GB2333480A

GB2333480A - Cutting apparatus

Info

Publication number: GB2333480A
Application number: GB9823929A
Authority: GB
Inventors: Paul Steabben Hepworth
Original assignee: Plasplugs Ltd
Current assignee: Plasplugs Ltd
Priority date: 1998-01-23
Filing date: 1998-11-03
Publication date: 1999-07-28
Also published as: CA2254243A1; GB9823929D0; DE19856336A1; FR2774019A1; AU9613598A; GB9801371D0

Abstract

The apparatus comprises a body 10 which defines a work surface 11 and 12, cutting means 13 and a guide fence 18. The guide fence 18 has two arms 19 and 20 which engage with lips 22 formed in the sides of the body 10, thus preventing disengagement of the guide fence 18 from the body 10 in a direction perpendicular to the work surface 11 and 12. The arms 19 and 20 also provide extensions 23 to the work surface 11 and 12. The body 10 comprises a fluid reservoir 10a in which a removable tray 34, for the collection of sludge from the cutting fluid, is wedged or interference fitted by means of a notch on the tray 34 and a projection 34 on the body 10. A spray guard 14 is fixed to a member 15 upstanding from the body 10 by means of a bolt 17, the head of which 16 is received in a recess in the spray guard 14 to which a cover 53 slidably snap fits.

Description

CUTTING APPARATUS This invention relates to cutting apparatus of the same type as that described and illustrated in PCT specification No: PCT/GB96/01767, namely cutting apparatus particularly for cutting flat plates such as ceramic tiles.

According to a first aspect of the invention cutting apparatus comprises a body having a work surface, cutting means for cutting an article received on the work surface, and guide means against which part of said article is intended to be located, in use, to position said article for said cutting thereof, the guide means being movable in an unlocked state over the work surface to adjust the spacing of the guide means from the cutting means and being lockable in a selected adjusted position, the guide means having two arms at respective sides of, and engaging with, said body so as to maintain the guide means parallel to the cutting means in any adjusted position thereof, and to prevent disengagement of the guide means in an unlocked state, from the body in a direction normal to said work surface.

According to a second aspect of the invention there is provided a fixing arrangement between a first member and a second member at least partly received in or at the first member, the first member having an aperture receiving a shank of a headed bolt, the shank passing through an aperture in the second member, the head of the bolt being at least partly received in a recess in a surface of the first member, and a cover member engageable with said first member at said recess by means of a projection and slot arrangement and being secured in a position to prevent access to said bolt head by snapfit means.

Preferably adjustment means are provided for locking the first and second members together or for allowing relative adjustment therebetween.

Preferably the first and second members are a spray guard and a support blade of cutting apparatus.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded schematic perspective view of cutting apparatus of the invention, Figure 2 is a perspective schematic view of the apparatus of Figure 1 in an assembled form, with a mitre guide not shown, Figure 3 is a top plan view of the apparatus of Figure 2, Figure 4 is a front view of the apparatus of Figure 2, Figure 5 is a rear view of the apparatus of Figure 2, Figure 6a is a fragmentary exploded perspective view of some components of a clip arrangement of the invention, shown fully in Figure 1, Figure 6b is a fragmentary underneath view of part of one of the components of Figure 6a, Figures 7a and 7b are respectively a rear perspective view and a central vertical sectional view of the clip of Figure 6, Figure 8 is a perspective view of the components of Figure 6 in assembled form Figure 9 is a fragmentary perspective view of an outer side of a tray of Figure 1, and Figure 10 is a schematic lateral cross-section showing how the tray is fitted in part of a body of the cutting apparatus.

As with the cutting apparatus of the abovementioned PCT specification, the apparatus of the present invention is constructed from one large generally square moulding, with several smaller mouldings. With the embodiment shown herein, the mouldings provide a reservoir with a sludge tray, a worktop including a removable reservoir cover, a motor housing, and a mitre guide. However the base is different in that the motor cavity and reservoir are formed from different sides and isolated from each other. This makes the motor compartment much easier to seal from water ingress.

Figure 1 shows that the apparatus comprises a main body moulding 10, and a worktop made up of a fixed part 11 and a removable cover part 12 which, when in place over a reservoir 10a of the moulding 10, forms with part 11 a generally continuous flat work or base surface for receiving a tile to be cut at 900 to its plane. A diamond impregnated or other cutting wheel 13, driven in a conventional manner from a motor and gearbox disposed within a compartment in the moulding 10 beneath part 11, projects somewhat above the base at a position between the parts 11 and 12. This part of the wheel 13 is shrouded by a plastics material spray guard 14 adjustably carried on a metal blade-like member or riving blade 15 extending upwards out of the moulding 10 in a conventional manner.

