WO2001056759A1

WO2001056759A1 - Apparatus for guiding a cutting or abrading machine along an inclined path

Info

Publication number: WO2001056759A1
Application number: PCT/GB2001/000393
Authority: WO
Inventors: Nicholas John Browne
Original assignee: Nicholas John Browne
Priority date: 2000-02-01
Filing date: 2001-01-31
Publication date: 2001-08-09
Also published as: AU3037401A

Abstract

An apparatus for guiding the movement of a cutting/abrading wheel (42) comprises a base member (2) and a support member (26). The support member (26) mounts the cutting/abrading wheel (42) in such a way that it is slidable toward and away from the base member (2). Means (8, 14) are provided for setting the support member (26) at a chosen vertical inclination relative to the base member (2). Also disclosed is a method of using such an apparatus to cut an inclined groove in e.g. a kitchen worktop or the like.

Description

APPARATUS FOR GUIDING A CUTTING OR ABRADING MACHINE ALONG AN INCLINED PATH

This invention relates to an apparatus for cutting, grinding or otherwise shaping a solid material and particularly, but not exclusively, to an apparatus suitable for forming grooves in a hard material such as marble, stone, wood, plastics or the like. One context in which it is often required to form grooves is to provide drainage for work surfaces such as kitchen worktops. The most common example is given by the inclined grooves in a sink surround which are intended to direct liquid towards an opening in the surround which receives a sink bowl . The grooves are inclined in the sense that their depth increases towards the sing opening, i.e. the bottom surface of the groove is inclined to the horizontal .

Forming such inclined grooves in a hard material such as marble or granite has to date been relatively difficult and labour intensive. Typically a slab of the material is cut to size and an aperture cut in it to receive a sink bowl. This aperture is often a substantial proportion of the width of the slab, thus leaving relatively weak connecting bridges of material either side of the aperture.

The slab is then moved onto a wet saw which cuts in a horizontal plane, meaning that the slab has to be propped up at one end to achieve the desired incline in the resulting groove. It has been found in practice that there is an undesirably high tendency for slabs to break during handling between the aperture cutting tool and the wet saw and especially as a result of being propped up since this applies high stresses to the above-mentioned connecting bridges.

Once the grooves have been cut, the slab is then removed from the wet saw onto a table where the grooves are polished smooth by hand - either by a smoothing block or a hand-held electrically-driven abrasive wheel. Further handling of course further increases the danger that the slab will break. A theoretical alternative would be to use a

Computer Numerically Controlled (CNC) machine to form such grooves. However the cost of and time taken by these machines render them impractical .

It is an object of the invention at least partially to alleviate the problems set out above and when viewed from a first aspect the present invention provides an apparatus for guiding the movement of a cutting/abrading means, comprising a base member, a support member mounted to said base member and serving to mount the cutting/abrading means in such a way that it is slidable toward and away from said base member, and means for setting the support member at a chosen vertical inclination relative to said base member.

Thus it will be seen that in accordance with the invention a cutting/abrading means can be moved in a sliding fashion along a vertically inclined path. In preferred embodiments, therefore, this allows an inclined groove to be cut into a slab of hard material placed below the apparatus, or indeed a previously cut groove to be smoothed or polished.

It will be appreciated by those skilled in the art therefore that it is no longer necessary in accordance with the invention to move a workpiece onto a saw machine and to prop it up to cut inclined grooves into it and then to remove it to a separate bench so that the grooves may be polished. Instead apparatus in accordance at least with preferred embodiments of the invention may be placed over the workpiece which can remain in si tu , and inclined grooves can then be cut and/or polished simply by using appropriate respective cutting/abrading means, without having to move the workpiece . This is novel and inventive in its own right and thus when viewed from a second aspect the present invention provides a method of forming an inclined groove in a workpiece comprising positioning above said workpiece an apparatus adapted to guide a cutting/abrading means along a path inclined with respect to said workpiece, and moving said cutting/abrading means in the direction of the desired groove along said path, thereby forming said groove. It will be appreciated that this method allows for example drainage grooves to be cut into a kitchen worktop once the aperture for the sink bowl has been cut without having to move the worktop from wherever it is cut . In the most preferred method an apparatus in accordance with the first aspect of the invention is used.

