On 20/03/2019 19:22, Harry Bloomfield wrote:
was thinking very hard :
As part of re-wiring the workshop I want to be able to pull down a
socket (on a flex) from the ceiling when required and then to have it
retract when not needed. The action would be something like a roller
blind: pull and let go to latch down, pull again to unlatch and
retract. The roller blind mechanisms are quite long and fit in a tube
whereas I need something that winds a string.
What do I need?

Rod, or tube, with a socket mounted on the bottom end, hinge the rod at
the top and add a spring to pull it up out of the way. Add a cord to
pull it down when needed and arrange the spring tension, so the extra
weight of an item plugged in, is enough to keep the socket pulled down.

The socket would need to be wired in flex, and probably ought to plug
into a fixed high level socket.
If the other suggestions don't bear fruit I could use a length of bungee
cord to do this. The flex will be connected to a flex outlet, ceiling
pull switch and an FCU from the workshop ring.