GB2358154A

GB2358154A - Apparatus and method for securing together reinforcing bars for reinforced concrete

Info

Publication number: GB2358154A
Application number: GB9928901A
Authority: GB
Inventors: Alexander George Stenhouse
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-12-08
Filing date: 1999-12-08
Publication date: 2001-07-18
Also published as: GB9928901D0

Abstract

An apparatus and method for securing together reinforcing bars for reinforcing concrete includes a wire feeding device (1) means (3) to hold together one end of the wire and another part of the wire along its length, means (4) to grip, twist and cut the wire, means (5) to take up slack between the two ends of the wire so cut and to tighten a knot made in the wire around the reinforcing bars to secure them.

Description

1 2358154 APPARATUS AND METHOD FOR SECURING TOGETHER REINFORCING BARS FOR

REINFORCED CONCRETE This invention relates to an apparatus and a method for securing together reinforcing bars for reinforced concrete.

Reinforced concrete is a widely used construction material and is concrete strengthened by steel reinforcing bars commonly called "rebar". The practise of fixing or securing these steel reinforcing bars is at present a manual operation and has remained basically the same for at least the past fifty years. The securing operation entails placing the bars in location and tying them together with wire called tying wire. The tying operation accounts for the major amount of time taken in fixing reinforcing bars.

According to one aspect of the present invention, there is provided an apparatus for - securing together reinforcing bars for reinforced concrete, the apparatus including a wire feeding device, means to hold together one end of the wire and another part of the wire along its length, means to cut the wire beyond said other parts remote from said one end, means to take up slack between the two ends of the wire so cut and to tighten a knot made in the wire around the reinforcing bars to secure them.

According to another aspect of the present invention, there is provided a method of securing together reinforcing bars for reinforced concrete using apparatus essentially as just defined, the method including feeding wire from a wire supply, forming a knot 2 in the wire around the reinforcing bars, holding togethr one end of the wire and another part of the wire alo ig its length, cutting the wire beyond said other 1Pa -t remote from said one end, taking up slack between the b,o ends of the wire so cut and tightening the knot made fn the wire around the reinforcing bars to secure them.

Means may be provided to cut off free ends of the wire once the reinforcing bars have been secured. The free ends can be collected.

The means to take up slack in the wire can include a tension controlling facility. The means to hold the sjie together can be a solenoid powered grip mechanism.

The means to take up slack can be an electrically powered motor drive with a variable torque cut-out.

For a better understanding of the invention and t 0 show how the same may be carried into--- effect, referEn(.-e will now be made, by way of example, to the accompanying drawings, in which:

Fig. 1 is a schematic view of an apparatus f>r securing together reinforcing bars for reinforAd concrete; 1 Figs. 2 to 5 are diagrammatic perspective views illustrating var-Jous forms of knot that can be provided to secure the bars; and Figs. 6 to 11 are diagrammatic perspective v..i.eqs illustrating successive stages in the method of secu:t.-Ag together two reinforcing bars.

The apparatus shown in Fig. 1 includes a tying wire magazine 1, a tying wire feed 2, a wire solenoid operated grip or keep 3 and a grip, twist and guillotine device 4.

The tying wire magazine 1 is preferably capable of holding about 1 kg. of tying wire in coiled form. The magazine 1 is preferably located in a position that does not exert an excessive torque to the hand of the operator.

The wire feeding device (inside the casing of the apparatus of Fig. 1) takes the wire from the magazine and pays it out as the feed of tying wire 2. The length of wire so fed can be variable and can depend upon the knot to be tied and operator preference. This operation can be activated by a trigger-induced signal, using the trigger 8. The wire feeding device can be a roller arrangement powered by an electric motor. 20 The apparatus is also provided with a tensioning ram 5, which may be operated by pressurised gas, a replaceable C02 gas cylinder being illustrated at 6, or it may be electrically operated.

Also schematically illustrated is a handle 7 with an operating trigger 8, a rechargeable battery 9 and a wire cut-off receiver 10.

Figs. 2 to 5 each show two reinforcing bars 11, 12 that are to be secured together by the tying wire 2.

