Patent GB-965285-A (GB)
Title: Tip-actuated ball point writing instruments
IPC: B43K24/02
Filed: 1961-04-07
Abstract: 965,285. Writing instruments. F. T. JOHMANN. April 7, 1961 [April 14, 1960], No. 12696/61. Heading B6P. Relates to various constructions of ball-point pens in which the cartridge is retracted by pressing the tip down on a hard surface and is projected by pressing the telescopic or flexible tip hood on the surface. As shown in Fig. 1 a tubular hood 16 is slidable in the front end of the barrel, being urged outwards by a spring 41 which abuts against an enlargement 21 on the writing unit 20. A sleeve 25 is mounted in the rear barrel part and is formed at its rear end with a series of slots 27, Fig. 10, separated by rearward projecting lugs 26. Each lug 26 is notched at its rear end to form two teeth 30, 31 and has a longitudinal groove 28 on its inner face. A latch actuating member 32 comprising a cylindrical portion having radial ears 34 abuts against the rear end of the writing unit 20 and is restrained against rotation by the engagement of the ears 34 in the slots 27 and grooves 28. The member 32 is toothed at its rear end adjacent to the ears 34. A cylindrical latch element 36 having radial lugs 37 is rotatably mounted in a recess in the rear end of the member 32 and is urged forwards in the barrel by a spring 39 which is stronger than the spring 41. In Fig. 1 the lugs 37 are shown at the front ends of the slots 29 (position 1, Fig. 10), the writing unit being then held in the projected position by the spring 39. Pressing the point of the instrument on a rigid surface causes the parts 16, 20, 32, 36 to move rearwards in the barrel until the front end of the latter abuts against the rigid surface. The lugs 37 are thereby carried out of the slots 29 and once they are clear of the lugs 26 camming action between the teeth on the member 32 and teeth formed at the lower edges of the lugs 37 causes the latch element 36 to rotate slightly. When pressure is relaxed the parts are carried forwards in the barrel by the springs 39, 41 but as the lugs 37 come to rest between the teeth 30, 31 (position 5, Fig. 10), being of too great a radius to enter the grooves 28, the writing unit is held in a retracted position. A second pressure on the point of the instrument causes the lugs 37 to move through positions 6 to 9 to position 1<SP>1</SP> wherein the parts are restored to the Fig. 1 position. In a modification the sleeve 25 is made slidable in the barrel and can be urged forwards by a plunger projecting from the rear end or from the side of the barrel in order to provide alternative means to effect projection or retraction of the writing unit. In another form (Fig. 12, not shown) the parts 32, 36, 39 are inverted, the front end of the spring 39 bearing against a closure member at the front end of the sleeve 25 which is slidable in the barrel, and the rear end of the actuating member 32 abutting against the closed rear end of the barrel. The teeth 30, 31 are directed forwards and the closure of the sleeve 25 abuts against the rear end of the writing unit. This instrument is operated in the same way as that shown in Fig. 1. As shown in Fig. 15 a sleeve 20 is mounted in the rear barrel part and has diametrically opposed long and short slots 71, 72 in its rear end which is of circular cross-section. The remainder of the sleeve is of rectangular cross-section, so as to prevent the rotation of a latch actuating member 73 and a latch 76 which are slidable therein, the latch being urged forwards in the barrel by a relatively powerful spring 82. The writing unit 20 is projected and retracted in the same way as in the Fig. 1 embodiment, the latch 76 being rocked in opposite directions by successive applications of pressure to the point of the instrument so that lateral portions 80, 81 thereof engage alternately in the slots 72, 71 respectively and latch the writing unit in retracted and projected positions. In all embodiments the hood 16 may be replaced by a resilient rubber tip secured to the barrel.