GB2507347A

GB2507347A - Depth stop for rotary cutting tool

Info

Publication number: GB2507347A
Application number: GB201219407A
Authority: GB
Inventors: Stanley Pritchard Daykin
Original assignee: MOIRA WENDY DAYKIN
Current assignee: MOIRA WENDY DAYKIN
Priority date: 2012-10-29
Filing date: 2012-10-29
Publication date: 2014-04-30
Also published as: GB201219407D0

Abstract

A depth stop, for use with a rotary cutting tool having a cutting disc 70 mounted on a shaft 40, comprises a contact member 110 and a spacing member 100, 120. Contact member 110 has a hole through which shaft 40 may rotate, and may comprise a flat plate or a ball bearing. Spacing member 100, 120 keeps contact member 110 spaced from the disc 70, and preferably comprises a sleeve 100 in the hole of contact member 110 and a collar 120 receiving sleeve 100 and rigidly connected to contact member 110. The spacing member also comprises a fixing device 130, for example a grub screw, for holding collar 120 to sleeve 100. Also disclosed is a tool with a depth stop and a method of using the tool. The regulator is particularly suitable for forming undercuts in plasterboard, polystyrene, bricks, breeze blocks and other masonry.

Description

APPARATUS AND MET! IOD FOR DEPTI 1 REGULATION OF ROTARY CUTflNG TOOLS The present invention relates generally to a depth regulation of rotary cutting tools and finds particular, although not exclusive, utility in a depth regulator for use with rotary cutting tools, a depth regulating rotary cutting tool, and a method of forming an undercut in a work piece of a predetermined depth.

Disc cutters are known in the art, in which a cutting disc (for cutting a solid material) is coupled at its centre to a first end of a shaft substantially perpendicular to a plane of the disc, whereby a rotation generator coupled to an opposing end of the shaft rotates the shaft about an axis of the shaft, such that the disc rotates in order to cut, grind and/or abrade a solid materiaL Such disc cutters may be used to form an undercut in a work piece, such as a wall, bench, or other structure, by inserting the disc into a recess in the work piece, rotating the disc with the rotation generator, and moving the disc in a direction within theplaneofthedisc. Inthisway,thedisccanbeusedtocutaslotintotheworkpiece having a thickness approximately equal to the thickness of the disc, and having an extent approximately equal to the radius of the disc. However, using currently known disc cutters, the depth of such a slot from a surface of the work piece cannot be regulated.

Further, the angle of the slot with respect to a surface of the work piece cannot be regulated. Still thrther, unintentional movement of the disc by transverse motion along the axis of the shaft, and/or by pivotal motion about any other axis, may cause damage to the disc cuttec Specifically, such unintentional movement may cause the disc to become deformed, weakened and/or broken.

According to a first aspect of the present invention, there is provided a depth regulator for use with a rotary cutting tool, the rotary cutting tool for forming an undercut in a work piece, the rotary cutting tool of the kind comprisinç a cutting disc for cutting a solid material; a shaft having a first end coupled to the centre of the disc substantially perpendicular to a plane of the disq and a rotation generator coupled to a second end of the shaft, wherein the rotation generator is arranged to rotate the shaft about an axis of the shaft wherein the depth regulator comprises: a contact member having a hole through which the shaft is arrangable to pass such that the shaft is rotatable within the holç and a spacing member configured ±br adjustably maintaining a spacing of the contact metnber from the disc within a predetermined range; wherein the depth regulator is configured for a surface of the contact member to contact a surface of the work piece in which the rotary cutting tool forms the undercut such that a predeternnned depth of the undercut in the work piece may he achieved.

Tn this way, by placing a surface of the contact member in contact with a surface of the work piece (for instance, against the work piece), the depth of the disc bclow the surface of the work piece may be maintained within a predetermined range, thereby allowing an operator to cut a slot in the work piece of a predetermined depth, arid thercby avoiding a risk of damage to the disc by unintentional transverse movement of TO the disc in a direction along the axis of the shaft.

