WO2009044089A1

WO2009044089A1 - Improvements in and relating to tools

Info

Publication number: WO2009044089A1
Application number: PCT/GB2007/004477
Authority: WO
Inventors: Gordon Mcwilliam
Original assignee: Neill Tools Limited
Priority date: 2007-10-03
Filing date: 2007-11-22
Publication date: 2009-04-09
Also published as: GB2453398A; GB0719262D0; GB0804353D0; WO2009044091A1

Abstract

A hand saw comprises a planar saw blade (12) and a handle (14) and further comprises illumination means (18) mounted on the handle (14). The illumination means (18) comprises a lighting unit including a light source and a lens system. The lens system is arranged to produce a planar light beam which is emitted from the heel (20) of the saw. The planar light beam is divergent and is arranged, in use, to project an illuminated line onto a material which indicates the cutting plane of the hand saw. Accordingly, a user is able to quickly ascertain the cutting angle of the saw blade by pushing an actuating member (24) to provide the illuminated indicator showing the cutting plane/angle.

Description

IMPROVEMENTS IN AND RELATING TO TOOLS

Field of the Invention

The present invention relates to improvements in and relating to saws and, specifically, to hand saws. More particularly, the present invention relates to providing indication means to indicate the direction and/or plane of the cutting direction or plane of a hand saw and to providing a method of indicating the cutting direction or plane of a handsaw.

Background to the Invention

Once a saw has commenced a cut within a material (for example, a workpiece) it can be difficult to change the direction of a cut due to the resistance to movement and restraint of the saw blade within the existing cut. Accordingly, it is important to commence the cut with a hand saw at the correct angle and in the correct plane.

A cut with a hand saw is generally commenced by creating a small incision or nick on an edge of the material. Generally, the commencement edge is located spaced from the user. The saw blade edge is laterally retained within the cut such that the saw blade cannot move out of the initial incision or nick. The hand saw then needs to be orientated such that the subsequent cuts will be in the correct and in the required direction and plane. This is of particular importance at the start of a relatively long cut since such a small initial error will gradually increase in magnitude the further the cut is further away from the initial misdirected cut. For example, the initial error is an angular error and the distance

(displacement) that the cut is from the required cut will increase as the distance from the incorrect starting incision increases.

At present, workmen may draw a line (e.g a guide line) on the surface of the material and attempt to follow the line using skill and judgement. It is a relatively skilled action to achieve an accurate cut. Such an accurate cut may be important and critical in certain circumstances. If an incorrect cut is achieved or performed then the material may be wasted and this increases both the time and expense of the work.

In some circumstances, it may not be possible to draw a guide line on the surface of the material, for example, the surface may have an irregular shape (e.g. as with cornices, coving etc), the surface may be decorative or the surface may be otherwise unsuitable for a guide line to be drawn on the surface. In these situations, a workman may mark a beginning point and an end point and then attempt to imagine the line between these points in order to attempt to visualise the position of the guide line. This is difficult and frequently leads to inaccurate cuts.

Furthermore, guide markings on the surface of the material may become visually obscured as the cut progresses due to the debris and contaminants created by the cut (e.g. sawdust). In addition, if the surface is tacky or is in the presence of moisture, then the debris (e.g. sawdust) may adhere to the material and it is not possible to simply blow the debris away in order for the guideline to be visible. Similarly, when cutting wood, resin may be present and this may adhere any contaminants (e.g. sawdust) which will obscure the visibility of the guideline.

The alignment of a saw when cutting non-perpendicularly along a material or work piece can be more difficult due to the ergonomics of the position of the user and/or the hand saw. In addition, when following guidelines there may be a tendency for the user to hold the saw such that the saw is towards a vertical position rather than in a substantially horizontal position and this can make the sawing action difficult and uncomfortable for a user.

Power saws as other power tools are frequently used. However, such power tools may be static and may require the workpiece to be moved to the location of the power tool rather than moving the tool to the workpiece. This can be inconvenient and impossible in some circumstances. Accordingly, manually powered tools, for example hand saws are still required and are necessary as a result of the variety of situations and circumstances in which they can be used. In addition, hand tools are not limited by the provision of a power source. Furthermore, power tools can be expensive.

