Patent GB-669958-A (GB)
Title: An improved tool for use in sharpening safety-razor blades
IPC: B24D15/08
Filed: 1949-10-31
Abstract: 669,958. Razors. TURNER, A. Sept. 21, 1950. [Oct. 31, 1949] No. 27799/49. Class 30. [Also in Group XXIII] A tool for use in the sharpening of doubleedged wafer blades has clamping members A, B, Fig. 2, the outer member A having a screwthreaded central stem C which passes through a central opening b<SP>1</SP> in the inner member B to engage a tapped axial bore d<SP>1</SP> in the handle D. The inner member B presents a concave face b<SP>2</SP> to the blade E and the longitudinal edges a<SP>1</SP> of the outer member A urge the blade towards this concave face so that the blade is flexed when the screw-threaded connection between the handle and clamping head is tightened up. Angular movement of the inner member B and blade E relatively to the stem C is prevented by locating dowels on the outer member A. A coiled compression spring G coaxial with the stem C is interposed between the inner member B and a shoulder d<SP>2</SP> on the handle D. The portion of the handle D beyond its tapped axial bore d<SP>1</SP> is made hollow to accommodate a spring-loaded plunger H having a chisel end h<SP>1</SP> adopted to engage a diametrel nick in the end of the stem C. Relative angular movement of the plunger H and handle D is prevented by a lateral projection h<SP>2</SP> on the former engaging a longitudinal slot or channel d<SP>3</SP> in the latter ; the plunger H is loaded by a coiled compression spring I bearing against a screw cap J. In a modification for use with single-edged wafer blades, the part of the blade E, Fig. 5, adjacent its blunt edge is gripped between the clamping members A, B at one side of the threaded stem C and locating dowels F ; the operative faces of both members are flat, and the inner member B is provided near its corners with locating projections N adapted to enter recesses in the blade E. The outer clamping member A is cut away at a<SP>2</SP> to clear these projections. The central hole in the inner member B is substantially larger than the threaded stem which passes through it, so that the member B can be rocked upon that edge of the outer member A which lies remote from the blade E for insertion or removal of the blade ; this rocking is effected through the medium of an arm O projecting from the inner member B. In a further modification for use with single-edged blades whose blunt edges are reinforced by a channel-section "back" e<SP>2</SP>, Fig. 7, a marginal lip b<SP>3</SP> on the inner member B co-operates with the adjacent edge of the channel e<SP>2</SP> ; alternatively, the blade back e<SP>2</SP> may abut a longitudinal shoulder on the member A and may lie in a suitable recess in the member B. By providing the tool with a guard, it can also be used as a razor. In one form, a guard P, Fig. 8, for the cutting edge of the blade E is supported, in spaced parallel relation to the adjacent edge of the clamping member B, by two spring steel strips Q projecting from the end portions of the member ; the strips Q are of bowed form so that the guard P normally assumes an inoperative position in which the cutting edge of the blade is exposed for sharpening. The guard P is moved into operative position by a screw R engaging a tapped hole o<SP>1</SP> in the lever arm O and having a thumb-wheel S. The guard P is notched or slotted, and the corners of the blade are protected by upstanding lugs q<SP>1</SP> on the spring strips Q or by equivalent projections on the guard P itself. The strips Q are secured to the members B, P by rivets T. In a modification for use with hollow-ground blades having relatively thicked backs e<SP>3</SP>, Fig. 12, the back is accommodated in a recess b' in the inner member B and is itself formed with recesses e<SP>4</SP> at opposite sides for engagement by a marginal tongue a<SP>3</SP> on the member A.