Screwdriver blade with inclined drive surfaces and method of manufacturing

摘要

A screwdriver blade has faces formed on front and back sides of a shank. Each face has a drive surface extending from each side edge inward toward a longitudinal axis. Each drive surface is inclined relative to a plane containing the axis and bisecting each of the side edges. A thickness of the blade increases from the shank distal end. Each of the drive surfaces appears curved when viewed in a distal end view. Each of the drive surfaces extends from the shank distal end to a face proximal end. A central portion between each of the drive surfaces may also appear curved when viewed in a distal end view, or it may be flat. The drive surfaces and the central portion may be formed at a single radius of curvature. The central portion may have a increasing width from the distal end or it may have a constant width.

主权项

1. A screwdriver blade, comprising:
a shank having a shank proximal end, a shank distal end and a longitudinal axis; a face formed on a front side of the shank and extending from the shank distal end toward the shank proximal end, the face having two side edges; a drive surface extending from each side edge inward toward the longitudinal axis, each drive surface being inclined relative to a plane containing the axis and bisecting each of the side edges; a thickness of the blade measured from each drive surface to a back side of the shank increasing from the shank distal end toward the shank proximal end; wherein: each drive surface has an inner margin; a central portion is located between the drive surfaces and joins the inner margins; and each inner margin is a straight line that is parallel to a closest one of the side edges when viewed in a front view, thereby defining a constant width for each of the drive surfaces.