GB2453532A

GB2453532A - Router with powered movement

Info

Publication number: GB2453532A
Application number: GB0719413A
Authority: GB
Inventors: Michael Waldron
Original assignee: GMCA Pty Ltd
Current assignee: GMCA Pty Ltd
Priority date: 2007-10-04
Filing date: 2007-10-04
Publication date: 2009-04-15
Also published as: GB0719413D0

Abstract

A power tool 2, such as a plunge router, comprises a body 8 from which a cutter 6 depends, the cutter and body being movable with respect to a base 4; and guide means 10 on which the body is mounted. Movement of the body and the cutter with respect to the guide means and base is powered, eg through provision of at least one motor. Control means may be provided, which causes movement of the body and cutter to a predetermined position with respect to the base. A display 57 may be provided to indicate the location of the cutter, which may be electronic or a Vernier arrangement. An electronic display may be provided which is connected to the tool but removable for remote use (see figure 2). Laser guide lines (62, 64, fig 3) may be provided in an aperture 34 of the base. Lighting means (66, fig 4) may be provided.

Description

1 2453532 Power Tool The invention to which this application relates is a power tool of a type which can be used to cut a portion of a work piece so as, for example, to form a channel into said work piece. In particular, although not necessarily exclusively, the power tool is of a type known as a router.

Routers can be have a fixed base or be of the plunge type the base of which may be removable. The tool typically comprises a body which is mounted on at least one guide means and when, in the form of a plunge router, is provided such that the body is slidably movable along the guide means. Protruding from the lower base of the body, is a cutting means hereinafter referred to as a cutter which is provided to be rotated about an axis, by connection to a motor typically housed within the body. Also provided is a base from which the guide means depends towards *::::* the body, said base having an aperture to allow the cutter to pass therethrough and into contact with the work piece on which the base is located, and thereby achieve the cutting action on the work piece. Typically, the body is also provided with one or more handle portions which allow the body to be gripped **S� *:*. in the appropriate location and also allow the body to be moved along the guide means so as to move the cutter into contact with the surface.

It will therefore be appreciated that conventionally, the cutter of the tool is moved along a longitudinal axis, said longitudinal axis also acting as the axis for rotation. When applying the cutter into contact with the surface of the work piece to form a cut portion therein, there is a need for the depth of cut which is to be achieved to be controlled, otherwise, the cutter may not cut into the surface of the work piece at all or may cut into the work piece to a depth which is too great or indeed pass straight through the work piece.

Conventionally, this control of depth of cut is achieved by providing a mechanical arrangement which is manually operable by the user of the tool. The process normally used is therefore to first set the location of the cutter to a required datum, then to adjust the position of the end of an elongate member to a set depth such that when subsequently the tool is used, and the cutter is moved into contact and into the work piece surface, advancement of the cutter continues until the elongate member hits a stop, at which position the user will assume that the required depth of cut has been achieved.

Although this system is widely used there are significant disadvantages, one of which is that because the mechanical adjustment is not entirely accurate, and/or relies on the user .. adjustment and/or the tolerances between the components the * *..

depth of cut which is achieved can, in many instances, not be *a..

that which is required. S.... * S

Furthermore, in certain instances, the router tool can be moved *S** . . : from a position in which the cutter is advanced downwardly * onto the work piece to perform the cut, through 1800 to a position in which the cutter is moved upwardly into contact with the work piece. It is found that in practise, in this arrangement, the router tool will typically be mounted underneath a routing table which makes the adjustment means difficult to access by the user and, furthermore, can be difficult to adjust accurately.

As a result of these problems, the aim of the present invention is to provide a means for movement of the body and cutter of the router tool, in a manner which is controllable and, allows accurate performance of the cut to be achieved.

In a first aspect of the invention, there is provided a power tool, said power tool including a body which is mounted to be movable with respect to at least one guide means, said body including a cutter depending therefrom, and a base, from which said guide means depend and wherein the movement of the body and cutter, with respect to the guide means and base, is powered.

