I have a variation of Trumpy's bayonet adaptor, designed to convert the bayonet to a 5amp two pin socket. There are the remnants of a retention cord, so I think it was originally attached to a mating plug. The appliance could thus be used in a wall socket or light socket as available. The other pictures show a CLIX plug, using springy brass cotter pins as connecting pins and also to attach the flex. The serrations inside the cover do "click" over the heads of the cotters as it is screwed down. The natural spring of the cotter pins ensures a good tight mating in a socket; and a lot better contact than some modern plug/socket arrangements I've encountered ! I consider this a particularly ingenious piece of design for its age. I'm guessing they date from about 1930 (?).
The cord was just used to tie the adapter to the plug/electrical cord to keep it from getting lost.
You could then just ignore the adapter and insert the plug straight into a wall outlet, or couple it up to the adapter and plug into a lighting pendant from the ceiling.
On that 5A plug, I remember having a lot of those around at my grandparents' house in the the 1970s. I'm not sure when the design first appeared, but I think they were probably still being made in the 1940s.
Paul, Now there is a device I've never thought existed. The lampholder contacts on the top of the adaptor look like brass screws. I would imagine that any cord you used on the plug would have to be reasonably light to prevent the plug from falling out of the socket due to the wieght of the cord?.
Let's face it, these days if you're not young, you're old - Red Green
The lampholder contacts on the top of the adaptor look like brass screws.
They are. It was a common arrangement on these adapters. Some had a slightly different arrangement in which the contacts were a flat head (sometimes hex shaped) set into the recess, then the screws to secure them went in from the sleeves of the 5A socket.
I would imagine that any cord you used on the plug would have to be reasonably light
Maybe if the plug contacts closed up (or the sleeves in the socket opened out), but the old 5A plugs can be a surprisingly tight fit.
The "splayed out cotter pin" style prongs of the plug pictured always used to hold very firmly.
My mother standing in the middle of the kitchen doing the ironing pluged into the light pendant . Then I would get hell for flicking the light switch off as I leave the room. (No neon indicators in those days)