It is an aim of the present invention to overcome at least one problem associated with the prior art whether referred to herein or otherwise.

Summary of the Invention

According to a first aspect of the present invention there is provided a hand saw comprising indication means which is arranged, in use, to indicate the cutting plane of the hand saw wherein the indication means comprises illumination means providing an illuminated indicator of the cutting plane which is projected on to a surface of a material to be cut.

Preferably the indication means provides an illuminated indicator of the plane of the saw blade and in particular illuminates the part of the material which lies in the plane of the saw blade and more preferably illuminates the part of the material which lies in a plane coincident with the plane of the saw blade and is also directly exposed to light from the illumination means.

Preferably the hand saw comprises a handle and a planar saw blade.

Preferably the material comprises a workpiece.

Preferably the illumination means comprises a lighting unit comprising a light source and a lens system.

Preferably the light source is a laser light source.

The light source may comprise a light emitting diode. -A-

The light source may comprise a laser diode.

Preferably the lens system is arranged to produce a planar light beam.

Preferably the illuminated indicator comprises a linear illuminated indicator.

Preferably the planar light beam is arranged to be coincident with the plane of the saw blade.

Preferably the illumination means and; in particular, preferably the lighting unit is permanently and/or fixably mounted to the handle.

Preferably the illumination means (and, in particular, preferably the lighting unit) is not moveable relative to the handsaw and/or saw blade and/or the handle. Accordingly, once mounted, the plane of the light beam projected from the lighting unit may not need to be adjusted relative to the plane of the saw blade.

Preferably the illumination means is arranged to project a planar light beam from a heel of the hand saw towards a toe of the hand saw.

Preferably the illumination means is arranged to project a substantially divergent planar light beam. Preferably the divergent light beam extends in a plane between a first direction and a second direction. Preferably the first direction is substantially parallel to a direction of a cutting edge of the saw blade.

Preferably the first direction is substantially parallel to, but spaced from, a direction of a cutting edge of the saw blade.

The illumination means may be arranged to project a divergent planar light beam having an angle of divergence greater than 22.5° and preferably having an angle of divergence greater than 45° and more preferably having an angle of divergence of substantially 60°. Preferably the illumination means may be arranged to direct a planar divergent light beam having an angle of divergence of less than 90° and more preferably less than 80°.

Preferably the saw blade is flexible.

Preferably the saw comprises a planar saw blade.

Preferably the illumination means is arranged to provide an illuminated line on a surface of a material to be cut. The width of the line maybe less than 5 mm and preferably the width of the illuminated line is less than 3 mm and more preferably the width of the illuminated line is substantially 1 mm.

Preferably the illumination means is arranged to provide a colored line on a surface of a material to be cut.

The indication means may comprise actuation means which is arranged to selectively actuate the illumination means. The actuating means may comprise an actuating member. The actuating member may comprise a trigger and preferably comprises a digit (finger or thumb) operated trigger or button. The actuating member may comprise a button and preferably comprises a push button. The push button may be arranged, in use, to be activated by a digit (e.g. a thumb or finger) of the user. The actuating member may be mounted on an upper surface of the handle of the hand saw.

Preferably the actuation means comprises bias means which is arranged to bias the actuating member in a non-operative position. Preferably the bias means comprises urging means to urge the actuating member towards a non-operative position. Preferably the actuating member is arranged to be manually moved from a non-operative position (in which power is not supplied to the light source) to an operative position (in which power is supplied to the light source). Preferably the actuating member is arranged to move from an operative position to a non-operative position by bias means.

Preferably the indication means comprises power means. Preferably the power means is arranged to supply power to the illumination means. The power means may be located in the handle of the hand saw. The power means may comprise a battery or a plurality of batteries.

