This invention relates to a rebating tool. A rebate having a defined longitudinal extent in a wooden workpiece, for example for a hinge, has traditionally been produced by use of a chisel. Such a rebate is required to extend only for the length of the hinge, and usually both ends of the rebate as spaced from the ends of the workpiece. The production of an accurate rebate for a hinge, using just a chisel and mallet, requires considerable skill, and even so a workpiece may easily be spoilt.

In an attempt to facilitate the production of a rebate for example for a hinge, in a wooden workpiece, it is known to utilise a box-like tool with sharp edges on three of the four edges of the box, and then to drive the sharp edges into the workpiece with a hammer, to yield a rectangular cut into the workpiece, as is described in US-4984613-A. However, the delineated material has to be removed by using a hand chisel, which still requires skill, and involves a risk of splitting the workpiece.

Against this background, in accordance with the invention there is provided a tool for cutting rebates in a workpiece, comprising: a body having guide means for aligning the tool against an edge of a workpiece; a first blade or first blades arranged for making, in a face of the workpiece, a cut or cuts extending around the periphery of the intended rebate from said edge, so defining an area of waste material to be removed; and a second blade mounted slidably in relation to the guide means so that it can be driven into the workpiece generally parallel to said face, from said edge, the position, shape and dimensions of the second blade being such that when so driven it separates from the workpiece the area of waste material defined by the cuts in the face of the workpiece.

In use, the guide means is placed against an edge of the workpiece at the position where the rebate is wanted. The first blade then is driven into the face of the workpiece, e.g. with a mallet, so defining the extent of the intended rebate. The second blade is then driven into the edge of the workpiece to pare off the waste material. As the blades are positioned and guided by the apparatus, the degree of skill needed to produce an accurate rebate is considerably reduced. In a preferred form, the first blade is, or the first blades are, located on three sides of a rectangle, and the second blade is rectangular. That form may be dimensioned suitably to produce rebates for hinges. In order to produce a rebate extending the correct amount along the edge for a particular hinge, a tool which is shorter than the hinge, may be used repeatedly. Indeed, repeated use of the tool enables a rebate to be extended for a considerable length, or even all, of the workpiece. Although it is envisaged that the first blade or first blades may be fixed in relation to the guide means, which would then slide on the workpiece as it or they are driven in, a preferred embodiment has the first blade or the first blades mounted movably in relation to the guide means. The guide means may then locate the tool positively against the edge.

In one arrangement, the first blade is or the first blades are mounted on a first carrier, extending through an aperture in the body, and mounted thereon by a plurality of posts on which the carrier is slidable and biased to a retracted position. In use, the guide means is located against the edge and the carrier may then be driven, e.g. with a mallet, to drive its blade(s) into the face of the workpiece with no danger of the guide sliding out of position.

The tool preferably includes means for limiting

the depth of cut by the first blade or first blades, approximately to correspond with the position of the second blade.

In order to produce an accurate rebate, the second blade preferably abuts the inside of the first blade or first blades when both the first and second blades are extended as if into the workpiece.

Although a simple non-adjustable version of the tool is envisaged, in a preferred form, the relative positions of the first blade or first blades and the guide means is adjustable so that the distance to which the cut or cuts extend from the said edge can be varied. That will allow the tool to accommodate hinges of differing widths. As has been explained, hinges of differing lengths can be accommodated by repeated use of the tool.

Such adjustment may be provided by said guide means comprising two posts threadedly received by holes in the body so as to be adjustable therein, and having pointed ends, for penetrating the workpiece edge, extending from respective shoulders for limiting the depth of__ said penetration. The pointed ends provide the positive location referred to above.

In order that the alignment of the tool may be adjusted whilst it is located against the edge, the said holes preferably extend through the body; and the posts are preferably provided with means by which they may be rotated in the holes, said means being accessible through or beyond the holes on the side of the body remote from the edge.

The relative positions of the guide means and the second blade can preferably be adjusted so that the depth from the said face at which the second blade cuts the workpiece can be varied. Repeated use of the second blade at different depths may permit the waste material to be pared off as a succession of shavings

rather than in one piece.

In one arrangement, the second blade is mounted in the body by one or more of a plurality of runners so arranged that use of different runners provides different depths of cut.

The first and/or the second blades are preferably replaceable.

