According to one aspect of this invention there is provided a mitring device comprising a sawing guide means located along an axis with respect a point on said axis, an abutment means for positioning* a member to be cut, said abutment means being spaced on the opposite side of said point from said sawing guide means and rotatable about said point, and means for predeterminedly setting the arcuate travel of said abutment means on each side of said axis.

In one embodiment there is provided a base means upon which the sawing guide means and the abutment means are located, said base means including a partially cylindrical end side wall having a cut-away portion which is symmetrically shaped on each side of said axis, and an adjustably positional limb extending from said abutment means for cooperating with said cut-away portion, whereby said axis bisects any two angularly opposed movements of the abutment means each defined by contact between said limb and opposed positions on said cut-away portion.

In another embodiment there is provided a base means upon which the sawing guide means and the abutment means are located, said base means including a sloping end sidewall positioned orthogonally to said axis, and an adjustably positional limb extending from said abutment means for cooperating with said end sidewall, whereby said axis bisects

two angularly opposed movements of the abutment means each defined by contact between said limb and opposed positions on said end sidewall.

Conveniently said point is a pivot in said base means for supporting the abutment means. Mvantageously the abutment means is a wedge-shaped member which is tapered toward said pivot and said limb is located at an end remote from said pivot whereby said limb is movable in a direction perpendicular to said axis so as to extendably protrude from said wedge-shaped member.

Conveniently securing means are provided for securing said limb in a desired position and advantageously a graduated scale is provided for determining the protruding length of said limb.

In a preferred embodiment the base means includes a fixed part circularly-shaped rim and said wedge-shaped member is located to rotate about a portion of said rim, and the wedge-shaped member is secured to an upper, in use, portion of the base means and at a position radially within said rim, the pivot being a pin having a circularly shaped portion about which the wedge-shaped member is rotatable.

Conveniently the wedge-shaped member is provided with a releasable clamping mβnber for securing said wedge-shaped member to said rim. Advantageously, an angular, graduated scale is provided around said rim for setting the angular position of said wedge-shaped member.

In a preferred embodiment the sawing guide means includes two portions which are each symmetrically disposed about said axis, the perpendicular distance between said portions across the axis being dimensioned to accept a saw or the like. In one embodiment of the invention the sawing guide means is slidable along said axis, and in said embodiment the sawing guide means is located in said base means by an inverted T-shaped member slidably mounted in a correspondingly shaped slot, advantageously in said one embodiment fixing means are provided for securing said sawing guide means at a desired position along said axis.

In an embodiment of the invention the end of said sawing guide means adjacent said point has an enlarged partially circular cross- section against which a member to be cut, in operation, abuts. According to another aspect of this invention there is provided a method of mitring a pair of adjoining members by the steps of:

1. setting the angular position of an abutment means against which a first member is to abut when being cut at a desired angle with respect to an axis, said abutment means being directed to a point on said axis, and a sawing guide means being located along said axis with respect to said point on an opposite side of said point from said abutment means,

2. cutting a mitre on said first member,

3. arcuately repositioning said abutment means about said point on a symmetrically opposite side of said axis,

4. providing a second member to be mitred against said abutment means, and

5. cutting a mitre on said second member.

In one embodiment the members to be mitred are located on a base means upon which the sawing guide means and the abutment means are located, the base means having a partially cylindrical end side wall having a cut-away portion which is symmetrically shaped on each side of said axis and the position of said abutment means is set by adjustably positioning a limb extending from said abutment means into contact with said cut-away portion to thereby limit the axial movement of said abutment means so that the angle between said axis and said abutment means is set, and whereupon pivotally moving said abutment means to the opposite side of said axis causes said limb to contact the symmetrically opposite side of said cut-away portion and said abutment means is thus moved through an identical angle on the opposite side of said axis.