Preferably the support member is mounted to the base member via a cantilever mounting. Such an arrangement can effectively provide an open-ended apparatus - i.e. one which does not require a frame to support the working end and so the size of the apparatus does not limit the size of workpiece which it can accommodate. This is novel and inventive in its own right and thus when viewed from a further aspect the present invention provides an apparatus for guiding the movement of a cutting/abrading means comprising a base member and an elongate support member mounted to said base member via a cantilever mounting, said support member serving to mount the cutting/abrading means in such a way that it is slidable toward and away from said base member.

It is also preferred to use an apparatus in accordance with this aspect of the invention in the method in accordance with the invention.

The support member may be mounted horizontally, but preferably it is vertically inclined with respect to the base member. Such inclination may be fixed, but is preferably variable. Thus in preferred embodiments of the aspect of the invention set out above the apparatus comprises means for setting the support member at a chosen vertical inclination with respect to the base member. This allows the apparatus to produce or treat inclined grooves as described earlier.

The apparatus may be arranged such that in use the cutting/abrading means is slidably mounted to the support member to provide the requisite sliding movement with respect to the base member, i.e. the support member could be fixed relative to the base member. In such embodiments the support member would therefore provide an inclined track on which the cutting/abrading means was arranged to slide. The support member providing this track may be substantially planar and inclined or an inclined part of a larger member. Preferably however the mounting for the cutting/abrading means is fixed with respect to the support member in the direction of sliding and thus the support member is itself slidable with respect to the base member.

In preferred embodiments the base member is elongate which in itself provides greater stability. It is further preferred in such embodiments that the support member is mounted so as to be movable in a direction substantially parallel to the longitudinal axis of said base member. This facilitates the forming of a plurality of parallel cuts or grooves without having to move the workpiece and base member relative to one another. Preferably the support member is carried by a carriage slidably mounted to the base member.

Where the base member is elongate, the support member may extend therefrom at any convenient angle or even at a variable angle chosen by the user. Preferably however it extends substantially normally from the longitudinal axis of the base member.

In use the base member may be arranged to rest on, or be attached to, the workpiece. Preferably however the base member comprises two laterally spaced base portions arranged to straddle the workpiece. Not only does this mean that the base member can be firmly attached to a bench or the like, but it is also especially beneficial in the context of elongate workpieces such as kitchen worktops since it means that the length of the workpiece no longer need be of concern. The height of the cutting/abrading means in use above the workpiece may be fixed, but preferably means are provided to vary said height . Means may be provided on the base member for varying the height of the support member. Preferably however means are provided for varying the height of the cutting/abrading means with respect to the support member, e.g. by mounting the cutting/abrading means on a mounting member which is rotatable with respect to the support member. This effectively allows the height of the cutting/abrading means, which will typically be circular in profile, to be adjusted, e.g. for wear, without having to move the entire support member.

The means for varying the inclination of the support member may be arranged to set the inclination at one or a plurality of discrete values, but preferably continuous variation of the inclination is provided. Most preferably a predetermined maximum angle through which the inclination may be varied is set. This maximum angle is preferably between 2° and 5°. Similarly the support member may be movable in a direction parallel with the axis of the base member in discrete steps, but preferably its position is continuously variable.

The apparatus in accordance with the invention may be designed to be fixed - i.e. so that workpieces must be placed underneath it. Preferably however the apparatus is portable - i.e. it can be placed over the workpiece .

The invention extends to an apparatus in accordance with the invention and a cutting or abrasive means. The apparatus may comprise means to provide the drive power for said means, but preferably the apparatus comprises means to connect a remote drive source. This enhances its versatility and portability. Any suitable power may be used e.g. electric, hydraulic or pneumatic power. The cutting/abrading means may be integrally mounted to the support member with the mounting therefor thus being an integral part of said means, but preferably the cutting/abrading means is removable as a unit. This allows it easily to be replaced if necessary. It is to be understood that this feature is separate from the replaceability of the consumable part of a cutting/abrading means such as an abrasive disc, polishing disc or the like.

