Among inventions patented in recent weeks at the U. S. Patent Office:
> An invisible hearing aid for the deaf, built entirely within a set of false teeth.
> A set of "police claws" to mount on the front bumper of a patrol car, grab a speeder's rear bumper.
> A muff for cornets and trombones, to fit over the keys, keep outdoor musicians' hands warm in winter. Also an electrically heated steering wheel to warm motorists' hands.
> A mailman's umbrella with slotted handle, to clip on the edge of a mail bag.
> A barber's vacuum tube that fits around customers'...