GB756151A - Improvements in and relating to reservoir writing instruments - Google Patents

Abstract

756,151. Reservoir pens. COMPANIA URUGUAYA DE FOMENTO INDUSTRIAL SOC. ANON. March 31, 1954 [April 2, 1953], No. 9138/53. Class 146(3) In a ball-point pen, the reservoir 3 is of capillary size and the wall thereof is substantially impervious to moisture, and there is provided between the end of the ink column 12 and the air vent a viscous plug 13 substantially impervious to moisture which is separated from the end of the ink column by an air or gas filled gap 14 and is adapted to follow the end of the ink column, as the latter recedes during writing, to prevent atmospheric moisture from coming into contact with the ink. When an oleaginous ink is used, the plug 13 may consist of a silicon liquid or semi-liquid or grease, or petroleum jelly, or a colloidal solution of a long chain polymer in an organic solvent: where the ink is non-oily, the plug may consist of a highly refined mineral oil of high viscosity, or a highly concentrated solution of colophony in ricinoleic acid, or a silicon liquid, semi-liquid, or grease. The plug may be inserted by squirting a suitable substance from a syringe into the required position in the reservoir. The reservoir tube may be of metallic or non-metallic material, and may be of polyethylene. Where a moisturepermeable material such as cellulose acetate is used, it must be coated with wax or metal. Specification 621,847 is referred to.