In one embodiment, the movement is achieved via the provision of at least one motor which is electrically powered and which, when operating, causes movement of the body and cutter with respect to the guide means.

In one embodiment, the powered movement is achieved via the ... provision of a movement assembly. S... *.S.

In one embodiment, the movement assembly is located within a guide means. In an alternative embodiment, the movement assembly is provided separate to said guide means. In one S...

embodiment, the movement of the base and cutter is along an * axis which is parallel with the axis of rotation of said cutter.

In one embodiment, the range of movement which can be achieved, is such as to ensure that the cutter can be moved between a first position, to one side of the base, and a second position to the opposing side of the base, said base including an aperture or slot, through which said cutter may move between said first and second positions.

Typically, in the first position, the cutter lies to the side of the base on which the body lies and in the second position, the cutter lies to the side of the base in contact with the workpiece or table so that cutting of the work piece is achieved.

In one embodiment, the tool includes an indicator to indicate the degree of movement which has occurred and/or the particular degree of movement which is required. Typically, the said indicator, provides an indication of the particular position of the cutter at any given time.

In one embodiment, the indicator includes a visual display, which display is connected to a measurement device provided as part of the tool. In one embodiment, the device is a Vernier device and a first part of the Vernier device is attached to the base and a second part of the Vernier device is attached to the body and the extent of movement between the body and the :. base is used to generate an indication of the particular position of the cutter as the position of the cutter with respect to the *�..

body is known. S... * **S.

In one embodiment, the display is an electronic display which is provided as an integral part of the tool. In addition, or S... . . . . . . : alternatively, an indication display can be provided which can be * ee connected to the tool via, for example, a cable connection.

In one embodiment, the movement assembly comprises a motor mounted on the guide means in connection with a threaded bar which extends along the axis of movement and the length of which defines the scope of movement which can be achieved, said threaded bar engaging with a fixed threaded aperture on the body so as to allow the movement of the body to be driven by rotation of the threaded bar.

Typically, the motor is provided with a gear arrangement such as, for example, an epicyclic gear box which engages with the threaded bar.

In one embodiment the body incorporates at least one, but more typically two spaced handles.

in one embodiment, the tool is provided with selection means which allows the tool to be adjusted by powered movement or, alternatively, for the powered movement assembly to be disconnected and manual movement of the tool to be provided.

In one embodiment, the tool is provided with a switch, which, when activated, causes the movement of the body and cutter to a predesignated position. In addition, or alternatively, the tool incorporates selector switches which, when actuated, allow the user to select the movement of the body and cutter in either up . or down directions depending on which switch is actuated. *S..

Typically, in this embodiment, the movement via actuation of S..

the switches is allowed until a predetermined position is reached, at which further movement is not possible using the switches.

S

* *: In one embodiment, pressure sensing means may be provided to sense the pressure exerted on the cutter as it is driven downwardly onto the work piece and, if the pressure is detected as reaching or exceeding a predetermined limit, the rotation of the cutter and/or continued downward movement of the cutter is stopped. This will prevent the damage to the work piece and/or cutter being caused by the use of excessive force.

In one embodiment, the tool is provided with any or any combination of, illumination means which allow the portion of the work piece which is to be worked on, and/or the cutter, to be illuminated and/or guidance means to allow the position of cut to be guided.

Specific embodiments of the invention will now be described with reference to the accompanying drawings, wherein:-Figure 1 illustrates a perspective view of a tool in accordance with one embodiment of the invention; Figure 2 illustrates a variation on the tool shown in figure 1; Figure 4 illustrates a tool of Figure 1 with the guidance means; and Figure 5 shows a power tool of Figure 1 with illumination means. * . * ***

Figure 1 illustrates a power tool 2 in accordance with one **..

embodiment of the invention in the form of a router which has a cutter 6 supported and depending from a body 8. The body is mounted on a guide 10 and a drive means assembly 12 both of which have longitudinal axis 14, 16 respectively, which are *S..

substantially parallel to the rotational axis 18 of the cutter. The cutter is powered by a motor (not shown) mounted within the body and via shaft 22. The body is provided with first and second handles 24, 26, which are positioned to either side of the body, to allow the same to be gripped and allow controlled movement of the body and cutter, with respect to a base 4. It is shown how the guide means depend upwardly from one side 28 of the base and the opposing side 30 of the base, is provided to be positioned directly onto a work piece surface 32 which is to be machined or alternatively, onto a table onto which a work piece is in turn t be located. The base is provided with an aperture 34 through which the cutter can be moved, by movement of the body and cutter along the guide means.

