FIELD OF INVENTION

This invention relates to a calibration device for calibrating the dimensions of an object such as for example, the thickness or diameter of an overhead powerline.

SUMMARY OF THE INVENTION

According to the invention there is provided a calibration device for calibrating the dimensions of an object which includes:- a pair of lasers which are capable of projecting beams of light onto an object at least five (5) metres away; and

a support member which is configured to support the lasers such that, in use, the beams are projected in a substantially parallel, spaced apart relationship relative to each other.

It shall be appreciated that the object to be calibrated may include but is not limited to a conventional overhead powerline.

The lasers may be in the form of any conventional laser which is capable of projecting a beam of light onto an object located between 5 and 30 metres away there-from. The support member may include a mounting means to allow a camera to be mounted thereon so as to permit a photograph to be taken of the beams of light projected onto the object in use.

An adjustment means may be provided to enable the spacing between the lasers to be varied according to a user's requirements. The adjustment means may also include height adjustment means to allow the height of the lasers to be adjusted relative to the support member to a position wherein, a centre of a camera lens and the lasers are in substantially the same plane or are in alignment with each other. The support member may include a mounting means to allow the support member to be mounted on a conventional camera tripod.

The calibration device may include an energising means for energising the lasers. The energising means may be in the form of a battery.

The support member may be configured to allow the battery to be mounted thereon.

The calibration device may include a switch located on the support member, which switch may be arranged in electrical communication with the battery.

The calibration device may include a calculating means for calculating dimensions, typically the thickness or diameter, of an object such as an overhead powerline on which the beams of light are projected by the lasers. The calculating means preferably is in the form of any conventional computer program which is capable of plotting the distance between the laser beams projected onto the object and the thickness of the object, and thereafter using simple proportion to calculate the thickness of the object based on the fact that distance between the lasers is know or fixed. More particularly, the plotting may be effected using a photograph taken by the camera, which photograph has the laser projections thereon.

A protective cover may be provided to cover the lasers and/or adjustment means.

BRIEF DESCRIPTION OF THE DRAWINGS

A calibration device for calibrating the dimensions of an object such as an overhead electrical power-line in accordance with the invention will now be described by way of example with reference to the accompanying drawings.

In the drawings:-

Figure 1 is a schematic front view of a calibration device in accordance with the invention;

Figure 2 is an operative schematic plan view of a calibration device shown in figure 1 ;

Figure 3 is a schematic view taken along lines 3-3 in figure 2; and

Figure 4 is a schematic front view of a second embodiment of a calibration device of the invention.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

Referring now to figures 1 to 3, reference numeral 10 generally depicts a calibration device for calibrating the dimensions of an object such as an overhead powerline 12 in accordance with the invention.

The calibration device 10 includes a pair of lasers 14 which are capable of projecting beams of light 16 onto the powerline 12, located typically in the region of 5 to 30 metres away, and a support member 17 which is configured to support the lasers 14 in a substantially parallel, spaced apart relationship relative to each other.

The support member 17 includes a generally rectangular base 18 which is dimensioned to allow a camera 20 to be mounted thereon between the lasers 14 so as to permit a photograph 21 (figure 3) to be taken of the beams of light 16 projected onto the powerline 12 in use.

More particularly, the lasers 14 are mounted on adjustment means in the form of adjustment members 22. The adjustment members 22 are configured so as to be displaceable relative to the base 18 to enable the spacing between the lasers 14 to be varied according to a user's requirements, and which is typically in the region of 80 millimetres.

The adjustment members 22 further includes a height adjustment means (not shown) to allow the height of the lasers 4 to be adjusted relative to the base 18 to a position wherein a centre of a camera lens 24 of the camera 20 and the lasers 14 are in substantially the same plane and in alignment with each other. The camera 20 may be mounted onto the base 18 via a conventional camera retaining arrangement 28 in the form of a screw 30 and a complementary aperture 32 arrangement in the base 18. A protective cover 26 is arranged to extend and cover each of the lasers 14 and the respective adjustment member 22. The base 18 has a mounting means (not shown) to allow it to be displaceably secured to a conventional camera tripod (not shown) to facilitate the aiming of the laser beams 14 onto the powerline 12 in use.

An energising means (not shown) is provided in the form of batteries (not shown) for energising the lasers 12. A switch 33 is located on base 18 and is arranged in electrical communication with the batteries. The switch 33 is configured to energise and de-energise the lasers 14, in use.

The calibration device 10 includes a calculating means (not shown) for calibrating the thickness 32 of the powerline 12. The calculating means is in the form of any conventional computer program which is capable of first plotting the distance between laser points 34 (figure 2 and 3) projected on to the powerline 12 and the thickness thereof 32, simple proportion being used thereafter to calculate the actual dimensions of the thickness of the power line 12 based on the fact that distance between the lasers 14 is know or fixed.

In use, the adjustment member 22 is orientated by a user such that the height of the lasers 14 and/or the spacing between the lasers 14 is varied according to a user's requirements. In particular, the height of the lasers 14 is adjusted relative to the base 18 to a position wherein the centre of the camera lens 24 and the lasers 14 are substantially in alignment and in the same plane relative to each other. The lasers 14 are then energised by the user to project the beams 16 onto the line 12, typically located between 5 to 30 metres from the device 10. The user then takes a photograph 21 of the laser points 34 projected on the powerline 12. Calculation of the thickness or diameter 32 is then effected using the photograph 21 captured by the camera 20. In particular, a rectangular block 42 is digitally sized to overlay the photograph 21 so that the block/s 42 boundaries are defined by the laser points 34 and the diameter of the power line 12. Thereafter, the thickness 32 is calculated in simple proportion using the known distance between the lines 16.

Figure 4 shows a further embodiment of a calibration device 1 10 wherein the camera 20 is arranged to one side of the lasers 14 in the base 18.

The inventor is of the opinion that a calibration device of the invention is advantageous in that it provides for a cost effective safe and remotely calculatable alternative to conventional methods for calibrating a thickness of an overhead powerline 12.

The inventor believes that the invention is of further advantage in that images and/or data generated by the calibration device 10 may be stored for future retrieval or reference.

It is of course to be appreciated that a calibration device 10 in accordance with the invention is not limited to the precise diameters of overhead powerline constructional and functional details as set out hereinabove.

Although only certain embodiments of the invention have been described herein, it will be understood by any person skilled in the art that other modifications, variations, and possibilities of the invention are possible. Such modifications, variations and possibilities are therefore to be considered as falling within the spirit and scope of the invention and hence forming part of the invention as herein described and/or exemplified.

It shall further be understood that the examples are provided for illustrating the invention further and to assist a person skilled in the art with understanding the invention and is not meant to be construed as unduly limiting the reasonable scope of the invention.