The cutting/abrading means preferably comprises means to rotate a suitable cutting/abrading disc. Most preferably this means is arranged to accommodate discs from 100mm to 180mm in diameter and/or discs up to 20mm thick.

The means for varying the inclination of the support member preferably comprises a rotary support portion of the base member to which the support member is mounted. In an alternative embodiment such means comprises a cam surface extending in the direction of sliding of the cutting/abrading means and a cam follower arranged to run along said cam surface. It is to be understood that the term

"cutting/abrading means" as used herein is intended to refer to means for cutting, grinding, filing, routing, smoothing, polishing, buffing or working on the workpiece in any other way involving direct contact with the workpiece.

Certain preferred embodiments of the present invention will now be described, by way of example only with reference to the accompanying drawings in which:

Figure 1 which is a perspective view of an apparatus in accordance with the invention; and Figure 2 is a perspective view of a second embodiment of the invention.

The apparatus shown in Figure 1 comprises a base member generally indicated at 2 which comprises a pair of laterally spaced base portions 4 which in use are intended to be clamped to a workbench e.g. using screws (not shown) . A shaft 6 extends between the two base portions 4 and is mounted at each end to a respective base portion so as to be rotatable about its axis. Crank handles 8 are attached to either end of the shaft 6 so as easily to enable it to be rotated manually. The handles 8 each comprise an arcuate slot 10 through which extends a threaded spigot 12 which receives a nut (removed for clarity) . This arrangement allows the shaft 6 to be rotated within a preset range of angles and to be fixed in any rotational position within this range .

A runner bar 14 is rigidly attached to the shaft 6 parallel to it by means of screws 16. This bar 14 provides a counter-moment to the cantilevered support member 26, described in greater detail below. The underside of the runner 14 provides support for a pair of rollers 18 (only one of which can be seen in the Figure) which are free to rotate about respective stub axles extending rearwardly from a carriage member 20. The shaft 6 extends through this carriage member 20, allowing it to slide laterally along the shaft 6. The inclination of the carriage member 20 is therefore determined by the rotational position of the shaft 6.

Two respective halves 22 of a sliding mechanism are fixed to the upper face of the carriage member 20. Each sliding mechanism half 22 comprises a generally U-shaped channel on its side with axles extending between the upper and lower channel walls at either end which mount horizontally disposed rollers 24.

A generally rectangular elongate support member 26 is disposed between the sliding mechanism halves 22 and is located vertically by the rollers 24 which locate in V-shaped grooves 28 on either side of the support member 26. This arrangement allows the support member 26 to slide freely backward and forward with respect to the base member 2. The inclination of the support member is determined by that of the support carriage - i.e. by the rotational position of the shaft 6.

A cutting/abrasive wheel assembly designated generally at 30 is provided at the distal end of the support member 26. This assembly 30 comprises a mounting block 32 which is pivotally mounted to the support member 26 by means of a shaft 34. The angle between the mounting block 32 and the support member 26 is determined by the relative positions of a toothed wheel (not shown) fixed to the shaft 34 inside the mounting block 32 and a cog wheel segment (also not shown) which is fixed to the laterally extending arm of an L-shaped lever 36 which extends through the casing of the mounting block 32.

The arrangement is such that as the lever 36 is rotated clockwise or anti -clockwise the mounting block 32 will be caused to rotate correspondingly about the shaft 34. A further lever 38 is provided to clamp the mounting block 32 relative to the support member 26 when the lever 38 is rotated. This therefore allows the mounting block 32 to be locked in its angular position when the desired angle has been achieved.