In the guide means 14, there is provided a movement assembly which comprises a powered unit 42 which typically includes a motor connected to an epicyclic gearbox which in turn is connected to a threaded shaft leading upwardly from the unit 42.

The threaded shaft extends partially along the guide means 14 and, at a position therealong, passes through a threaded aperture formed either as part of the body, or for example, provided in a nut which in turn is provided in a fixed location on the body.

Operation of the motor causes rotation of the threaded shaft, which in turn, causes movement of the base with respect to which the shaft is fitted with respect to the body and hence cutter, in the direction of arrows 46, 48.

The extent of movement can be controlled with respect to either *. a predetermined position and/or selective actuation of one or more switches 50 which are provided in the handle 26 as shown. U...

The tool is also provided with indication means 57 which, in the * . case of Figure 1 is provided as an integral part of the body but which may also alternatively, as shown in Figure 2, be provided *.S.

: in connection with the tool but be usable remotely therefrom.

* The indication means are provided to represent the position of the cutter with respect to the base and/or work piece, at any given time. As a result, movement of the body and cutter with respect to the base, causes a change in the display 50 which is generated. If required, user actuation means 56 can be provided which allow the determining of a predetermined position of the cutter which is then saved in memory such that subsec1uent movement of the cutter can be achieved until that predetermined position is detected as being reached. In addition, or alternatively, the indication means can be provided as an indication to allow the user to decide at which point downward or upward movement of the cutter is to be stopped.

The actual position of the cutter and hence body, can be detected in one arrangement, using a Vernier type arrangement, which arrangement sends a signal representative of the respective positions of the body and base at that particular time, to the indication means displayed. Typically, the Vernier arrangement comprises a first part which is mounted on the base and a second part which is mounted on the body and the relative movement between the said first and second parts, is then detected and used to generate the display and be representative of the position of the cutter.

Thus, in normal operation of the tool in accordance with the embodiment shown, the user will firstly determine the depth to which they wish the cutter to be moved below the base surface *. 30 and into the work piece 32. They will input this value into S...

the memory of the indicator means 52 which will then use that S...

as a datum in the subsequent movement of the cutter. With the * * desired depth set, the user can then grasp the handles of the device and then operate the selector switches 50 to actuate the *... . same to cause actuation of the movement assembly which in turn will cause, in this particular case, the body 8 and cutter 6 to move downwardly, with the cutter passing through the aperture 34 in the base 4 and into the work piece 32 until the required depth is detected as having been reached by the Vernier arrangement. Once the required depth is reached, the further powered movement downwardly of the body and cutter, is prevented and hence the user can be certain that the required depth has been reached. If, during the movement of the cutter to the required depth, particular resistance is detected from the work piece to the insertion of the cutter to the required depth, then the user may use the up switch 50' to stop downward movement of the cutter until a particular cutting action has occurred and then can recommence the downward movement of the cutter by selection of the switch 50. When a movement demand is created by actuation of the switch, the motor causes the threaded shaft to rotate and hence move the body and cutter with respect to the base during the threaded shaft.

In Figure 1, the power tool is shown with a safety guard 60 which sits between the base 4 and body 8 so as to prevent debris from impacting towards the user of the tool when holding the same Figure 2 illustrates a further embodiment of the invention in which an indicator device with display 52, is provided to be selectively attachable to the tool 2 50 as to allow the display to be visible in all potential uses. It is found that this is particularly useful when the router is being used underneath a Figures 3 and 4 illustrate further features which may be * * incorporated, namely the generation of laser guide lines 62, 64 on in the aperture 34 on the base 4, as shown in Figure 3 and **S. . . . . . *. : the provision of lighting means 66 as shown in Figure 4 which * may be switched on to shine downwardly onto the aperture 34 of the base 4 and hence the work piece 32 and the cutter 6 which is cutting into the work piece at that time.

