Patent ID: 7540187
Filing Date: 2009-06-02
Classification: G01F

Abstract:
1. A sight glass apparatus for providing visual information of the presence or absence of a liquid in a structure comprising: a housing having a chamber connectable to the structure for holding liquid in communication with the liquid in the structure, a clear window mounted on the housing allowing light to enter into the chamber and a person to view said chamber, a sight glass located in said chamber, said sight glass having a clear glass first body, a clear glass second body, and a fastener retaining said first and second bodies axially aligned with each other in said chamber and secured to said housing, said first body having an outwardly converging cone-shaped prismatic surface and an inwardly converging cone-shaped prismatic surface, said second body having a convex lens surface facing the inwardly converging cone-shaped prismatic surface of the first body and an inwardly converging cone-shaped prismatic surface, and a member having a colored surface facing the inwardly converging cone-shaped prismatic surface of the second body whereby light is directed away from the outwardly converging cone-shaped prismatic surface when the chamber is devoid of liquid and light is reflected from the colored surface of the member and entrance by the convex lens surface into a colored toroid image when the chamber is full of liquid.