GB753531A - Improvements in and relating to pencil sharpeners - Google Patents

Abstract

753,531. Pencil sharpeners. WILLIAMSON MANUFACTURING CO., Ltd. Nov. 30, 1954 [Nov. 30, 1953], No. 33266/53. Class 146(3) A sharpener for wood-sheathed or unsheathed pencils comprises a guide to guide a pencil into a sharpening device mounted on a power-driven shaft movable endwise against spring pressure whereby to operate means to bring the power drive into and out of action when the pencil is inserted and withdrawn. In one form a recessed sharpener body having a tungsten carbide &c. cutter is mounted directly on the upper end of a vertical shaft of a lowspeed (100-200 r.p.m.) electric motor, the shaft having slight end play and engaging, at its lower end, a pair of spring contacts constituting the motor control switch; the shaft passes through the flat top of a casing (surrounding the motor) by means of an upstanding sleeve bearing larger than the sharpener body, and a transparent plastic tray to receive cuttings has a central walled aperture which fits closely round the bearing; a conical transparent plastic hood is clipped on to the outer wall of the tray and has a guide aperture for the pencil lead at its apex. In the form shown the sharpener body 1 is mounted on shaft 4 driven from the electric motor 12 through reduction gearing 17, the gear on the shaft 4 being sufficiently wide to allow the required end play for operation of the motor control contacts by a spring blade 16 engaged by a shoulder 18 on the shaft; the cuttings are received in a recess 19 surrounding the sleeve bearing 6 and covered by a transparent hood 10. A lead-holder of the collet type may be guided and advanced by a spring-loaded sliding guide as described with reference to Fig. 5 in Specification 660,589 [Group XX], or may be held against a semi-circular or V-section guide 20 carried by a hinged arm 21 held in the full or brokenline positions shown by a blade spring 22. A lead guide in the form of an accurately fitting tube may be provided, either secured to the top of the sharpener body or screwed into the hood 10; a guide such as this, or as shown, may also be provided on the coaxial form of the invention described above. The Provisional Specification refers to a coaxial arrangement including a reduction gear.