In another embodiment the members to be mitred are located on a base means upon which the sawing guide means and the abutment means are located, the base means having a sloping end sidewall positioned orthogonally to said axis and the position of said abutment means is set by adjustably positioning a limb extending frcm said abutment means into contact with said end sidewall to thereby limit the axial movement of said abutment means so that the angle between said axis and said abutment means is set, and whereupon pivotally moving said abutment means to the opposite side of said axis causes said limb to contact the symmetrically opposite side of said end sidewall and said abutment means is thus moved through an identical angle on the opposite side of said axis. Advantageously the angular position of the abutment means is set by one of (a) measuring the desired angular movement with respect to said axis by an arcuate graduated scale, (b) using a graduated scale to

measure the amount of extension of said limb required to abut a desired part of said cut-away portion, and (c) measuring an angle with a bevel and using said bevel to determine the angular movement desired of said abutment means with respect to said axis. He invention will now be described by way of example with reference to the accompanying drawings in which:-

Figure 1 shows a perspective view of a mitring device in accordance with one embodiment of this invention,

Figure 2 shows a vertical side cross-section of the device shewn in Figure 1,

Figure 3 shows an end view in the direction of arrow-headed line

III of Figure 2,

Figure 4 shows an end view in the direction of arrow-headed line

IV of Figure 2, Figure 5 shows a perspective view of part of the apparatus of Figures 1 to 4 indicating one manner in which a desired angle is set on the device,

Figure 6 shows a top plan view of a mitring device in accordance with another embodiment of this invention, Figure 7 shews a cross-section along double arrow-headed lines VII-VII of Figure 6,

Figure 8 shews a partial cross-section along double arrow-headed lines VIII-vTII of Figure 6,

Figure 9 shews another form of bevel for use with the embodiment of Figures 6-8, and

Figure 10 shows a perspective view of a mitring device in accordance with a further embodiment of this invention.

In the Figures like reference numerals denote like parts. The mitring device shown in Figure 1 has a base 1, a top surface of which is recessed to receive a fixed rim 2 and radially located within rim 2 is a recessed, rotatable disc 3 the upper surface of which is below the upper surface of the rim. The disc is mounted on a circularly cross- sectioned head 4 of a pin 16 having a square cross-sectioned shank 5 (shewn in Figure 2) secured within the base 1; the shank has a square cross-section to prevent the pin from rotating in the base.

A sawing guide member 6 having an inverted T-shaped cross-section (as viewed in Figure 3) is slidably mounted along an imaginary

longitudinal axis crossing the head 4 and the leg of the member 6 has a longitudinal slot 7 located directly on said axis, the slot 7 having a width across said axis for locating a saw or the like. The end of the member 6 adjacent to the pin 16 has a partially circular, enlarged cross- 5 section providing faces 8, 9 which render it unnecessary to readjust the member 6 when making a pair of mitre cuts. The imaginary axis is extended through the rim 2 remote from member 6 and a saw-cut 10 is provided in the rim 2 on the axis into which a saw or the like will travel when in operation. 1.0 A wedge-shaped member 11 is secured to disc 3 and arcuately movable about rim 2, the member 11 having the thinner edge 12 thereof positioned adjacent to member 6 and the pin 16. The thicker end 13 of the member 11 is provided with a limb 14 which is movable in a vertical direction, as shewn in the Figures, that is perpendicularly to the 5 imaginary axis. A semi-circular aperture 19 is formed in the top of ^" member 11 to permit a user to readily grasp narrow members to be cut, or for use by a user having small hands.

An end 20 of the base is arcuate and has a cut-away portion which is disposed to provide two symmetrical surfaces 15, 16 which each extend 0 from a side, upper surface of the base to a low point which is in the plane of the imaginary axis.

Referring now to Figures 2 and 3, the sawing guide member 6 in side elevation has a U-shaped section formed of limbs 21 and 22 interconnected by a member 23, the member 23 being movable in a slot 24 5 in the base along the imaginary axis. The limb 21 is positioned on an upper part of the base and the limb 22 is movable in a recess 25 in the base. As shown in Figure 3, in end elevation, the member 6 is an inverted T-shape with the recesses 24, 25 being shaped to slidingly accept the member 6. The slot 7 extends downwardly through the limb 21 0 (leg) of the T-shaped section to a depth sufficient to take the slot beneath the upper surface of the base 1 to permit a saw or the like to pass completely through a member to be cut. A pair of securing screws 30 located in screw-threaded holes within the base 1 are provided on each side of the limb 21 and the screws contact the underside of the cross 5 piece of the T-shaped section of member 6, i.e. the upper side of limb 22, to prevent the member 6 frαn moving.

