GB854118A - Protraction-retraction mechanism for writing instruments - Google Patents

Abstract

854,118. Reservoir pens. JOHMANN, F. T. Sept. 29, 1958, No. 31058/58. Class 146(3). A writing instrument having a retractable writing point includes a cartridge unit housed within a barrel and urged-longitudinally of the barrel to a projected position by means of a spring, latching means adapted to retain the cartridge unit in a retracted position, and a reciprocally movable release member having one end which normally projects outwardly from the barrel and the other and adapted to engage the latching means to release the cartridge unit from its retracted position. when pressure is exerted' on the projecting point. The cartridge unit 24 carrying a cylindrical latch element 29 at its inner end, and a coaxial sleeve 18 are urged towards a projecting position by springs 32 and 22 respectively. On depressing the cartridge unit and sleeve against a fixed surface 39 when in the projected position, Fig. 1, the bottom of the element 29 moves up past the top of the deformable spring latch 36 which then moves inwardly under the element 29, thereby holding the cartridge unit in the retracted position. On lifting the pen clear of the fixed surface, the sleeve returns to its original position under the action of spring 22. A second depression of the sleeve 18 forces its upper end into engagement with the terminal portion 38 of the deformable spring thereby causing the spring to assume the position indicated by the dotted lines in Fig. 3 (not shown), and so release the cartridge unit. The spring 36 is mounted in a groove 391 in a fixed block 13 which forms a stop for the spring 22. In a modification, Fig. 4 (not shown), the spring 22 is eliminated and the terminal portion of the deformable spring is tapered so that the sleeve is returned to its original position under the action of gravity and the action of the deformable spring. Reference has been directed by the Comptroller to Specification 810,719.