• A contraption to facilitate the birth of a child by centrifugal force.

The mother, who is in labour, is strapped to a table that spins around at high speed, forcing out the child, who is caught in a net.
Filed in 1963 by George and Charlotte Bronsky.

• A "photon push-pull radiation detector for use in chromatically-selective cat flap control and 1,000 megaton earth-orbital peace-keeping bomb".

Filed by prolific Sussex inventor Arthur Pedrick in 1974, this was a cat flap connected to an atomic bomb in space.

The device was fitted with a colour sensor, designed to admit his ginger cat but block the passage of a neighbour’s black moggie.
It also stopped a nuclear war.

• A space saving combined helmet and parachute for aviators.
Filed in 1918 for use by US airmen.

Other bizarre ideas include:

• A soup spoon to protect men with moustaches from dirtying their upper lip.
Filed in 1896 by Charles Cooper, the spoon had a lid which stopped the liquid spilling on to the moustache.

• A ladder to allow spiders to climb out of the bath "or any item of sanitary ware".
Filed in 1994 by Patrick Doughney.

Via: Telegraph