Referring to Figures 2 and 4, the rim 2 is secured to the base 1 by a fixing screw 31 and the member 11 is secured to the disc 3 by screws 32. The member 11 has a portion extending under the rim 2 and a screw 33 is provided to raise and lower a clamping jaw 34 so that the member 11 5 may be predeterminedly secured to the rim 2. The edge 13 is provided with a vertical slot 40 along one side of which is a graduated scale 41. A marker 42, which is vertically movable, is located within the slot 40 and adjustably secured in a predeterminedly required position by a knurled locking knob 43, the marker 42 being connected to move in a

10 corresponding fashion to the vertical movement of limb 14.

As shown in Figure 1 a recessed aperture 51 is provided to accept a pin (not shown) located at the pivot point of a bevel 52 having arms 53, 54 (shown in Figure 5).

In one method of operation, where cornice is to be fitted to a

15 corner of a pair of walls, the angle between the walls is measured by the bevel 52. Having measured the angle, the pin of the bevel 52 is located in the aperture 51 of the mitring device of this invention with limbs 53, 54 positioned symmetrically on each side of the imaginary axis, over the longitudinal centre of slot 10. To provide visual assistance in

20 symmetrically positioning the bevel 52, segments of differing widths in different outline colours (not shown) may be provided symmetrically over the imaginary axis. The wedge-shaped member 11 is brought into abutment with arm 53 and the limb 14 lowered into contact with surface 15. The limb 14 is then secured in position by tightening knob 43 and the member

25 11 is secured by tightening screw 33 to clamp jaw 34 although it is to be understood that these two steps may be reversed. The bevel is then removed. A member to be cut is placed against the same face of the member 11 as the arm 53 was positioned and the member 16 is slidably adjusted until the face 9 abuts the member to be cut and the member 6 is

30 secured in position by tightening screws 30. The member to be cut is held in abutment with the member 11 and a saw or the like is passed along slot 7 to cut a mitre on the member. en the member has been cut the member 11 is rotated so that the limb 14 abuts surface 16 and another member which is to abut with the first member is positioned on the device

35 so that the said another member contacts the opposed face of the wedge- shaped member 11 that was contacted by the first member and such that it abuts face 8. The said another member is then cut. By such an operation a mitre is formed on two adjoining members.

In the embodiment of Figures 6 to 8, the mitring device has a base

101 having a top surface to which is fixed a part circularly-shaped rim

102 and radially located within the rim is an arcuate slot 163. A hollow, square cross-sec ionally shaped channel 164 is pivotally located by a hollow pin 118 having an axial longitudinal aperture 151, the channel 164 being located on an underside of the rim 102. The pin 118 is located in both a plate 165 lying adjacent an underside of the rim 102 and a Z-shaped bracket 166 so that the pin 118 is held in position by the plate 165 and bracket 166. A wedge-shaped member 111 is secured to the channel 164 by a bolt 167 which is screwed into an underside of the wedge-shaped member 111 through the arcuate slot 163. Located over the bolt 167 inside the slot 163 is a spacer 168.

The wedge-shaped member 111 has a thinner edge 112 positioned adjacent to pin 118 and a thicker end 113 of the member 111 is provided with a limb 114 which is movable in a vertical direction, as shown in Figure 8, that is perpendicularly to the imaginary axis which is represented by section lines VII-VII. A semi-circularly shaped aperture 119 is formed in the top of the member 111 to permit a user to readily grasp members to be cut. The thicker end 113 has an aperture 169 in which is located a locking screw 143 for securing the limb 114 in a predetermined vertical position.

