Abstract: A tool sharpening device (11) has a rotary grindstone (14), a tool support (34) and linear guides (32, 33) along which the tool support (34) is displaceable in use of the device. The linear guides (32, 33) extend transversely of the axis of rotation of the rotary grindstone (14) and their location is such as to guide a tool carried by the tool support (34) so as to transit across the end face (15) of the rotary grindstone (14). The tool support (34) is releasably connected to the linear guides in such a way that the tool support (34) can be positioned on the linear guides (32, 33) with a tool support face (35) lying at one of two different inclinations to the plane defined by the end face (15) of the grindstone (14).

Abstract: Apparatus for sharpening an edge tool having a linear cutting edge, such as a chisel, plane iron or gouge, comprises a rotary grindstone having a cylindrically curved surface mounted for rotation about an axis coincident with the axis of the cylinder, and tool mounting assembly on which an edge tool to be sharpened can be located, the tool mounting assembly including a guide assembly orientated such that relative movement between the tool and the rotary grindstone can take place substantially perpendicular to the plane including the point of contact between the edge tool and the stone and the axis of the grindstone.

Abstract: A twist drill sharpening tool comprises a body housing a cylindrical rotatable grindstone with a small diameter and longer axis, and a drill holder which can be fitted into a bore in the body so as to hold the tip of a twist drill in contact with the curved surface of the grindstone at a position which is offset from the centreline and inclined at between 10.degree. and 12.degree. from a diametral plane of the grindstone passing through the drill tip contact line with the grindstone. A face cam is engaged by a cam follower of the drill holder so as to vary the projection distance of the drill as it is turned, carried by the holder, around its own axis. The bore for the drill holder may be formed in part of the body which can be moved to different positions to vary the drill tip angle.