Instrument for guiding the blind in filling open-top vessels

Claim 1

A self-contained signal-generating instrument to guide a blind person in filling an open-top domestic container such as a drinking vessel with a liquid, which comprises in combination, a. a housing substantially smaller than vessels with which it is to be used; b. hanger means for temporarily supporting the housing on a vessel to be filled including a rigid wire-like primary electrode and a rigid wire-like counter electrode extending through an upper portion of the housing to engage a vessel lip with the housing hanging outside such vessel and the electrodes additionally having downwardly directed portions in such vessel terminating in free lower ends spaced from the housing for contact with liquid at a predetermined vessel fill level; c. an electrical power source in the housing; d. indicating means in the housing to produce a sensible signal; e. amplifying switch means electrically connected to the counter electrode and operatively connected to the indicating means; and, f. said primary electrode being connected to the power source whereby the amplifying switch is coupled to the power source and converted to its conducting state when liquid contacts the lower ends of the electrodes and electrically connects the counter electrode to the primary electrode and the power source.