GB2077155A - Blade sharpening jig - Google Patents

Abstract

A jig for holding a plane iron or like blade 4 for sharpening, provides two opposed abutments 1a, 2a between which a wedge 5 is inserted alternatively to hold the blade against the chosen abutment. The abutments are set at different predetermined angles in relation to a datum surface 7 from which in use the blade is angled to project to enable it to be sharpened by a stone aligned with the datum surface. <IMAGE>

Description

SPECIFICATION Plane iron sharpening jig This invention relates to a jig for holding a plane iron or like tool blade for the purpose of sharpening the same.

According to the invention a tool blade sharpening jig comprises a body provided with a pair of oppositely facing abutment surfaces extending at different predetermined angles from a datum surface, and a wedge adapted for insertion between the abutment surface so as alternatively to hold a tool blade against one or the other abutment surface to project from the datum surface at the selected angle.

One embodiment of a jig in accordance with the invention is illustrated in the accompanying drawing which is a perspective view of the jig.

Referring to the drawing a tool blade sharpening jig comprises a body formed by blocks 1 and 2 mounted on a base 3. The blocks 1 and 2 are respectively formed with oppositely facing abutment surfaces 1 a and 2a against which a plane iron 4 or like blade may be held by a wedge 5 acting between the blocks.

In use the cutting edge of the blade 4 is arranged to project a convenient distance beyond the outer edges 6 and 7 of the blocks 1 and 2, which edges are aligned to form a datum surface, and with which a sharpening stone 8 may in turn be aligned.

The abutment surface 1 a is suitably set at an angle of 25 to the datum surface and the abutment surface 2a at 30t. Thus after a blade set against the 25 abutment 1 a has been sufficently sharpened by the application of the stone 8, which during operative strokes will be maintained parallel to the datum surface, the blade may be re-set against the opposite 30 abutment 2a for a final honing of the cutting edge.

It may be found convenient to affix the jig to a workbench 9 by, for example, screws 10 to facilitate vigorous application of a sharpening stone. If desired the cutting edge of the plane iron may be slightly curved by suitable application of the stone 8 and similarly the jig may be employed for sharpening plough and rebate irons with a slip stone. It will also be appreciated that the predetermined angles at which the abutment surfaces 1 a and 2a are set may be other than angles of 25 and 30t.

1. A tool blade sharpening jig comprising a body provided with a pair of oppositely facing abutment surfaces extending at different predetermined angles from a datum surface, and a wedge adapted for insertion between the abutment surfaces so as alternatively to hold a tool blade against one or the other abutment surface to project from the datum surface at the selected angle.

2. A tool blade sharpening jig substantially as herein described and illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Plane iron sharpening jig This invention relates to a jig for holding a plane iron or like tool blade for the purpose of sharpening the same. According to the invention a tool blade sharpening jig comprises a body provided with a pair of oppositely facing abutment surfaces extending at different predetermined angles from a datum surface, and a wedge adapted for insertion between the abutment surface so as alternatively to hold a tool blade against one or the other abutment surface to project from the datum surface at the selected angle. One embodiment of a jig in accordance with the invention is illustrated in the accompanying drawing which is a perspective view of the jig. Referring to the drawing a tool blade sharpening jig comprises a body formed by blocks 1 and 2 mounted on a base 3. The blocks 1 and 2 are respectively formed with oppositely facing abutment surfaces 1 a and 2a against which a plane iron 4 or like blade may be held by a wedge 5 acting between the blocks. In use the cutting edge of the blade 4 is arranged to project a convenient distance beyond the outer edges 6 and 7 of the blocks 1 and 2, which edges are aligned to form a datum surface, and with which a sharpening stone 8 may in turn be aligned. The abutment surface 1 a is suitably set at an angle of 25 to the datum surface and the abutment surface 2a at 30t. Thus after a blade set against the 25 abutment 1 a has been sufficently sharpened by the application of the stone 8, which during operative strokes will be maintained parallel to the datum surface, the blade may be re-set against the opposite 30 abutment 2a for a final honing of the cutting edge. It may be found convenient to affix the jig to a workbench 9 by, for example, screws 10 to facilitate vigorous application of a sharpening stone. If desired the cutting edge of the plane iron may be slightly curved by suitable application of the stone 8 and similarly the jig may be employed for sharpening plough and rebate irons with a slip stone. It will also be appreciated that the predetermined angles at which the abutment surfaces 1 a and 2a are set may be other than angles of 25 and 30t. CLAIMS

1. A tool blade sharpening jig comprising a body provided with a pair of oppositely facing abutment surfaces extending at different predetermined angles from a datum surface, and a wedge adapted for insertion between the abutment surfaces so as alternatively to hold a tool blade against one or the other abutment surface to project from the datum surface at the selected angle.

2. A tool blade sharpening jig substantially as herein described and illustrated in the accompanying drawing.