AU2003204275A1

AU2003204275A1 - A carrier for cables

Info

Publication number: AU2003204275A1
Application number: AU2003204275A
Authority: AU
Inventors: Alan Michael Ridgway
Original assignee: CABLE HANDLING SERVICES Pty Ltd
Current assignee: CABLE HANDLING SERVICES Pty Ltd
Priority date: 2002-05-22
Filing date: 2003-05-21
Publication date: 2003-12-11
Also published as: AU2010235855B2; AUPS244202A0; AU2010235855A8; AU2010235855A1

Description

TITLE

A carrier for cables FIELD OF THE INVENTION This invention relates to a carrier for cables.

DEFINITIONS

In this specification the word "cable" is to be understood as any elongate flexible member. While the invention is particularly suited to the carrying of electrical cables, it is to be understood that the invention can be used to carry any elongate flexible member that is usually difficult to carry and move around, either due to the sheer weight of the cable or because the cable requires special handling to avoid damage.

BACKGROUND TO THE INVENTION In many industrial applications, cables are particularly heavy and difficult to manipulate. Electrical cable, in particular, can be extremely heavy. Furthermore, such electrical cables are of a high cost and can be damaged if bent excessively.

Excessive bending creates extreme compressive and tensile forces in the cable, which can cause damage to internal components of the cable conductors, insulating material and conductor earth screens. This damage results in a breakdown of components and material in the cable that can lead to catastrophic failure of the cable or any equipment electrically connected to the cable.

The Applicant has discovered that a primary cause for damage to such cables is the generation of excessive stress concentrations when the cables are supported in a particular position or carelessly moved from place to place. For example, it is known that some workers will simply slip a sling or rope over the cable and drag it from one place to another with a suitable vehicle. Applicant has found that high, damaging stress concentrations occur at regions where the cable leaves a zone of contact with the sling or rope or any other device that has been used to engage the cable. The reason for this is that the cable is subjected to excessive bending and uneven loading about edges of the sling or rope.

It will be appreciated that the damaging stress concentrations can affect ropes and cables as well, especially those that are subjected to high tensile forces during operation. This would significantly shorten the life of such ropes and cables.

Applicant has conceived the present invention in order to address the problems associated with the creation of stress concentrations in ropes and cables.

SUMMARY OF THE INVENTION According to the invention, there is provided a carrier for cables, the carrier including an arcuate channel member that is shaped to accommodate a cable; a connecting arrangement that is attached to the channel member at a position intermediate ends of the channel member to permit a pulling device to be connected to the channel member; and a releasable holding device that is mounted on the channel member to hold the cable on the channel member.

The releasable holding device may form part of the connecting arrangement so that, when the pulling device acts on the connecting arrangement, the holding device is operable to hold the cable.

The connecting arrangement may include a connector that is pivotally mounted on the channel member. The holding device may be in the form of a clamping member that is fast with the connector, the connector and the clamping member being configured so that a pulling device can be connected to the connector to pull the connector and thus the channel member in a first direction and so that a force applied to the connector in said first direction results in the clamping member being pivoted towards the channel member.

The connector may have a first extremity that is pivotally attached to the channel member, a second extremity that is connectable to the pulling device and a third extremity that is fast with the clamping member, such that the clamping member and the mounting formation define a first class lever.

The connector may define a zone of weakness that is configured to fail when a predetermined load is applied to the connector.

The channel member may have an arcuate transverse profile to accommodate the cable and to define a floor with a peripheral line of maximum depth.

The carrier may include a retaining member that is fast with the channel member. The retaining member may be configured to engage the pulling device so that the pulling device is restrained from excessive lateral movement.

The retaining member may be shaped to define a guide opening that is spaced from the channel member and substantially aligned with the peripheral line of maximum depth. The pulling device may include a rope that is received through the guide opening so that a force applied to the channel member is substantially orthogonal to said line of maximum depth.