Typically, dust collection means will also be provided to remove dust or debris from the aperture 34 at which the working of the work piece is occurring, to either be collected in a bag or to be removed for collection at a location remote from the tool. Any suitable dust or debris collection means can be utilised for this purpose.

The present invention therefore provides a useful and efficient manner of moving the cutter and body of the power tool with respect to the base and to do so in a manner which allows increased ease of use to a user and, more importantly, increased accuracy in the performance of the operation of the power tool on the work piece. S. * . * *.. * .*. * S S*e. **.S * S **..

S..... * . S...

S S... S. S S S* S.

Claims

Claims 1. A power tool, said power tool including; a body which is mounted to be movable with respect to at least one guide means, said body including a cutter depending therefrom; and a base, from which said guide means depend towards said body and wherein the movement of the body and cutter with respect to the guide means and base is powered.
2. A tool according to claim 1 wherein the said movement is achieved through the provision of at least one motor which is electrically powered and which causes movement via a movement assembly, of the body and cutter with respect to the guide means.
3. A power tool according to claim 2 wherein the movement assembly allows engagement and movement between the body and the guide means.
4. A power tool according to claim 3 wherein the movement assembly is located within a guide means.
5. A power tool according to claim I wherein the movement of the base and cutter is along an axis parallel with the axis of rotation of said cutter. * S. * . S * S.
6. A power tool according to claim 1 wherein the range of S...

movement is sufficient to ensure that the cutter can be moved *SSS ""etveen a first position to one side of the base and a second *.*S.. . * vosltlon to the opposing side of the base. S. * *

*
7. A power tool according to claim 6 wherein the base *** * rncludes an aperture or slot through which the said cutter moves between said first and second positions.
8. A power tool according to claim 6 wherein in the first position, the cutter lies to the side of the base to which the body lies and in the second position, the cutter lies to the side of the base in contact with the workpiecc or table allow a cutting operation to be performed by the cutter.
9. A power tool according to claim I wherein the tool includes an indicator to indicate the degree of movement of the cutter which has occurred and/or the degree of movement of the cutter which is rejuired to perform a cutting operation.
10. A power tool according to claim 9 wherein the indicator provides an indication of the particular position of the cutter at an instant of time.
11. A power tool according to claim 9 wherein the indicator includes a visual display connected to a measurement device provided as part of the tool.
12. A power tool according to claim 11 wherein the measurement device is a vernier device having a first part attached to the base and a second part attached to the body and the extent of movement between the body and base is used to generate an indication of the particular position of the cutter at * ** *that time. * . * ***
1 3. A power tool according to claim II wherein the display is electronic display mounted as part of the tool, or is ** ..* * tonnected to the tool. ** * .

*
i4. A power tool according to claim 2 wherein the movement *S.S** * ssembly comprises a threaded bar which extends along the axis of movement and the length of which defines the range of movement which can be achieved, said threaded bar engaged with a threaded aperture so as to allow the movement of the body to be driven by rotation of the threaded bar.
15. A power tool according to claim I wherein the tool is provided with selection means to allow the body and cutler to be moved by powered movement, or for the movement assembly to be disconnected and manual movement of the tool to be possible.
16. A power tool according to claim 1 wherein control means are provided which, when activated, cause movement of the body arid cutter to a pre-designated position with respect to the base.
17. A power tool according to claim 16 wherein the control means allow the selection of a range of user selectable positions to which the body and cutter can be moved.
18. A power tool according to claim 1 wherein pressure sensing means are provided to sense the pressure exerted on the cutter when driven downwardly onto the workpiece and, if the pressure is detected as reaching, or exceeding, a predetermined limit, the rotation of the cutter and/or continued downward *:*::* movement of the cutter is stopped. * * ***. * S I...

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