GB695886A - Improvements in reservoirs, particularly reservoirs for writing instruments of the ball tip type - Google Patents

Abstract

695,886. Reservoir pens. FEHLING, H. R. Aug. 13, 1949. [July 9, 1949] No. 24660/50. Divided out of 695,861. Class 146 (iii). In a ball-point reservoir pen having a smooth tubular reservoir 1 of cross-sectional area between 5 and 40 sq. mm., and a sealing member, such as a hollow piston 5, Fig. 2, or a solid plug 5a, Fig. 3, which is a sliding fit in the reservoir, the sealing member has at its end remote from the ball an annular rim 11 presenting a sharp inner edge 9 serving to limit inward spread, on the remote end, of the meniscus of ink that lies between the sealing member and the inner surface of the reservoir. The piston 5 is buoyant, and the plug 5a non-buoyant, in the ink. The distance Y between the inner edge 9 of the piston 5 and the interior surface of the reservoir is preferably less than 0.7 mm., and the annular gap between the piston and reservoir lies between 0.05 and 0.2 mm. In modifications, the sealing members are used in conjunction with balancing members in the reservoir, as described in Specification 695,861. Specifications 564,173, 571,698, 573,747 and 621,847 also are referred to.