End portions of the channel member may each define an inwardly directed lip to accommodate angular movement the cable.

The carrier may include a bracing structure that is connected to the channel member and spans an area included by the channel member to brace the channel member.

The invention is now described, by way of examples, with reference to the accompanying drawings. The following description is not intended to limit the broad scope of the preceding paragraphs.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 shows a bottom three-dimensional view of a first embodiment of a carrier for cables, in accordance with the invention, without a cable.

Figure 2 shows a bottom three-dimensional view of the carrier of figure 1 in an operative condition.

Figure 3 shows a top three-dimensional view of the carrier of figure 1, without a cable.

Figure 4 shows a top three-dimensional view of the carrier of figure 1, in an operative condition.

Figure 5 shows a bottom three-dimensional view of the carrier of figure 1, in an inoperative condition.

Figure 6 shows a side sectioned view of a clamping member of the carrier of figure 1.

Figure 7 shows a top three-dimensional view of a second embodiment of a carrier for cables, in accordance with the invention.

Figure 8 shows a front view of the carrier of figure 7, in an operative condition.

Figure 9 shows a bottom three-dimensional view of the carrier of figure 7, in an inoperative condition.

Figure 10 shows a side view of the carrier of figure 7, in an operative condition.

Figure 11 shows a top three-dimensional view of the carrier of figure 7, in an operative condition.

Figure 12 shows a three-dimensional view of a clamping area of the carrier of figure 7.

DETAILED DESCRIPTION OF THE DRAWINGS In Figures 1 to 5, reference numeral 10 generally indicates a first embodiment of a carrier for cables. In this description, reference is made to an electrical cable 14 for illustrative purposes.

The carrier 10 includes an arcuate channel member 12. The channel member 12 includes an angle of not less than 180 degrees. The channel member 12 is semi-circular in shape. The channel member 12 has an arcuate transverse profile so that the electrical cable 14 can be seated in the channel member 12. In particular, the channel member 12 has a floor portion 16 and a pair of opposed walls 18 which together define the arcuate transverse profile.

The floor portion 16 defines an inwardly directed lip 28 at each end 20 of the channel member 12.

The carrier 10 includes a bracing structure in the form of a planar web member 24 that extends between the ends 20 of the channel member 12. The web member 24 has a plurality of openings 26 that are configured so that the web member 24 does not impart excessive weight to the carrier 10, while retaining a suitable structural strength.

The carrier 10 includes a connecting arrangement that is attached to the channel member 12 at a position intermediate the ends 20 of the channel member 12 to permit a pulling device to be connected to the channel member 12. The connecting arrangement includes a pair of spaced lugs 30 that are fast with one of the walls 18.1. Each lug 30 includes a reinforcing formation 32 that is fast with and extends transversely across the wall 18.1 and the floor portion 16. The lugs define a pair of aligned pivot openings 34, so that a pivot pin 36 can be received through the openings 34.

The lugs 30 are fast with the wall 18.1 at a point halfway between the ends of the channel member 12.

The carrier 10 includes a connector 38 (figure The connector 38 includes a planar body member 40. The body member 40 defines three extremities 42. A pivot opening 44 is defined by a first extremity 42.1. The first extremity 42.1 is positioned between the lugs 30 so that the openings 34, 44 are aligned. The pivot pin 36 is received through the openings 34, 44 so that the connector 38 is pivotally mounted on the lugs A connecting opening 46 is defined by a second extremity 42.2. The connecting opening 46 is configured so that a pulling device (not shown) can be connected to the connector 38 to pull the carrier 10 in a first direction, indicated by an arrow 50 (figures 3 and 4).

A clamping member 48 is fast with the connector 38 and is shaped to conform to the cable 14 received in the channel member 12. The clamping member 48 extends from a third extremity 42.3 of the body member 40. The clamping member 48 is oriented so that, when the cable 14 is positioned in the channel member 12, a line between the pivot opening 44 and the connecting opening 46 is angularly displaced with respect to said first direction. Thus, when the pulling device applies a force in said first direction, the clamping formation 48 bears against the cable 14, as shown in figures 2 and 4, to ensure that the cable 14 is clamped in position in the channel member 12.

