GB727962A - Improvements in or relating to ball-pointed writing instruments - Google Patents

Abstract

727,962. Reservoir pens. MENTMORE MANUFACTURING CO., Ltd. March 15,1951 [March 22, 1950], No. 7193/50. Class 146(3). Leakage of ink from the reservoir of a ball-point pen is prevented by providing a partition within the reservoir above the ink meniscus comprising a flexible member of elastic material formed with at least one aperture the walls of which are normally pressed closely upon each other under the action of the elasticity of the material of which the member is composed. The ink reservoir may be of cap. illary or non-capillary dimensions. As shown in Fig. 1, the reservoir tube 1 has a non- capillary bore in which is fitted, at a short distance from the open end 2, a tubular element 3 having a capillary bore. A plug 6 having an air-intake 10 is fitted into the open end of the reservoir, and has a reduced portion 7 over which fits a conical, &c. cap 8 of elastic material, such as rubber or plastic. The cap 8, at its apex, is formed with a rectilinear or curvilinear slit 9 the opposed walls of which normally press closely upon each other, but which allow replacement air to enter the reservoir. Several slits may be present, arranged in various ways. In the form shown in Fig. 7, instead of slits, a number of fine perforations 9a are distributed over the conical end of the cap 8, and are formed by piercing the wall of the cap with a fine point so that the walls of the perforations will close together as the point is removed. The flexible cap, Fig. 10, may be formed by moulding and comprises a cylindrical portion 8a merging into a flat end 8c along the length of which is formed a narrow slit 9. The conical flexible cap could be mounted directly in the open end of the reservoir, thus obviating the plug 6, by forming it with an extended tubular skirt which is rolled over the edge 2 of the reservoir. Specification 706,314 is referred to.