GB2129730A

GB2129730A - Wood turning tool

Info

Publication number: GB2129730A
Application number: GB08224555A
Authority: GB
Inventors: Gordon Stokes
Original assignee: ASHLEY ILES
Current assignee: ASHLEY ILES
Priority date: 1982-08-26
Filing date: 1982-08-26
Publication date: 1984-05-23
Also published as: GB2129730B

Abstract

A wood turning tool has a blade (1) with an integral shank or tang (2) for insertion in a handle (3). The longitudinal axis of the shank or tang (2) is laterally offset relative to the longitudinal axis of the blade (1), the cutting edge (4) of which is straight and inclined to the longitudinal axis of the blade. By this means the user is easily able to counter the twisting moment exerted on the blade in use when one edge of the blade is supported, so that full use can be made of the cutting edge of the blade. <IMAGE>

Description

SPECIFICATION Woodturning tool This invention relates to woodturning tools.

The tools used in woodturning include edge cutting tools or chisels having cutting edges which make only partial contact with a workpiece. For example, one known type of woodturning tool is the so-called skew chisel which has a flat blade provided at its free end with a straight cutting edge inclined to the longitudinal axis of the blade and extending between opposite sides of the blade. In use, this tool is applied to the workpiece with one side of the blade supported against a fixed tool rest. Only the part of the cutting edge near this side of the blade can be used safely, since if the point of contact of the wood with the cutting edge is on the opposite side of the longitudinal axis of the blade from the supported side a twisting moment is exerted on the tool handle, tending to lift the blade from the tool rest, and making the tool difficult to control.

The present invention seeks to provide an improved woodturning tool in which the abovementioned problems are overcome.

According to the invention there is provided a woodturning tool comprising a shank or tang for insertion in a handle and an integral blade with a cutting edge at its end remote from the shank or tang, in which the shank or tang has a longitudinal axis which is laterally offset relative to the longitudinal axis of the blade.

By the simple expedient of offsetting the axis of the shank or tang from the axis of the blade it is possible to make full use of the cutting edge of the blade. Moreoverthetool is given improved balance and is easier to use.

The invention is preferably applicable to tools with flat blades and straight cutting edges. Thus in a preferred embodiment of the invention the cutting edge is inclined to the longitudinal axis of the blade and has an acute-angled corner through which the longitudinal axis of the shank or tang passes. The acute angled corner is preferably rounded to prevent its use as a cutting edge.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of a woodturning skew chisel according to one embodiment of the invention, and Figure 2 is a plan view of the tool shown in Figure 1.

The illustrated tool is a skew chisel for use in woodturning. The chisel has a forged carbon manganese steel blade 1 formed with an integral tang 2.

Prior to use of the tool a handle3 usually of wood, is fitted onto the tang 2, as shown in broken outline in the drawings.

The blade 1 has a straight cutting edge 4 at its end remote from the tang 2. The cutting edge 4 is inclined to the longitudinal axis A of the blade 1, defining an acute angled corner 5 at one end and an obtuse angled corner 6 at the other end. In use of the tool, the cutting edge 4 is brought into working engagement with the wood to be turned. The acute angled corner 5 has no cutting edge and is rounded with a radius of, typically 1/8 inch (3 mm) to prevent its use. When using the skew chisel to make a 'smoothing' cut in woodturning, the shorter side of the blade 1, that is, the side which intersects the corner 6, is supported on the tool rest of the lathe, while the longer side is lifted clear of the rest and is not directly supported.

In a conventional skew chisel the longitudinal axes of the blade 1 and the tang 2 are coincident. This means in practice that only the part of the cutting edge 4 near the corner 6 can be used safely, since otherwise the reaction of the wood on the cutting edge would exert a torque about the tool axis tending to lift the blade 1 from the tool rest.

In the tool according to the invention the tang 2 has a longitudinal axis B which is parallel to the longitudinal axis A of the blade, but laterally offset therefrom. In the illustrated example, the lateral offset of the tang axis B is such that the rounded corner 5 of the blade 1 lies on the axis B of the tang 2.

This means that in use of the tool the reaction of the wood on the cutting edge 4 generates a torque about the axis B of the tang 2 by which the tool is held which is such as to maintain the shorter side of the blade 1 against the tool rest, whichever part of the cutting edge 4 is used. The tool is therefore safer to use and easier to control. Furthermore, the wear on the cutting edge 4 can be evenly distributed.

