WO1994004327A1 - Apparatus for cutting material at one or more angles and cutting aid - Google Patents

Abstract

A cutting aid (30, 31, 32) for use with guillotine-type wood mitring machines (1), the cutting aid preferably comprising a pair of releasably attachable plates (30, 31) comprising one long (30) and one short plate (31). The plates (30, 31) are preferably provided with a bevelled end portion which in use, co-operate to define a recess in which a blade (9a, 9b) of the machine (1) may be disposed during the cutting process. In addition to the releasably attachable plates (30, 31), the invention also includes the permanent modification of mitring machines to incorporate a recess in the back fence (18) of the machine.

Description

"Apparatus for cutting material at one or more angles and Cutting Aid"

This invention relates to Apparatus for cutting material at one or more angles and a cutting aid.

It is especially, although not exclusively adaptable for use with guillotine-type wood mitring machines.

In the field of wood mitring, conventional machines are known to comprise a vertically movable blade and a cutting platform to support the wood, the blade engaging with the wood on the platform to cut the wood at 45° to form a mitre in the wood, such as the machine shown in Fig. 1.

When cutting soft wood or mouldings it is common practice to support the back of the moulding in place on the platform in order to ensure that the final cut made by the blade does not damage the moulding. This support is generally provided by waste board which is disposed against the moulding to be cut. In use, the blade cuts not only into the moulding, but the distal edge of the blade also cuts into the waste board, thereby facilitating a clean cut edge on the moulding. However, because the waste is cut during the operation, this results in the production of small cuttings of waste which foul the blade and must be removed. In addition, the waste must be re-positioned or replaced for subsequent cutting actions. Both re- positioning/replacement and removal of waste cuttings are generally manual operations which have high inherent risks of injury from the blade. When the moulding is unsupported, the cutting process frequently causes chips in the moulding. This has been attributed to the final cut being made by the point of the blade, which is unstable and generally blunt in comparison to the remainder of the blade.

According to the present invention there is provided apparatus for cutting material at one or more angles, having a cutting head which comprises a blade, and a fence member having first and second portions which have faces for restraining movement of the material during the cutting process, the first portion and the second portion being disposed in the apparatus to define a recess or gap in the fence member between said face of the first portion and said face of the second portion, a portion of the blade being engageable in the recess or gap without engaging the first portion or the second portion of the fence member.

Further according to the present invention there is provided a cutting aid for a mitring machine, the machine having a blade, and a fence member to restrain movement of the material during the cutting process, the cutting aid comprising spacer means to space the material from the fence member and having first and second faces defining a recess between them in which recess a portion of the blade may be disposed during the cutting process without engaging the spacer means.

Preferably, the cutting aid comprises one or more plates which may be formed from a material resistant to cutting by the blade.

Preferably, at least one of the said faces of the spacer means comprises a bevel.

The plates are preferably magnetized or may include a magnetic insert to hold the or each plate to the machine.

In use, the or each plate is disposed along a back fence of the cutting platform of a conventional mitring machine, preferably on each side of the blade with the bevelled ends of the plates in contact.

The or each plate may include a non-slip coating, preferably on the lower back face of the or each plate.

Guillotine machines of any kind generally comprise both a cutting edge and a shear face or edge. Currently the twin-bladed mitring machines in use in the framing industry are provided with the shear face on the bed of the machine. One embodiment of the present invention, by introducing a hard vertical face on each side of the cutting head, provides an additional shear face in the vertical plane ensuring a better cut down the back of the moulding thereby reducing chipping and tearing down this surface.

Multi-part frames comprising three or more mouldings can include one or more mouldings with rebates (a groove or recess generally rectangular in section) on each side of the moulding. Such double-rebate mouldings are generally too unstable to be cut efficiently on conventional twin fixed-blade mitring machines.

One embodiment of the present invention is disposed in use, along the back fence of a machine supporting the back rebate of the moulding, making it possible to process double rebate mouldings in the same way as any standard moulding.

One embodiment of the invention comprises two pairs of plates, two plates in each pair. The two plates in each pair are identical in height and width but different in length and are designed to lie longitudinally on the machine on respective sides of the cutting head, vertically along the back fence of the machine and touching the cutting head when it is fully forward. The longer of the two plates in each pair lies on the machine to the left of the cutting-head and extends along the length of the machine from the cutting head to the end of the machine. The second, shorter plate in each pair lies to the right of the cutting head and is of a length to allow the continued operation of an end-stop mechanism of the machine which is itself fitted with a further plate, mitre to mitre. The second and third plates are of a length suitable to allow the end-stop to be moved into close proximity to the blade . The three plates ensure that a moulding is moved forward of the back fence of the machine uniformly throughout its length within the body of the machine.

By moving the moulding forward of the back fence closer to the cutting-head of the machine, the final cut of the moulding is made by the section of the cutting blades backward of the point formed by their junction, and the edges of the bevelled faces of the plates forming the cutting-aid support the back/outer face of the moulding. The said section of the blade is generally sharper and is more stable than the point of the blade during the cutting process.

