GB2431983A

GB2431983A - Hand tool with angled spotlight consisting of ring-shaped LED

Info

Publication number: GB2431983A
Application number: GB0621959A
Authority: GB
Inventors: Christoph Cramer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2004-05-29
Filing date: 2005-05-24
Publication date: 2007-05-09
Anticipated expiration: 2025-05-24
Also published as: GB2431983B; GB0621959D0

Abstract

A hand tool 100 has a light 106a for illuminating the work area 111 of a workpiece 101. The light is disposed to spotlight the work area at a defined angle a , preferably 40{. The light consists of a ring-shaped LED that produces a focussed cone of light rays. The light may adopt a first working position 'A' where the light marks a centre spot 109 for the tool. In a second position ('B', fig 2), the light serves to illuminate a wider area 110.

Description

Hand tool with angle-of-incidence light system

Background art

The invention proceeds from a hand tool having the generic features of claim 1.

From DE 8529779 Ui an electric tool is known, which has a lamp provided on or in the housing of the electric tool.

The lamp is used to illuminate the work point that is to be machined by the electric tool. The lamp is disposed in such a way that it emits a divergent light cone, which obliquely illuminates the work point. Thanks to provision of the lamp, a user may work with the electric tool even in poor light conditions. The lamp is designed in such a way that the entire work point and its surrounding area are widely and extensively illuminated.

WO 99/02310 discloses i.a. lighting for a circular saw. In this case, the lighting comprises a plurality of light sources, each of which performs one of two different functions. A separate light source is used for wide and general illumination of the work point, while another separate light source is used to project a thin streak of light onto the work surface in order to define the sawing direction for the user. The disclosed lighting therefore comprises a separate light source for generally and extensively illuminating the work area and a further separate light source to be used by the user for the purpose of orientation during machining. This lighting system corriprising a plurality of separate light sources is however complex and cost-intensive, so that here a lighting device for hand tools would be desirable, which in as simple a s,ay as possible provides both local illumination for orientation purposes and general illumination.

Advantages of the invention In contrast, the hand tool according to the invention having the characterizing features of claim 1 has the advantage that, with it, a hand tool is provided, which has a lighting system offering both local illumination for orientation purposes and general extensive illumination and at the same time is particularly simple and cost-effective.

The term, hand tool, generally includes all tools that may be operated manually. It may therefore be a matter of both electrically operated tools and tools without a drive or with a manual drive.

In a preferred manner, it is a matter of hand tools that are used to penetrate the surface of work areas, i.e. tools that may be used to drill holes, mill, saw or remove material from surfaces.

In a preferred manner, the hand tool is designed in such a way that during machining of the respective surface it is displaced axially in the direction of the surface. In particular, the hand tool may penetrate the surface to be machined at right angles, i.e. in the direction of the normal of the surface. In a particularly preferred manner, the hand tool is a milling tool, in particular a routing cutter.

The lighting according to the invention is advantageous particularly for tools that may adopt a first working position and a further different second working position in relation to the work area.

In said case, the first working position is a position, in which the hand tool is placed on or applied against the work area. The first working position is the position, in which the user of the hand tool aligns the hand tool in relation to the work area. The first working position might therefore be described as an alignment or adjustment position. In the case of a routing cutter, for example, this alignment position corresponds to the state, in which the routing cutter is situated over the work area but has not yet penetrated or "plunged" into it.

In contrast thereto, the second working position is the actual working or operating position of the hand tool. It corresponds to the state, in which the work area is machined by the hand tool. A routing cutter, for example, is situated in this operating position after it has penetrated or "plunged" into the work area.

The light source may be of any type. For example, it may be an incandescent lamp. In a preferred manner, the light source is an LED or light-emitting diode, in particular a circular diode. Here, by a circular diode is meant a diode arrangement, which forms a circle and emits light along the entire circle.

The light source may be a white light source, but may alternatively be a coloured light source, in particular a yellow or a red light source.

