GB870151A - Improvements in writing instruments - Google Patents

Abstract

870,151. Reservoir pens. PARKER PEN CO. Feb. 21, 1958 (Feb. 22, 1957], No. 5754/58. Class 146(3). A writing instrument e.g. a ball-point pen comprises a writing unit 2 reciprocable. within the barrel 1 between retracted and projected positions and urged rearwards by a spring 12, a cam member 6 associated with the writing unit and having longitudinal grooves 7, 7<SP>1</SP> and skew teeth 8, 8<SP>1</SP> positioned alternately around it, a tubular grinding part 13 connected to the barrel and having an internally projecting stop lug for engaging the cam member 6 and longitudinal opening in its side wall, a manually reciprocable tubular part, comprising two elements 22, 23, telescoped over the part 13 and having an internal drive lug projecting through the opening in the part 13 for engagement with the cam member 6, a spring 33 biasing the parts 22, 23 rearwards and a cap 30 telescoped over the parts 22, 23. The part 13 is formed with two stop lugs 19, 20 and two longitudinal openings 15, 16 (Fig. 2, not shown) respectively adjacent thereto through which project drive lugs 24, 25 formed on the parts 22, 23 respectively. The cap 30 is secured to the parts 22, 23 by a screw 31 engaging in threads thereon and which also secures a pocket clip 32. In addition to the teeth 8, 8<SP>1</SP> the generally cylindrical cam member 6 has two inclined surfaces 10, 10<SP>1</SP> which are engaged, as shown, by the stop lugs 19, 20 when the writing unit 2 is in the projected position. To retract the unit the cap 30 is depressed which brings the drive lugs 24, 25 into contact with the teeth 8, 8<SP>1</SP> whereby the unit is first projected slightly further until the stop lugs clear the verticai sides of the teeth and then rotated slightly under the camming influence of the co-operating inclined edges of the teeth 8, 8<SP>1</SP> and the lugs 24, 25, 19, 20. When pressure is removed from the cap 30 and the lugs 24, 25 are moved to the rear (by the action of spring 33 on the parts 22, 23), this camming action continues until the stop lugs 19, 20 engage in the longitudinal grooves 7<SP>1</SP>, 7, the writing unit being then retracted. Projection is ettected by a further depression of the cap 30 whereby the drive lugs 24, 25 engaging the surfaces 10<SP>1</SP>, 10 force the cam and writing unit forwards until the stop lugs 19, 20 are clear of the longitudinal grooves 7<SP>1</SP>, 7. and upon rotation of the cam are free to reassume the position of Fig. 8. Specification 758,412 is referred to.