GB669973A - Improvements in or relating to writing instruments - Google Patents

Abstract

669,973. Reservoir pens. HENRIKSEN, E. J. J. Jan. 6, 1947 [Jan. 5, 1946; Jan. 10, 1946], Nos. 451/47 and 452/47. Class 146 (iii). In a ball-point pen wherein a tubular reservoir 3 has an air inlet 5 at the opposite end to the ball-tip 9, there is disposed between the column of ink 7 and the air inlet, a plug 6 consisting of a layer of liquid or a viscous or pastelike substance such as a thickened mineral oil, which does not mix with the ink and which prevents contact between the air and the ink. The consistency of the plug may be such as to prevent ink escaping from the reservoir. The colour of the plug may be different from that of the ink so that approaching exhaustion of the reservoir is indicated when the writing changes colour. According to the Specification as open to inspection under Sect. 91, the plug may consist of a paraffin composition or of a substance having the same viscosity as the ink or may be made of light metal. Alternatively, it may be constituted by or provided with a permanent magnet, and a ring of ferro-magnetic material may encircle the outside of the barrel; the ring follows the plug and thus indicates the level of the ink. The following constructions also are described : (1) The reservoir 3, Fig. 1 (Cancelled), is slidably mounted in an outer casing 1, and has a tubular ball-point section 8 projecting through a tapered end 2 of the casing. The end of the reservoir is closed by a lid 4 provided with an air vent. A pin 10 is pressed against the lid 4 by a spring 11 housed in an air-tight cap 12 fitted to the end of the casing 1. Air is admitted to the vent in the lid via the space between the parts 2, 8, grooves in a seating 15, and a narrow longitudinal channel between the parts 1, 3. The lid 4 may be air-tight and the chamber between it and the plug may contain a gas under pressure. (2) The reservoir may be constituted by a number of longitudinal passages joined in series by recesses in end pieces. (3) The tubular point-section 8 may be curved to enable the pen to be held inclined to the paper instead of vertically during writing. (4) Two curved ball-point sections each communicating with its own reservoir may be provided at one end of the pen. (5) A barrel may have a ball-point section at each end fed from separate reservoirs provided with a common air-intake at the centre of the barrel. (6) The reservoir 3, Fig. 15 (Cancelled), may be slidable against the action of a spring 36 in an outer casing 1 having a cap 35 carrying a rod 37 extending into the reservoir with a piston 38 at its end. Pressure on the ball-point causes relative movement between the piston and the reservoir to set up pressure above the plug 6 and on the ink column 7. In a modification, a spring-retracted knob is mounted in a recess at the end of the cap and the recess communicates with the reservoir by an air duct. When the knob is pressed inwardly, pressure is applied to the ink. This subject-matter does not appear in the Specification as accepted.