GB2307756A

GB2307756A - Drill alignment device using light beam

Info

Publication number: GB2307756A
Application number: GB9524295A
Authority: GB
Inventors: Daniel Bone
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 1995-11-28
Filing date: 1995-11-28
Publication date: 1997-06-04
Anticipated expiration: 2015-11-28
Also published as: GB2307756B; GB9524295D0

Abstract

A device 1 for aligning a drill bit 9 perpendicular to a workpiece (35 figure 2) has a light source 21 and a target 25. The light source 21 is held on a mount 15 pivotally connected to the end of a rod 11 which is slidably received by a support 3 attached to the drill body 7. The mount 15 has feet 19 which are pressed against the workpiece and the drill 7 body is orientated so that the light source 21 is aligned with the bulls-eye 29 of the target 25.

Description

AN ALIGNMENT DEUCE This invention relates to alignment devices, and in particular to a device for facilitating correct alignment of a drill bit upon entry into a workpiece.

When using a power drill to drill into a workpiece, it is not always clear to the user of the drill whether or not the drill bit is normal (ie perpendicular) to the workpiece surface. Hence, holes are sometimes produced at an angle to a workpiece surface, which is undesirable. It is therefore known to use alignment mechanism to assist a user during drilling of a workpiece.

One known prior art alignment mechanism comprises a rod carried by a drill with a ball mounted on the end of the rod. The ball is received in a cup which sits on the surface of a vW orkpiece during use. The surface of the ball which is received in the cup is coloured very brightly, whereas the surface of the ball which is not received in the cup when the drill bit is normal to the workpiece is not brightly coloured. Hence, if the drill bit is not normal to the workpiece surface, in use, a portion of the brightly coloured surface of the ball is exposed. It is, therefore, clear to the user of the drill that the drill bit is not correctly aligned.

In a second known prior art alignment device. a rod attached to a drill body carries a foot at its free end for abutting a workpiece surface. The foot carries a pointer which, when the rod is perpendicular to the workpiece surface, is spaced from and parallel to the rod. The pointer is free to move in a cavity carried bs the rod, which cavity has a transparent target through which the pomter can be viewed. When the drill bit is normal to the workpiece surface, the pointer is positioned in the centre of the target. If the drill bit is not normal to the workpiece surface, the pointer lies behind an area of the target spaced from the centre of the target. Hence, a user of the drill can see that the drill bit is not correctly aligned.

In both of the prior art embodiments described above, it is necessary for a user of a drill to glean information from an alignment mechanism which is situated adjacent a workpiece being drilled.

This may entail peering around the drill body and may prove difficult if a significant amount of dust and debris is being produced during drilling. Further, due to the short distance in each case behx een the tuo components which are moved relative to each other to indicate misalignment, a very coarse alignment device is provided. Hence, the present invention aims to improve upon the prior art alignment devices known to date.

With the foregoing in mind, the present invention provides a device for facilitating correct alignment of a drill bit upon entry into a workpiece, comprising a support for attachment to a drill carrying the drill bit, a rod slideably received by the support, a mount pit totally attached to the end of the rod spaced from the dnll. a source of a collimated beam of radiation and a target, the collimated beam of radiation passing between the mount and the support to strike the target, wherein, in use, the mount is placed against a workpiece and the drill bit is correctly orientated relative to the workpiece when the collimated beam of radiation is aligned with the target.

By separating the source of the collimated beam from the target in this way, a significant improvement in accuracy is provided.

Preferably the source of radiation is carried by the mount and the target is carried by the support. In such an arrangement, the target is very close to the user of the drill and can be readily viewed.

If, however, the target were carried by the mount and the radiation source were carried by the support, an improvement m the accuracv of the alignment device would still be achieved but the advantage of having the target closer to the user would not be provided.

The source of radiation is preferably a light source. However, in theory, some other form of radiation could alternatively be used.

Preferably the target includes a translucent area. The translucent area may be etched glass or any other appropriate target material which allows the position of the beam to be ascertained by a user of the drill.

In a preferred embodiment, the mount includes three feet and the source of radiation is carried by one of the feet.

The mount is preferably pivotally attached to the rod in such a way that the mount can pivot relative to the rod without rotating relative to the rod. As a result, the source of radiation will always be corrected positioned relative to the target.

The mount is preferably attached to the rod by means of a rubber block or other appropriate connection.

The support may act as a remote depth-stop for the drill bit. Further, the rod may carry a scale to assist in determining the depth that the drill bit is to enter a workpiece.