The depth regulator may be attachaNe to the rotary cutting toul, for instance to the shaft, the disc, and/or the rotation generator.

The cutting disc may comprise a cutting edge and/or a cutting surface. The cutting disc may he sharp and/or rough. The cutting disc may he suitable for applying an acutely directed force that may separate a solid material to either side of the disc.

Alternatively, the cutting disc may be suitable for abrading and/or grinding a region of a solid material to form a s'ot therein. The disc may be substantially circular in form, for instance having a lenticular or cylindrical three-dirtierisional shape. Alternatively, the disc may he rotationally asymmetric about its centre, or may have a finite order of rotational symmetry, such as I-fold, 2-fokl, 3-fold, 4-fold, 5-fold, 6-fold, 7-fuld, or 8-fold rotational symmetry. The centre of the disc may be its centre of mass, projected into a plane of the disc. Alternatively, the centre of the disc may he spaced from its centre of mass, projected into a plane of the disc. The disc may comprise metal, ceramic, diamond or other suitable material. The disc may comprise at least one hole for receiving the shaft therethrough for attachment therewith.

The shaft may he substantially cylindrical in form. The shaft may he a rod. The shaft may comprise metal or some other suitable material. The shaft may he an arhour and/or mandrel. Thc shaft may comprise a first part having a first axial diamcter, and a second part having a second axial diameter larger than the first axial diameter. The second part may he configured to support the disc thereon substantially perpendicular to the shaft. The shaft may comprise a threaded conncctor for co-operation with the disc. The shaft may comprise a nut for threadaNy engaging with the threaded connector such that the disc is held on the shaft. The nut and the second part of the shaft may be configured to clamp the disc therebetween. The shaft may comprise a screw for securing the disc to the second part.

The rotation generator may comprise an electric power tool, electric hand tool, anti/or mechanical hand tool. The rotation generator may comprise a chuck for receiving the second end of the shaft therein. The chuck may he configured to releasably hold the shaft. The rotation generator may be configured to rotate the shaft relative to an operator. The rotation generator may comprise a housing.

The spacing member may comprise a sleeve arranged within the hole in the contact member, and the sleeve may be configured to receive the shaft therein. The lO sleeve may provide a clearance from the shaft of less than 1mm. The sleeve may be in contact with the shaft substantially around an entire circumference of the shaft. There tiny he a low-friction engagement between the sleeve and the shaft, such as a bearing arrangement. The spacing member may comprise a fixing device for releasably holding the sleeve within the hole at a predetennmed location along a length of the sleeve. In this way, the spacing member may he usable with any rotary cutting tool having a suitably si2ed shaft, irrespective of the rotation generator used. In particular, the sleeve may be free to rotate about its axis independent of the shaft, and may be disposed on the shaft to be movable, for instance by sliding, between a first position adjacent the disc and a second position adjacent the rotation generator, for instance the chuck. The sleeve may be substantially tubular. The sleeve may have an internal diameter of between approximately 3mm and 10mm, in particular between approximately 4mm and 6mm, particularly approximately 5mm. Additionally, the contact member may he held at a desired location along the sleeve. The movement of the sleeve along the shaft allows for movement of the contact member within a predetermined range.

The spacing nienther may further comprise a collar rigidly connected to the contact member and configured to receive the sleeve therein, wherein the fixing device releasably connects the collar to the sleeve. In this way, the contact member may he held substantially at a desired orientation with respect to the sleeve. In particular, the contact metnber may be held substantially perpendicular to an axis of the sleeve; however, alternative arrangements are also envisaged. The collar may he ring-like, and/or may form an annulus. The collar may he welded to the contact member, or otherwise attached such as by gluing, riveting or screwing. The fixing device may he disposed within the collar and may he a screw, for instance a grub screw, or other suitable clamping arrangement. Tightening of the fixing device may clamp the sleeve within the collar.

The sleeve may he conhgured to extend along the shaft substantially from the disc to the rotation generator, for instance to the chuck. Alternatively, the sleeve may he configured to extend along the first part of the shaft substantially from the second pan of the shaft to the rotation generator. In this way, motion of the sleeve along the shaft may be limited. The skeve may be disposed on the shaft such that it is substantially inhibited from moving in a direction along the shaft.