As is explained further below, the mechanism described above thus allows the height of the cutting/abrading disc 42 above a workpiece to be varied. At its lower end, the mounting block 32 serves to mount a drive shaft 40. A cutting wheel 42 is fixed to the distal end of the drive shaft 40 so as to be rotated thereby. The drive shaft 40 is driven by a remote drive cable (not shown) which is connected to a drive connector 44. A safety guide 46 is provided over the cutting wheel 42 and may be tilted up to allow access to the disc for the purpose of checking or changing it . A handle 48 is provided on an L-shaped bracket 50 which is pivotally mounted to the drive connector 44. This allows the handle 48 to be rotated to a comfortable working position. This handle 48 is provided to enable the support member 26 to be moved backwards and forwards in the sliding mechanism 22.

A method of cutting inclined grooves in a stone worktop in accordance with the invention, using the apparatus described above, will now be briefly described. Firstly, an aperture for receiving a sink bowl is cut in a worktop using a known cutting machine (none of these is shown) . The apparatus shown in Figure 1 is then placed over the worktop so as to straddle it with the two base portions 4 either side of the worktop. These base portions 4 are then screwed to the bench on which the worktop is sitting using special threaded holes provided for this purpose in the bench.

The nuts 12 are loosened and the user then uses handles 8 to set the angle at which the support member 26 is inclined by rotating the shaft 6 and runner bar 14. A scale is provided above the arcuate slots 10 in the handle 8 to allow this angle to be accurately set. Once the angle has been set, the nuts 12 are retightened to lock the shaft 6 and runner bar 14 in position. A diamond coated cutting wheel 42 is firmly attached to the drive shaft 40 and the safety guard 46 is then replaced. The grinding wheel assembly 30 is set to an appropriate height, taking into account the length of the desired groove and the angle of inclination which has been set, by pulling lever 38 to loosen the assembly 30 and allow it to rotate freely and setting the desired position using the other handle 36. The locking handle 38 is then returned to its locking position.

The inclined groove is formed in the worktop simply by pushing on the handle 48 to slide the support member 26 and thus the grinding wheel assembly 30 rearwardly thereby moving the cutting edge of the grinding wheel 42 along a fixed inclined path and forming the desired inclined groove. In order to form further grooves parallel to the first, it is simply necessary to pull the handle 48 so that the cutting wheel 42 moves back beyond the end of the workpiece and then the whole assembly comprising the cutting/abrasive wheel assembly 30, support member 26 and carriage member 20 can be slid along the shaft 6 to the desired position and the whole cutting process repeated. Once all the desired grooves have been formed, the guard 46 can be lifted and the cutting wheel 42 replaced with a suitable polishing wheel . The back and forth motion of the support member 26 may then be repeated in each groove in order to smooth and polish the formed grooves.

A second embodiment of the invention is shown in Fig. 2. In common with the first embodiment, a support member 26' is mounted so as to be slidable toward and away from a transverse shaf 6 ' extending between two base portions 4'. In contrast to the first embodiment however, the transverse shaft 6' is fixed to the base portions 4 ' and a different mechanism is used to set the inclination of the support member 26' and thus the path traced by the cutting wheel 42 ' . In order to set the inclination of the support member 26', a roller track bar 50 is provided, the flat upper surface 50a of which forms a cam surface and along which runs a cam follower in the form of a roller 52. The roller 52 is carried by a leg 54 attached to the support member towards the distal end thereof. The roller track bar 50 is pivotally attached by means of an axle 55 at its proximal end to the carriage 20' on which - li the support member slides. Two thumbscrews 56, 58 are provided in threaded bores in the roller track bar 50. Each comprises a thumb disc at the top, a vertical threaded shaft engaging the aforementioned threaded bore, and a base disc. One such thumbscrew 56 is provided towards the distal end of the roller track bar 50, whilst the other 58 is provided towards the distal end.

In use the distal end of the support member 26 ' rests on and is supported by the roller track bar 50 ' via the leg 54 and roller 52. Thus as the support member is pushed and pulled by means of the handle 44 ' to reciprocate backwards and forwards, the cutting wheel 42 ' follows a path parallel to the cam surface 50a of the roller track bar.

