GB2278304A

GB2278304A - Tool sharpening jig

Info

Publication number: GB2278304A
Application number: GB9311184A
Authority: GB
Inventors: David Thomas Seear
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-05-29
Filing date: 1993-05-29
Publication date: 1994-11-30
Also published as: GB9311184D0

Abstract

A jig for sharpening an edge of a tool such as a plane blade comprises: a holder 4 for holding the tool so that the edge of the tool extends in one direction; a grinding device 11 such as a cup grinding wheel for sharpening the edge of a tool held by the tool holder; and a guide arrangement 1, 10 for guiding the tool holder and grinding device for sliding movement relative to each other generally in that direction during a sharpening operation so that the grinding device sharpens the tool. In order to reduce the required width of the jig in the case where the grinding device is smaller than the maximum length of the edge to be sharpened, during such a sharpening operation the tool holder and a tool held thereby are stationary, and the grinding device moves. <IMAGE>

Description

Tool Sharpenig Jig Discription.

1/ SLIDING RODS. To maintain accurate level when the cradle is moved sideways.

2/ SPLIT COLLAR. To accommodate drill neck and firmly hold the drill at 89" to the flat iron bed.

3/ Height adjusting bolt. To adjust position of cup grinding wheeland also to alter the grinding angle of the cup grinding wheel in relation to the flat iron bed.

4/ FLAT IRON BED. To position and support blades in a desired position to effect continual and accurate grinding.

5/ WING NUTS. To lock the flat iron bed in a required position.

6/ PIVOT. To allow the flat iron bed to pivot.

7/ ADJUSTING SLOT. To allow the flat iron bed to be secured in various positions.

8/ CLAMP. To secure a blade or similar to be secured on the flat iron bed.

9/ END PLATE. To hold the sliding rods and flat iron bed in a stable position at required distances.

10/ CRADLE. To hold the drill/motor in a firm position and carry sideways whilst maintaining a consistant level.

11/ CUP GRINDING WHEEL. The cup grinding wheel is positioned at 89" to the flat iron bed to enable only one side of the cup wheel to make contact with the blade or similar positioned and secured on the flat iron bed.

12/ CUP GRINDING WHEEL POSITION.

The cup grinding wheel is also positioned as such that when contact is made between the cup grinding wheel and the blade or similar, the rotation of the cup grinding wheel effects a pulling action thereby moving the cradle along the sliding rods.

Claims

1. A jig for sharpening an edge of a tool, comprising a holder for holding the tool so that the edge of the tool extends in one direction; a grinding device for sharpening the edge of a tool held by the tool holder; and means for guiding the tool holder and grinding device for sliding movement relative to each other generally in said one direction during a sharpening operation so that the grinding device sharpens the tool; characterised in that: during such a sharpening operation, the tool holder and a tool held thereby are stationery and the grinding device moves. (Advantage: reduces required width of jig if grinding device is smaller than maximum length of edge to be sharpened.)

2. A jig as claimed in Claim 1, wherein the grinding device includes a cradle which is guided by the guide means during such a sharpening operation, a power tool for a grinding wheel, and means for removably clamping the power tool to the cradle. (Advantage: enables an existing power tool to be used.)

3. A jig as claimed in Claim 1 or 2, further comprising a first adjuster means for adjusting the position of the grinding device in a direction generally at right angles to said one direction. (Advantage: can be adjusted to take into account, at least partly, position of edge, wear of grinding device, and required sharpening angle.)

4. A jig as claimed in any preceding claim, wherein the grinding device is arranged to rotate a grinding wheel, and the axis of rotation is inclined at an angle which is close to, but not equal to, a right angle relative to said one direction. (Advantage: the sharpening action assists or causes the grinding device to slide.)

5. A jig as claimed in Claim 4, wherein said angle is less than 5 degrees and preferably about 1 degree off a right angle.

6. A jig as claimed in any preceding claim, wherein the tool holder includes a bed extending in said one direction, and means for clamping a tool to the bed.

7. A jig as claimed in Claim 6, wherein the arrangement is such that the tool can be clamped flat against the bed with the edge thereof projecting slightly from the bed, and wherein the bed is of substance so as to absorb heat from the tool during a sharpening operation.

(Advantage: tool edge'is not overheated.)

8. A jig as claimed in Claim 6 or 7, wherein the tool holder includes means for supporting the bed and second adjusting means for adjusting an angle of tilt of the bed relative to the support means about an axis generally parallel to said one direction. (Advantage: can be adjusted to take into account, at least partly, position of edge, wear of grinding device, and required sharpening angle.)

9. A jig as claimed in any of Claims 6 to 8, wherein the bed and clamping means are arranged so that the position of the tool is adjustable relative to the bed. (Advantage: can be adjusted to take into account, at least partly, wear of grinding machine, and to align tool edge.)

10. A jig as claimed in any of Claims 6 to 9, wherein the bed and clamping means are arranged so that a variety of different sizes and/or types of tools can be clamped to the bed. (Advantage: multi-purpose.)

11. A jig substantially as described with reference to the drawing.