The manner of making the spray guard undetachable by covering the hexagonal head 16 of a fixing bolt 1 7 is one inventive aspect of the cutting apparatus, and is also inventive in isolation, and will be described in detail hereinafter. The compartment containing the motor is isolated, i.e. sealed, from compartment 10a below the part 12 which forms a main reservoir.

Conventionally, the apparatus has a guide fence 18 arranged for slidable movement over the part 12. The fence is formed of a main straight edge part 18a, which has at its respective opposite ends alignment arms 19, 20 which extend normally from part 18a. Each arm is rebated so that its inner, reduced thickness portion 21 fits under a lip 22 extending along opposite parallel sides of the exterior of the moulding 10, at the top thereof, each lip upper surface lying at the same level as the upper surfaces of parts 11 and 12 respectively. These arms keep the fence accurately parallel to that of the wheel cut, and additionally each provide a small worktop extension 23 to support a tile, given that the full depth portion of each arm has its upper surface lying flush (Figures 4 and 5) with the upper surface of the lips 22, and parts 11 and 12, which are supported by a peripheral ledge 24 around the inside of, and just below the open top of, the moulding 10. At each end of the part 1 8a its upper surface is formed with a cylindrical recess 25 having a central circular through hole 26 in the base thereof. Fitted at the recess is a stepped locking knob 27, defining an upper cylindrical grasping portion 28, of substantially the same diameter as the recess 25, and a lower reduced diameter part 29 received in the recess 25. A headed bolt 30, held captive with the knob against relative rotation, has part of its threaded stem 31 extending out from the lower end of the part 29 so as to pass through hole 26 and threadedly engage a nut 32 held captive against rotation in a recess in the underside of a rectangular clamp plate 33, which itself is located in a correspondingly shaped, open inner sided recess in the underside of the part 1 8a directly below the recess 25. The inner edge of the clamp plate 33 is disposed inwardly of the inner edge of the extension part 23, so that during normal movement of the guide fence part of the lip 22 is received between the upper surface of the innermost part of the clamp plate and a flat downwardly directed undersurface of the part 1 8a.

Accordingly by screwing up the knob 27, the clamp plate is effectively drawn relatively upwards to clamp the lip tightly against said underside of part 18a, thereby locking the guide fence in a selected, adjusted position.

When it is desired to adjust the position of the guide fence, the knob is unscrewed, releasing the clamping action of the clamp plate, so that the gap between the clamp plate and said underside of part 1 8a is now large enough for the guide fence to be slid along the lip. Once a selected adjusted position is reached, the guide fence can again be locked in position by screwing up the knob. Of course the construction and actions described for one of the locking knobs is the same for the other knob at the opposite end of part 1 8a.

The construction of the fence 18, and its fitting relative to the parts 11 and 12, by way of the arms 19, 20 is a further inventive aspect of the invention. The use of the lips 22 with the arm portions 21 therebeneath holds the guide fence against disengagement therefrom by upwards lifting, even with the knobs 27 unlocked. Accordingly it can only be removed when slid off the end of the moulding 10.

In use, the tile cutting process, carried out conventionally by use of the wheel 13, produces a fine powder, and this settles out into a sludge after a few minutes. In another inventive aspect of the cutting apparatus, a sludge tray 34 is provided in the bottom of the main reservoir 10a. The tray is a shallow removable receptacle which, when necessary, can be easily lifted out, after removal of part 12, so that the accumulated sludge can be removed and the cleaned tray thereafter reinserted. The tray 34, which is shaped and sized to fill the lower part of the rectangular reservoir 1 0a, has a retaining notch 34a, Figure 9, in the centre of the exterior surface of one of its longer sides. The facing sides of the notch converge upwardly so that the notch tapers. In the reservoir 1 Oa, a central rectangular rib 34b is formed on the internal surface of a side wall of the moulding 10, the rib being normal to the surface and extending upwards a short distance from the reservoir internal base surface. This rib is provided to hold the sludge tray in position, and thus to stop any raising of the tray by the effect of air bubbles in the water in the reservoir.