As can be seen in figure 5, the connector 38 and thus the clamping member 48 are able to pivot away from the channel member 12 to allow the cable 14 to be positioned in the channel member 12. The connector 38 has a recess 64 to accommodate the wall 18.1 of the channel member 12 when the clamping member 48 pivots back into clamping engagement with the cable 14.

The carrier 10 includes a retaining member 52 that is fast with the wall 18.1.

The retaining member 52 defines a retaining formation in the form of an opening 54. The opening 54 is dimensioned so that the pulling device can be received through the opening 54 to engage the connector 38. Thus, the retaining member 52 serves to prevent excessive lateral movement of the pulling device. The retaining member 52 includes a pair of spaced legs 56, the connector 38 being positioned between the legs 56. The legs 56 are connected to the wall 18.1 using reinforcing ribs 58 and webs 60 to provide structural strength and to dissipate the build up of stress concentrations.

In use, the cable 14 is picked up and positioned in the channel member 12.

As the pulling device acts on the connector 38 in said first direction, the cable 14 is clamped in position and a tension is set up in the cable 14. It will be appreciated that, as a result of the configuration of the channel member 12, the cable 14 exits the channel member 12 in a second direction indicated by arrow 66 that is directly opposite to said first direction. It follows that the cable 14 is supported throughout its bent portion and no bending occurs at the points of exit from the channel member 12. The fact that the floor portion 16 defines the inwardly directed lips 28 also serves to protect the cable 14 since the lips accommodate possible angular displacement of the cable 14 relative to the channel member 12, without the buildup of excessive stress concentrations in the cable 14.

The cable 14 is a heavy-duty electrical cable, such as those used in heavy industry, such as mining. The cable 14 is therefore sensitive to excessive minimal bending radii, especially when the cable 14 is subjected to high loads and tensile forces during handling and supporting. This excessive bending can result in damage to the internal structure and components of the cable 14. Such damage causes but is not limited to a weakening of conductor properties creating a higher point of electrical resistance in the cable 14 resulting in heat conduction, which can cause catastrophic failure of the cable 14 and equipment powered by the cable 14.

In a mining operation, for example, this can be extremely costly. The fact that the cable 14 is supported all the way through a bent portion serves to prevent the build up of stress concentrations in the cable 14. Thus, damage to the cable's structure is prevented.

The pulling device can often include a vehicle that has a pulling strength far greater than can be withstood by the cable 14 and even, at times, the carrier Thus, the clamping member 38 is configured to fail when a predetermined force is applied to the clamping member 38 by the pulling device. In particular, the body member 40 is configured to define a zone of weakness, indicated by dotted lines 62 in figure 3. Thus, at the predetermined force, the clamping member 38 breaks away from the channel member 12. This serves to protect both the cable 14 and the channel member 12.

In figures 7 to 12, reference numeral 70 generally indicates a second embodiment of a carrier for cables, in accordance with the invention. With reference to figures 1 to 6, like reference numerals refer to like parts, unless otherwise specified.

The carrier 70 also includes a retaining member 72 that is fast with the channel member 12.

The retaining member 72 includes a pair of spaced legs 74 that are attached to the channel member 12. A pair of spaced reinforcing ribs 76 extends from the legs 75 and is fixed to the wall 18.1 and the floor portion 16 of the channel member 12.

A mounting formation 78 extends between the reinforcing ribs 76 to brace the retaining member 72 against deformation and to provide a mounting location for the connector 38.

The mounting formation 78 has a pair of opposed lugs 80 that define a pair of opposed, aligned pivot openings 82 that are complementary to the pivot opening 44 of the body member 40. Thus, the connector 38 is pivotally connected to the mounting formation 78 with a pivot pin 84 that extends through the openings 82, 44.

