AU723411B2 - Cable feeding apparatus - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

no 0* 0* 0

S

Name of Applicant: Actual Inventor: Address of Service: Invention Title: HEINEMANN ELECTRIC PTY LTD, ACN 007 308 670 Scott MANSER SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 "CABLE FEEDING APPARATUS" Details of Associated Provisional Application No. PO 4491 dated 7th January, 1997 The following statement is a full description of this invention, including the best method of performing it known to us:- The present invention relates to an apparatus to facilitate the insertion of an elongate flexible cable, wire, optical fibre or line through an aperture, hole, passage or conduit.

The invention has been developed primarily to facilitate the insertion of electrical and optical fibre cabling into conduits, ducts or wall cavities and will be described hereinafter with reference to these applications. It will be appreciated, however, that the invention is not limited to these particular fields of use.

In order to install electrical wiring, it is frequently necessary to run a considerable 0length of flexible electrical cable through wall cavities, conduits, skirting boards, cable 06-00 10 ducting, and the like, often over considerable distances. Feeding the wiring or wire pulling device by hand is particularly awkward and time consuming, because being !!:"-flexible, the wiring or wire pulling device is only able to sustain minimal compressive load without buckling or bending.

0. "In an attempt to ameliorate this problem, a length of flexible cable pulling wire or i 15 "fish tape" collectively known as a "draw wire" is sometimes used. Such draw wires can 0060 be formed from any suitable material, but are typically formed from coiled spring steel, :0o.0o plastic or the like. The combination of rigidity and resilience enables the draw wire to be pushed through a passageway more easily than many other types of wire. The electrical cabling or wiring is then attached to one end of the draw wire, which is withdrawn from the passageway. The cabling or wiring is thereby drawn through the passageway.

To facilitate the placement of a draw wire or cabling into a passageway, cable feeding devices are sometimes used. One such device employs a pair of telescopically -3engagable tubes adapted to reciprocate in a pumping action, and a cooperating ratchet mechanism adapted progressively to feed the cable through the tubes. A problem with such devices, however, is that the ratchet mechanism operates to feed the flexible draw wire or cabling in one direction only. Accordingly, such devices cannot be used to withdraw cabling in the opposite direction, which is often an equally awkward and time consuming procedure. Such devices are also costly, relatively complex, unreliable and generally not adapted to accommodate a range of cable thickness. Also, the ratchet mechanism can damage the cables or wires.

•Other devices are known which are capable of feeding a draw wire or cabling in 99** both directions. However, these have also tended to be costly, unreliable, excessively complex, prone to jamming, and cumbersome to use. Furthermore, again the ratchet mechanisms are capable of damaging the outer protective sheath of electrical wiring, e •thereby posing potential safety hazards.

It is an object of the present invention to overcome or substantially ameliorate at 15 least some of the disadvantages of the prior art.

Accordingly, the invention as presently contemplated provides an apparatus for manually feeding a flexible cable through an aperture, said apparatus including a first relatively rigid sleeve defining a first axially extending bore, a second sleeve defining a second bore coaxial with the first, said first and second sleeves being telescopically engagable for relative sliding movement between an extended configuration and a retracted configuration, said apparatus further including manually operable clamping means associated with one of said sleeves and adapted alternately to engage and release the flexible cable whereby manual reciprocation of said sleeves between the extended -4and retracted configurations in conjunction with the operation of said clamping means progressively feeds the cable through the sleeves.

It will be understood that the term "flexible cable" includes, but is not limited to, electrical or optical wires or cables, as well as draw wires.

Preferably, the second sleeve is slidable within the first sleeve, with the clamping means associated with the second sleeve.

Preferably, the second sleeve is proximal to the user whilst the first sleeve is remote from the user, whereby movement of the second sleeve away from the user toward the first, with the clamping means engaged, feeds a corresponding length of flexible cable through the first sleeve and into an aperture, in a pumping action.

Preferably also, the clamping means include a clamping surface against which the flexible cord is adapted to be manually urged by the user during relative movement of the second sleeve toward the retracted position. Preferably, the clamping surface is integral with a handle member by which the user controls the clamping means as well as 15 the axial sliding movement of the associated second sleeve.

ooo° Preferably, the second sleeve includes a removeable inner sleeve having a bore sized to accommodate the flexible cable.

Preferably, the apparatus further includes a nozzle, tip or guide releasably attachable to the remote end of the first sleeve whereby the cable may be fed out at an oblique angle with respect to the sleeve. In one preferred embodiment, the tip is adapted to divert the cable emerging from the sleeves through 900, to facilitate feeding into wall cavities and the like.

