Mechanical fluid indicator

Claim 1

In a mechanical fluid depth indicator for measuring the level of liquid held in a tank from the top of the tank of the type comprising a first pulley mounted at the top of the depth indicator and a second pulley mounted at the bottom of said depth indicator with an endless belt having a float and marking elements affixed thereto extending about the pulleys such that when the depth indicator is in a liquid the float will rise and fall with the liquid to thereby drive the belt about the pulleys and allow one to read the amount of liquid in the tank from the marking elements, the improvement wherein: said fluid depth indicator further comprising a single tube extending its entire length, said tube having holes machined in its walls at both ends thereof and a first shaft means mounted in the holes at one end thereof and a second shaft means mounted in the holes at the other end thereof, said first and second shaft means respectively rotatably mounting said first and second pulleys thereon inside said tube so that said belt and its attachments are entirely inside said tube.