GB984437A - Mechanical lead pencil - Google Patents

Abstract

984,437. Propelling pencils. H. OWADANO. Jan. 1, 1962, No. 57/62. Heading B6P. In a retractable, mechanical lead pencil of the screw type in which a lead holding tubular member 4 is slidably and concentrically mounted in a female threaded tube 2 within the barrel portions la, 1b of the pencil, the threaded tube 2 and the tubular member 4 are projected by a push-button 14 against the bias of a compression spring 15. A lead plunger 10 with a pin 11 that extends through a longitudinal slot 9, Fig. 3 (not shown), in the tubular member 4, and co-operates with the helical groove 12 of the tube 2, can be removed from the base end of the tubular member simply by removing the cap 14. In the embodiment shown, the barrel portions 1a, 1b may be rotated with respect to each other. The base portion 1b has a square section bore associated with the base portion of the tube 2, also of square section in this section of the pencil, Fig. 2 (not shown). A key groove 7 within the barrel portion 1a engages a key 6 integral with the tubular member 4, Fig. 4. Relative rotation of the barrel portions provides relative rotation between the lead holding tubular member 4 and the female threaded tube 2, providing the propelling action of the pencil. The lead and tubular member 4 are held in the projected writing position by the key 17 of a pocket clip 16 engaging a shoulder 18 against the force of the spring 15. Disengagement of the key 17 from the shoulder 18 allows retraction. In another embodiment (not illustrated), the cap 14 may be used to provide the relative rotation and hence the propelling action. A number of leads may be loaded at the rear of tubular member 4 when the plunger 10 is removed, providing a magazine action. Synthetic plastic material is used in the manufacture of the pen, but metals and other suitable materials may also be used.