GB684094A - Improvements in or relating to fountain pens - Google Patents

Abstract

684,094. Stylographic pens. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 13, 1949. [July 22, 1948] No. 12801/49. Class 146 (iii). A stylograplaic fountain pen comprises a, barrel 135, a writing tube 151, and a wire 155 extending through the tube, while a crossshaped weight member 157 alongside the wire is axially slidably guided in a tube 146 within the barrel, the weight member being secured to a weighting portion 161, such that shoulders 163, 164 and 166 on the portion may engage a screw head 165. The bent-over end 162 of the wire 155 is loosely confined within a socket 160 of the portion 161. The portion 161 may rock transversely of the longitudinal axis of the pen by tilting the pen accordingly, so as to control the length of axial stroke of the member 161 to a short or long stroke, as determined by the shoulders 164 and 166 respectively, a long stroke sometimes being necessary to free the tube 151 of incrusted ink by axial movement of the wire 155 therethrough. Air to replace ink used in writing is drawn through a tube 171 extending into an air chamber 131 which traps overflowing ink. When ink is drawn down the tube 151 during writing, any ink in the chamber 131 flows through an aperture 153 before air can enter a reservoir 145, such overflow ink being used before ink from the reservoir 145. The pen has a cap provided with a rubber stopper pivoted to a nut screwed into the end of the cap, such that the cap may be turned during its application to and removal from the pen without damaging the writing tube 151. The Specification as open to inspection under Sect. 91 also comprises the following subjectmatter. As shown in Fig. 2, (Cancelled) the nib section comprises a plug 7 on which a writing element in the form of a capillary tube 9 is pivotally mounted by a shaft 11 journaled in bearing slots 13. The tube 9 is reinforced by a sheath 19 fitted in a hole 21 in the shaft 11. An elastic stopper 23 is fitted into an opening 25 above the shaft and seals the lower end of an ink reservoir 3. The inner end of the tube 9 is inclined to provide a valve face bearing against a valve seat 27 under the influence of a coil spring 31. The end of the plug 7 is covered by a shield 33 slotted at 35 to permit limited movement of the tube 9 when pressure is applied to the writing end thereof during writing, thus allowing ink to flow from the reservoir past the valve seat 27 to the writing surface. An air channel 41 connects the atmosphere with the bore of a nipple 45 which receives a spiral tube 47 of capillary size which winds up through the barrel and down to an opening 49 adjacent the valve seat 27. Ink is caused to flow from the tube 9 during writing by capillary action of the tube 9 aided by the hydrostatic pressure depending on the head of ink in the reservoir. For uniformity of flow the variation of the head should be kept low. When ink is drawn from the reservoir during writing the level of ink therein as shown in Fig. 5, (Cancelled) by the line S-S will be lowered, thus causing a reduction in pressure of the air in the chamber 52. Atmospheric pressure will force air against the interface at the opening 49 and a bubble of air will enter and rise to the chamber 52, thus increasing the volume of air in the chamber 52 and so causing the ink to rise in tube 47 to a level O-O. The level of the ink in the tube 47 will not be raised as high as if the same volume of ink flowed into a vertical tube. Ink may also flow into the tube 47 as a result of a reduction in atmospheric pressure or as a result of expansion of air in the chamber 52. The substantial length of the tube 47 tends to reduce the evaporation of ink. To remove incrusted ink from the tube 9 a pin secured to a tip is provided, such tip being screwed to the barrel. When the pen is not in use, the tube 9 is covered by a cap having a soft rubber plug in which the tube 9 is embedded. The inner space of the cap is ventilated by a small hole, while the cap itself bears on the outer end of the pen, so as to not completely close the channel. In a further embodiment, the spiral air inlet tube is replaced by a labyrinthine duct in the wall of the barrel. The upper section of the reservoir is in the form of a replaceable cartridge screwed into the lower section. This subject-matter does not appear in the Specification as accepted.