Figure 10 shows, schematically, how the tray is fitted in place. Firstly it is placed at an angle in the reservoir with its un-notched side adjacent the central dividing wall of the moulding 10, and with the lower edge of said side on the reservoir base surface. In this position, shown in the Figure, the top of the rib 34b is received in the bottom of the notch, and the outer vertical surface of the rib contacts the inner base surface of the notch. The tray is then pressed fully down into the reservoir, resulting in a dual holding action. Firstly the tapering of the notch and the thickness of the rib are such that the upper part of the rib is a tight interference fit in the upper part of the notch which is of reduced width between its tapered sides. Secondly as the distance that the rib projects from the reservoir side wall is somewhat greater than the depth of the notch, the tray tends to wedge at point A as shown in Figure 10 as it is pressed down. The material of the rib and/or the tray is such as to allow for such deformation required to allow the wedged tray to be pressed down fully onto the reservoir base surface. However the tray can nevertheless readily be released when required for emptying/cleaning etc. Only one of the two holding means could of course be provided.

Alternatively the tray could be retained by its friction fit onto spikes or the like upstanding from the base surface of the reservoir 1 0a, or by other suitable means which preferably allow easy removal.

The water level in the reservoir 10a may be just above or below the upper edge of the tray 34. The fine ceramic material particles settle out during and between periods of cutting use and form a semi-solid layer in the tray.

As described, the tray is easily removable for cleaning.

Figure 1 shows a mitre guide 35 which is of generally conventional form.

It has each of its opposite side walls formed with a configurated recess 36 to allow the mitre guide to be fitted at opposite inner sides of the main moulding, extending rearwardly and upwardly at the required mitre cut angle, in the same general manner as with known mitre guides.

Figures 6 to 8 show details of the inventive feature mentioned above to prevent access to the bolt head 16. The end of the spray guard at which it is carried by the blade 15 is bifurcated to form two arms, 37, 38 respectively, which are sufficiently springy to be forcibly moved together, but normally spring apart. The blade 15, which is received between the arms, has a central vertical, elongated slot 39 therein. The arm 37 has a circular hole 40 therethrough, which breaks into a recess in the outer side surface of the arm 37, which recess is open at its lower end. As will be described, the threaded shank of the fixing bolt 1 7 extends through the slot 39 and the hole 40 and away from said side surface of the arm 37.

Threadedly engaged on said shank is a clamping knob 41. As it is tightened it engages arm 37 and forces the arms towards one another thereby clamping the spray guard tightly in position on the blade. If the knob 41 is unscrewed the arms spring apart to allow the spray guard to be moved up or down on the blade, by virtue of the bolt stem sliding in said slot 39, or to be pivoted about said blade. Once the required adjustment has been made, the knob 41 is tightened to lock the spray guard in position on the blade.

The arm 38 has in its outer side surface a recess 42 which extends upwardly from the lower edge surface of the arm. The innermost part of the recess 42 is a base surface 43 through which a circular hole 44, coaxially aligned with, and of the same diameter as, hole 40, extends to the other side surface of the arm so that the bolt shank can extend through the hole 44 and then through slot 39 and hole 40. This hole 44 can be extended upwardly with parallel opposite straight sides, to form a slot.

Moving outwards, the next level of the recess is formed by an angled shoulder portion 45 at the closed innermost part, or top, of the recess 42, which thus lies over part of base surface 43. The portion defines symmetrical sloping straight surfaces 46, 47 respectively meeting at a point lying on an extended diameter of the hole 44. The angle between the two shoulders formed by the surfaces 46, 47 is 120 , so as to define a location for two sides of the hexagonal head 16 of bolt 17 thereby preventing said bolt rotating.

At the same level of the recess as the portion 45 and of the same depth thereas are formed two facing grooves 48, 49 respectively in opposite sides of the recess, each extending from the open end of the recess to the portion 45. Finally, the outermost level of the recess is formed with opposite parallel side surfaces 50, 51 respectively extending from the open end of the recess to an inner concavely curved surface 52 disposed beyond the surfaces 46, 47 to define the upwards boundary of the outwardly facing surface of shoulder portion 45.

Fitted at said recess 42 to prevent access to said bolt head 16, and thus possible removal of the spray guard, is a one-piece clip 53, moulded of plastics or other resilient material. The clip has a main cover part 54 substantially matching the shape of the recess, the part 54 having a flat outer face. Its inner face is formed with a hexagonal recess 55 sized to receive the hexagonal head 16 as a close fit. The outer, upper surface 56 of the clip is curved to match the curved surface 52, whilst between the surface 56 and recess 55 is a shoulder portion 57 of the same shape and size as portion 45, and defining at its inner side symmetrical sloping straight side surfaces 58, 59 respectively equivalent to surfaces 46, 47.

The head 16 of bolt 1 7 is of such a thickness that an inner part thereof adjacent the bolt stem has two adjacent side surfaces engaging surfaces 46 and 47, and an outer part remote from the stem has the same two adjacent side surfaces engaging surfaces 58 and 59. A base part 60 of the clip extends rearwardly from the part 54 around the sides of the recess 55 other than sides 58, 59.