According to a second aspect of the present invention there is provided a method of indicating the cutting plane of a hand saw comprising operating illuminating means mounted to the hand saw in order to project an illuminated indicator of the cutting plane on to a surface of a material to be cut.

The method may comprise indicating a non-perpendicular cut on the material.

The method may comprise providing an illuminated line indicating the cutting line on the material of the saw.

The method may comprise providing an illuminated indicator on a first surface and a second surface of a material to be cut. The first surface may be substantially perpendicular to the second surface.

The method may comprise pushing an actuating member in order to provide the illuminated indicator.

The method may comprise providing bias means in order to urge the actuating member from an operative position to a non-operative position.

The method may comprise substantially releasing the hand saw whilst operating the actuating member. Brief Description of the Drawings

For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which:

Figure 1 is a side view of a preferred embodiment of a hand saw.

Figure 2 is a perspective view of part of a workpiece including a cutting guide line.

Figure 3 is a perspective view of part of a preferred embodiment of a hand saw in which the illuminated indicator demonstrates that the hand saw is not correctly aligned.

Figure 4 is a perspective view of a part of a preferred embodiment of a hand saw in which the illuminated indicator demonstrates that the hand saw is correctly aligned.

Figure 5 is a perspective view of a part of a preferred embodiment of a hand saw approximately mid-way through a cut in which the illuminated indicator demonstrates that the hand saw is not correctly aligned.

Figure 6 is a perspective schematic view of a example of a cutting plane in a workpiece.

Figure 7 is a perspective schematic view of another example of a cutting plane in a workpiece.

Description of the Preferred Embodiments

There will now be described by way of example only a specific mode contemplated by the inventors. In the following description numerous specific details are set forth in order to provide a thorough understanding. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the description.

As shown in figure 1 , a hand saw 10 comprises a planar saw blade 12 and a handle 14. The saw blade 12 extends in a single plane from an upper edge 15 to a lower cutting edge 16. The cutting edge 16 comprises a series of cutting teeth.

The saw blade 12 comprises a metal and is flexible laterally. The saw blade 12 extends from a heel 20 to a toe 22 in a longitudinal direction and the saw blade 12 has two planar faces.

The hand saw 10 includes illumination means 18 mounted on the handle 14 thereof. The illumination means 18 comprise a lighting unit including a light source and a lens system. The light source comprises a laser which is arranged to produce a single beam. The lens system is arranged to produce a planar light beam which is emitted from the heel 20 of the saw 10 to the toe 22.

The planar light beam is divergent. The angle of divergence, θ, may be substantially 45° to 60° such that the full angle of the illumination of the planar light beam is between 90° and 120°. However, further suitable angles of divergence can be used in order to generate suitable lengths of linear illuminator indicator.

The illumination means includes actuating means comprising an actuating member 24. The actuating member 24 comprises biasing means to urge the actuating member 24 from an operative position to a non-operative position.

Accordingly, the illumination means 18 is normally in a default position such that no illumination is provided. When a user pushes the actuating member 24 then the illumination means provides an illuminated linear light on the material to be cut where the cutting plane of the saw blade is coincident with the surface of the material to be cut.

The hand saw 10 includes power means including a power supply in order to provide power to the light source. In particular, the power supply may comprise one or more batteries.

The light emitting unit is permanently and fixably mounted to the handle 14 such that the planar light beam is coincident with the plane of saw blade 12. The light emitting unit is arranged to be mounted and calibrated during manufacture such that the subsequent user does not have to align the light source. In addition, the fixed mounting prevents or inhibits the light emitting unit from moving relative to the plane of the saw blade 12 during use.

The planar light beam extends between a first direction 26 and a second direction 28. The first direction 26 is arranged to be substantially parallel to the cutting edge 16 of the saw blade 12. In addition, the first direction 26 is spaced slightly from the cutting edge 16 of the saw blade 12. As shown in figure 1 , the second direction 28 extends rearwardly relative to the hand saw although this is dependent upon the angle of divergence of the planar light beam.

