AU636802B2

AU636802B2 - Router attachment

Info

Publication number: AU636802B2
Application number: AU86820/91A
Authority: AU
Inventors: Nigel Gibson
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-10-29
Filing date: 1991-10-29
Publication date: 1993-05-06
Anticipated expiration: 2011-10-29
Also published as: AU8682091A

Description

1

AUSTRALIA

Patent Act COMPLETE SPECIFICATION

(ORIGINAL)

Class I V 0 nt. Class Application Number: Lodged: 90 *0 o 0 0*9* 00 o *0 0 0! 0 0r 0009r O 0 'Iii 0* (4 Complete Specification Lodged: Accepted: Published: Priority: Related Art: Names(s) of Applicant(s): NIGEL GIBSON Actual Inventor(s): NIGEL GIBSON Our Address for service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street MELBOURNE, Australia 3000 Complete Specification for the invention entitled: ROUTER ATTACHMENT The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1 0804N ROUTER ATTACHMENT This invention relates to a router attachment which is capable of producing variable depth routing, a template adapted for use therewith, a router including such an attachment and a method of routing.

Known techniques and apparatus for providing variable depth routing are generally either too expensive, requiring large and complex machinery, such as overhead routers and computerized robot-like routers, or are excessively labour intensive, such as methods of hand carving. This is particulairly so, where symmetrical or more complex patterns are involved. Thus, most modern techniques of variable depth a0 t routing, and more importantly the modern designs and patterns 0 V 6 1 of variable depth routing, are beyond the means of most ~,businesses and tradesman.

Accordingly, it is an object of the present invention to overcome or at least alleviate one or more of the difficulties associated with the prior art.

The present invention resides in a router attachment including: ruea body member, having a mounting end mountable to a rouerand a work end having an inclined guide surface capable of engaging a variable width slot in a template; said body member having a centrally located bore able to co-operate with a cutter member of a router.

The router attachment is suitable for use with a router having a cutter member. The cutter member preferably comprising a shaft, which is releasably secured within a collet or a chuck, and a cutter tip which includes a cutter blade or blades. The collet is rotatably secured to the body of the router for rotation about a central axis. The body member is preferably substantially annular with the centrally located bore extending there through communicating with each end of the body member. Most preferably, the bore is coaxialy arrd~nged within the body member. The bore may be in a stepped arrangement, to allow for fittings so the router attachment can connect to a router.

39 Accordingly, a further embodiment of the present WDN D- -2

I

invention resides in a variable depth router including a cutter member having a cutter tip and a shaft, and a router attachment as previously described; wherein the router attachment is adapted to cooperate with the cutter member so that the cutter member is located within the bore of the body member, the shaft being releasably secured within or in association with a collet located near the mounting end and the cutter tip protruding externally of the work end.

The router attachment may be mounted on a router by passing the cutter member through the bore to allow for the arrangement where the cutter tip is at least partially ~projecting through the inclined guide surface of the work o o o end. The router attachment may be mounted by means of a plate o attached the router, or may include a sleeve that passes over S. the shaft to connect directly within or to the collet. The oooo o sleeve may turn with the collet. Bearings attached between the sleeve and work end may be used to prevent the inclined guide surface from rotating therewith, particularly when the inclined guide surface strikes the template. With the cutter member secured within the router attachment, the router S attachment is capable of moving with the cutter member in a lateral direction.

o 4The work end of the body member preferably comprises a 2 single inclined guide surface in the form of an inverted and o truncated cone. When mounted on a router, the guide surface is inclined towards the axis of the cutter member from a point of maximum width to a point of minimum width. The minimum a width of the guide surface preferably corresponds generally with the maximum width of the cutter tip itself.

It will be appreciated that the inclined guide surface may be radially discontinuous, such as may be provided by simply having opposing inclined arms mounted on either side of the cutter member. Any such configuration may be utilized provided the cutter member is capable of being supported away from each side of a template slot, and provided there is an inclined surface to act as a guide.

It is most preferred that the router attachment of the 39 present invention includes a substantially planar template WDN 3 having at least one slot. The slot is preferably variable but it should be appreciated that it may be of constant width. It is preferred that the attachment member and template form a kit to complete the router attachment.

The inclined guide surface, should be capable of engaging with the slot of the template, the slot being of such a width to allow the cutter tip to pass through the slot.

