GB472350A - Improvements in mechanical lead pencil - Google Patents

Abstract

472,350. Pencil holders; erasers. EAGLE PENCIL CO. July 27, 1936, No. 20779. Convention date, Aug. 13, 1935. [Class 146 (iii)] In a mechanical lead pencil of the type in which a lead tube and propeller wire have lateral extensions adapted to engage a helical groove in the pencil casing, so as to produce unison movement and finally to expel the lead from the tube, both propelling and ejecting movements are actuated from a ferrule rotatably mounted on the rear end of the pencil, and which slidably carries an eraser, which is adapted to be expelled therefrom by rearward movement of the lead propeller wire, which first abuts against the eraser or its casing and then, the movement continuing, expels it from the ferrule. The pencil is moulded, preferably from a phenol-formaldehyde condensation product, with an internal helix 11 with which engage a loop-shaped lug 19, Figs. 2, 3, on a propeller 18 and a roller 21 on a lead-holding tube 20. The lug 19 and roller 21 project through a slot 14 in a tube 13. The tube 13 is split to form two straps 17 which are bowed outwards to grip the track 11 frictionally, and at the rear end is split into two strips 24 which are outwardly and reversely bent and lie in a reduced portion 26 of the case. An eraserholding ferrule 15 is provided with longitudinal flutings 29, Fig. 4, in two of which lie the strips 24. The ferrule is indented at 30 and the strips 24 at 28 so as to engage an annular depression 27 on the pencil case. The movement of the ferrule and tube 13 longitudinally of the pencil is thus prevented, but the tube 13 and ferrule 15 are firmly keyed together for rotation of the one by the other. The eraser is gripped between tongues 35 of a sheet-metal cup and may be retained in several positions by the engagement of ridges 36 on the tongues 35 with beads 31, 32, 33 in the ferrule. When the pusher 18 is fully retracted it engages and ejects the cup 34 and eraser. The metal tip 12 is formed with a spindle-shaped shank 42 around which is moulded the material 43 of the case so that the tip is firmly gripped and there is no substantial reduction in the cross-section of the case. A collar 29 on the rear end of the tube 13 has a tongue projecting into the slot 14 to prevent the feeding of the propeller out of the helix.