GB2422798A

GB2422798A - Apparatus with an adjustable fence

Info

Publication number: GB2422798A
Application number: GB0502436A
Authority: GB
Inventors: Alistair Cook
Original assignee: COOKS EXP SERVICES Ltd
Current assignee: COOKS EXP SERVICES Ltd
Priority date: 2005-02-05
Filing date: 2005-02-05
Publication date: 2006-08-09
Anticipated expiration: 2025-02-05
Also published as: GB0502436D0; GB2422798B

Abstract

The apparatus comprises a tool 4, a work-table 2 with a first slot 14 therein, a fence 12 which has a second slot 16 therein and a threaded locking member 18. The locking member 18 is received through the two slots 14 & 16 and is operable between an unlocked condition where the fence 12 is pivotable about the locking member 18 relative to the work-table 2 and can be moved in any direction, and a locked condition where the fence 12 is fixed relative to the work-table 2. The locking member 18 is locked by means of a nut (24, Fig. 2) which is prevented from rotating when the locking member 18 is rotated as it abuts part of an L-shaped track (26, Fig. 2) which runs adjacent to the first slot 14 on the underside of the work-table 2. Figure 1 shows a manually driven grinding wheel tool 4. The fence 12 can also be used with a belt sander, a mitre saw, table saw or band saw, or a drilling or milling tool.

Description

TITLE

A tool having an adjustable fence

DESCRIPTION

Technical Field

The present invention relates to an adjustable guide fence that can be used on a manually-operated, machine or power tool such as a sanding tool like a disc sander or belt sander, a cutting tool like a mitre saw, table saw or band saw, or a drilling or milling tool, for example.

Summary of the Invention

The present invention provides a tool comprising a first elongate slot; an adjustable fence for guiding a workpiece and having a second elongate slot; and a locking member that is received through the first elongate slot and the second elongate slot and operable between an unlocked condition where the fence can pivot about the locking member relative to the first elongate slot and can move in a direction parallel to the first elongate slot and in a direction parallel to the second elongate slot, and a locked condition where the fence is fixed in a desired position relative to the first elongate slot.

The tool preferably further comprising a table having a flat upper surface for supporting a workpiece. The first elongate slot is preferably formed in the table.

The fence preferably defines at least one workpiece guiding surface that is preferably substantially at right angles to the upper surface of the table. The fence also preferably defines a mounting surface for securing the fence to the table. The second elongate slot can be formed in the mounting surface.

When the locking member is in the unlocked condition, the user can pivot the fence so that it adopts a pre-selected angle relative to the first elongate slot. The tence can also be moved in the direction parallel to the second elongate slot so that the workpiece can be supported properly at the end where the sanding, cutting, drilling or milling or other work is taking place. In other words, any gap that is created between the end of the fence and the sanding disc or belt, or the cutting blade, for example, when the fence is pivoted about the locking member can be kept to a minimum.

The fence can be pivoted about the locking member in either direction and the pre- selected angle can be any angle between 0 degrees and 90 degrees.

The locking member preferably comprises a locking pin having a first part and a second part that extends through the first and second elongate slots and has a screw thread on at least part of its outer surface, and a locking nut adapted to be received on the second part of the locking pin. Relative rotation between the locking nut and the locking pin therefore causes the mounting surface of the fence and the table to be firmly clamped between the first part of the locking pin and the locking nut.

The tool may further comprise a locking plate having an aperture for receiving the second part of the locking pin and which is positioned between the first part of the locking pin and the mounting surface of the fence. Means such as a track or rail can be provided below the table to prevent the locking nut from rotating with the locking pin.

The tool can be a disc sander, for example. In this case the tool preferably further comprises a sanding disc having an axis of rotation that is substantially at right angles to the first elongate slot. The sanding disc may be turned by hand or by an electric motor.

The tool can also be a different sort of sanding tool like a belt sander, a cutting tool like a mitre saw, table saw or band saw, or a drilling or milling tool, for example. In general, the adjustable fence is suitable for use with any tool where a guiding surface is needed to support a workpiece and where some degree of adjustability in angle and/or position is called for.

Drawings Figure 1 is a top view of a manually-operated disc sander according to the present invention; Figure 2 is a detail cross section view along line A-A showing the adjustable fence of the manually-operated disc sander of Figure 1; and Figure 3 is a front view showing the manually-operated disc sander of Figure 1 but without the adjustable fence.

Figures 1 to 3 show a manually-operated disc sander that can be used to sand the rough edges of a workpiece. The sander includes a table 2 having a flat upper surface 2a for supporting the workpiece (shown ghosted in Figure 1 and labelled W) . A sanding disc 4 is rotatably mounted to a downwardly extending flange 6 of the table 2 and includes a handle 8 so that a user can turn it. Of course, the sanding disc 4 can also be adapted to be driven by an electric motor. The planar face 4a of the sanding disc 4 adjacent the table 2 is coated with an abrasive material such as sandpaper, glass paper or the like. Alternatively, the sanding disc itself may be made of an abrasive material. The table 2 is supported by legs 10 having sufficient length to provide clearance between the bottom edge of the sanding disc 4 and the surface on which the sander is positioned.

