Patent GB-595436-A (GB)
Title: Fountain pen
IPC: B43K5/18
Filed: 1945-05-23
Abstract: 595,436. Fountain pens; ink. DEHN, F. B. (Parker Pen Co.). May 23, 1945, No. 12912. [Class 146 (iii)] A fountain pen more particularly for use with a quick drying alkaline ink comprises a feed structure having a fine capillary passage, and a nib enclosing between it and the structure a second capillary passage and having a slit constituting a third capillary passage, the passages communicating with one another to supply ink from the reservoir to the nib, the nib and structure being enclosed, except for the writing point, in a shell which provides between itself and the nib and structure capillary ink spaces which control the flow of ink; the assembly of feed structure, nib and shell is mounted on a member which secures them together as a unit removable from the pen barrel without disturbing their relationship. As shown, the shell 11 connected by a screwthreaded nipple 36 to the barrel 10 houses the feed bar 15 and a governor 14 provided with an axial bore of varying diameters to hold frictionally the feed bar at 16 and the tubular nib 12 whose tip 13 has a narrow slit terminating in a hole 23. The shell 11 is arranged to leave a small capillary space 22 between it and the nib but it has a bent portion 24 which contacts the tip 13 of the nib. A capillary space 18 between the nib and the feed bar 15 connects with a hole 32 in the feed bar leading to a bore 31 in which a breather tube 30 may be mounted. The governor 14 has a plurality of circumferential cells 33 of capillary size increasing in width towards the pen point, separated from the shell 11 by an annular capillary space 35 and having a wide longitudinal air channel 34 which does not connect directly with the reservoir in the barrel 10 and a narrow capillary channel 25 leading through a capillary channel 26 to the barrel 10, the channel 25 being on the opposite side of the governor to the tip of the nib so that ink from the reservoir has to pass through the cells 33 and air can pass into the reservoir only through the cells and therefore cannot pass when the cells are full of ink. The sizes of the various capillary channels are such that the ink tends to flow away from the governor 14 when the pen is in use. The nipple 36 carries a capretaining ring 41 and is sealed to the shell 11 and barrel 10 by two cements having different physical properties so that the barrel can be removed without disturbing the accurate alignment of the parts within the shell 11, e.g. two thermoplastic cements are used, the one on the barrel having the lower critical temperature. The pen is stated to be particularly suitable for use with a thin ink having an alkaline base, e.g. the hydroxides of sodium (caustic soda), potassium (caustic potash), lithium, caesium or subidium. For use with such inks the pen sections may be made of methyl methacrylate resin, polystyrene, vinyl type of resin, vinylidene chloride resin, melamine resin, natural or synthetic rubber, alkyl resin or most of the higher grade of plastics and the nib may be made of gold, platinum, rhodium, ruthenium, osmium, iridium, or alloys thereof with baser metals, or certain alloys of the baser metals such as stainless steel. Specifications 534,657 and 537,269 are referred to.