The spacing member may be configured for adjustably maintaining a spacing of lO the contact member from one end of the sleeve within a predetermined range. The spacing member may be configured for adjustably maintaining a spacing of the contact member from the housing substantially at a predetermined distance.

The contact member may he a substantially fiat plate. In this way, the contact member may he slid across a flat surface of the work piece in order to move the disc in its plane, such that a slot of uniform depth may he cut. Also, the contact member may act to prevent passage of dust from the disc side region of the contact member to the rotation generator side region of the contact member.

Alternatively, the contact riietriher may he a hearing arrangement. In this way, the contact member may he rolled across a flat surface of the work piece in order to move the disc in its plane, such that a slot of uniform depth may be cut. For instance, the bearing arrangement may be a plurality of balls located in a plane, such that the balls may engage a surface of the work piece.

The depth regulator inay he constructed substantially from metal, in order to he robust against damage and/or wear. However, other suitable materials could he used.

The depth regulator may he configured for substantially an entire surface of the contact member to he engagahle with the work piece. In this way, uniform contact with a work piece may he enabled such that contact pressure between the contact member and the work piece may he distributed.

According to a second aspect of the present invention there is provided a depth regulating rotary cutting tool comprising: a rotary cutting member for forming an undercut in a work piece, the rotary cutting member of the kind comprising: a cutting disc for cutting a sohd material; a shaft having a first end coupled to the centre of the disc substantially perpendicular to a plane of the disc; and wherein the second end of the shaft is configured to be coupled to a rotation generator, such that the rotation generator may route the shaft about an axis of the shaft; a contact member having a hole through which the shaft is arrangahie to pass such that the shaft is rotatable within the hole; and a spacing member configured for adjustably maintaining a spacing of the contact member from the disc within a predetermined range; wherein the depth regulating cutting tool is configured for a surface of the contact member to contact a surface of the work piece in which the rotary cutting tool forms the undercut such that a predetermined depth of the undercut in the work piece may be achieved.

According to a third aspect of the present invention, there is provided a depth regulating rotary cutting tool comprising a rotary cutting tool for forming an undercut in a work piece, the rotary cutting tool comprising a cutting disc for cutting a solid material; a shaft having a first end coupled to the centre of the disc substantially perpendicular to a plane of the disc; and a rotation generator coupled to a second end of the shaft, wherein the rotation generator is arranged to rotate the shaft about an axis of the shaft; a contact member having a hole through which the shaft is arrangable to pass such that the shaft is rotatable within the hole; and a spacing member configured for adjustably maintaining a spacing of the contact member from the disc within a p11etT1itttx1 range wherein the depth regulating rotary cutting tool is configured for a surface of the contact member to contact a surface of the work piece in which the rotary cutting tool forms the undercut such that a predetermined depth of the undercut in the work piece may be achieved.

According to a fourth aspect of the present invention, there is provided a method of forming an undercut in a work piece, comprising the steps of: providing a depth regulating rotary cutting tool; selecting a predetermined range of the spacing of the contact member from the disc; maintaining the contact member within that range; inserting the disc into a recess in a work piece; engaging a surface of the contact member with a surface of the work piece such that the disc lies at a predetermined depth within the recess; rotating the shaft about the axis of the shaft; moving the depth regulating rotary cutting tool in a direction substantially parallel to the surface of the contact membcr (for instance, parallel to the surface of the work piece); and cutting an undercut in the work piece using the disc.

A size of disc may be selected to optimise the extent of a slot to be cut, given the size of recess in which the slot is to be cut. For instance, a disc for use in a recess having a circular cross section of a first diameter may have a disc diameter of a second diameter substantially the same as the first diameter. For instance, the diameter of the disc may he 1mm less than the diameter of the recess.

The cutting tool of the preseirt invention may he used to form cuts in plasterboard, polystyrene, hreee block, brick work, and/or other foms of masonry.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is a perspective view of an embodiment of the invention.

