GB880633A - Improvements in retractable-point writing instruments - Google Patents

Abstract

880,633. Reservoir pens. SCRIPTO Inc. April 11, 1958 [July 30, 1957], No. 11549/58. Class 146(3) A retractable writing instrument, e.g. a ballpoint pen, comprises a rearwardly spring-biased writing unit, a plunger projecting from the rear end of the barrel, and a latch member supported between the rear end of the writing unit and the plunger member substantially on its longitudinal axis for rocking movement into and out of engagement with the holder, the opposed ends of the latch member and the plunger each having two laterally spaced contact points for abutment between the two members on depression of the plunger, the contact points being so disposed that the latch member is rocked in opposite directions on consecutive depressions of the plunger. A tubular cap 14 is screwed on to the rear end of the barrel 12 and houses a sleeve 38 formed with diametrically opposed slots 68, 70. The writing unit 16 is biased rearwardly by a spring 32 and carries at its rear end a latch member 42 which engages the unit with a rounded protrusion 62. A hollow plunger 40 is slidable in the rear ends of the cap 14 and the sleeve 38 and houses one end of a spring 44 the other end of which engages a centring member 54 formed on the latch 42. The plunger 40, sleeve 38 and latch 42 have flattened portions on opposite sides to prevent relative rotation thereof. The latch 42 has arms 64, 66 extending radially at the lower end thereof which are engageable with shoulders 72, 74 respectively formed by the upper ends of the slots 68, 70 in the sleeve 38. When the arm 64 engages the shoulder 68 (see Fig. 1) the unit 16 is in retracted position. The rear end of the latch member 42 is so dimensioned that when the plunger 40 is depressed it engages the said rear end at one side only (see Fig. 3) thereby causing the latch member to move forward out of engagement with the shoulder 72 and to rock about the protrusion 62 until the arm 66 enters the slot 70 and engages under the shoulder 74. When pressure on the plunger is released the latch 42 rocks about the arm 66 under the influence of the spring 32 until it engages the side of the sleeve 38 adjacent to the slot 70. The unit 16 is then in the projected position shown in dotted line in Fig. 1. A second depression of the plunger rocks the latch in the opposite direction and on release of pressure the parts resume their retracted positions. Specification 804,903 is referred to.