CLAIMS (Filed on 26.9.83.) 1. Awoodturning tool comprising a shank or tang for insertion in a handle and an integral blade with a cutting edge at its end remote from the shank or tang, in which the shank or tang has a longitudinal axis which is laterally offset relative to the longitudinal axis of the blade.

2. A tool according to Claim 1, in which the blade is flat and the cutting edge is straight.

3. A tool according to Claim 2, in which the cutting edge is inclined to the longitudinal axis of the blade and has an acute-angled corner through which the longitudinal axis of the shank or tang passes.

4. A tool according to Claim 3, in which the acute-angled corner of the cutting edge is rounded.

5. A tool according to any one of the preceding claims, including a handle fitted onto the shank or tang.

6. A woodturning tool substantially as herein described with reference to an as shown in the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Woodturning tool This invention relates to woodturning tools. The tools used in woodturning include edge cutting tools or chisels having cutting edges which make only partial contact with a workpiece. For example, one known type of woodturning tool is the so-called skew chisel which has a flat blade provided at its free end with a straight cutting edge inclined to the longitudinal axis of the blade and extending between opposite sides of the blade. In use, this tool is applied to the workpiece with one side of the blade supported against a fixed tool rest. Only the part of the cutting edge near this side of the blade can be used safely, since if the point of contact of the wood with the cutting edge is on the opposite side of the longitudinal axis of the blade from the supported side a twisting moment is exerted on the tool handle, tending to lift the blade from the tool rest, and making the tool difficult to control. The present invention seeks to provide an improved woodturning tool in which the abovementioned problems are overcome. According to the invention there is provided a woodturning tool comprising a shank or tang for insertion in a handle and an integral blade with a cutting edge at its end remote from the shank or tang, in which the shank or tang has a longitudinal axis which is laterally offset relative to the longitudinal axis of the blade. By the simple expedient of offsetting the axis of the shank or tang from the axis of the blade it is possible to make full use of the cutting edge of the blade. Moreoverthetool is given improved balance and is easier to use. The invention is preferably applicable to tools with flat blades and straight cutting edges. Thus in a preferred embodiment of the invention the cutting edge is inclined to the longitudinal axis of the blade and has an acute-angled corner through which the longitudinal axis of the shank or tang passes. The acute angled corner is preferably rounded to prevent its use as a cutting edge. The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of a woodturning skew chisel according to one embodiment of the invention, and Figure 2 is a plan view of the tool shown in Figure 1. The illustrated tool is a skew chisel for use in woodturning. The chisel has a forged carbon manganese steel blade 1 formed with an integral tang 2. Prior to use of the tool a handle3 usually of wood, is fitted onto the tang 2, as shown in broken outline in the drawings. The blade 1 has a straight cutting edge 4 at its end remote from the tang 2. The cutting edge 4 is inclined to the longitudinal axis A of the blade 1, defining an acute angled corner 5 at one end and an obtuse angled corner 6 at the other end. In use of the tool, the cutting edge 4 is brought into working engagement with the wood to be turned. The acute angled corner 5 has no cutting edge and is rounded with a radius of, typically 1/8 inch (3 mm) to prevent its use. When using the skew chisel to make a 'smoothing' cut in woodturning, the shorter side of the blade 1, that is, the side which intersects the corner 6, is supported on the tool rest of the lathe, while the longer side is lifted clear of the rest and is not directly supported. In a conventional skew chisel the longitudinal axes of the blade 1 and the tang 2 are coincident. This means in practice that only the part of the cutting edge 4 near the corner 6 can be used safely, since otherwise the reaction of the wood on the cutting edge would exert a torque about the tool axis tending to lift the blade 1 from the tool rest. In the tool according to the invention the tang 2 has a longitudinal axis B which is parallel to the longitudinal axis A of the blade, but laterally offset therefrom. In the illustrated example, the lateral offset of the tang axis B is such that the rounded corner 5 of the blade 1 lies on the axis B of the tang 2. This means that in use of the tool the reaction of the wood on the cutting edge 4 generates a torque about the axis B of the tang 2 by which the tool is held which is such as to maintain the shorter side of the blade 1 against the tool rest, whichever part of the cutting edge 4 is used. The tool is therefore safer to use and easier to control. Furthermore, the wear on the cutting edge 4 can be evenly distributed. CLAIMS (Filed on 26.9.83.)

1. Awoodturning tool comprising a shank or tang for insertion in a handle and an integral blade with a cutting edge at its end remote from the shank or tang, in which the shank or tang has a longitudinal axis which is laterally offset relative to the longitudinal axis of the blade.