Whilst the shorter pair of plates will equally well move the workpiece forward where the workpiece is a standard moulding, and therefore serve a similar purpose to the deeper plates, they also function as rebate/check supports for double rebate mouldings supporting the back rebate of the moulding along the back fence of the machine thus preventing rocking of the moulding when the cutting head is forward of the central pillar moulding. The support provided minimizes damage and inaccuracies during the cutting process.

While modifications and improvements may be incorporated without departing from the scope of the invention, an embodiment of the present invention will now be described by way of example, with reference to the accompanying drawings in which:

Fig. 1 shows a plan view of a conventional wood mitring machine.

Fig. 2 shows a plan view of the wood mitring machine of Fig. 1 with an embodiment of the invention attached thereto.

Fig. 3 shows a plan view of the machine shown in Figs. 1 and 2 with a wood moulding also in place.

Fig. 4 shows a side elevation of the machine of Fig. 1 with a wood moulding in place.

Fig. 5 shows a side elevation of the machine of Fig. 1 with a double rebated wood moulding in place.

Fig. 6 shows a side view of some of the embodiments of the invention.

Fig. 7 shows a plan view of one of the embodiments shown in Fig. 6.

Fig. 8 shows a perspective view of a saddle.

Referring now to the drawings, Fig. 1 shows a plan view of a conventional mitring machine 1. The machine 1 comprises a cutting head 9 which is generally rectangular in section and has two removable blades 9a and 9b which act in tandem to cut a 90° angle in a moulding 10, a platform 15 on which the moulding 10 is supported during the cutting process, and a back fence 17 which is disposed at one edge of the platform 15. Back fence 17 comprises two sections 17a and 17b which may pivot independently around attachment point 18 on the platform 15. The two sections 17a and 17b are contiguous at 18 and are manoeuvred by handles 20a, 20b. Thus the sections of back fence 17a and 17b can be manipulated to present a moulding to the cutting head 9 at any angle between 45° and 90° to the cutting head 9. The cutting head 9 is moved back and forward along its line of symmetry 8 by means of a mechanism operated by a third handle 21. moved uniformly forward of the back fence 17 and the measure bar 18 by the plates 30, 31 and 32 which are of identical thickness. For excessively long mouldings 10, the plate 32 can move laterally parallel to the axis of the moulding in conjunction with the end-stop 25 along the measure bar 18 to any position required by the constraints of the length of moulding 10 to be cut. The lengths of plates 31 and 32 are selected to allow the movement of the end-stop 25 into close proximity to the cutting head 9 for cutting short mouldings.

The point of the cutting head 9 is shown in its final cut position beyond the back of the moulding 10, the moulding 10 being held away from the back fence 17 the plates 30, 31 and 32; thereby allowing the final cut on the moulding 10, to be made on the section of the blades 9a, b backwards of the point and not by the point itself.

Fig. 4 shows a side elevation of the mitring machine 1; the forward and downward cutting movements made by the cutting head 9 are indicated by the arrows. The plate 30 is shown in position against the back fence 17 and a moulding 10 is shown in situ . The check of the moulding is also supported by a rebate support 35.

Fig. 5 shows the same schematic as Fig. 4 but in this figure the embodiment of the invention shown is a plate 37 of shorter height than the plates 30, 31 and 32, although the plate 37 is identical to the taller plates 30, 31 and 32 in other respects. The plate 37 is used as a rebate support for a double rebated moulding 11. In this position, the plate 37 spaces a central pillar lla of the moulding 11 from the back fence and thus prevents it from rocking during the cutting process. The machine has an end-stop 25 whose position can be fixed to determine the length of moulding cut. A vernier scale 27 is used to determine the positioning of the end-stop 25 to achieve the correct length of moulding cut relative to the width of the moulding. Alternative machines may have a scale inscribed on the platform 15

Fig. 2 shows the same schematic as Fig. 1, with one embodiment of the present invention in place on the machine 1. A plate 30 is disposed on one side (the left) of the cutting head whilst a second plate 31 is disposed on the other (the right) . A third plate 32 is also disposed to the right of the cutting head and its mitred end 32a fits into the angle formed between the end-stop 25 and a measure bar 18 to which the end-stop 25 is fixed.

Plates 30 and 31 are disposed such that their bevelled ends 30a and 31a are in contact on the line of symmetry 8 of the cutting head or are in close proximity thereto, the bevelled faces forming a recess. When it is fully forward, the cutting head 9 engages in the recess without touching the upper surfaces of the plates 30 and 31. The bevelled ends 30a and 31a on each of the plates 30 and 31 are shaped to complement the angle formed between the back fence 17 and the cutting head 9 (45° although other angles can be selected) . Plates 30, 31, and 32 are slidable parallel to the axis of the back fence 17, but all plates may be held securely in position when the cutting head 9 is cutting the material.

