GB579913A - Improvements relating to fountain pens - Google Patents

Abstract

579,913. Fountain pens. BIRO, L. J. July 19, 1944, No. 13804. [Class 146 (iii)] In a fountain pen having a writing tip constituted by a rotatable ball 9 and wherein the end 5<1> of the air-intake tube b is situated centrally of the ends and the sides of the inkreservoir a, an intermediate ink-chamber c is provided between the reservoir and the feed conduit 10 and is separated from the reservoir by a partition 11 having a central funnelshaped part 11<1> projecting into the chamber c and terminating in an orifice 12<1> which constitutes the only means of communication between the reservoir and the chamber. The size of the orifice 12<1> is such that while ink is prevented from flowing back into the reservoir from the chamber c when the pen is inverted, a small reserve is maintained in the orifice and tends to prevent the formation of air bubbles when the position of the pen is reversed for writing. Any air-bubbles formed will be trapped in the space 13 between the part 11<1> and the wall of the pen. The chamber c may be charged through the conduit 10 or by removing the tip 7, the shank 14 of which is frustro-conical and seats in a similarly shaped socket. Air enters the reservoir through channels 1, 2, ink-trap chambers 3, 4 and the tube b. The position of the orifice 5<1> prevents ink entering the tube b when, as in practice, the maximum amount of ink is not more than half the capacity of the reservoir. A deflecting member 6 prevents ink running on to the end of the tube. Specification 564,173 is referred to.