In use, the user initially creates a small cut or incision or nick 34 in an edge 32 of a workpiece 30, as shown in figure 2. The workpiece 30 has a guideline 36 which is manually drawn onto the surface or the surfaces 35, 37 of the workpiece by the user. Normally, a user would then simply attempt to manually move the plane of the saw blade in order to try progress the cut along the guideline 36. However, as previously discussed, it can be difficult to obtain and maintain an accurate cut.

In the present invention, the cutting edge 16 of the saw blade 12 is inserted into the initial cut 34 such that the saw blade 16 is retained laterally relative to the workpiece 30. As shown in figure 3, the user then operates the actuating member 24 to provide an illuminated line 40 which indicates the location of the cut that would be achieved from that particular orientation of the saw blade 12. The saw 10 can then be manually moved to the correct position such that the illuminated indicator line 40 is coincident with the guideline 36, as shown in figure 4. The user can then release the actuating member and commence sawing. Since the user is confident that the correct orientation of the saw 10 has been achieved, the user is able to initially be relatively aggressive in the sawing action.

The user can then check the progress of the cut by simply stopping the sawing action and operating the actuating member 24 to provide an illuminated line, as shown in figure 5. At this position, it is important and beneficial that the user does not manually flex the saw blade 12 within the cut since this would provide inaccurate feedback of the orientation plane of the saw blade 12 of the position of the intended cut.

The user can continue to illuminate and monitor the cut as the cut progresses and the user can take any action that may be required to realign the actual cut with the required position of cut.

As shown in figures 3 to 5, the illuminated indicator line is provided on at least two surfaces 35, 37 of the work piece 30 and, in particular, the illuminated line 40 is displayed on an upper surface 35 and a facing surface 37 of the workpiece 30. This extended illuminate line 40 is provided due to the angle of divergence of the planar light beam.

Since the illuminated line 40 is provided on a facing surface 37 of the workpiece 30, the angle (φ) of the cutting edge 16 of the saw blade 12 can be kept relatively shallow in order to provide a better cutting position. This shallow angle φ provides a more ergonomically beneficial position for the user and enables the user to use the larger appropriate muscles of the upper trunk rather than the lower arm. Whilst the preferred embodiment has been described above in relation to a perpendicular cut on a rectangular workpiece 30, the present invention is particularly useful in aligning a hand saw for irregular cuts and, in particular, cuts which do not have any perpendicular angles to the surface of the work, for example as shown in figure 6. In this example, the plane of the cut is at a lateral angle α to the workpiece 30 and a vertical angle β. In this example, neither the angle α to the upper surface 35 or angle β to the facing surface 35 are perpendicular.

In some circumstances, it is sometimes required to cut a relatively planar slice 30 from an end of the workpiece 30 as shown in figure 7. This can be particularly difficult since when the saw blade 12 starts drifting from the guide line it can be difficult to re-align the saw blade. In particular, a part of the planar slice may fracture the workpiece 30 whilst attempting to realign the saw blade 12. Accordingly, the present invention provides a particular benefit in this situation.

Claims

Claims:

1. A hand saw comprising indication means which is arranged, in use, to indicate the cutting plane of the hand saw wherein the indication means

5 comprises illumination means providing an illuminated indicator of the cutting plane which is projected on to a surface of a material to be cut.

2. A hand saw according to claim 1 in which the indication means provides an illuminated indicator of the plane of the saw blade and illuminates the o part of the material which lies in the plane of the saw blade.

3. A hand saw according to claim 2 in which the indication means provides an illuminated indicator of the plane of the saw blade and illuminates the part of the material which lies in a plane coincident with the plane of the saw5 blade and is also directly exposed to light from the illumination means.

4. A hand saw according to any preceding claim in which the hand saw comprises a handle and a planar saw blade.

0 5. A hand saw according to any preceding claim in which the material comprises a workpiece.

6. A hand saw according to any preceding claim in which the illumination means comprises a lighting unit comprising a light source and a lens5 system.

7. A hand saw according to claim 6 in which the light source is a laser light source.

0 8. A hand saw according to claim 6 or claim 7 in which the light source comprises a light emitting diode.