At the free end of the base part, opposite vertical sides thereof are formed with laterally extending tongues 61, 62 respectively. The spacing of these tongues from the outer flat face of the clip, and their thickness, is such that they are a close sliding fit in the grooves 48, 49 respectively on assembly, with the outer flat surface of the clip being proud of the outer surface of the arm 38.

The arrangement is that on assembly, with the bolt head in position in the recess 42 and its outer surface flush with, or just proud of, the outer surface of arm 38, the clip is pushed slidingly upwardly to cover the recess with its tongues 61, 62 received in the grooves 48, 49 respectively.

As the shoulder portion 57 engages the bolt head it is resiliently deformed outwardly, until it reaches the position where it is clear of the bolt head and effectively overlies shoulder portion 45, whereupon it snap-fits over the bolt head, so that the bolt head is fully received in recess 55, the cover part 54 lying proud of the outer surface of arm 38, as shown in Figure 8.

In this position the lower surface of the clip forms an exact continuation of the lower surface of the arm 38 so that the clip thus tidily visually conceals the recess 42 with the bolt head therein. Moreover as the snapfit of the clip brings it tightly into engagement with the bolt head with part of the thickness of its curved surface portion 56 within the recess and at the inner surface 52 of the recess 42, it is very difficult for anyone to unsnap the clip from the bolt head by prising it out of the recess 42, by, for example, insertion of a blade under the portion 56 of the clip, and certainly under normal circumstances, i.e. without specialist effort and tools, the bolt, and thus ultimately the spray guard, cannot be removed from the riving blade, thus meeting German Approvals Board requirements.

Instead of the surfaces 46, 47 as well as the recess 55 serving to prevent rotation of the bolt head, and thus the bolt itself, the surfaces 46, 47 or recess 55 alone could be provided. The recess need not be in the flat outer side surface of arm 38, but could instead be in an equivalent surface outward thereof, and preferably parallel thereto.