Fig. 2 shows a saddle knot.

4 Fig. 3 shows a crown knot.

Fig. 4 shows a slashed knot with the reinforcir,g bars 11, 12 crossed.

Fig. 5 shows- a slashed knot with the reinforcJ.rg bars 11, 12 lapped.

Fig. 6 simply illustrates the wire 2 being paid out once a suitable length of tying wire has been pa Id out, the operator winds the wire around the i-_ 0 reinforcing bars 11, 12 (rebar) in the manner applicab e for the desired knot (Fig. 3); then, both the free a d continuous ends of the wire 2 are placed in the Keep This winding operation could also be mechanised.. 1 Upon receiving a further trigger-activated signa both the free end of the wire and the other parts of t e wire in the keep 3 are secured by the solenoid power d grip mechanism. The means to cut the wire may be a solenoid-powered guillotine and this cuts the wire 0 that it then has two ends 2A, 2B.

The grip, twist and guillotine mechanism 4 is th n actuated to rotate the two ends 2A, 2B together to twi t the wire 2 together in order to take up the slack wire n the knot. This stage is shown in Fig. 8 and can De achieved by a electrically-powered motor drive with!a variable torque cut-out.

As shown in Fig. 9, the apparatus then ties the kn)t by pulling in the direction of the arrow shown in Fig. 9 and this is achieved by extending the ram 5 which beas against the reinforcing bars 11, 12, or one of them, until a predetermined tension, that can be variable, is achieved in the ends 2A, 2B of the knotted wire. The ram is powered by the gas cylinder.

This action produces fresh slack in the wire because the reinforcing bars 11, 12 have been drawn together and so, as shown in Fig. 10, the ends 2A and 2B are again twisted to take up the slack. The tying of the knot is now basically complete.

Before moving on to the next knot, the apparatus also severs the excess of the twisted ends 2A, 2B of the wire (Fig. 11) by using a guillotine in an appropriate position. Subsequently, the cut-off wire ends are grasped by a tool associated with the apparatus and deposited in the wire cutoff receiver 10.

It will be appreciated that the present apparatus is sufficiently robust to survive on a construction site and preferably the battery power can operate continuously for at least a period of twenty-four hours and the' gas cylinder should preferably have capacity to operate continuously for a minimum of six hours.

The apparatus should be capable of accommodating different gauges of tying wire to replace the condition where doubled wire is used in common practise to tie heavy weight rebar.

6

Claims

1 An apparatus for securing together reinforc,-ig bars for reinforced concrete, the apparatus including a wire feeding device, means to hold together one end cf the wire and another part of the wire along its lengl,,1', means to cut the wire beyond said other parts remote fipc m said one end, means to take up slack between the two enc s of the wire so cut and to tighten a knot made in the w-",i e around the reinforcing bars to secure them.

2. A method of securing together reinforcing bais for reinforced concrete using apparatus according to claim 1, the method including feeding wire from a wi..1 1 e supply, forming a knot in the wire around the reinforcirg bars, holding together one end of the wire and anothEZ part of the wire along its length, cutting the wiiie beyond said other part remote from said one end, tak.j,rg up slack between the two ends of the wire so cut ir d tightening the knot made in the wire around t:He reinforcing bars to secure them.

3. An apparatus or method according to claim 1 cr 2, respectively, wherein means are provided to cut aff free ends of the wire once the reinforcing bars have been secured.

4. A method according to claim 2 or 3, wherein t.,e free ends are collected.

5. An apparatus according to claim 1 or 3, wher=--iin the means to take up slack in the wire includes a tensi.cn controlling facility.

6. An apparatus according to any one of the preceding claims except claim 2, wherein the means to hold the wire together is a solenoid powered grip mechanism.

7. An apparatus according to any one of the preceding claims except claim 2, wherein the means to take up slack is an electrically powered drive with a variable torque cut-out.

8. An apparatus for securing together reinforcing bars for reinforced concrete, substantially as hereinbefore described with reference to the accompanying drawings.

9. A method of securing together reinforcing bars for reinforced concrete using apparatus according to claim 1, substantially as hereinbefore described with reference to the accompanying drawings.