An adjustable fence 12 is provided to support a side surface of the workpiece while it is being sanded. The fence 12 has an oppositely facing pair of guiding surfaces 12a that are substantially vertical and a mounting surface 1 2b. Although the fence 12 has a U-shaped cross-section, it will be readily appreciated that it can also have a square, rectangular or L-shaped cross-section depending on the design of the sander. If the fence 12 has a square or rectangular cross-section then an aperture having the same length as the elongate slot 16 is provided in the surface opposite the mounting surface I 2b so that the upper part I 8a of the locking pin 18 (described below) can be accessed by the user.

An elongate slot 14 is provided in the table 2. A further elongate slot 16 is provided in the mounting surface 12b of the fence 12. The elongate slot 14 extends in a direction that is substantially perpendicular to the axis of rotation of the sanding disc 4. The elongate slots 14 and 16 can be of any suitable length depending on how far the fence 12 might have to be moved in normal use.

A locking pin 18 includes a cylindrical upper part 1 8a and a cylindrical lower part I 8b. An aperture 20 is provided in the upper part I 8a for receiving a bar tool to assist the user in rotating the locking pin 18. The surface of the upper part I 8a is also knurled to provide the user with a better grip. The lower part 1 8b includes a screw- thread on its outer surface and extends through the elongate slot 16 in the mounting surface 12b of the fence 12 and through the elongate slot 14 in the table 2. A locking plate 22 is located between an annular shoulder I 8c of the locking pin 18 and the mounting surface I 2b of the fence. The locking plate 22 includes a circular aperture for receiving the lower part I 8b of the locking pin 18. A locking nut 24 is screwed onto the lower part 1 8b below the table 2 as shown in Figure 2. (Although Figure 2 shows a slight gap between all of the individual component parts, this is simply to improve the clarity of the drawing and it will be readily appreciated that the component parts are normally in direct contact with each other.) The locking nut 24 runs along an L-shaped track 26 that prevents the locking nut from rotating with the locking pin 18. Rotation of the locking pin 18 by the user in a first direction (or locking direction) will draw the locking nut 24 upwardly towards the table 2. Once the locking nut 24 comes into contact with the underside of the table 2, further rotation of the locking pin 18 in the locking direction will cause the annular shoulder 1 Sc to bear down hard against the locking plate 22 to clamp the mounting surface 1 2b of the fence firmly in position between the locking plate and the upper surface 2a of

the table 2.

Rotation of the locking pin 18 by the user in an opposite direction (or unlocking direction) will release the mounting surface 12b of the fence 12. The fence 12 is then free to pivot about the locking pin 18 to adopt any angle relative to the planar face 4a of the sanding disc 4. The fence 12 is also free to move in a first direction parallel to the elongate slot 14 provided in the table 2 and in a second direction parallel to the elongate slot 16 provided in the mounting surface I 2b of the fence. More particularly, the fence 12 can move in the first direction parallel to the elongate slot 14 by sliding the lower part 18b of the locking pin 18 along the elongate slot 14. The fence 12 can also move in the second direction by sliding the lower part I 8b of the locking pin 1 8 along the elongate slot 16 provided in the mounting surface 1 2b. A combination of linear movement in the first and second directions is possible. In other words, the lower part 1 Sb of the locking pin 18 can be allowed to slide along both of the elongate slots 14 and 16.

The fence 12 can be used to support a workpiece at any angle relative to the planar face 4a of the sanding disc 4. For example, if the workpiece is one side of a picture frame where both ends of the workpiece are mitred at an angle of 45 degrees, then the angle and position of the fence 12 can be adjusted so that the mitred end of the workpiece to be sanded is parallel to the planar face 4a and the rest of the workpiece extends away from the planar face at an angle of 45 degrees. The fence 12 can be adjusted as follows.

