The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 07, 1996
Filed:
Dec. 30, 1993
William D Key, Leo, IN (US);
Other;
Abstract
A leak detector and circuit interrupter for detecting the presence of a liquid in the base of a dispenser containment box and interrupting the supply of electrical power when such liquid is detected is disclosed. There is a user enableable circuit for selectively enabling the pump and an override circuit which is operable when enabled to disable the user enableable circuit. An optical liquid sensing probe is positioned near the bottom of the containment box with optical coupling to the override circuit. The optical probe is coupled to a light emitting diode, a photosensitive transistor, and includes a light path with at least one total internal reflection surface normally coupling the light emitting diode and the photosensitive transistor. The probe normally maintains the override circuit in an ineffective state, but, when the light path is interrupted by an accumulation of liquid in the bottom of the containment box, changes state thereby enabling the override circuit and disabling the pump. The override circuit remains in its enabled condition once it is enabled regardless of the state of the optical liquid sensing probe. A modified circuit and series connected optical switches provide a safety power disconnect in the event of attempted entry into a dispenser without first disabling the power supply.