9. A hand saw according to any one of claim 6 to claim 8 in which the light source comprises a laser diode.

10. A hand saw according to any one of claim 6 to claim 9 in which the lens system is arranged to produce a planar light beam.

11. A hand saw according to any preceding claim in which the illuminated indicator comprises a linear illuminated indicator.

12. A hand saw according to claim 11 when dependent upon claim 10 in which the planar light beam is arranged to be coincident with the plane of the saw blade.

13. A hand saw according to any preceding claim in which the illumination means is permanently mounted to the handle.

14. A hand saw according to any preceding claim in which the illumination means is not moveable relative to the handsaw and/or saw blade and/or the handle.

15. A hand saw according to any preceding claim in which the illumination means is arranged to project a planar light beam from a heel of the hand saw towards a toe of the hand saw.

16. A hand saw according to any preceding claim in which the illumination means is arranged to project a substantially divergent planar light beam.

17. A hand saw according to claim 16 in which the divergent light beam extends in a plane between a first direction and a second direction.

18. A hand saw according to claim 17 in which the first direction is substantially parallel to a direction of a cutting edge of the saw blade.

19. A hand saw according to claim 17 or claim 18 in which the first direction is substantially parallel to, but spaced from, a direction of a cutting edge of the saw blade.

20. A hand saw according to any one of claim 16 to claim 19 in which the illumination means is arranged to project a divergent planar light beam having an angle of divergence greater than 22.5°.

21. A hand saw according to any preceding claim in which the saw blade is flexible.

22. A hand saw according to any preceding claim in which the illumination means is arranged to provide an illuminated line on a surface of a material to be cut.

23. A hand saw according to any preceding claim in which the indication means comprises actuation means which is arranged to selectively actuate the illumination means.

24. A hand saw according to claim 23 in which the actuating means comprises an actuating member.

25. A hand saw according to claim 24 in which the actuating member comprises a digit (finger or thumb) operated button.

26. A hand saw according to any one of claim 24 to claim 25 in which the actuation means comprises bias means which is arranged to bias the actuating member in a non-operative position.

27. A hand saw according to claim 26 in which the bias means comprises urging means to urge the actuating member towards a non-operative position.

28. A hand saw according to any one of claim 24 to claim 27 in which the actuating member is arranged to be manually moved from a non-operative position (in which power is not supplied to the light source) to an operative position (in which power is supplied to the light source).

29. A hand saw according to any preceding claim in which the indication means comprises power means.

30. A hand saw substantially as herein described with reference to, and as shown in, any of the accompanying drawings.

31. A method of indicating the cutting plane of a hand saw comprising operating illuminating means mounted to the hand saw in order to project an illuminated indicator of the cutting plane on to a surface of a material to be cut.

32. A method of indicating the cutting plane of a hand saw according to claim 31 in which the method comprises indicating a non-perpendicular cut on the material.

33. A method of indicating the cutting plane of a hand saw according to claim 31 or claim 32 in which the method comprises providing an illuminated line indicating the cutting line on the material of the saw.

34. A method of indicating the cutting plane of a hand saw according to any one of claim 31 to claim 33 in which the method comprises providing an illuminated indicator on a first surface and a second surface of a material to be cut.

35. A method of indicating the cutting plane of a hand saw according to claim 34 in which the first surface is substantially perpendicular to the second surface.

36. A method of indicating the cutting plane of a hand saw according to any one of claim 31 to claim 35 in which the method comprises pushing an actuating member in order to provide the illuminated indicator.

37. A method of indicating the cutting plane of a hand saw according to claim 36 in which the method comprises providing bias means in order to urge the actuating member from an operative position to a non-operative position.

38. A method of indicating the cutting plane of a hand saw according to claim 36 or claim 37 in which the method comprises substantially releasing the hand saw whilst operating the actuating member.

39. A method of indicating the cutting plane of a hand saw substantially as herein described with reference to, and as shown in, any of the accompanying drawings.