On Jul 16, 9:26*pm, wrote:
I seem to remember having used/seen long bolts (or studs) which are
'hinged', i.e. they poke through a slot and when the nut (usually a
wing nut) has been loosened you can swing the stud aside and and
release what they are holding.

Can anyone suggest a source of such things?

--
Chris Green

Think what you are looking for are called eye bolts, Have a look here
to see if this is what you require , near bottom of page.
http://www.aaametalsuppliers.com/pro...d_eye_nuts.htm