It is advantageous when the hand tool comprises not just a single light source but a plurality of light sources. This enables better and more uniform illumination of the work area. In a preferred manner, the hand tool according to the invention comprises a first and a second light source, wherein the second light source illuminates and spotlights the work area in an identical manner to the first light source.

When the second light source is disposed opposite the first light source, a particularly uniform and effective illumination may be achieved.

It is of course also possible to provide more than two, for example three or four light sources.

The work area may be any article having a surface that is to be machined by the hand tool. In said case, it may be a matter of a flat or curved work surface. The work surface may be part of a workpiece but may alternatively be, for example, part of a wall or building.

The angle of incidence is the angle, at which the light emitted by the light source falls onto the work area. In particular, the angle of incidence is the angle arising between the pencil of substantially parallel rays emitted by the light source and the normal of the surface to be machined. The angle may also be defined as the angle arising between the pencil of rays and the principal axis or axis of rotation of the hand tool.

According to the invention, the light source emits a pencil of substantially parallel rays. Here, substantially parallel means that the pencil of rays has a low divergence. The divergence should, in particular, be low enough to allow the light source to perform fully both the function of spotlighting for the purpose of orientation prior to machining and the function of general wide illumination of the work area during machining.

By virtue of the oblique alignment of the light source and by virtue of the emitting of a pencil of substantially parallel or hardly divergent rays, the lighting according to the invention not only enables general wide illumination of the work area during machining, but also produces at the work area a bright spot or delimited circle, which may be used for the purpose of orientation when positioning the hand tool prior to machining. According to the invention, therefore, the pencil of rays may form an orientation device on the surface of the work area prior to machining thereof. As already mentioned, the orientation device comprises a spot of light or a circle of light of a small diameter, which indicates to the user of the hand tool the point, at which the tool will be positioned at the start of machining.

When the hand tool, as already mentioned, may adopt a first and a second working position, it is advantageous when the pencil of rays in the first working position forms on the surface of the work area the orientation device or marking for alignment of the hand tool and in the second working position two-dimensionally illuminates the surface of the In a preferred manner, the angle of incidence of the pencil of rays is between 5 and 45 . In a particularly preferred manner, the angle of incidence is substantially 400.

Drawings There now follows a detailed description of an embodiment of the invention with reference to the accompanying drawings.

The drawings show: Figure 1 a cross section of an embodiment of the hand tool according to the invention in the retracted state with two light sources, Figure 2 the hand tool according to Fig. 1 in the inserted state.

Fig. 1 shows a routing cutter 100 in cross section. The routing cutter 100 is applied against a work area or alternatively against a surface 111 that is to be machined.

The surface 111 may be, for example, the surface of a workpiece 101 that is to be machined. The routing cutter 100 is supported on the surface 111 by means of a foot plate 102. The foot plate 102 of the routing cutter 100 is connected to the housing 103 of the routing cutter 100 by guide columns 104. The routing cutter 100 moreover comprises a routing attachment 105.

The lighting of the routing cutter 100 comprises two obliquely disposed light-emitting diodes 106a and 106b.

The light-emitting diodes 106a and 106b are seated on the tool holder 107.

The light-emitting diodes 106a and 106b are fastened in such a way to the tool holder 107 that they emit pencils of rays 108a and 108b, which form an angle a relative to the normal. The angle a is in said case so selected that the two pencils of rays meet precisely on the surface 111 to be machined, when the routing cutter 100 is in the retracted state. The angle a is moreover so selected that the two pencils of rays meet at the point where the routing attachment 105 during insertion of the routing cutter 100 touches down on the surface 111 (see Fig. 2). In the illustrated embodiment, the angle a is 40 .

Fig. 2 shows the routing cutter 100 in the inserted state.

In this state, the machining of the surface 111 has already begun, and the routing attachment 105 has penetrated into the surface 111. The two pencils of rays 108a and 108b now illuminate, no longer the starting point of the routing attachment 105, but the area around the routing attachment 105.

There now follows a description of the mode of operation of the routing cutter 100 according to the invention.

