GB2405608A

GB2405608A - Honing apparatus

Info

Publication number: GB2405608A
Application number: GB0404379A
Authority: GB
Inventors: John Alan Ross
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-09-04
Filing date: 2004-02-27
Publication date: 2005-03-09
Anticipated expiration: 2024-02-27
Also published as: GB2405608B; GB0404379D0; GB0320752D0

Abstract

Honing apparatus for sharpening tools such as chisels and plane irons comprises a tool holder and at least one sharpening stone 8. A tool 7 to be sharpened is located in the holder using two clamping members 5 which move relative to each other by means of a screw 4 having two opposite threads. The tool 7 is located at the desired angle by abutment with two or more bars 3b which pass between the clamping members 5. The holder also comprises two side supports 1 each with a roller 6. The side supports 1 and rollers 6 are sufficiently spaced to enable the rollers 6 to lie outwardly of the sharpening stone 8 when the apparatus is being used. The apparatus may comprise two or more sharpening stones, each with different roughness. Each sharpening stone may comprise three of more adjustable legs (9, Fig. 2) by which its height can be changed.

Description

Honine Guide This invention relates to a honing guide. In particular, it

relates to a honing guide and honing apparatus for sharpening tools such as chisels, plane irons, or other woodworking tools, but may also be applicable to the honing and sharpening of many other types of tool.

Woodworking tools clearly require frequent sharpening to keep them in best condition for the job. Generally, a tool is sharpened against a sharpening stone by holding the tool at a desired angle relative to the stone and moving the tool relative to the stone so that its edge is sharpened. Different roughnesses of stone may be used for fine and course sharpening.

It is important that the tool be held at the correct angle relative to the stone so that 1 S the functional edge is correctly sharpened at the correct angle. Tools and guides arc available to clamp and hold a woodworking or other tool at the correct angle. Sometimes these tools comprise a clamp and one or more rollers which sit upon a sharpening stone so that the guide, with a tool clamped at the correct angle, can be moved relative to the stone by movement of its rollers over the stone to move the tool back and forward to sharpen the edge of the tool.

There are two main problems with this type of honing guide. Firstly, since the device moves upon the stone itself and the rollers of it sit upon the stone, the rearward most - 2 part of the sharpening stone cannot be used as the tool generally extends forwardly of the wheels and therefore if the wheels reach the rear end of the stone the tool cannot utilise the rear end of the stone. This means that the whole length of the stone cannot be used.

Secondly, swarf and debris is formed as the tool is sharpened. This debris can collect on the stone itself and since the wheels of the guide lie and move upon the stone, this debris can collect at the wheel and the pivots or axles and this can tend to impede their smooth movement, also leading to wear of the axles and bearings with consequent inaccuracy.

The present invention arose in an attempt to provide an improved honing guide and 1 0 apparatus.

According to the present invention there is provided a housing apparatus, comprising a sharpening stone supported on a base, a clamp including means for retaining a tool to be sharpened by the stone at a desired angle and two side supports, each having a roller for contacting the base on each respective side of the stone, whereby the guide is reliable along the base causing the tool to be sharpened by the stone.

Preferably, the clamp comprises means for locating and retaining the tool at the desired angle.

Preferably, two or more sharpening stones are provided, of different roughnesses, these stones being spaced apart on the base; whereby the guide is usable interchangeably on both stones. - 3

The or each stone preferably includes one or more adjustable legs such that its height above the base can be varied.

In a further aspect, the invention provides a honing guide comprising a sharpening stone and a clamp means, the clamp means comprises means for retaining a tool to be sharpened at a desired angle, two side supports, each side support being provided with a roller, whereby the side supports and rollers are spaced apart sufficiently that the roller lies outwardly of the edges of the stone when the guide is positioned above the stone.

By moving the guide on a base or other support, the blade may be moved back and forth along the full length of the abrasive stone, whereas with the prior art design, the full length of the stone could not be used since the wheels or rollers had to move upon the stone itself. Using the full length of the stone results in even wear of the stone and the stone requires flattening and treatment less often.

By providing two or more abrasive stones ranging from course to fine, and adjusting the stones to the same height, a sharpening process can commence with a course stone to shape the cutting edge of the blade more quickly and progress steadily to the finer stone or stones to produce a very sharp edge.

Since the wheel or rollers do not contact the abrasive stone directly they do not pick up the mixture of lubricant, abrasive dust and particles which are formed by the honing process and the life of the bearings in the rollers is therefore much extended. - 4

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a honing guide on an abrasive stone with a tool clamped in position; Figure 2 shows a cross section from the side; and Figure 3 shows a base having two different sharpening stones mounted upon it.

