Sight glass

An apparatus for providing information of the level of liquid in a structure containing a liquid comprising:

• a housing adapted to be connected to the structure for accommodating said liquid, said housing having a chamber for holding said liquid therein, said housing having an opening into the chamber, means having a window mounted on the housing totally losing the opening for allowing external light into the chamber and facilitating a person to view the chamber, a transparent liquid level indicator located within the chamber having means providing prismatic indentations along the length thereof for reflecting light laterally when exposed to a gas in the chamber and transmitting light along the indicator when exposed to a liquid, means mounting the indicator on the housing to locate the indicator in an upright position alignment with the window, said liquid level indicator comprising a linear transparent body having a first viewing end, a second end, and a side wall between the first and second ends, said side walls having said means providing prismatic indentations for reflecting light laterally when exposed to a gas in the chamber and transmitting light along the body when exposed to a liquid lens means on the first end of the body for increasing the intensity of the light directed into the body to enhance reading of the visual information of the level of the liquid in the chamber, and a color member on the second end of the body for reflecting the light transmitted through the body back through the body and lens means to provide color visual information regarding the presence and level of liquid in the chamber.

An apparatus for providing information of the presence of a liquid in a structure containing a liquid comprising:

• means adapted to be connected to the structure for accommodating said liquid said means having a chamber for holding said liquid and an opening in communication with the chamber, a liquid level indicator located within the chamber providing visual information regarding the presence of said liquid in the chamber and the level of said liquid in the chamber, said indicator having a transparent head, cap means supporting an surrounding the head mounted on the means having the chamber whereby the cap means and head closes the opening therein, an elongated linear transparent body joined to the head extended downwardly into the chamber, said body having a side wall and an end opposite the head, and a color member on said end for reflecting light back through the body to provide color viewing information regarding the presence of said liquid in the chamber, said side wall having a plurality of surfaces providing at least a pair of prismatic indentations in opposite sides of the side wall spaced along the body above said end for reflecting light in the body laterally when exposed to a gas in the chamber and transmitting light along the body when exposed to a liquid whereby the light reflected back through the body from the color member provides visual information as to the level of said liquid in the chamber and the presence of said liquid in the chamber, said head having a convex outer surface forming a convex lens to increase the intensity of the light directed into the body to enhance reading of the visual information of the level of the liquid in the chamber.

In combination a structure having a generally horizontal passage for accommodating a liquid, an apparatus connected to the structure providing visual information of the level of liquid in the passage of the structure, said apparatus having a housing connected to the structure, said housing having an internal chamber open to said passage for holding liquid at the same level as the liquid in the passage, said housing having a top wall with an opening open to said chamber, a liquid level indicator located within the chamber having a transparent head, and a linear transparent body joined to the head, said body having a bottom end and a side wall between the head and the bottom end, means mounting the head on the top wall of the housing closing the opening therein and locating the body in a vertical position in the chamber, said side wall having a plurality of surfaces spaced along the body providing prismatic indentations for reflecting light laterally when exposed to gas within the chamber and transmitting light along the transparent body when exposed to said liquid in the chamber, said head having a convex outer surface forming a convex lens to increase the intensity of the light directed into the body to enhance reading of the visual information of the level of the liquid in the chamber, and a member on the second end of the body for reflecting the light transmitted through the body back through the body and convex lens to provide visual information regarding the presence and level of liquid in the chamber and passage.

In combination, a structure having a generally horizontal passage for accommodating a liquid, an apparatus connected to the structure providing visual information of the level of liquid in the passage of the structure, said apparatus having a housing connected to the structure, said housing having an internal chamber open to said passage for holding liquid at the same level as the liquid in the passage, said housing having a top wall with an opening open to said chamber, a liquid level indicator located within the chamber having a transparent head, and a linear transparent body joined to the head, said body having a bottom end and a side wall between the head and the bottom end, means mounting the head on the top wall of the housing closing the opening therein and locating the body in a vertical position in the chamber, said side wall having a plurality of surfaces spaced along the body providing prismatic indentations for reflecting light laterally when exposed to as within the chamber and transmitting light along the transparent body when exposed to said liquid in the chamber, a concave surface at the second end of the body for reflecting the light transmitted through the body back through the body to provide visual information as to the presence of liquid in the chamber and level of said liquid in the chamber and passage of the structure and to enhance reading of the visual information of the level of liquid in the chamber.