Patent GB-641595-A (GB)
Title: Improvements in reservoir writing instruments
IPC: B43K24/08
Filed: 1946-12-12
Abstract: 641,595. Reservoir pens. COMPANIA URUGUAYA DE FOMENTO INDUSTRIAL SOC. ANON. Dec. 12,1946. No. 36780. [Class 146 (iii)] A ball-point pen has the reservoir and the writing extremity formed as a unit mounted in a hollow casing with an aperture at one end through which the ballpoint protrudes, the unit being capable of withdrawal from and insertion into the casing through the aperture. In one simple form, Figs. 5, 6, the reservoir 16 consists of a tube of resilient material such as polythene or synthetic rubber curved along its length so that when inserted into the straight bore 24 of the casing 1 it is gripped frictionally. The part 27 adjacent to the point may be of slightly greater diameter than the reservoir so as to be a friction fit in the bore 24. The pen tip is grooved, corrugated or provided with bosses at 28 to facilitate the withdrawal of the unit from the casing. In a modification, the reservoir is straight and an enlarged part corresponding to the part 27 is gripped by jaws on the casing formed by slitting the sides of the casing at its mouth. The unit may be frictionally gripped in the casing by the inner surfaces of a tubular spring which can be slid longitudinally of the casing by means of a button extending through a slot in the casing so as to project the ball-point from or retract it into the casing. In another construction, Fig. 14, the unit 103 is adapted to be frictionally gripped by a nozzle-shaped member 109 attached to a tube 110 slidable in a bush 111 on the casing 1 and carrying an operating knob. A spring 107 bearing against the part 108 of the member 109 tends to withdraw the pen point within the casing. To project the pen, the tube 110 is pressed inwardly until a pressed-out tongue 112 thereon latches behind a shoulder 113 on the sleeve 111. To retract the pen, the tongue 112 is freed from the shoulder 113 by pressure on a clip 116 fixed at one end to a spring strip 120 attached to the casing by a ring 126. In one modification, instead of the strip 120 a resilient split ring is mounted within the casing, to which the end of the clip 116 is fixed. Further, a tongue similar to the tongue 112 may carry a stud which snaps into an opening in the casing when the pen is projected, the stud being released by pressure on the free end of the clip 116 when it is desired to retract the pen. Also, the end of the reservoir may be a friction fit in the operating cap thus rendering a gripping-member such as 109 unnecessary. In another modification, the tongue 112 is dispensed with, and a curved spring attached to the tube 110 carries a stop adapted to snap into an opening in the casing to hold the pen in projected position. As shown in Fig. 15, the spring strip 120 is attached to a spring ring 128 split diametrically opposite to the strip and provided at one free end with an inwardly-directed projection 129 which snaps into a recess 130 in the tube 110 to hold the pen in projected position. Inward pressure on the clip 116 distorts the ring 128 so as to release the projection 129 and allow the pen to be retracted. Reference has been directed by the Comptroller to Specification 629,240.