GB804903A - Improvements relating to writing instruments - Google Patents

Abstract

804,903. Writing instruments. SCRIPTO, Inc. April 18, 1957 [Dec. 31, 1956], No. 12728/57. Class 146(3) A retractable writing instrument, e.g. a ball-point pen, having a rearwardly biased writing unit 16, includes a freely floating latch member 54 longitudinally slidable within the barrel to the rear of the writing unit and in front of a plunger 70 slidably carried in the rear end of the barrel, said plunger :and latch member having the adjacent ends thereof formed for contact so that each successive depression of the plunger rocks the latch member transversely in the direction opposite to that of the preceding depression, and means within the barrel for engaging the latch member in the projected and retracted positions of the writing unit 16. The plunger 70 is rearwardly biased by a spring 74 and has inclined faces 80, 82 at its front end for alternate engagement with corresponding cam surfaces 56, 58 respectively of the latch member 54. The writing unit 16 is held in projected position, as shown, by the engagement of a latch arm 60 of the member 54 with a latch shoulder 44 on a channel-shaped insert 42, the rearward bias of the unit causing the member 54 to rock laterally until it contacts the insert 42 at 68 also. When the plunger 70 is depressed the face 82 engages the cam surface 58 of the latch member, causing the member to rock about the fulcrum 68 and thus disengaging the latch arm 60 from the shoulder 44. Pressure on the plunger being released, the unit 16 and latch member 54 are carried backwards by a spring at the front end of the barrel, until a latch arm 62 on the member 54 engages with a shoulder 46 on the insert 42. The spring 74 carries the plunger 70 backwards until it no longer contacts the member 54 which then rocks and contacts the insert 42 at 67 also. When the plunger is depressed a second time, the face 80 contacts the cam surface 56 and the latch member and unit 16 are carried forwards until the latch arm 60 is forward of the shoulder 44: the member then rocks about fulcrum 67 and the arm 60 engages the shoulder 44. A plug 28 fitting into the end of the unit 16 has an axial passage and is closed by a cap 32, venting being provided by external grooves in the plug. Specification 801,910 is referred to.