On 13 Apr 2012 13:05:57 GMT, John Stumbles
wrote:

My mum's got one of those contraptions of 4 strips of wood suspended from
a pair of metal hangers, raised and lowered from pulleys screwed into the
ceiling by sash-cord-type rope. She's getting on and finding it hard to
manage the weight so I'm thinking of some sort of winch which would give
her a mechanical advantage, or maybe even some sort of electric gizmo. My
Google-fu isn't winning he anyone have any suggestions for sources of
suitable devices?

If it is like mine then the sash-cords are passed through a simple
pulley system which gives the operator a mechanical advantage of 2:1.
If the layout of the room would allow, I'd use an additional sash cord
and pulley and double the mechanical advantage. You will now have have
about four foot of cord pulled through for every one foot of elevation
(and one pound of effort (less friction) for every four pounds
lifted). If you were to mount something like a cable reel drum on the
wall to wind up the cord with, the cord would be kept tidily out of
the way and you would gain even more mechanical advantage over the
load. Heath-Robinson, eat your heart out.

Nick