Claims

CLAIMS 1. Cutting apparatus comprising a body having a work surface, cutting means for cutting an article received on the work surface, and guide means against which part of said article is intended to be located, in use, to position said article for said cutting thereof, the guide means being movable in an unlocked state over the work surface to adjust the spacing of the guide means from the cutting means and being lockable in a selected adjusted position, the guide means having two arms at respective sides of, and engaging with, said body so as to maintain the guide means parallel to the cutting means in any adjusted position thereof, and to prevent disengagement of the guide means, in an unlocked state, from the body in a direction normal to said work surface.
2. Cutting apparatus as claimed in Claim 1, wherein said respective sides of the body are formed with lips, the respective undersides of which are engaged by parts of said arms respectively.
3. Cutting apparatus as claimed in Claim 2, wherein each arm is rebated to provide an inwardly disposed reduced thickness part which engages the underside of its associated lip.
4. Cutting apparatus as claimed in any one of Claims 1 to 3, wherein said arms provide at opposite sides of the body respective extensions to the plane of the article reception surface provided by said work surface.
5. Cutting apparatus as claimed in Claim 4, wherein said guide means is formed of a main, straight, elongated body part with its opposite ends extending beyond the respective opposite sides of the body, with said arms extending normally from said opposite ends respectively and providing said extensions both laterally and longitudinally of the body sides.
6. Cutting apparatus as claimed in Claim 5, wherein releasable locking means are provided at said opposite ends of the guide means respectively, for either locking the guide means in one locked position or releasing it therefrom so that it can move in its unlocked state.
7. Cutting apparatus as claimed in any one of Claims 1 to 6, wherein the body is formed with a fluid reservoir in which a tray is removably disposed.
8. Cutting apparatus as claimed in Claim 7, wherein there is an Interference fit between the tray and part of said body to hold the tray in position.
9. Cutting apparatus as claimed in Claim 8, wherein a side of said tray has a notch in its exterior surface, in which a projection on the body engages as said interference fit.
10. Cutting apparatus as claimed in Claim 9, wherein the rib engages with tapered sides of the notch.
11. Cutting apparatus as claimed in Claim 7, wherein there is a wedging engagement between the tray and part of said body to hold the tray in position.
12. Cutting apparatus as claimed in Claim 11, wherein a side of said tray has a notch in its exterior surface, against which a projection on the body engages to wedge the tray in position.
13. Cutting apparatus as claimed in Claim 7, wherein the tray is removably retained in position by both an interference fit and a wedging action with part of said body.
14. Cutting apparatus as claimed in Claim 7, wherein the tray is removably held in position by means of a friction fit.
15. Cutting apparatus as claimed in any one of Claims 1 to 14, wherein a spray guard shrouds the cutter means, the spray guard being mounted on a member upstanding from the body by fixing means to part of which access is restricted by a cover member.
16. Cutting apparatus as claimed in Claim 15, wherein the cover member is secured in position by a snap-fit engagement.
17. Cutting apparatus as claimed in Claim 16, wherein the cover member conceals a head of a fixing bolt connecting the spray guard to said upstanding member, the head being disposed in an outwardly open recess in the spray guard, into which recess part of the cover member is slidable snap-fittingly to engage with said head so as normally to conceal the recess and prevent access to said bolt head.
18. Cutting apparatus as claimed in Claim 17, wherein the cover member has oppositely directed lateral wings which are received in respective associated grooves at the respective sides of the recess when said cover member is slid into said snapfilling engagement.
19. A fixing arrangement between a first member and a second member at least partly received in or at the first member, the first member having an aperture receiving a shank of a headed bolt, the shank passing through an aperture in the second member, the head of the bolt being at least partly received in a recess in a surface of the first member, and a cover member engageable with said first member at said recess by means of a projection and slot arrangement and being secured in a position to prevent access to said bolt head by snap-fit means.
20. A fixing arrangement as claimed in Claim 19, wherein the recess has a shoulder portion against which at least a plurality of sides of the bolt head engages to prevent rotation of the bolt.
21. A fixing arrangement as claimed in Claim 19 or Claim 20, wherein respective grooves are provided at opposite sides of the recess and said cover member has respective oppositely directed lateral wings received in said grooves, said wings and grooves constituting said projection and slot arrangement.
22. A fixing arrangement as claimed in any one of Claims 19 to 21, wherein an inwardly facing surface of said cover member has a lip which, when the cover member is moved into engagement with said first member, snaps over said bolt head, thereby securing the cover member in position.
23. A fixing arrangement as claimed in any one of Claims 19 to 22, wherein the cover member has a recess in an interior surface thereof which receives at least the extremity of the bold head therein as a nonrotatable fit.
24. A fixing arrangement as claimed in any one of Claims 19 to 23, wherein adjustment means are provided for locking the first and second members together or for allowing relative adjustment therebetween.
25. A fixing arrangement as claimed in any one of Claim 24, wherein said adjustment means is a knob threadedly engaged on part of said shank extending from a surface of the first member opposite to said surface in which said recess is formed.
26. A fixing arrangement as claimed in any one of Claims 19 to 25, wherein the second member has a slot therein defining said aperture, to permit adjustment of the first member relative to the second member by movement of the shank along, or angular movement of said shank in, the slot.
27. Cutting apparatus including a fixing arrangement as claimed in any one of Claims 19 to 26, wherein the first member is a spray guard shrouding cutting means, and the second member is a slotted blade element upstanding from a body of the apparatus.
28. Cutting apparatus comprising a body having a work surface, cutting means for cutting an article received on the work surface, and guide means against which part of said article is intended to be located, in use, to position said article for said cutting thereof, the body defining a fluid reservoir in which is provided a tray for collecting, as a sludge, powder resulting from the cutting process.
29. Cutting apparatus as claimed in Claim 28, wherein the tray is removably fixed in position in said reservoir.
30. Cutting apparatus as claimed in Claim 29, wherein there is an interference fit between the tray and part of said body to hold the tray in position.
31. Cutting apparatus as claimed in Claim 30, wherein a side of said tray has a notch in its exterior surface, in which a projection on the body engages as said interference fit.
32. Cutting apparatus as claimed in Claim 31, wherein the rib engages with tapered sides of the notch.
33. Cutting apparatus as claimed in Claim 29, wherein there is a wedging engagement between the tray and part of said body to hold the tray in position.
34. Cutting apparatus as claimed in Claim 33, wherein a side of said tray has a notch in its exterior surface, against which a projection on the body engages to wedge the tray in position.
35. Cutting apparatus as claimed in Claim 29, wherein the tray is removably retained in position by both an interference fit and a wedging action with part of said body.
36. Cutting apparatus substantially as hereinbefore described, with reference to, and as shown in Figures 1 to 5 of the accompanying drawings.
37. A fixing arrangement substantially as hereinbefore described, with reference to, and a shown in Figures 6 to 8 of the accompanying drawings.
38. Cutting apparatus substantially as hereinbefore described, with reference to, and as shown in Figure 1 as modified by Figures 9 and 10.