GB769912A - Improvements in fountain pens - Google Patents

Abstract

769,912. Reservoir pens. PLATEN, B. C. VON. May 5,1952 [May 4, 1951], No. 11355/52. Class 146(3). In a reservoir pen of the kind having a non-capillary reservoir in which the air pressure is below atmospheric pressure, tc allow air to pass into the reser. voir during writing, the reser. voir communicates at its nit end via a capillary ink outlet channel 64 with an overflow chamber 70 of porous material having capillary channels ir communication with the atmos phere. A partition 11 providec with an aperture 12, divides the reservoir into parts 1a and 1b, the part 1a being sealed by a piston 13. A wall across the bottom of the part 1b includes the aperture 64 through which ink flows from the reservoir part 1b to a nib 5, this ink being replaced by air flowing to the reservoir part 1b through an inlet 32 and the channel 64. The chamber 70, formed of porous glass, e.g., sintered glass particles, is enclosed by a cover 72 and provided with capillary channels 71, preferably tapered towards their top ends. Ink, forced out of the part 1b by the expansion of air, fills the channels 71. When the space 1b contains air only air may pass through the aperture 12 into the part 1a to replace ink used. However, when the part 1b contains ink, air cannot pass through the aperture 12 as well as the channel 64 due to the available forces being insufficient to cause air to bubble in through first the channel 64 and then the aperture 12.