AU2006200175A1 - Draw strings and devices for drawings cables - Google Patents

Description

O DRAW STRINGS AND DEVICES FOR DRAWING CABLES DThis invention relates to draw strings and devices for drawing cables through conduits and other passages. The invention has particular application to draw strings for drawing electrical cables and data cables through such passages. However, the invention may have application in other fields.

Various methods have been used over the years to draw electrical cables and data S cables through conduits. One method is to push a relatively stiff draw wire through the conduit and then attach the cable to be drawn to one end and pull it through with the stiff draw wire. Another method is to attach a weight to a string line and drop the weight into the O conduit so that it pulls the string line through the conduit under the influence of gravity. That method requires the conduit to be inclined fairly steeply depending on its length and it generally requires a predetermined length of string to be uncoiled from its reel so that it can be drawn through the conduit by the weight without catching or tangling. Both of those methods have significant drawbacks. The first method requires a relatively stiff wire to be unrolled and rerolled after each use and after only a few uses the wire often becomes unusable because of bends along its length which contact the inner face of the conduit making it difficult to force it through while the second method is difficult to use with long conduits. Both methods also have other drawbacks.

The present invention is aimed at providing a device for drawings cables and the like through conduits and similar passages which overcomes to some extent at least one of the aforementioned problems.

With the foregoing in view, the invention resides broadly in a device for drawing cables through conduits and similar passages, including: a reel having a string line wound thereon, said reel being mounted on or in a reel support for rotation relative thereto; guide means operatively connected to said reel support for guiding said string line in a predetermined direction as it is unwound from said reel; a magnetically attractive end piece connected to the outer end of said string line and adapted to slidably fit within a conduit or passage through which a cable is to be drawn; and a magnet adapted to be slidably engaged with the outer face of the conduit to thereby draw the end piece and the attached string line through the conduit as it is moved therealong.

/cgel02101 filed 17 January 2006 In another aspect the invention resides broadly in a device for drawing cables through conduits and similar passages, including: a reel having a string line wound thereon, said reel being mounted on or in a reel support for rotation relative thereto; guide means operatively connected to said reel support for guiding said string line in a tt) S predetermined direction as it is unwound from said reel; a magnetically attractive end piece adapted to be releasably connected to the outer end 'A of said string line and adapted to slide within a conduit or passage through which a cable is to 0 be drawn along its length; and a magnet adapted to be slidably engaged with the outer face of the conduit to thereby draw the end piece and the attached string line through the conduit as it is moved therealong.

In yet another aspect the invention resides broadly in a method of drawing a cable through a conduit or similar passage, including: providing a reel having a string line wound thereon, said reel being mounted on a reel support for rotation relative thereto and said string line having a magnetically attractive end piece attached to the outer end of said string line and adapted to slide within the conduit or passage through which a cable is to be drawn along its length; placing the end piece within an end portion of the conduit or passage; and sliding a magnet along the outer face of the conduit or the wall defining the passage to thereby draw the end piece and the attached string line through the conduit as it is moved therealong.

Preferably, the guide means is arranged to guide the string line such that it leaves the reel and enters the conduit generally tangentially to the reel of string. In a preferred form, the guide means is adapted to be coupled to the conduit such that the conduit is generally tangential to the reel of string. In a more preferred form, the device includes a housing for the reel with the base and side wall of the housing forming the reel support while the guide means is provided by a tubular portion or fitting extending from the side wall of the housing.

In such form it is preferred that the housing and the end piece and magnet be selected so that the end piece and the magnet are adapted to fit in the housing with the reel when not in use for easy storage. In a preferred form, the magnet is shaped to fit within the reel outside the string wound thereon.

/cgel02101 filed 17 January 2006 Preferably, the end piece includes quick connection means adapted to allow for quick connection and disconnection to the string line.

In order that the invention be more clearly understood and put into practical effect the invention will now be described by reference to the accompanying drawings which illustrate preferred embodiments of the invention and wherein; Fig. 1 is a pictorial representation of a cable drawing device according to the present 3 invention; 3 ,,Fig. 2 is a plan view of the cable drawing device of Fig. 1 with the lid of the housing 3 removed; Fig. 3 is a plan view of another cable drawing device according to the present invention; Fig. 4 is a pictorial representation of the cable drawing device of Fig. 1 in use with the string line being drawn into a conduit for connection to a cable to be drawn through the conduit.

The cable drawing device 10 illustrated in Fig. 1 includes a housing 11 in which a reel 12 is mounted for rotation, the reel having wound thereon a string line 13 to which an end piece 14 is releasably connected and a magnet comprised of two detachable halves 16a and 16b. Each half of the magnet is almost a semi-cylindrical prism.

The housing has a tubular body portion 18 which is constructed of 90mm PVC tube with an end cap 19 secured thereto at one end to form a base and an end cap 21 fitted to the other end to provide a removable closure, the tubular body portion and the two end caps defining a cylindrical chamber 20. A short piece of 19mm nominal bore electrical conduit 22 extends outwardly from the side wall of the tubular body portion and is secured thereto with the hollow of the conduit opening into the chamber 20. Suitably, the extension 22 is adapted to receive thereon the female end of a complementary electrical conduit 23. In other embodiments, the extension piece may be of a different sized conduit and adapted to engage with the female end of corresponding conduits, either larger or smaller. As can be seen in Fig.