A secure ent device for the member 111 is formed by a plate 171 which is pivoted by a screw 172 which is secured into the underside of member 111 and which is a loose fit in a hole in the plate 171 and a lock nut 173 positioned along the length of the screw 172 so that the plate 171 is a loose fit between the head of the screw 172 and the lock nut 173. A lower part of the channel 164 remote from the pin 118 is cut away to leave wall 170. The screw 172 passes through a hole in the wall 170 and is spaced from an underside of the member 111 by a spacer 174. A locking screw 175 is secured by inter-engaging screw threads in the plate

171 to abut an underside of the member 111 on one side of the pivot formed by screw 172. On the opposite side of the pivot formed by screw

172 from the locking screw 175 is a pin 176 fixedly located in plate 171 and which passes through an enlarged opening in wall 170 to contact an underside of rim 102. Thus by tightening screw 175, by pivotal action about screw 172, so pin 176 is forced against the underside of rim 102 and arcuate movement of member 111 may thus be arrested.

A sawing guide member 106 is formed by a pair of L-shaped limbs 181, 182 which are each located on a respective side of the axis denoted by section line VII-VII and secured to the base by bolts 183 so as to define therebetween a slot 107 for locating a saw or the like. The limbs 181, 182 extend toward the pin 118. A sheet-like member 184 is provided along an upper, inner, side of each member 181, 182 to provide additional guidance of a saw or the like and to protect the saw teeth.

A slot 110 is provided through the rim 102 along the imaginary axis represented by section lines VII-VII and the parts of the rim are secured together by the plate 165 and a strap 284.

A graduate scale 155 is provided around the rim 102. An end 120 of the base is arcuate and has a cut-away portion which is disposed to provide two symmetrical surfaces 115, 116 which each extend from a side, upper surface of the base to a low point which is in the plane of the imaginary axis.

A bevel 152 having arms 153, 154 is shown in Figure 9, the arms being interconnected by a pivot pin 190 which is arranged to extend through the arms for location in aperture 151. The arms 153, 154 each have one straight surface 191 and a recessed surface 192 formed by an enlargsnent 193 about pin 190 and pads 194, the bevel having such a shape so that both inside and outside corners may be measured thereby. A recess (not shown) is provided in each major side face of the wedge- shaped member 111 so that a respective pad 194 may be located therein in use so that the major face of the wedge member may abut surface 192. By providing a bevel of the type shown in Figure 9 the necessity for enlarged cross-section faces 8, 9 is avoided.

In use of the device shewn in Figures 6 to 8 and the bevel of Figure 9, the bevel is used to measure the angle of a corner and then pin 190 is located in aperture 151. A centering device is formed _. a circular member 200 having a diametric runner secured to the underside thereof for location in slot 110 is slid along slot 110 and between the arms 153, 154 of the bevel. The circular member 200 automatically centres the arms of the bevel so that they are symmetrically disposed about slot 110. Wfedge-shaped member 111 is then brought into contact with one of the bevel arms, say arm 153, the screw 175 is tightened thereby forcing pin 176 into engagement with the underside of rim 102 to thereby lock member 111 relative to rim 102. Limb 114 is lowered into

contact with surface 115 and the limb 114 is then secured in position by tightening locking screw 143. The bevel is removed and a member to be cut is placed against the same face of the member 111 as the arm 153 was positioned. The member to be cut is held in abutment with the member 111 and a saw or the like is passed along slot 107 to cut a mitre on the member. When the member has been cut, the member 111 is unlocked by releasing screw 175 and rotated about pin 118 so that the limb 114 abuts surface 116. Another member which is to have a mitre abuting with the first cut member is positioned on the device so that the said another member contacts the opposite face of the wedge-shaped member 111 that was contacted by the first member. The said another member is then cut so that by such an operation a mitre is formed on each of the two adjoining members.

In an alternative method of using the device, instead of using a bevel, (a) the wedge-shaped member 11 may be set in position by using either the graduated scale 41 or (b) members 11 or 111 may be set by using the graduated scale 55 or 155 respectively.

For some shapes of material to be mitred it may be desired to position a member to be cut against the opposite face of the wedge-shaped member 11 frαn that shown in Figure 1 and against the surface 9 so that the member passes between adjacent ends of members 6 and 11.

In the ^' further embodiment of Figure 10 the two symmetrical surfaces 15, 16, 115, 116 are replaced by a linear sloping end side face 201 which is orthogonal to the longitudinal axis defined by slot 107. The embodiment of Figure 10 functions in similar manner to that of the above described embodiments.

By using this invention members to be mitred may be accurately cut and members of awkward shapes may be similarly accurately cut.