Although the target will preferably include a bullseye, other gradation lines or target indicators may also be incorporated on the target, if appropriate.

The rod is preferably biased away from the support by means of a spring carried by the support. More preferabln, a helical spring is provided within the support which bears against the end of the rod.

A specific embodiment of the present invention is now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a drill bit alignment device according to the present invention; and Figure 2 is a side view of the alignment device which, in solid lines, is shown perpendicular to a workpiece surface and, in phantom lines, is shown angled relative to the workpiece surface.

As shown in the drawings, a drill bit alignment device 1 comprises a support 3 which can be bolted or screwed by a fastener 5 to a drill body 7 carrying a drill bit 9. The support 3 may be a conventional depth-stop device, or may be used as such a device without the remainder of the alignment device of this invention.

A rod 11 is slideably received in the support 3 and is biased awao from the support 3 by means of a helical spring 13, which is shown in figure 2. The end of the rod 11 spaced from the support 3 carries a mount 15 via a pivotal connector, here block connector 17. The mount 15 has three feet 19, for stability on worksurfaces, one of which carries a light source 21 for producing a collimated beam 23.

The mount 15 is able to pivot relative to the rod 11, but cannot rotate to any significant degree about the rod 11. Hence, the light beam 7 when travelling parallel to the rod 11, will always strike a target 25 carried by the support 3.

The target 25 is fixed relative to the support 3 and provides an etched glass area 27 upon which a bulls-eye 29 and other gradation lines 31 are marked.

During use, a user 33 may view the target 25 with relative ease, because the target 25 is adjacent the drill 7 and spaced from the workpiece 35. If the drill bit 9 is perpendicular to the workpiece surface, the light beam 23 will strike the bulls-eye 29 of the target 25. Drilling of the workpiece can then commence. If, howes er, the light beam 23 is not perfectly aligned with the bulls-eye 29, the drill 7 can be moved until alignment is achieved. Incorrect drilling of the workpiece can thereby be avoided.

As shown in figure 2, if the drill bit 9 is badly mis-aligned, the light beam 23 will miss the target 25 altogether. This should, of course, be obvious to the user of the drill 7 and result in significant realignment before drilling.

The rod 11 includes a scale 37 which can be used to indicate the depth that the drill bit 9 enters the workpiece 35. More particularly by adjusting the position of the drill bit 9 in the chuck 39 of the drill 7 and/or the positions of the target 25 and/or the support 3 until the length of the drill bit 9 extending below the target 25 is correct control of the depth of drilling can be determined. This is the case because the drill bit 9 cannot enter the workpiece 35 any further once the target 25 has come to a stop against the light source 21 on the foot 19 of the mount 15. Hence, the target 25 acts as a depth-stop for the drill.

It will of course be understood that the present invention has been described above purely by way of example, and that modifications of detail can be made within the scope of the invention.

Claims

1 A device for facilitating correct alignment of a dnll bit upon entry into a workpiece, comprising a support for attachment to a drill carrying the drill bit, a rod slideably received by the support, a mount pivotally attached to the end of the rod spaced from the drill, a source of a collimated beam of radiation and a target, the collimated beam of radiation passing between the mount and the support to strike the target, wherein, m use the mount is placed against a workpiece and the drill bit is correctly onentated relative to the workpiece when the collimated beam of radiation Is aligned with the target.

2 A device as claimed in claim 1, wherein the source of radiation is carried by the mount and the target is carried by the support.

3 A device as claimed in claim 1 or claim 2 wherein the source of radiation is a light source.

4 A device as claimed in any preceding claim, wherein the target includes a translucent area.

5 A device as claimed in claim 4, wherein the translucent area is etched glass.

6 A device as claimed in any preceding claim, wherein the mount includes three feet, the source of radiation being carried by one of the feet.

7 A device as claimed in any preceding claim, wherein the mount is pivotally attached to the rod by means of a rubber connection.

8 A device as claimed in any preceding claim, wherein the support acts as a depth-stop for the drilling bit.

9 A device as claimed in any preceding claim, wherein the rod carries a scale to assist in determining the depth that the drill bit enters the workpiece, in use.

10 A device as claimed in any preceding claim, wherein the rod is biased away from the support by means of a spring carried by the support.

11 A device as claimed in any preceding claim, wherein the rod is biased away from the support by means of a spring carried by the support.

12 A device as claimed in claim 11, wherein the spring is mounted within the support and bears against an end ofthe rod.

13 A device for facilitating correct alignment of a drill bit upon entry into a workpiece, substantially as hereinbefore described with reference to and shown in accompanying drawings.