4, the string line is adapted to pass through the extension piece as it unwinds from the reel.

An end piece 15 is releasably secured to the end of the string line and is adapted to slide within the conduit 23 along its length. Suitably, the end piece is made of steel although any other magnetically attractive material would be satisfactory. In this embodiment, the end /cgel021O1 filed 17 January 2006 piece has a cup shaped head similar to that of a cup head bolt and a shank 24 extending therefrom of generally cylindrical form having an end portion of generally rectangular crosssection 25. A hole 26 passes through the end portion from side to side through which the string can be passed and a slot 27 is formed in the end of the rectangular portion which is adapted to receive therein the string line. The string can be readily passed through the hole and wedged in the slot to thereby secure it to the end piece. Alternative end pieces may be used if desired, for example, a hollow end piece with an internal hook may be constructed if S desired.

0 D In use, a user can fit the end piece to the string line and fit it into the end of the S conduit through which the cable is to be drawn and then connect the female end of the conduit to the extension piece 22. The end piece is fitted by passing the string line through the hole 26 and then wedging it in the slot 27 which is suitably sized to make a tight fit. The user can then pass the magnet along the outer face of the conduit starting at the end nearest the extension piece to draw the end piece along the conduit with the magnet, the magnetic flux urging the end piece toward the magnet. As the end piece is drawn along the conduit the string line unwinds from the reel which rotates within the housing. Once the end piece has reached the other end of the conduit the end piece can be detached from the string line and the string line can be connected to the cable to be drawn through the conduit which can be done by simply removing the device from the conduit and pulling the string line in the reverse direction to pull the cable therethrough. Although the magnet is shown being moved along the conduit with the open side against the side of the conduit, it could be used with a different orientation if desired. For example, the two magnets could be used around the conduit coaxial therewith or one magnet could be used in that manner. After use, the reel 13 can be removed from the housing and the string rewound by hand. Suitably, the magnet being almost semi-circular in cross-section can be easily accommodated in the housing between the flanges 29 of the reel.

The device shown in Fig. 3 is the same as that shown in Fig. 1 except that the extension piece 22 is fitted to the body so that string line leaving the reel can leave it tangentially thereby reducing drag on the string line.

The foregoing description has been given by way of illustrative example of the invention and many modifications and variations which will be apparent to persons skilled in /cgel02101 filed 17 January 2006 the art may be made without departing from the spirit and scope of the invention as defined in the appended claims.

/cgelO2IOfiled 17 January 2006

Claims (12)

1. A device for drawing cables through conduits and similar passages, including: Sa reel having a string line wound thereon, said reel being mounted on or in a reel support for rotation relative thereto; Sguide means operatively connected to said reel support for guiding said string line in a predetermined direction as it unwinds from said reel; a magnetically attractive end piece connected to the outer end of said string line and 0 D adapted to slidably fit within a conduit or passage through which a cable is to be drawn; and a magnet adapted to be slidably engaged with the outer face of the conduit to thereby draw the end piece and the attached string line through the conduit as it is moved therealong.

2. A device for drawing cables through conduits and similar passages, including: a reel having a string line wound thereon, said reel being mounted on or in a reel support for rotation relative thereto; guide means operatively connected to said reel support for guiding said string line in a predetermined direction as it unwinds from said reel; a magnetically attractive end piece adapted to be releasably connected to the outer end of said string line and adapted to slide within a conduit or passage through which a cable is to be drawn along its length; and a magnet adapted to be slidably engaged with the outer face of the conduit to thereby draw the end piece and the attached string line through the conduit as it is moved therealong.

3. A method of drawing a cable through a conduit or similar passage, including: providing a reel having a string line wound thereon, said reel being mounted on or in a reel support for rotation relative thereto and said string line having a magnetically attractive end piece attached to the outer end of said string line and adapted to slide within the conduit or passage through which a cable is to be drawn along its length; placing the end piece within an end portion of the conduit or passage; and /cgel02101 filed 17 January 2006 sliding a magnet along the outer face of the conduit or the wall defining the passage to thereby draw the end piece and the attached string line through the conduit as it is moved S therealong.

4. A device according to Claim 1 or Claim 2 wherein said guide means is arranged to S guide the string line such that it leaves the reel and enters the conduit generally tangentially to S the reel of string. 0 S

5. A device according to Claim 4 wherein said guide means is adapted to be coupled to a 3 'A conduit generally tangential to the reel of string.

6. A device according to any one of the preceding claims including a housing which has a base and side wall forming said reel support.

7. A device according to Claim 6 wherein said guide means includes a tubular portion extending from the side wall of said housing.

8. A device according to Claim 6 or Claim 7 wherein said housing is adapter to receive therein the end piece and the magnet for storage with the reel when not in use.

9. A device according to Claim 8 wherein the magnet is shaped to fit within the reel beyond the string wound thereon.

A device according to Claim 9 wherein said magnet includes two detachable halves each of which is substantially a semi-cylindrical prism.

11. A device according to any one of the preceding claims wherein said end piece includes quick connection means adapted to allow for quick connection and disconnection to the string line. /cgel02101 filed 17 January 2006

12. A device for drawing cables through conduits and similar passages as hereinbefore described with reference to the accompanying drawings. Dated this 17 th day of January 2006 GERARD HENRY GELTCH AND TERRINA MICHELLE GELTCH By their Patent Attorneys AHEARN FOX /cgel02101 filed 17 January 2006