the intermediate portion; a hook comprising a hook extension and a grapple, the hook extension having a first end coupled to the first elongated arm at an obtuse angle and a second end extending towards the second elongated arm, the grapple having a first end coupled to the second end of the hook extension at an acute angle and a second end extending towards the intermediate portion; and a loop comprising a loop extension and a catch, the loop extension having a first end coupled to the second elongated arm at an obtuse angle and a second end extending towards the first elongated arm, the catch having a first end coupled to the loop extension at an acute angle and a second end extending towards the intermediate portion; characterised in that said intermediate portion is shaped such that it is substantially bowed or convex.

4. The tie of claim 3 wherein the intermediate portion is coupled to the first elongated arm by a first curved portion and is coupled to the second elongated arm by a second curved portion such that the first curved portion and the second curved portion form a substantially U-like configuration.

5. The tie of claim 3 wherein the intermediate portion is coupled to the first elongated arm by a first angled portion and is coupled to the second elongated arm by a second angled portion such that the first angled portion and the second angled portion form a substantially V-like configuration.

6. The tie of claim 3 wherein the first elongated arm, the intermediate portion and the second elongated arm form a tie plane, the hook lying in the tie plane.

7. The tie of claim 6 wherein the loop extension extends away from the tie plane and the catch extends towards the tie plane.

8. The tie of claim 7 wherein the catch passes through the tie plane, the loop further comprising a catch extension having a first end coupled to the second end of the catch at an acute angle and extending towards the second elongated arm in the direction of the tie plane.

9. The tie of claim 3, the first elongated arm having a first portion and a second portion, the first portion of the first elongated arm having a first end and a second end, the first end of the first portion coupled to the first end of the intermediate portion, the second portion of the first elongated arm comprising a receding part and a protruding part, the receding part having a first end coupled to the second end of the first portion and having a second end that extends towards the second elongated arm, the protruding part having a first end coupled to the second end of the receding part and a second end that extends away from the second elongated arm and is coupled to the hook extension, and the second elongated arm having a first portion and a second portion, the first portion of the second elongated arm having a first end and a second end, the first end of the first portion coupled to the second end of the intermediate portion, the second portion of the second elongated arm comprising a receding part and a protruding part, the receding part having a first end coupled to the second end of the first portion and having a second end that extends towards the first elongated arm, the protruding part having a first end coupled to the second end of the receding part and a second end that extends away from the first elongated arm and is coupled to the loop extension.

10. The tie of claim 9 wherein the first elongated arm, the intermediate portion and the second elongated arm form a tie plane, the hook lying in the tie plane.

11. The tie of claim 10 wherein the loop extension extends away from the tie plane and the catch extends towards and through the tie plane.

12. The tie of claim 12 wherein the tie has a circular cross-sectional shape.

13. The tie of claim 12 wherein the tie is made of a ductile, resilient material.

14. The tie of claim 13 wherein the material is one of metal and plastic.

15. A tie for connecting reinforcing bars, the tie comprising: an intermediate portion having a first end and a second end; a first elongated arm coupled to the first end of the intermediate portion; a second elongated arm coupled to the second end of the intermediate portion; a first crook having a first end coupled to the first elongated arm, the first crook extending at least in part towards the second elongated arm; and a second crook having a first end coupled to the second elongated arm, the second crook extending at least in part towards the first elongated arm, wherein the first elongated arm, the intermediate portion and the second elongated arm form a tie plane, the first crook comprising a first portion and a second portion, the first portion of the first crook coupled to the first elongated arm and extending below and away from the tie plane and the second portion of the first crook extending towards the tie plane and the intermediate portion, the second crook comprising a first portion and a second portion, the first portion of the second crook coupled to the second elongated arm and extending above and away from the tie plane and the second portion of the second crook extending towards the tie plane and the intermediate portion; characterised in that said intermediate portion is shaped such that it is substantially bowed or convex.

16. The tie of claim 15 wherein the intermediate portion is coupled to the first elongated arm by a first curved portion and is coupled to the second elongated arm by a second curved portion such that the first curved portion and the second curved portion form a substantially U-like configuration.

17. The tie of claim 15 wherein the intermediate portion is coupled to the first elongated arm by a first angled portion and is coupled to the second elongated arm by a second angled portion such that the first angled portion and the second angled portion form a substantially V-like configuration.

18. The tie of claim 15 wherein the second portion of the first crook is coupled to a first crook extension, the second portion of the second crook is coupled to a second crook extension, and wherein at least one of the crook extensions passes through the tie plane.

