GB938485A - Improvements in or relating to writing instruments - Google Patents

Abstract

938,485. Writing instruments. F. T. JOHMANN. Nov. 17, 1960 [Dec. 14, 1959], No. 39558/60. Class 146 (3). A writing instrument has a retractable writing point at each end, and depression of one or either of the ends against a rigid surface causes simultaneous projection or retraction of the points. As shown in Fig. 1 the twopart barrel 10, 10<SP>1</SP> has a sleeve 21 slidably mounted therein. One end 22 of the sleeve is closed and carries a tubular nipple 23 in which the rear end of a ball-point writing unit 15<SP>1</SP> is frictionally engaged. Two annular latch members 24, 25 are frictionally fitted in the sleeve 21, the member 25 having teeth 28 and the member 24 having pairs of teeth 27 separated from each other by deep recesses 26. The teeth 28 are circumferentially offset from the teeth 27. A cylindrical member 29 is slidable in the bores of the latch members 24, 25 and carries in an annular recess a laterally projecting ball 32. A second ball-point writing-unit 15 is frictionally engaged in a blind bore at one end of the member 29. The unit comprising the member 29 and writing- unit 15 is biased away from the unit comprising the sleeve 21 and latch members 24, 25 by a spring 34, but the units are held together by the ball 32 which engages either in a deep recess 26 of the latch member 24 (as shown) or in a shallow recess between the teeth 27. The outer ends of the writing units 15, 15<SP>1</SP> are telescopically arranged in hoods 14, 14<SP>1</SP> respectively, which are themselves slidable in the open ends of the barrel portions 10, 10<SP>1</SP> and which are biased towards positions in which they enclose the ball points 18, 18<SP>1</SP> by springs 36, 36<SP>1</SP>. As shown, both ball points are exposed for writing; pressing of either ball point on a rigid surface causes the ball 32 to move out of the recess 26 and into engagement with the inclined edge of a tooth 28 which causes the ball to rotate slightly in relation to the latch member 24. When pressure is released the spring 34 brings the ball 32 into engagement with a shallow recess between two teeth 27 so that the combined length of the parts 15<SP>1</SP>, 21, 29, 15 is shortened, and a new balance of the opposing springs 36, 36<SP>1</SP> is established so that the sleeve 21 moves a short distance longitudinally in the barrel and both ball-points are enclosed by the hoods 14, 14<SP>1</SP>. A further depression and release of either ballpoint causes the ball 32 to return to the recess 26 and both ball points are thereby returned to the projected position. Specification 876,206 is referred to.