Accordingly, a further aspect of the present invention resides in a substantially planar template for use in a variable depth router as previously described wherein the template includes at least one slot, the width of the slot not being wider than the maximum width of the inclined guide S surface and a minimum width equal to or greater than the maximum width of the cutter blades. It should be appreciated I If 1' however that these widths are merely preferred and it is

'I

1 contemplated that widths that extend beyond or less than these t preferred widths are contemplated.

I I When in use, the template is placed on a surface of a piece to be routed, and the router, with the router attachment member of the invention mounted thereto, engages the template. The inclined guide surface is placed in contact with a slot, preferably with the router held vertically, and is moved to slide along the slot while remaining in contact o°°o with the slot. As the width of the slot varies the contact 0. 40 25 point with the guide surface of the attachment moves axially up or down the guide surface, which adjusts the rise and fall a 4ft of the cutter tip towards or away from the piece to be routed. Thus, if the minimum width of the slot is such that, S when in place, the point of the cutter tip is immediately adjacent the piece, any increase in width of the slot will guide the cutter tip into the piece to begin the routing process.

Of course, a large range of configurations of slots for templates may be used depending on requirements for particular designs. It will also be appreciated that where a particular design requires a constant depth of cut, slots of constantV width may be used.

Further, a number of templates may be used in 39 combination to provide a particular design. For instance,

V

WDN 4 many complex designs are symmetrical about either a line or lines, or a point. Thus, one template may produce half a design and then turned over or translated to produce the other half. Alternatively, one template may produce one quarter of a design, or be required to be placed in four positions.

Further still, two or more templates may be used over the same area of work to add additional features. This is particularly useful where a particular pattern would require a template to have an annular slot, which of course would cause the solid centre to fall out. Such patterns not obtainable by a single template may be produced by overlapping two or more templates with appropriate slots.

In a preferred form the templates may be secured in a S frame for stable use over a work-piece. The frame may be subsequently secured to the work-piece so that if the template requires turning, or if a second template is required as described above, the correct alignment with the work-piece is maintained. Further, a frame may also be used to hold a number of templates together, in a side-by-side relationship.

It is envisaged that the templates adapted for use with the router attachment may be produced by the use of a computer-aided-design (cad) system linked to a digitizer or the like. The patterns may either be directly drafted into the cad system, or may be sketched and then scanned with the digitizer. Preferably the system will then be capable of S determining the required number and configuration of slots and S templates, and will be linked to a penta graph cutting system for possible mass production. An advantage of this system is that software may be transferred to manufacturers and distributors, rather than transferring templates themselves.

In a preferred form, the router attachment of the invention is mounted to a plunge router. Plunge routers generally have support means which support the cutter tip perpendicularly to the work-piece, and are spring loaded such that the cutter tip is urged away from the work-piece. In this way, the plunge router may be placed over the work-piece and the user forces the cutter member into the work-piece to begin routing. With the router attachment of the invention 39 mounted to such a plunge router, the adapted plunge router may WDN 5 be readily used with the above described template to produce a variable depth carving.

In yet a further aspect of the present invention, the invention resides a method of producing a routed article by providing a variable depth router as previously described; and affixing a template with at least one variable width slot to a surface to be routed, wherein the variable depth router is urged toward the template to engage the inclined guide surface with the slot, and apply relative lateral movement such that the relative height of the cutting blade will vary depending upon the width of the slot, and will contact the surface to be routed at least at one point.

It shall also be appreciated, that the thickness of the It template, and the relative depth at which the cutter ti-p extends beyond the inclined guide surface, will. effect the *depth of the routered groove. In use, these variables should be kept constant, however various effects can be gained by altering one or both of these variables. A preferred depth for the cutter tip to extend beyond the inclined guide surface would be so that a constant line at 450 relative to the shaft is obtained between a cutter blade and the inclined guide surface.

A carved work produced by this invention may also be used as a mold to produce a raised pattern on plaster works or the like.

In order to assist in arriving at an understanding of the present invention, a preferred embodiment is illustrated in the attached drawings. However, it should be understood S that the following description is illustrative only and should not be taken in any way as a restricion on the generality of the invention as described above.

In the drawings: Figure 1 is a section view of a plunge router fitted with a router attachment according to an embodiment of the present invention; Figure 2 is a section view of the mounting plate for the attachment in Figure 1; Figure 3 is a plan view of the mounting plate for the 39 attachment of Figure 1; WDN D- -6 Figure 4 is a section view of the router attachment in Figure 1; Figure 5 is a perspective view of a template on a work-piece for use with the emobodiment of Figure 1; and Figures 6a and 6b are. partial side views of the embodiment of Figure 1 in use with the template of Figure Figure 7 is a section view of an alternative embodiment of a router attachment in accordance with the invention.

