View Single Post
Old 8th Feb 2012, 1:18 am   #80
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 3,094
Default Re: Another unusual plug and some other questions

Thank you very much Lucien for identifying the adapter. I had searched for GEC patents in the range 1930 to 1940, but I see that the patent GB 294317 that is mentioned in the 1936 catalogue was issued in 1928: copy available here:

http://worldwide.espacenet.com/publi...m&locale=en_EP

From the picture in the 1936 catalogue and Figures 1 and 2 of the patent, it seems that I have a Friday afternoon model where the normal bayonet pin and the threaded pin have been transposed: no wonder I was having problems in working out how it would work with a bayonet pin being used as a terminal! The catalogue also explains why the cover was so much longer than the other BC adaptors in my collection.

The use of the metal case of the lampholder as an electrode was evidently still practiced in 1936 in the form of the CC (centre contact) lampholder listed as S719 that is just visisble at the bottom of 1936 GEC catalogue extract, presumably for low voltage use.

Last edited by emeritus; 8th Feb 2012 at 1:29 am. Reason: Additional comment
emeritus is online now