Fig. 3 shows the same schematic as Fig. 2 but with the addition of a wood moulding 10 whose position is shown In addition, the plate 37 may also abut a lower face lie of the rebate to support it during the cutting process. The preferred dimensions of the plate 37 are such that its width is not less than the depth of the moulding 11.

Fig. 6 shows in elevation various designs of plate which may comprise the cutting aid of the invention. Plates 30 and 31 together with 32 may be used in conjunction as described with reference to Figs. 2-4 to give support to taller mouldings and to metal-clad wood mouldings throughout the whole of the depth of the back of the moulding. The bevelled ends of the respective plates are shown at 30a, 31a and 32a respectively. The shorter height embodiment described with reference to Fig. 5 comprises plates 37, 38 and 32 which are designed to act as a rebate support for double rebated mouldings. The bevelled ends are shown at 37a, 38a and 32a.

Fig. 7 shows a view on A of the element 30 and is intended only to indicate the position of the mitre on the individual elements and possible thickness of the material involved in their construction. Plates 30, 31, 32, 37 and 38 are all of equal thickness, although naturally this thickness may be selected. In Fig. 6 the points indicated as 40 are magnets, the number and size of which, together with their locations, may vary. In addition, the angle of the bevel on the plates may vary according to the angle of the cut being made on the moulding 10, 11 being processed. The preferred thickness of the plates (and thus the preferred depth of the recess) is between 5mm and 10mm, most preferably approximately 6mm. One modification of conventional mitring machines to use Aluminium for the construction of the measure bar 18 means that magnets cannot then attach to it, and an alternative means of fixing the plate 32 to the measure bar 18 must be used. The magnetically attached plate 32 may be replaced by a saddle 41 as shown in Fig 8. The saddle comprises three rectangular plates 42, 43, and 44, two of which 42 and 44 are dependant from the central plate 43. The plate 42 has one edge 42a which comprises a bevel. The plate 42 is of the same width and has the same angle of bevel as the plate 32 to be replaced. In use on a machine which has an Aluminium measure bar 18, the saddle 41 is disposed over the measure bar 18 such that the plate 43 is disposed on the upper surface of the measure bar 18, and the plates 42 and 43 are disposed on the inner and outer faces of the measure bar respectively. The bevelled face 42a then interacts with the end-stop 25 in the same manner as the plate 32, and the saddle is retained in place on the measure bar 18 by virtue of a close fit (the space between the plates 42 and 44 closely accommodates the width of the measure bar 18) .

While the invention has been specifically described with reference to non-permanent attachments for conventional mitring machines, the principle of having a permanent recess in the back fence of a mitring machine is within the scope of the invention. Such permanently modified mitring machines may be easily constructed for example, simply by permanently attaching the plates 30, 31 and 32 to the back fence 17 of the machine. Alternatively, the back fence can simply be replaced with a fence including a recess which may have bevelled sides, such as that created by the bevelled ends 30a and 31a of the plates 30 and 31.

Claims

1 Apparatus for cutting material at one or more angles, having a cutting head which comprises a blade, and a fence member having first and second portions which have faces for restraining movement of the material during the cutting process, the first portion and the second portion being disposed in the apparatus to define a recess or gap in the fence member between said face of the first portion and said face of the second portion, a portion of the blade being engageable in the recess or gap without engaging the first portion or the second portion of the fence member.

2 Apparatus as claimed in Claim 1, wherein at least one of the first and second portions of the fence member includes a bevelled face.

3 Apparatus as claimed in Claims 1 or 2, wherein the apparatus includes a support and at least one of the first and second portions of the fence member is releasably attachable to the support.

4 Apparatus as claimed in Claims 1, 2 or 3 wherein the first and second portions are held in place by magnetic forces.

5 Apparatus as claimed in Claim 3, wherein the first and second portions are slidable on the support.

6 Apparatus as claimed in any one of the preceding Claims, wherein at least one of the first and second portions is dimensioned to engage a groove in the material during the cutting process. 7 Apparatus as claimed in any one of the preceding Claims, wherein at least one of the surfaces on at least one of the first and second portions comprises a non-slip material.

8 A cutting aid for a mitring machine, the machine having a blade, and a fence member to restrain movement of the material during the cutting process, the cutting aid comprising spacer means to space the material from the fence member and having first and second faces defining a recess between them in which recess a portion of the blade may be disposed during the cutting process without engaging the spacer means.

9 A cutting aid as claimed in Claim 8, wherein at least one of the said first and second faces of the spacer means is bevelled.

10 A cutting aid as claimed in Claim 8 or 9, wherein the spacer means comprises first and second plates to be disposed, in use, on respective sides of the blade.

11 A cutting aid as claimed in Claim 10, wherein the or each plate comprises a magnet.

12 A cutting aid as claimed in Claim 10 or 11, wherein the or each plate is dimensioned to engage a groove in the material to support the material during the cutting process.

13 Apparatus for cutting material at one or more angles substantially as hereinbefore described, with reference to and as shown in the accompanying drawings .

A cutting aid substantially as hereinbefore described, with reference to and as shown in the accompanying drawings.