First of all, if the fence 12 is already firmly clamped in an initial position, the user will rotate the locking pin 18 in the unlocking direction such that the locking nut 22 moves downwardly away from the table 2. Once the mounting surface 12b is free, the fence 12 can be pivoted left or right to the desired angle. The upper surface 2a of the table 2 can be provided with a series of markings (not shown) to assist the user in pivoting the fence 12 to the desired angle. The markings may take the form of a series of lines radiating from a centre point of the elongate slot 14 or a series of parallel lines running across the full width of the upper surface 2a of the table 2 at regular intervals. The fence 12 can be pivoted until one of the guiding surfaces 1 2a is aligned with an appropriate marking. Alternatively, a spacer, template or setting plate (not shown) can be used to set the angle of the fence 12 to a particular angle.

if the fence 12 is initially positioned such that it extends substantially at 90 degrees to the planar face 4a of the sanding disc 4 (i.e. as shown in Figure 1) then it will be readily appreciated that a gap will develop between the end of the fence and the sanding disc if the fence is pivoted to the left or right. This means that the workpiece will project beyond the end of the fence 12 and will not be properly supported when the sander is being used. To avoid this problem, the user can move the end of the fence 12 towards the planar face 4a of the disc in such as way that the locking pin 18 slides along the elongate slot 16. On the other hand, if the fence 12 is pivoted towards the centre (or the 90 degree position) then it will sometimes be necessary to first move the end of the fence away from the planar face 4a of the sanding disc 4.

The fence 12 can also be moved left or right across the upper surface 2a of the table 2 in such a way that the locking pin 18 slides along the elongate slot 16. It can sometimes be useful to move the fence 12 in this way even if the angle of the fence is kept at 90 degrees to the planar face 4a of the sanding disc 4. For example, if the abrasive material is worn in the centre of the sanding disc 4 then the fence 12 can be moved to the left or right so that the surface of the workpiece to be sanded can be brought into direct contact with a different part of the sanding disc 4 where the abrasive material is less worn.

In practice, any linear movement of the fence 12 will be carried out carefully so that the guiding surface 1 2a stays at the required angle relative to the planar face 4a of the sanding disc 4.

Once the fence 12 has been properly positioned, it can be firmly clamped by rotating the locking pin 18 in the locking direction. The surface of the workpiece facing the planar face 4a of the sanding disc 4 can then be sanded by pushing it along a guiding surface 1 2a of the fence 12 and into direct contact with the planar face while the handle 8 is turned.

Figure 1 shows a fence 12' that has been adjusted in the maimer described above to support a workpiece W at a required angle of about 35 degrees.

Claims

1. A tool comprising: a first elongate slot; an adjustable fence for guiding a workpiece and having a second elongate slot; and a locking member that is received through the first elongate slot and the second elongate slot and operable between an unlocked condition where the fence can pivot about the locking member relative to the first elongate slot and can move in a direction parallel to the first elongate slot and in a direction parallel to the second elongate slot, and a locked condition where the fence is fixed in a desired position relative to the first elongate slot.

2. A tool according to claim 1, wherein the fence includes a workpiece guiding surface and a mounting surface and wherein the second elongate slot is formed in the mounting surface.

3. A tool according to claim 2, further comprising a table for supporting a workpiece and wherein the first elongate slot is formed in the table.

4. A tool according to claim 3, wherein the locking member comprises a locking pin having a first part and a second part that extends through the first and second elongate slots and has a screw-thread on at least part of its outer surface, and a locking nut adapted to be received on the second part of the locking pin and wherein relative rotation between the locking nut and the locking pin causes the mounting surface of the fence and the table to be firmly clamped between the first part of the locking pin and the locking nut.

5. A tool according to claim 4, further comprising a locking plate having an aperture for receiving the second part of the locking nut and positioned between the first part of the locking pin and the mounting surface of the fence.

6. A tool according to claim 4 or claim 5, further comprising means for preventing the rotation of the locking nut.

7. A tool according to any preceding claim, further comprising a sanding disc having an axis of rotation that is substantially at right angles to the first elongate slot.

8. A tool substantially as herein described and with reference to the drawings.

Amendments to the claims have been filed as follows:

1. A tool comprising: a first elongate slot; an adjustable fence for guiding a workpiece and having a second elongate slot; a locking member that is received through the first elongate slot and the second elongate slot and operable between an unlocked condition where the fence can pivot about the locking member in either direction to adopt all pre-selected angles between 0 degrees and 90 degrees relative to the first elongate slot and can move in a direction paralleJ to the first elongate slot and in a direction parallel to the second elongate slot, and a locked condition where the fence is fixed in a desired position relative to the first elongate slot; and a sanding disc having an axis of rotation that is substantially at right angles to the first elongate slot.

7. A tool substantially as herein described and with reference to the drawings.

7 A tool according to claim 1, wherein the fence includes a workpiece guiding surface and a mounting surface and wherein the second elongate slot is formed in the mounting surface.

4. A tool according to claim 3, wherein the locking member comprises a locking pin having a first part and a second part that extends through the first and second elongate slots aM has a screw-thread on at least part of its outer surface, and a locking nut adapted to be received on the second part of the locking pin and wherein relative rotation between the locking nut and the locking pin causes the mounting surface of the fence and the table to be firmly clamped between the first part of the locking pin and the locking nut.

5. A tool according to claim 4, further comprising a locking plate having an apertute for Leceiving the second part of the locking nut and positioned between the first part of the locking pin and the mounting surface of the fence. (U