GB886414A - Improvements in writing instruments - Google Patents

Abstract

886,414. Writing instruments. SHAW REGENT Ltd. May 16, 1960 [Feb. 17, 1959], No. 5502/59. Class 146(3) In a retractable writing instrument, e.g. a ball-point pen, comprising a rearwardly biased writing unit 12, a plunger 19 depressible to project the writing unit, and a latch member 23 cooperating with a fixed stop 29 in the barrel to lock the unit in projected position, the latch member 23 has an abutment part 24 which is positioned between a downwards directed abutment on the plunger 19 and an upwards directed abutment on the writing unit 12 or the biasing means therefor and which bears slidably against the side of the barrel remote from the stop, the abutments on the plunger and on the writing unit being capable of exerting on the abutment part 24 a couple which tends to rotate the latch member in the direction required to engage it with the stop. The plunger has a forked portion at its inner end between the arms 21 of which the member 23 is positioned. The abutment part 24 of the member 23 is disc-shaped and in the projected position shown the flat forward face thereof lies in contact with the flattened rear surface of a pin 17 mounted on the rear end of the writing unit 17. The rear end 27 of the latch member projects through a hole in the side of the barrel the rear edge of which constitutes the stop 29. When the end 27 is pressed into the barrel the writing unit is retracted by a spring 16, the end 27 being then housed almost completely in the space between the arms 21 so that the part 24 engages the pin 17 only with its lower left-hand portion as seen in Fig. 1. When the plunger 19 is depressed to project the unit the front ends of the arms 21 engage bevelled portions 25 on the part 24 and this, together with the rearward thrust exerted on the part 24 by the spring 16 through the pin 17, tends to rock the latch member clockwise so that when the end portion 27 thereof registers with the hole in the barrel it will move radially outwards into it and thereby lock the unit 12 in writing position.,