Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
Publication of GB132678ApublicationCriticalpatent/GB132678A/en
132,678. Graham, J. W. Nov. 30, 1918. Bulbs.-A protective cover of rubber, cork, or other resilient material is cemented over the bulb tip; the central aperture comprises a cylindrical part a<2>, a conical part a<1>, and a concave mouth a'.