To cut an inclined groove in a workpiece the two base portions 4 ' are placed either side of the workpiece so that the apparatus straddles it. The thumbscrew 56, the base of which rests on the workpiece, is turned to lower the roller track bar 50 and thus the tip of the cutting wheel 42 ' until the latter just touches the workpiece at the end of the intended groove. The other thumbscrew 58 is set just above the workpiece, say 2 mm above it, in order to act as a stop when the desired inclination of groove is cut.

The cutting wheel 42 ' is then set spinning and the handle 44' used to reciprocate the support member 26' and cutting wheel 42' to cut a shallow inclined groove. The thumb wheel 56 is gradually turned to lower the cutting wheel 42' to cut a more steeply inclined groove, until the base of the proximal thumbscrew 58 comes into contact with the workpiece, signifying that the desired inclination of groove has been reached. The procedure may then be repeated by sliding the carriage 20' along the transverse shaft 6' to cut a parallel groove.

It will be apparent to those skilled in the art that many modifications and variations could be made to the embodiments described above within the scope of the invention. For example, the described apparatus need not be used to cut inclined grooves in a worktop but may instead be used to make complete cuts e.g. in tiles or the like. Furthermore, the apparatus may be used to work with any suitable material, not necessarily stone or marble e.g. it may be useful for working with wood, plastics or glass.

Claims

Claims :

1. An apparatus for guiding the movement of a cutting/abrading means, comprising a base member, a support member mounted to said base member and serving to mount the cutting/abrading means in such a way that it is slidable toward and away from said base member, and means for setting the support member at a chosen vertical inclination relative to said base member.

2. An apparatus as claimed in claim 1 wherein said support member is mounted to said base member via a cantilever mounting.

3. An apparatus for guiding the movement of a cutting/abrading means comprising a base member and an elongate support member mounted to said base member via a cantilever mounting, said support member serving to mount the cutting/abrading means in such a way that it is slidable toward and away from said base member.

4. An apparatus as claimed in claim 3 comprising means for setting the support member at a chosen vertical inclination relative to said base member.

5. An apparatus as claimed in claim 1, 2 or 4 wherein said means for setting the support member at a chosen vertical inclination comprises a rotary support portion of the base member to which the support member is mounted.

6. An apparatus as claimed in claim 1, 2 or 4 wherein said means for setting the support member at a chosen vertical inclination comprises a cam surface extending in the direction of sliding of the cutting/abrading means and a cam follower arranged to run along said cam surface .

7. An apparatus as claimed in claim 1, 2 or 4 to 6 wherein said inclination is continuously variable.

8. An apparatus as claimed in any preceding claim wherein said base member is elongate.

9. An apparatus as claimed in claim 8 wherein said support member is mounted so as to be movable in a direction substantially parallel to the longitudinal axis of said base member.

10. An apparatus as claimed in claim 8 or 9 wherein said support member extends substantially normally from the longitudinal axis of said base member.

11. An apparatus as claimed in claim 8, 9 or 10 wherein said base member comprises two laterally spaced base portions .

12. An apparatus as claimed in any preceding claim wherein said support member is slidably mounted with respect to the base member.

13. An apparatus as claimed in any preceding claim comprising means for varying the height of said cutting/abrading means above a workpiece.

14. An apparatus as claimed in claim 13 comprising means for varying the height of the cutting/abrading means with respect to the support member.

15. An apparatus as claimed in any preceding claim including a cutting/abrading means.

16. An apparatus as claimed in claim 14 wherein said cutting/abrading means is removable as a unit.

17. An apparatus as claimed in claim 15 or 16 comprising means to rotate a cutting/abrading disc.

18. An apparatus as claimed in claim 15, 16 or 17 comprising means to connect said cutting/abrading means to an external drive source .

19. An apparatus as claimed in any preceding claim which is portable.

20. A method of forming an inclined groove in a workpiece comprising positioning above said workpiece an apparatus adapted to guide a cutting/abrading means along a path inclined with respect to said workpiece, and moving said cutting/abrading means in the direction of the desired groove along said path, thereby forming said groove.

21. A method as claimed in claim 20 wherein said apparatus is as claimed in any of claims 1 to 19.