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view showing a cable feeding apparatus according to the invention; Figure 2 shows the apparatus of figure 1, with a draw wire passing through the sleeves in the extended position; Figure 3 shows the apparatus of figure 2 with the sleeves in the retracted position; Figure 4 shows the apparatus of figures 1 to 3 with a releasable tip adapted to divert the draw wire merging from the sleeves through a 900 angle; Figure 5 shows the tip of figure 4 fitted to the apparatus with the draw wire diverted through 90'; and Figure 6 shows the apparatus of figure 5 feeding the cable into a wall cavity.

Referring firstly to figures 1 to 3, wherein like features are denoted by corresponding reference numerals, the invention provides an apparatus 1 for feeding a a: °i 15 cable in the form of a draw wire 2 into an aperture, conduit, wall cavity, skirting, ducting system, or the like. The apparatus includes a first outer sleeve 5 defining a first axially extending bore and a second inner sleeve 6 defining a second bore coaxial with the first.

The second sleeve 6 includes a handle member 7 to be gripped by one hand of the user, with the other hand grasping the first sleeve 5. In this orientation, it will be appreciated that the second inner sleeve is proximal to the user whilst the first outer sleeve is remote.

The first and second sleeves are telescopically engagable for relative sliding movement between an extended configuration (as shown in figure 2) and a retracted configuration (as shown in figures 1 and 3).

The apparatus further includes clamping means 10 associated with the proximal second sleeve 6. The clamping means in this case takes the form of a clamping surface 11 formed on the inner face of the handle 7. Thus, when the draw wire 2 is manually held against the clamping surface 11 of the handle 7, relative movement of the flexible cable through the proximal sleeve 6 is prevented. Conversely, when the user's grip on the handle is relaxed, the draw wire can slide freely over the clamping surface and through the inner and outer sleeves. In alternative embodiments, other manually operable clamping mechanisms, such as clamping jaws, are contemplated which do not involve direct contact between the user's hand and the draw wire.

Turning now to describe briefly the operation of the device, the draw wire is initially fed through the sleeves, so as to protrude marginally beyond the end of the remote sleeve 5. The user then grips the device, with one hand holding the handle 7 which is integral with the proximal inner sleeve 6, and the other hand gripping the remote outer sleeve 5. The hand gripping the handle also encompasses the adjacent •:1i 15 section of the draw wire. The sleeves are then slid outwardly toward the extended configuration, as shown in figure 2. At this point, the grip on the handle 7 is tightened, :'"""whereby the portion of draw wire adjacent the handle is releasably urged into frictional engagement with the clamping surface 11. With this grip maintained the handle and hence the proximal sleeve 6 are slid forwardly, into telescopic engagement with the remote sleeve 5, into the retracted configuration as shown in figure 3. During this "pumping" movement, the draw wire is fed by a corresponding amount beyond the end of the remote sleeve, and into the appropriate aperture, conduit, cavity or ducting toward which the apparatus is directed. When the point of maximum telescopic engagement has -7been reached, in this case when the handle on the inner sleeve abuts the adjacent edge of the outer sleeve, the user's grip on the handle is relaxed, and the inner sleeve moved backwardly once again toward the extended position as shown in figure 2. It will be appreciated, however, that with the grip on the handle 7 relaxed, the draw wire is released from engagement with the clamping surface 11, and so is not simultaneously retracted. In this way, manual reciprocation of the inner sleeve within the outer sleeve, in conjunction with appropriately synchronised alternate manual clamping and releasing of the draw wire, progressively feeds the draw wire through the apparatus to the required extent. It will be also appreciated that by alternatively actuating the clamping mechanism during the extension phase, the draw wire can be simply and easily withdrawn by a reverse of the above procedure.

Figures 4 and 5 show a tip member 15 adapted for releasable attachment to the S remote end of the first sleeve 5. As best seen in figure 5, the tip 15 is adapted to divert the flexible draw wire through an angle of approximately 900, although interchangeable 15 tips defining any desired diversion angle may also be used. Figure 6 shows the use of the diversion tip 15 to facilitate the feeding of draw wire into a wall duct 16, which *o would otherwise be a particularly awkward and time consuming procedure.

The second sleeve may also be fitted with replaceable inner sleeves having various size bores in order to accommodate draw wires of different diameter. This serves to reduce the risk of the draw wire buckling or bending in the sleeve during feeding.

When the draw wire has been fed through the passageway or aperture, a cable or the like is attached to its leading end. The draw wire is then withdrawn, which in turn pulls the cable back through the passageway.