Referring to Figure 1, a honing guide I is shown which supports the blade 7 of a woodworking tool in such a position that the blade can be sharpened against a sharpening stone 8.

The guide itself comprises two side supports 1 which are spaced apart by three steel rods 2, 3a and 3b. The side supports (or legs) are generally triangular and include at their lower edge lb a respective roller 6, wheel or other rotatable means, each mounted on an axle 6a.

The side supports 1 are spaced apart by a distance which is greater than the width of the stone block 8. In a typical example, the overall width from the outside face of one support to the outside face of the other support is approximately 12.5 cm.

A threaded bolt 4 is also mounted between the two side supports.

Two clamping members 5 are mounted between the side panels 1 so that bolt 4 and two of the steel members 3a and 3b extend through each of the clamping members 5. Part - 5 of the bolt 4 is provided with a left-handed thread and part with a right-handed thread.

Subsequently, half the length of the bolt is taken up by left-handed thread and half is taken up by right-handed thread. The part of the respective clamping members 5 through which the bolt extends is also provided with a complimentary thread such that rotation of the screw or bolt 4 causes the clamping members 5 to be drawn towards or away from each other to thereby clamp the blade 7 of a tool as shown in Figures 1 and 2.

In use, the clamps are loosened and a tool mounted between the two and abutted against the underside of rods 3a and 3b. The clamps are then tightened towards each other to securely clamp the tool. The amount of projection of the blade 7 from the front of the clamps 5 determines the required angle of sharpening. That is, referring to Figure 2 for example, it will be seen that if the blade projected further from the front of the clamp member 5, then the angle that the blade makes with the stone 8 would be less than that shown in Figure 2 and so the desired angle can be adj usted in this embodiment by selection ofthe amount of projection ofthe tool. Once this has been chosen, the clamps 5 are tightened towards each other and the tool is held tightly clamped.

The guide, with tool attached, is then placed over the sharpening stone 8 such that the rollers lie on either side of the stone. It will be noted that the stone includes adjustable legs, eg in the form of adjustable screws 9 which enable the height of the or each stone above the base to be selected. The height of the stone and projection of the tool are determined and then the guide can be rolled backwards and forwards to cause the blade to be sharpened by the stone. In use, applying downward hand pressure while moving the - 6 honing guide backwards and forwards over the whole length of the abrasive stone is possible. Generally, a suitable lubricant will be used to aid the honing process.

In a modification shown in Figure 3, two separate sharpening stones 8a and 8b, of different roughnessess, or degrees of abrasion are provided. In other embodiments, more than two such sharpening stones may be provided. Note that the adjustable legs have not been shown in this figure for clarity, although in some embodiments diamond 'stones' for example, the legs may be omitted.

Generally, however, three or more adjustable legs may be provided. These are used to ensure that the top surface of the stone lies parallel to the surface upon which the rollers lie and so that the height of the top surfaces should be the same as before flattening, which will slightly reduce the thickness of the stones.

The structure of Figure 3 is used by firstly clamping the tool in a desired disposition within the honing guide and then first applying the honing guide over the first rougher sharpening stone 8a. Subsequently, the guide is applied over the finer grade stone fib. - 7

Claims

Claims 1. A honing guide comprising a sharpening stone and a clamp means,

the clamp means comprising means for retaining a tool to be sharpened at a desired angle and two side supports, each side support being provided with a roller, whereby the side supports and rollers are spaced apart sufficiently that the roller lies outwardly of the edges of the stone when the guide is positioned above the stone.
2. A housing apparatus, comprising a sharpening stone supported on a base, a clamp including means for retaining a tool to be sharpened by the stone at a desired angle and two side supports, each having a roller for contacting the base on each respective side of the stone, whereby the guide is reliable along the base causing the tool to be sharpened by the stone.
3. Honing apparatus as claimed in Claim 2, wherein the clamp comprises means for locating and retaining the tool at the desired angle.
4. Honing apparatus as claimed in Claim 2 or Claim 3, wherein two or more sharpening stones are provided, of different roughnesses, these stones being spaced apart on the base; whereby the guide is usable interchangeably on both stones.
5. Honing apparatus as claimed in any preceding claim, wherein the or each stone includes three or more adjustable legs. - 8
6. Honing apparatus as claimed in Claim 3, including two or more bars mounted between clamping members, against which the tool can be abutted, to set the clamped angle of the tool.
7. Honing apparatus as claimed in any preceding claim, wherein the clamping means are drawn towards or away from each other, to clamp or release a tool, by means of a screw having two opposite threads.
8. Honing apparatus substantially as hereinbefore described, with reference to, and as illustrated by, the accompanying drawings.