Since, at least in a preferred version, the first blade is or the first blades are hidden in use, the tool is preferably marked to show the position and/or centre of the first blade or the first blades in use.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is an exploded side view of a rebating tool embodying the invention;

Figure 2 is a top plan of a first blade carrier of the tool of Figure 1;

Figure 3 is an underneath plan of the carrier of Figure 2; and

Figure 4 is a pictorial view of a body of the tool of Figure 1.

Referring to the drawings, the tool has a generally rectangular body 2 rebated at 4 to accommodate a workpiece 6. A surface 8 of the rebate acts as a guide to align the tool against a face 9 of the workpiece. Further alignment is provided against an edge 11 of the workpiece by threaded posts 10 extending from the other surface 12 of the rebate 4. The posts 10 are received by threaded holes 14 through the body 2 and have slotted ends 13 so that they can be adjusted by use of a screw driver when the tool is in position, as shown in Figure 1, against a workpiece.

The other ends of the posts are provided with pointed spikes 16 extending from a shoulder 18. The spikes are intended to penetrate the workpiece, which may be wood.

as far as the shoulder, thus positively locating the tool and preventing it from sliding in use.

Over the rebate 4, a rectangular hole 20 is formed through the body 2. A blade carrier 22 is mounted for movement into the hole by four posts 24 mounted one in each corner of the hole and received slidingly by corresponding holes 25 in the carrier. Inward movement of the carrier into the hole is arrested by a shoulder 26, from which the posts 24 extend. The carrier is biassed outwardly by springs 28 on each post (only one is shown in the drawing) , and held captive by nuts 27 (two are shown in Figure 2) engaging threaded ends of the posts.

Referring to the underside of the carrier 22 shown in Figure 3, a blade 30 is mounted on the carrier and extends round three sides of a rectangle. The blade preferably has a single bevel defining a sharp edge 32 which is on the outside of the rectangle.

In use the tool is located against the workpiece as shown in Figure 1 and the carrier 22 is then struck with a mallet to drive the blade 30 into the workpiece until the carrier 22 meets the shoulder 26, so defining in the face 9 the periphery of an area of waste material to be removed from the workpiece. The blade may then return to its retracted position by the bias of the springs 28.

The body has an aperture extending though a side 36 to the surface 16 of the rebate 4. Opposed sides 38 of the aperture are formed with a plurality of parallel grooves 38, in the case illustrated the grooves are triangular in section so that triangular ridges are formed between them. A second blade 40 is mounted on a second carrier 42 which has a plurality of runners in the form. of triangular ridges 44 arranged to engage slidingly in the grooves in the sides 38. A stop 46 portion prevents the carrier 42 from passing right

through the aperture 34.

The carrier 42 is struck with the mallet to drive the blade 40 into the edge 11 of the workpiece to separate the waste material from the workpiece. The action of the blade 40 forces the waste material upwards, by the thickness of the blade, into the rectangular cavity defined by the blade 30 from which it will drop or can be removed when the tool is removed from the workpiece. Ideally, the cutting edge of the blade 40 would just reach the position of the cutting edge of the blade 30.

The plurality of grooves in the side walls 38 and the plurality of ridges 44 in the sides of the second carrier enable the latter to be placed at various spacings from the surface 8 producing corresponding variations in the thickness of the material pared off tne workpiece. This facility may be used to make rebates of different depths. The thicker section provided by a step 50 provides greater adjustment than would be obtained with a carrier only the thickness of the blade 40. Other means for adjusting the spacing of the blade 40 from the surface 8 may be used.

Adjustment of the threaded posts 10 enables the width of the rebate from the edge 11 of the workpiece to be varied to suit particular hinges. Although the extent of the rebate along the workpiece (normal to the plane of the paper in Figure 1), the length of the rebate can be increased as desired by repeated use of the tool along the edge. The blades 30 and 40 may be replaceable. The blade 30 may be formed as one continuous blade, as illustrated, or may be formed by three sections, one on each side of the rectangle.

In operation, the blades 30 and 40 are covered by the body 2 and are guided so that little skill is needed and the opportunity for accidents is reduced.

In order that the operator shall know where the hidden blade 30 will cut, their position is indicated by lines marked 50 on the body.

Although in the example illustrated, the blade 30 defines the periphery of a rectangular rebate in the face 9, any desired shape may be utilised, provided it is not greatly re-entrant. The shape is preferably not re-entrant. A re-entrant shape will lead to areas of the workpiece adjacent the rebate being undercut by the blade 40 and, since that blade has significant thickness, could lead to the undercut area breaking off.