-8- Although the above description deals with the use of the invention to insert a draw wire into a passageway or the like, it will be understood that other types of cables with sufficient rigidity may be used directly with the device. Whilst the device may be used with many types of electrical wiring in this manner, it is also envisaged that fibre optic cabling may be installed in a similar fashion. Typically, fibre optic cables are used in bundles of many tens or hundreds of individual strands, the bundles being bound in a protective sheath. Such cables tend to be relatively rigid, and are thus particularly well suited to use with the present invention. Furthermore, the manual nature of the present device, particularly in its preferred form, reduces the likelihood of damage to the sheath .10 or individual fibres during installation, compared with feeding devices which employ ratchet mechanisms and the like.

Particularly when feeding fibre optic cables, a cap (not shown) may be fitted over a leading portion of the cable to reduce fouling as the cable is pushed into conduits and the like. In one embodiment, the cap is generally spherical with an internal bore to receive o. 15 the end portion of the cable. The cable is retained in the bore by an interference fit, although clamping means such as a grub screw or the like may be employed. The cap includes roller means in the form of wheels positioned to engage an inner surface of the conduit or passageway, thereby to reduce fouling of the cable as it is pushed through. In other embodiments the wheels are replaced with bearings, or may be omitted altogether.

In yet another embodiment, the roller means are replaced with resilient fingers which extend laterally from the cap to bias it away from the walls of a passageway, thereby reducing fouling through tight bends and over joints in the passageway.

-9- Particularly when feeding long cables, the apparatus may be made from a split system whereby the sleeves can be disassembled and removed from the draw wire without having to remove the sleeve from the end of the draw wire. This may be done by simply providing a longitudinal split in the first and second sleeves such that they may be conveniently withdrawn from the draw wire.

It will be appreciated that the present invention provides a simple, relatively inexpensive, and reliable device which greatly facilitates the installation of flexible cable, wire, optical fibres and the like into conduits, cavities and ducts in a rapid, efficient and effective manner. The invention can also be used without modification to 10 withdraw cables in a like manner. The invention achieves this with a minimal number of ooo moving parts and without costly ratchet mechanisms which are prone to reliability ooo* problems, sensitive to cable thickness, and which can often damage the cable sheaths. In all these respects, the invention represents a commercially significant improvement over .o the prior art.

15 Although the invention has been described with reference to specific examples, it oa o will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims (9)

1. An apparatus for manually feeding a flexible cable through an aperture, said apparatus including a first relatively rigid sleeve defining a first axially extending bore, a second sleeve defining a second bore coaxial with the first, said first and second sleeves being telescopically engagable for relative sliding movement between an extended configuration and a retracted configuration, said apparatus further including manually operable clamping means associated with one of said sleeves and adapted alternately to engage and release the flexible cable whereby manual reciprocation of said sleeves between the extended and retracted configurations in conjunction with the operation of 10 said clamping means progressively feeds the cable through the sleeves.

2. An apparatus according to claim 1, wherein the second sleeve is slidable within the g. first sleeve, with the clamping means being associated with the second sleeve.

3. An apparatus according to claims 1 or 2, wherein in use, the second sleeve is o• proximal to the user and the first sleeve is remote from the user, whereby movement of 15 the second sleeve away from the user toward the first, with the clamping means engaged, °0o. feeds a corresponding length of flexible cable through the first sleeve and into the aperture, in a pumping action.

4. An apparatus according to claim 3, wherein the clamping means includes a clamping surface against which the flexible cord is adapted to be manually urged by the user during relative movement of the second sleeve toward the retracted position.

An apparatus according to claim 4, wherein the clamping surface is integral with a handle member by which the user controls the clamping means as well as the axial sliding movement of the associated second sleeve. -I1-

6. An apparatus according to any one of claims 2 to 5, wherein the second sleeve includes a removeable inner sleeve having a bore sized to accommodate the flexible cable.

7. An apparatus according to any one of claims 2 to 6, further including a nozzle, tip or guide releasably attachable to the remote end of the first sleeve whereby the cable may be fed out at an oblique angle with respect to the sleeve.

8. An apparatus according to claim 7, wherein the nozzle, tip or guide is adapted to divert the cable emerging from the sleeves through approximately 900, to facilitate feeding into wall cavities and the like.

9. An apparatus for manually feeding a flexible cable through an aperture substantially as hereinabove described with reference to any one of the embodiments of the invention shown in the accompanying drawings. DATED this 7th day of JANUARY, 1998 HEINEMANN ELECTRIC PTY LTD 15 Attorney: CAROLINE M. BOMMER Fellow Institute of Patent Attorneys of Australia 0. of SHELSTON WATERS o* ot