Figure 2 is a cross sectional view of the embodiment of the invention shown in figure 1.

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto hut only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the swe of sonic of the elerrients rriay he exaggerated arid riot drawn to scale for ill ustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to he understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for descrihing relative positions. It is to be understood that the tenns so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

It is to he noticed that the term "comprising", used in the claims, shouki not he interpreted as being restricted to the means listed thereafter; it does not exclude other eletnents or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, hut does not preclude the presence or additti)n of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not he limited to devices consisting only of components A and B. Tt means that with respect to the present invention, the only relevant components of the device are A and B. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in i0 connection with thc embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same enthodiment. but may refer to different embodiments.

Furthemore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly, it should be appreciated that in the description of exemplary ernhodinierits of the invention, various features of the invention are sortietirnes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This mcthod of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, xvhilc some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invcntion, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details arc set forth.

Hoxvever, it is understood that embodi ents of the invention may he practised wiln)ut these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of

this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an in(Iication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term "at least one" may, in some embodiments, mean only one.

The invention will now he described by a detailed description of several ernbo(Iinlents of the invention. It is clear that other embodiments of the invention can he contigured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended churns.

Figure 1 shows a depth regulating rotary cutting tool 10, comprising rotation generator 20 having a chuck 30 that grips a shaft 40. The shaft 40 comprises a first part and a second part 60, having a diameter greater than that of the first part 50. The chuck 30 is shown gripping an end of the first part 50 opposite the end of the first part connected to the second part 60.

A disc 70 is received on the second part 60 such that they are coaxial. The disc 70 is of a greater diameter than the second part 60. The disc 70 is connected to the second part 60 by means of a nut (not shown) threadably received on a threaded connector 90, which extends into the second part 60.

Disposed around the first part 50 is a sleeve 100 that is free to rotate independently of the first part 50. The length of the sleeve 100 is such that axial movement of the sleeve 100 along the first part 50 is limited to less than 1mm. The sleeve 100 extends substantially between the second part 60 and the chuck 30.

Disposed around the sleeve 100 is a substantially fiat 110 plate that can be moved axially along the sleeve 100 such that the spacing between the disc 70 and the fiat plate 110 can he varied.

welded to the flat plate 110 is a ring-like collar 120 that is also disposed around the sleeve 100 such that it can be moved axially along the sleeve 100. A grub screw 130 disposed radially within the collar 120 projects toward the sleeve such that, when tightened, the grub scre\v 130 engages the sleeve 100 such that relative movement between the grub screw 130 and the sleeve 100 is prevented. In this way, relative axial movement between the flat plate 110 and the disc 70 is also prevented. Relative rotational movement between the fiat plate 110 and the disc 70 is permitted due to the shaft 50 rotating freely in the sleeve 100.

Figure 2 shows a cross sectional view of the depth regulating rotary cutting tool in use within a recess 140 in a wall 150. Nut SO, threadably received on the threaded connector 90, clamps the disc 70 against the second part 60.

Tn use, a user determines the desired depth of an undercut 160 in a wall 130, and moves the flat plate 110 along the sleeve 100 until the separation between the disc 70 and the contact plate equals the desired depth of undercut 160. The screw 130 is tightened, for instance by means of an Allen key or other suitable screw drive, thereby maintaining the spacing of the flat plate! 10 from the disc. The disc 70 is inserted into the recess 140 until the fiat plate 110 contacts a surface of the wail 150. As the disc 70 is rotated, the tool 10 is moved in a direction within the plane of the disc 70 such that a slot 160 is cut into the wall 150 that runs parallel to the surface of the wail 150. The flat plate 110 is slid across the surface of the wall 150 in order to provide smooth movement of the disc 70 within the recess 140 and the slot 160. The fiat plate 110 acts to seal the recess 140 such that dust and/or debris from cutting the slot 160 does not exit the recess 140, and additionally maintains the disc 70 parallel to the surface of the wall 150.

Friction between the fiat plate 110 and the wall 150 prevents the fiat plate 110 from rotating.

