DIME PUT IN SLOT RINGS DOORBELL (Jul, 1933)
DIME PUT IN SLOT RINGS DOORBELL
To save a busy housewife from frequent annoyance by unwelcome callers, a doorbell that works only upon the insertion of a dime is soon to be marketed. The coin slides into an inside receptacle, where it closes an electric contact that permits the bell to be rung. If the caller proves to be a friend, the dime is returned as the guest enters; if the visitor is a stranger or one to whom entrance is refused, the money is retained. Dimes kept by the device provide a fund for charities.