| 摘要 |
751,537. Thermionic valves. PHILIPS ELECTRICAL INDUSTRIES, Ltd. April 30, 1954 [May 4, 1953], No. 12608/54. Class 39 (1). [Also in Group XI] In order to reduce the risk of breakage due to expansion of the glass at the " head " or end 2 of an electric lamp or.discharge tube which is embraced by a cap 3 cemented thereon, the part of the head just below the edge 5 of the cap is provided with a groove 6, and adjacent to the groove and further within the cap the head is formed with a portion 7 of increased diameter such that its periphery is adjacent to the inner wall of the cap, the cement 4 being applied only in the space between cap and head on that side of the widened portion remote from the filament. A resilient mass such as a rubber ring 9, Fig. 2 (not shown), may be provided within the groove 6. Preferably the part 8 of the bulb wall which abuts against the edge 5 of the cap is substantially transverse to that edge and supports the cap and ensures correct adjustment during capping. |
