GB795902A - Improvements in fountain pens - Google Patents

Abstract

795,902. Reservoir pens. KOVACS, T. April 18, 1956 [April 18, 1955], No. 11758/56. Class 146(3) A fountain pen having an overflow chamber situated in the front part of the barrel consists of at least one longitudinally extending capillary intermediate space of annular cross section contracting towards the ink reservoir and communicating at the front with the atmosphere and at the rear through an air-passage with the ink reservoir, the surfaces of the bodies forming the capillary, intermediate space or spaces being divided into longitudinal lands by longitudinal grooves formed therein, the grooves having a lower capillary potential with the intermediate spaces. The front part of the barrel 1 is constricted at its front end 2 and a hollow stem 3 inserted. The stem 3 surrounds a feed bar 17 and nib 19 and is itself surrounded by a sleeve 9, thus defining capillary spaces 13, 16 which form an overflow chamber. The hollow stem 3 has a longitudinally hyperboloid surface 8 narrowing towards the ink reservoir, and the sleeve 9 also has a longitudinally hyperboloid surface 15 narrowing towards the ink reservoir. Between the rear ends of the barrel 1, sleeve 9, and stem 3 narrow annular spaces as 12 are formed and these communicate via coaxial bores 35, 36, 37 with a bore 34 leading to the ink reservoir. At the rear end portions of the stem 3 and sleeve 9 narrow slots 27, 28 are provided which, when wet, prevent the passage of air. The intermediate space 16 is arranged to narrow slightly in cross-section towards the nib side of the barrel. Longitudinal grooves 25 and 26 are provided in the stem 3 and sleeve 9 respectively. An air admission passage 21 is provided at the front of the feed bar which communicates, via a bore 22 and bore 23 with the space 13 and via three bores 24, equally spaced around the circumference of the sleeve 9, with the space 16. In operation, during writing, ink flows from the ink reservoir through conduit 20 to the nib 19, replacement air flowing through the passage 21, the overflow chamber, and an air passage 29 into the ink reservoir. Any excess ink flows from the ink reservoir via the slots 27, 28 and the passage 29 into the overflow chamber. During further writing ink is drawn from the ink reservoir via the conduit 20, the reduced pressure thus created in the reservoir causing excess ink to be drawn back from the overflow chamber. The grooves 25 and 26, having a lower capillary potential than the spaces 13, 16 ensure complete filling of the overflow chamber, if necessary, due to the fact that air can escape through the grooves not covered with ink. The longitudinal profiling of the spaces 13, 16 is designed to eliminate non-uniform capillary potential in the spaces and the outer space 16 possesses a higher capillary potential than the space 13 so that the spaces will fill and empty in sequence. Reference has been directed by the Comptroller to Specification 732,982.