GB2420089A

GB2420089A - Blade honing system

Info

Publication number: GB2420089A
Application number: GB0422258A
Authority: GB
Inventors: Dennis Robert May
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-09-08
Filing date: 2004-10-07
Publication date: 2006-05-17
Also published as: GB0419888D0; GB0422258D0

Abstract

Apparatus for sharpening and honing handheld woodworking chisel and plane blades comprises a base and a wheeled blade holder. The base either holds a sharpening stone or has an integral sharpening surface, with a margin of the base lying on either side of the sharpening surface and the sharpening surface being flush with the base surface. In use wheels of the blade holder are rolled along the base margins, optionally in grooves therein (fig. 13), with only the blade being in contact with the sharpening surface. The blade can either be held with nuts (figs. 5-8) or using eccentric cam levers (fig. 9). Correct positioning of the blade can be done using calibrations marked on the base (fig. 12) and/or a separate gauge (figs. 10 and 11) which is attached to the base by a clip or slot and then removed before sharpening.

Description

A NEW HONING SYSTEM

DESCRIPTION

Honing guides are commonly used when sharpening handheld woodworking chisels and plane blades.

However, guides currently available have an mbuilt inefficiency due to the fact that they roll along the honing surface, leaving a shortened section of that surface available to actually sharpen the tool. This results in the sharpening strokes being shorter and less efficient.

The roller of a honing guide bearing on the honing surface also causes unnecessary wear on the stone and roller itself. Also, should the roller become jammed for any reason, it will become flattened by pushing it along the honing surface, rendering the device unusable The honing guide outlined herein overcomes the above problems, resulting m a more efficient and faster sharpening system using existing sharpening media.

The two components of the system are the BASE and the GUIDE

THE BASE

The base unit serves two mam functions, namely to accommodate the sharpening stone or surface, and to provide an even surface for the GUIDE to operate. The essential design feature of the base is that the surface on which the guide operates and the sharpening surface are flush (Fig 14).

THE GUIDE

The honing guide holds the tool being sharpened at a constant pre-set angle whilst it is moved along the BASE.

INTRODUCTION TO DIAGRAMS

Fig I. General plan of base unit.

Fig 2. Section A-A through base to hold double sided diamond stone.

Fig 3. Section A-A through base to hold single bench mountable diamond stone.

Fig 4. Section A-A through base to hold conventional carbonmdum type stone.

Fig 5. Rear view of honing guide.

Fig 6. Plan view of honing guide.

Fig 7. Section B-B through honing guide.

Fig 8. Cross section through the mechanism of a spring loaded pressure bar.

Fig 9. Alternative tightening mechanism using eccentric cam levers.

Fig 10. Side elevation of a gauge that can be clipped onto the guide to ensure the tool is correctly positioned before sharpening.

Fig 11 A plan view of a gauge that can be clipped onto the guide to ensure the tool is correctly positioned before sharpening.

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Fig 12. Plan of a base unit with a gauge to ensure the tool is correctly positioned before sharpenmg.

Fig 13. Lateral cross section through a base unit with grooves to accommodate the rollers or wheels of the guide Fig 14. End elevation of honing guide in position on a base unit Variations in the design of the base can be made for a variety of stones in common use, allowing the guide to be used with the customer's personal choice. Some examples are given in figs 1-4.

The correct position of the tool in the guide may be set using a gauge or grid pattern marked out on the base (Fig 12).

The base may have slots or grooves (17) in which the wheels of the guide move during sharpemng (Fig 13).

The tool is held by placing it between the main body of the guide (3) and the pressure bar (6). The pressure bar is hand tightened down using the knurled nuts (8) which are threaded onto studs (7) set into the main body. The sharpening or honing angle is determined by the distance by which the tool projects from the front edge of the guide (14). Such features are common to existing systems.

To accommodate both short and long blades the guide can be used with either edge as the leading edge.

Setting and holding the tool in the right position may be made easier by fitting a sprung pressure bar (Fig 8). This may be achieved by the inclusion of springs (9) between the locking nuts (3) and the bar, allowing fine adjustment of the tools position to be made before finally tightening the nuts. Suitable bushes (13), would then nullify the springs action, preventing the tool from moving during the sharpening process. The spring and nut are separated by appropriately sized washers, (11 and 12).

The pressure bar may be tightened using eccentric cam levers (15) (Fig 9).

Correct positioning of the tool in the guide may also be achieved by the use of a separate gauge which is attached to the body of the guide by a clip or slot mechanism (Figs 10 and 11). This would establish the tool is at the required projection and angle m the guide. The gauge would then be removed before sharpening commences.

The guide is used by rolling it backwards and forwards, with the rollers or wheels (4) acting on the base either side of the sharpening surface. Only the tools working edge comes into contact with the abrasive surface as it is being sharpened. The rollers or wheels are mounted on an axle, (5), which passes through the main body of the guide.

Backing off the newly sharpened edge is normally possible whilst the tool is still in the guide.

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Claims

A NEW HONING SYSTEM CLAIMS

1. A device used for honing or sharpening tools, that operates such that only the edge of the tool being sharpened is in contact with the sharpening surface.

2. A base according to claim 1 that contains an integral sharpening surface which is positioned between non abrasive margins upon which a honing guide can move during the sharpening process.

3. A base according to claim 1 to act as a holder for a sharpening stone, or other sharpening medium, used for honing and or sharpening tools such that the top surface of the holder is flush, i.e. in the same plane as the sharpening surface.

4. A honing guide that is able to be moved along the top surface of a device according to claim 2, claim 3, to hold a tool at preset angles whilst being sharpened.

5. A honing guide according to claim 4 that has a sprung holder that allows the position of the tool being sharpened to be finely adjusted to the desired position.

6. A honing guide according to claim 5 with locking screws to secure the tool in position such that it will not move whilst being sharpened.

7. A honing guide according to claim 5 with eccentric cams to secure the tool in position such that it will not move whilst being sharpened.

8. A base according to claim 2 or claim 3 with calibrations marked thereon to allow a tool to be positioned in a honing guide according to claims 4, 5 and 6, such that the correct sharpening angles are achieved.

9. A device that may be attached to a honing guide as in claims 4, 5, 6 and 7 to ensure that a tool is positioned in the honing guide such that the tool is sharpened at the required angles.

10. A base according to claims 2 and 3 with grooves or slots therein for the wheels or rollers of a honing guide to move within during the sharpening process.

11. A honing guide according to claims 5, 6 and 7 that can be used with either edge as the leading edge to accommodate short or long blades.

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