GB808617A - Leakproof ink tube for ball point pen - Google Patents

Abstract

808,617. Reservoir pens. SCRIPTO Inc. Oct. 8, 1957, No. 31492/57. Addition to 801,910. Class 146(3) In order that quickdrying ink may not leak from the reservoir 32 of a ball-point pen when the ink seal at the ball point 44 is broken and atmospheric pressure is established against the ink-column at the ball point end, a plug 30 is inserted in the end of the reservoir and a cap 40 fitted thereover, and a groove is formed in either the inner surface of the cap or on the outer surfaces of the plug to establish an air vent between the reservoir and atmosphere, the groove being of such restricted crosssection and length that any ink flowing therealong will be of such a small amount that it will dry before escaping from the groove and thus seal the groove. As disclosed there are three grooves 46 (not shown) in the outer surface of the plug 30, which has a central bore throughout its length and a chamfered end to establish communication between the bore and the grooves when the cap 40 is fitted thereover. The grooves are about 0.0025 inch deep, from 0.002 to 0.04 inch wide, and from a quarter to half an inch long. The length of the cap 40 is such that it does not wholly cover the grooves. A grease seal 44 may be provided in the reservoir where the inner diameter exceeds 3 mm. The reservoir tube 32 may be of metal or transparent plastic material, and the plug 30 may be of polystyrene.