19. In a reinforced concrete structure having a tie that fixes a plurality of reinforcing bars to each bar, the tie comprising: an intermediate portion having a first end and a second end; a first elongated arm coupled to the first end of the intermediate portion, the first elongated arm having a first portion and a second portion; a second elongated arm coupled to the second end of the intermediate portion, the second elongated arm having a first portion and a second portion; and a means for fastening the second portion of the first elongated arm to the second portion of the second elongated arm, the means for fastening adapted to be interengaged, wherein the first portion of the first elongated arm and the first portion of the second elongated arm include a position wherein each first portion is twisted around the other to form an entwined portion wherein the entwined portion is a result of a process that includes the step of twisting without pulling, the entwined portion having a length such that the means for fastening securely engages and deforms about the plurality of reinforcing bars, whereby the security of the interengagement of the means for fastening increases as the length of the entwined portion increases; characterised in that said intermediate portion is shaped such that it is substantially bowed or convex.

20. In a reinforced concrete structure having a tie that fixes a plurality of reinforcing bars to each bar, the tie of claim 19 wherein the means for fastening comprises a hook and a loop, the hook comprising a hook extension and a grapple, the hook extension having a first end coupled to the first elongated arm at an obtuse angle and a second end extending towards the second elongated arm, the grapple having a first end coupled to the second end of the hook extension at an acute angle and a second end extending towards the intermediate portion, and the loop comprising a loop extension and a catch, the loop extension having a first end coupled to the second elongated arm at an obtuse angle and a second end extending towards the first elongated arm, the catch having a first end coupled to the loop extension at an acute angle and a second end extending towards the intermediate portion so that the loop and the hook face each other.

21. In a reinforced concrete structure having a tie that fixes a plurality of reinforcing bars to each bar, the tie of claim 19 wherein the means for fastening comprises a first crook and a second crook, the first crook having a first end coupled to the first elongated arm, the first crook extending at least in part towards the second elongated arm; and the second crook having a first end coupled to the second elongated arm, the second crook extending at least in part towards the first elongated arm.

22. A magazine for use in a tie gun, the magazine comprising: a plurality of tie devices, each tie device having a top side profile, a bottom side profile, an intermediate portion having a first end and a second end, a first elongated arm coupled to the first end of the intermediate portion, the first elongated arm having a first portion and a second portion, a second elongated arm coupled to the second end of the intermediate portion, the second elongated arm having a first portion and a second portion, and a means for fastening the second portion of the first elongated arm to the second portion of the second elongated arm, the means for fastening adapted to be interengaged, wherein the intermediate portion, the first elongated arm, the second elongated arm, and the means for fastening are configured so that the bottom side profile of each tie device in the plurality of tie devices is complementary in shape to the top side profile of the remaining tie devices in the plurality of tie devices and wherein the intermediate portion, the first elongated arm, and the second elongated arm form a tie plane, the means for fastening comprises a hook and a loop, and at least one of the hook and the loop spiral through the tie plane and wherein, except for a first tie device, the bottom side profile of each tie device in the plurality of tie devices is stacked on the top side profile of any other tie device in the plurality of tie devices in a nesting fashion and wherein said intermediate portion is shaped such that it is substantially bowed or convex.

23. The magazine of claim 22 wherein the intermediate portion, the first elongated arm, and the second elongated arm form a tie plane, the means for fastening comprises a first crook and a second crook, and at least one of the first crook and the second crook spiral through the tie plane.

24. A tying apparatus for tying a tie device about two or more reinforcing bars, said tie device being substantially U- or V- shaped having an intermediate portion and hook means at end portions thereof, said tying apparatus including: delivering means, to deliver said tie device to a tying position substantially about said bars, such that said hook means are provided beyond the opposed side of said bars; connecting means to interengage and connect said hook means; and twisting means to twist said intermediate portion of said tie device and thereby tighten said tie device about said object(s); characterised in that, said connecting means are operatively attached to said delivering means, such that as said delivering means moves said tie device to an intermediate position, said delivering means moves said connecting means and thereby interengages and connects said hook means of said tie device, said connecting means thereafter being biased to return to its starting position as said delivering means returns to its initial position.

25. A tying apparatus as claimed in claim 24, wherein said delivering means includes a roller and said connecting means, includes a cam, whereby said roller abuts said cam to operate said connecting means.

26. A tying apparatus for tying a tie device about two or more reinforcing bars, said tie device being substantially U- or V-shaped having an intermediate portion and hook means at end portions thereof, said tying apparatus including: delivering means, to deliver said tie device to a tying position substantially about said bars, such that said hook means are provided beyond the opposed side of said bars; connecting means to interengage and connect said hook means; and, twisting means to twist said intermediate portion of said tie device and thereby tighten said tie device about said object(s); characterised in that, said twisting means is in the form of at least one pair of horizontally mounted twist plates or at least one pair of vertically mounted twist plates having different bevelled surfaces thereon, adapted to allow said hook means to pass on opposite sides of said plates, and further being adapted to cooperate with said intermediate portion of said tie device and release from said tie device without requiring movement in a reverse direction to that in which said twisting means are twisted.

27. A tie device, substantially as herein described with reference to Fig. 5 of the accompanying drawings.

28. A tying apparatus, substantially as herein described with reference Fig. 4 of the accompanying drawings.