Illustrated in Figure 1 is a plunge router 10 having a body 12 supported on legs 14 above a work plate 16. The legs 14 are mounted on springs 18 which serve to urge the body 12 away f rom the base plate 16. Hand grips 20 are provided for a user to urge the router towards a work-piece placed below the work plate 16.

The router 10 includes a collet 22 for releasably 4 1 securing a cutter member 24. Collet 22 is rotatably secured tT to the motor (not shown) of the router 10 by an attachment shaft 26. The cutter member 24 comprises a shaft 28 and a cutter tip Mounted to the body 12 of the router 10 is the router attachment 32 of the present invention. The router attachment 32 is bolted to a mounting plate 34 which in turn is mounted to the body 12. The router attachment 32 comprises a substantially annular body which is defined by a cylindrical section 36, and an inverted and truncated conical section 38 which is turn defines an inclined guide surface Figure 2 and Figure 3 shows the mounting plate 34 in greater detail. Illustrated is a base plate 42 having four bolt holes 44 for attachment to the body of the router.

Hollow spacers 46 are provided to separate the base plate 42 from the body of the router, which are capable of receiving bolts (not shown) therethrough. Centrally located on base plate 42 is an annular boss 45. Boss 45 includes external4 threaded apertures 47 and an alignment aperture 48 for receiving and securing to the router- attachment 32. Thus, boss 45 acts as a bush and is sleeved by the mounting end of the router attachment 32 (see Figure 4) when the router attachmen-Lt 32 is attached thereto. Grub screws may then be V- used to secure the router attachment to the mounting plate.

0. _X I -1 ~-rr*rr Figure 4 shows a router attachment 32 having a mounting end 50 and a work end 52. The mounting end 50 is defined by an annular sleeve portion 54 which may be secured to boss by grub-screws 56 in threaded apertures 58. The work end 52 is defined by an inclined guide surface 60 formed by an inverted and truncated cone. Intermediate the mounting and work ends 50, 52 is an annular body of constant diameter.

The router attachment 32 is substantially annular and surrounds an opening defined by a mounting bore 62, an intermediate bore 64, and a work bore 66. The opening is such that the attachment 32 is capable of being mounted about a router collet to be spaced therefrom. When mounted on a router, the cutter tip projects beyond the work end 52 such o o that the widest part of the cutter tip is adjacent or slightl-y oo oJ i5 beyond the narrowest part of the work end 52. This is readily S discernible from Figures 6a and 6b.

*000 0o00 Figure 5 illustrates a template 70, having a variable width slot 72, resting on the surface of a work-piece 74. A variable depth carving 76 is shown in the surface of the work-piece 74. Figure 6a corresponds to the narrow end 78 of S slot 72 when a router having a router attachment 32 is placed therein. Due to the thickness of the template 70, the contact o o thereof with the bottom portion of the inclined guide surface ooo 60 prevents the cutter tip from contacting the work-piece 74.

As the router is moved along the slot 72 from the narrow end 000000 78 to the wide end 80, with the inclined guide surface remaining in contact with the template 70 on either side of the slot 72, the increase in width allows the point of contact S to move along the inclined guide surface 60, allowing the cutter tip to fall, and produce a carving having a gradual increase in depth and width. The position of the router at the point of slot maximum width is shown in Figure 6b, where a maximum depth cut has been produced. In this example, the template is 18mm thick, and has a minimum slot width of 32mm and a maximum slot widthi of 58mm. This allows a cutter tip of diameter 26mm and depth 13mm to produce a maximum cut at the widest slot diameter, given the presence of a 3mm clearance from the shoulder of the cutter tip to the attachment, and a 39 further 2mm stop along the axial distance of the inclined WDN 8 guide surface, Of course, various of these dimensions may be altered depending on requirements for particular works, and specifially depending on depth of cut required, size and configuration of cutter tip, and the angle of inclination of the guide surface. In respect of this latter parameter, the illustrated attachment has a guide surface at an angle of 450. This angle is preferred as greater angles require less movement to provide the same depth cut, and thus require great care in use, and smaller angles require very large variations in slot width which are impractical and difficult to work with.

Figure 7 illustrates an alternative embodiment to the .0 ap invention, where the body 12 includes a sleeve 13 and an 00 0 inverted truncated cone 61. The sleeve 13 is fitted over the shaft 28. The sleeve defines the mounting end of the body o-f oQ! 0 5 the router attachment while the inverted truncated cone provides the work end. The sleeve 13 is held over tha shaft by a recessed adjusting screw 90 in bush 91. This embodiment allows for a more universal application of the attachment, and removes the need to include a mounting plate. The screw and bush 91 may form part of or be connected directly to a ~00: router. The shaft 28 may also include a internal crevice 19 0 that allows the screw and bush to be secured within the shaft.