The legs 74 are bridged with a guide plate 86 that defines a guide opening 88. The guide plate 86 is positioned so that a line from the guide opening 88 to a peripheral line 92 of maximum depth of the channel member 12 is substantially orthogonal to said line of maximum depth. Thus, a force vector exerted by a strap or rope of the pulling device is co-linear with an opposed force vector exerted by the cable 14. This serves to minimize any unbalanced forces acting on the carrier in use.

In figures 11 and 12, the planar body member 40 of the connector 38 defines a narrowed portion 90 at the extremity 42.2. This demarcates the zone of weakness 62 to ensure that the body member 40 fails at the zone 62, as described above.

An important feature of both carriers 10, 70 is that the lip 28 on each end of the channel member 12 is defined by a reverse radius. This permits angular displacement of the cable 14 relative to the channel member 12 without the buildup of stress concentrations at the intersection of the channel member 12 and the cable 14.

It will be appreciated that the carrier 10, 70 can have many different dimensional combinations depending on the type of cable used. The description 9 and drawings have, for the purposes of convenience, been limited to two particular configurations. It is to be understood, however, that the principles and advantages of all possible configurations are embodied in the described examples.

Applicant believes that the invention provides a means whereby a cable can be carried and handled both conveniently and safely. Most importantly, the Applicant believes that the carrier 10, 70 provides a means whereby the cable 14 is supported entirely along a bent portion so that stress concentrations are avoided.

This serves to lengthen the life of the cable significantly, therefore reducing the risk of failure and resultant expensive downtime.

Claims

1. A carrier for cables, the carrier comprising an arcuate channel member that is shaped to accommodate a cable; a connecting arrangement that is attached to the channel member at a position intermediate ends of the channel member to permit a pulling device to be connected to the channel member; and a releasable holding device that is mounted on the channel member to hold the cable on the channel member.

2. A carrier as claimed in claim 1, in which the releasable holding device forms part of the connecting arrangement so that, when the pulling device acts on the connecting arrangement, the holding device is operable to hold the cable.

3. A carrier as claimed in claim 2, in which the connecting arrangement includes a connector that is pivotally mounted on the channel member and the holding device is in the form of a clamping member that is fast with the connector, the connector and the clamping member being configured so that a pulling device can be connected to the connector to pull the connector and thus the channel member in a first direction and so that a force applied to the connector in said first direction results in the clamping member being pivoted towards the channel member.

4. A carrier as claimed in claim 2 or 3, in which the connector has a first extremity that is pivotally attached to the channel member, a second extremity that is connectable to the pulling device and a third extremity that is fast with the clamping member, such that the clamping member and the mounting formation define a first class lever.

A carrier as claimed in claim 4, in which the connector defines a zone of weakness that is configured to fail when a predetermined load is applied to the connector.

6. A carrier as claimed in any one of the preceding claims in which the channel member has an arcuate transverse profile to accommodate the cable and to define a floor with a peripheral line of maximum depth.

7. A carrier as claimed in claim 6, which includes a retaining member that is fast with the channel member, the retaining member being configured to engage the pulling device so that the pulling device is restrained from excessive lateral movement.

8. A carrier as claimed in claim 7, in which the retaining member is shaped to define a guide opening that is spaced from the channel member and substantially aligned with the peripheral line of maximum depth, the pulling device including a rope that is received through the guide opening so that a force applied to the channel member is substantially orthogonal to said line of maximum depth.

9. A carrier as claimed in any one of the preceding claims, in which end portions of the channel member each define an inwardly directed lip to accommodate angular movement the cable.

A carrier as claimed in any one of the preceding claims, which includes a bracing structure that is connected to the channel member and spans an area included by the channel member to brace the channel member.

11. A new carrier for cables, substantially as described herein, with reference to the accompanying drawings.

12 Dated this 2 1 't day of May 2003 By my patent attorneys Eagar Newcomb Buck