A user would like to use the routing cutter 100 to machine the surface 111 of a workpiece 101. The workpiece 101 may be, for example, a wooden panel. For this purpose, the user places the routing cutter 100 onto the wooden panel 101.

This state is shown in Fig. 1. The user has not yet inserted the routing cutter 101. There is accordingly still a gap or distance 112 between the routing attachment 105 and the wooden panel 101. The light-emitting diodes 106a and 106b emit two pencils of rays lOBa and 108b, which meet directly under the routing attachment 105 on the surface 111 of the wooden panel 101. There, the two pencils of rays 108a and 108b form a spot of light or circle of light 109 of a small diameter. The circle of light 109 indicates to the user the point, at which the routing attachment 105 will touch down when he inserts the routing cutter 100 in order to machine the wooden panel 101. With the aid of this orientation point 109, therefore, the user may easily establish whether he has positioned the routing cutter 100 also at the point where he would like to machine.

Once the user has established from the circle of light 109 that the routing cutter is applied at the correct location, he inserts the routing cutter 100 in order to start the machining of the wooden panel 101. The routing attachment then penetrates into the wooden panel 101.

The state then reached is shown in Fig. 2. The routing attachment 105 has penetrated into the wooden panel 101.

As a result of inserting the routing cutter 100 and hence shortening the distance between the light-emitting diodes 106a, 106b and the surface 111 of the wooden panel 101, the light rays lOBa and 108b then meet a different area 110 of the wooden panel 101. The light-emitting diodes lO6a, 106b now illuminate a peripheral area llOa and liOb around the inserted cutter 105. This peripheral illumination allows the user precisely to see the results of his machining and then align the further machining of the wooden panel 101 accordingly.

By virtue of the oblique arrangement of the light-emitting diodes 106a and 106b and their production of pencils of substantially parallel rays 108a and 108b, the lighting of the cutter 100 in the simplest manner simultaneously performs two functions.

In the retracted state, the light-emitting diodes 106a, 106b indicate to the user the point, at which the routing cutter 100 will touch down on the workpiece 101.

The user may therefore align the routing cutter 100 precisely in accordance with his requirements before starting the routing operation. By virtue of the orientation aid of the circle of light 109 of the light rays 108a and 108b, the user may be certain that the cutter 100 during routing will touch down precisely at the point where he intends the routing to occur.

During the actual routing of the workpiece by means of the routing cutter 100, the light-emitting diodes 106a and 106b therefore change their function and are used for general illumination of the work area to be routed, namely at the points llOa and 11Db adjacent to the "plunged" routing attachment.

This change of function is achieved in a simple manner in that the reduction of the distance between the light-emitting diodes 106a, 106b and the surface 111 leads to a corresponding variation of the point of incidence of the pencils of rays 108a and 108b. The light-emitting diodes are therefore quasi automatically "switched over" in terms of their function by the reduction of their distance from the surface 111. The "switchover" is consequently effected without any additional components. Use is made merely of the function that already exists in a routing cutter, namely the plunging into the workpiece. A lighting system is accordingly achieved, which performs the two functions of central, precisely delimited illumination for alignment of the tool and peripheral illumination for generally improved viewing conditions, and yet at the same time is of a simple design and cost-effective.

Claims

Claims 1. A hand tool having a light source for illuminating a work

area to be machined by the hand tool, wherein the light source is a ring diode producing a convergent conical shell of substantially parallel light rays which light the work area obliquely at a defined angle of incidence.

2. A hand tool according to claim 1, wherein the hand tool may adopt a first working position and a second working position in relation to the work area.

3. A hand tool according to claim 2, wherein the cone of light rays in the first working position forms on the surface of the work area a marking for alignment of the hand tool.

4. A hand tool according to claim 2 or 3, wherein the cone of light rays in the second working position two-dimensionally illuminates the surface of the work area.

5. A hand tool according to one of the preceding claims, wherein the hand tool is a drilling, sawing or milling tool.

6. A hand tool according to one of the preceding claims, wherein the angle of incidence is between 5 and 45 .

7. A hand tool according to one of the preceding claims, wherein the angle of incidence is substantially 40 .