The inclined guide surface 60 with protective stops 63 is connected to the sleeve 13 by means of sealed and caged 2,9 bearings 15. The sleeve may releasably be secured within a 4* collet (not shown) and will spin with the collet. The bearings will prevent the work end from spinning, particularly when in contact with a template. The cutter blades 17 are at 0 an angle of 450 to the shaft and forms a relatively continuous line with the angle of the inclined guide surface 0 Thus, the attachment of the present invention provides a simple alternative to the known sophisticated machinery, which may be easily attached to a standard router. The attachment allows for an provides rapid variable depth routing when used in conjunction with the templates of the invention.

Those skilled in the art will appreciate that there may be many variations and modifications of the configurations described herein which are within the scope of the present i nvention.

N 9

Claims

1. A router attachment including: a body member, having a mounting erd, mountable to a router; and a work end having an inclined guide surface capable of engaging a variable width slot in a template; _for e( said body member having a centrally located bore abl4e- toA- c cpratc wieth a cutter member of a router.

2. A router attachment according to claim 1, further including a template having at least one slot, said slot being -oo of such a width to engage said inclined guide surface of the body member; o wherein the body member and template are capable of lateral movement relative to each other. I

3. A router attachment according to claim 1 or 2, wherein the inclined guide surface is in the form of an inverted and truncated cone. a was, I

4. A router attachment according to anyone of claims 1 to 3 wherein the body member is of a substantially annular configuration, having a coaxial axis with said bore, and capable of co-operating to surround said cutter member, said cutter member being locatable within a collet of a router. S9, A

5. A router attachment according to any one of claims 1 to 3 wherein the mounting end includes a sleeve capable of co-operating to surround said cutter member, said sleeve being locatable within a collet of a router..

6. A variable depth router including; a cutter member including a cutter tip and a shaft; a router attachment according to anyone of claims 1 to wherein the router attachment is adapted to co-operate with the cutter member so that the cutter member is located within the bore, the shaft being releasably secured within or F in association with a collet located near the mounting end of 10 24 the body member, and the cutter tip protruding externally of the work end.

7. A variable depth router according to claim 6 wherein the cutter tip protrudes sufficiently so that the edge of a cutter blade and the inclined guide surface provide a substantial.j!y continuous line at a specified angle relative to the shaft.

8. A variable depth router according to claims 6 or 7 further including biasing means to urge the cutter member away ,~from a surface to be routed.

9. A variable depth router according to anyone of claims -6 to 8 wherein the biasing means includes at least one spring 4 ~located within a frame supporting the cutter member.

A substantially planar template for use in a variable depth router according to anyone of claims 6 to 9 wherein the template includes a slot, the width of the slot not being (,si wider than the maximum width of the inclined guide surface and a minimum width equal to or greater than the maximum width of the cutter tip. 23

11. A template according to claim 10 wherein the template, in use, is removably affixed to the surface of an object to be ,ik routered; and is of a depth to allow the cutter tip to contact the S surface of the object to be routered.

12. A template according to claim 10 or 11 wherein the slot is of a variable width.

13. A method of producing a routered article including the steps of; providing a variable depth router according to anyone of claims 6 to 9; and affixing a template with at least one variable width 39 slot to a surface to be routered; WDN 11 wherein the variable depth router is urged toward the template to engage the inclined guide surface with the slot, and apply relative lateral movement between the router attachment and template such that the relative height of the cutter blade will vary, dependent upon the width of the slot, the cutter blade contacting the surface to be routered at least at one point.

14. A method according to claim 13 wherein the template may bc translated or transposed along a line of symmetry to produce a symmetrical routered pattern.

A router attachment according to claim 1 substantially as hereinbefore described with reference to any one of the ji 5 drawings.

16. A variable depth router according to claim 6, substantially as hereinbefore described with reference to any one of the drawings. DATED: 29 October, 1991 PHILLIPS ORMONDE FITZPATRICK Attorneys for: el# NIGEL GIBSON *.y 39 WDN WDN 12 ABSTRACT A router attachment including: a body member, having a mounting end, mountable to a router; and a work end having an inclined guide surface capable of engaging a variable width slot in a template; said body member having a centrally located bore able to co-operate with a cutter member of a router. 7909N 3 39 I WD 1