Claims

CLAIMS1. A depth regulator for use with a rotary cutting tool. the rotary cutting tool for forming an undercut in a work piece, the rotary cutting tool of the kind comprising: a cutting disc for cutting a solid material; a shaft having a first end coupled to the centre of the disc substantially perpendicular to a plane of the disc; and a rotation generator coupled to a second end of the shaft, wherein the rotation generator is arranged to rotate the shaft about an axis of the shaft; lO wherein the depth regulator comprises: a contact member having a hole through which the shaft is arrangable to pass such that the shaft is rotatable within the hole; and a spacing member configured for adjustahly maintaining a spacing of the contact member from the disc within a predetermined range; wherein the depth regulator is contigured for a surface of the contact member to contact a surface of the work piece in which the rotary cutting tool forms the undercut such that a predetermined depth of the undercut in the work piece may be achieved.
2. The depth regulator of claim 1, wherein the spacing member comprises a sleeve arranged within the hole in the contact member, the sleeve configured to receive the shaft therein, and a fixing device for releasably holding the sleeve within the hole at a predetermined location along a length of the sleeve.
3. The depth regulator of claim 2, wherein the spacing menther further comprises a collar rigidly connected to the contact member and contigured to receive the sleeve therein, wherein the flxing device releasably connects the collar to the sleeve.
4. The depth regulator of claim 2 or claim 3, whcrein the slecvc is configured to extend along the shaft substantially from the disc to the rotation generator.
5. The depth regulator of claim 2 or any one of claims 3 to 4, when dependent directly or indirectly on claim 2, wherein the spacing member is configured for adjustably naintaining a spacing of the contact member from one end of the sleeve within a predetermined range.
6. The depth regulator of any p ceding claim, wherein the spacing member is configured for adjustably maintaining a spacing of the contact member from the rotation generator substantially at a predetermined distance.
7. The depth regulator of any preceding claim, wherein the contact member is a substantially flat plate. lo
8. The depth regulator of any one of claims I to 6, wherein the contact member is a hearing arrangement.
9. The depth regulator of any preceding claim, wherein the depth regulator is configured for substantially an entire surface of the contact member to he engagable
10. The depth regulator of claim 2 or any one of clairTis 3 to 9 when directly or indirectly dependent upon claim 2, wherein the fixing device is a grub screw.
11. The depth regulator of claim 2 or any one of claims 3 to 10 when directly or indirectly dependent upon claim 2, wherein the sleeve is substantially tubular.
12. The depth regulator of claim 3 or any one of claims 4 to 11 when directly or indirectly dependent upon claim 3, wherein the collar is ring-like.
13. The depth regulator of claim 3 or any one of claims 4 to 12 when directly or indirectly dependent upon claim 3, wherein the collar is welded to the contact member.
14. A depth regulator substantially as hereinhcforc described with reference to the accompanying drawings.
15. A depth regulating rotary cutting tool comprising:IIthe depth rcgulator of any preceding claim; and a rotary cutting member for forming an undercut in a work piece, the rotary cutting member of the kind comprising.a cutting disc for cutting a solid material; a shaft having a first end coupled to the centre of the disc substantially perpendicular to a plane of the disc; and wherein the second end of the shaft is configured to be coupled to a rotation generator, such that the rotation generator may rotate the shaft about an axis of the shaft.
16. The depth regulating rotary cutting tool of claim 15, thrther comprising a rotation generator coupled to a second end of the shaft, wherein the rotation generator is arranged to rotate the shaft about an axis of the shaft.
17. A method of forming an undercut in a work piece, comprising the steps ofi providing the depth regulating rotary cutting tool of claim 16; selecting a predetermined range of the spacing of the contact member from the disc; maintaining the contact member within that range; inserting the disc into a recess in a work piece; engaging a surface of the contact member with a surface of the work piece such that the disc lies at a predetermined depth within the recess; rotating the shaft about the axis of the shaft; moving the depth regulating rotary cutting tool in a direction substantially paraliel to the surface of the contact member and cutting an undercut in the work piece using the disc.