Self-stabilizing pneumatic position sensor

Pneumatic position indicator for measuring position by blowing a compressed gas against a surface to be sensed, the indicator comprising:

• means defining a closed chamber for being filled with compressed gas;
• a hollow, axially movable measuring means extending through the chamber;
• a compressed gas entrance hole into the measuring means and positioned on the measuring means to be within the chamber;
• a nozzle aimed for directing gas against a surface to be sensed, the nozzle communicating with the measuring means and being located outside the chamber at one side of the chamber;
• the measuring means having an exit opening that is located outside of the chamber at the other side of the chamber from the nozzle;
• an additional member attached to the measuring means and being movable together with the measuring means, the additional member being located on the side of the exit opening of the measuring means that is away from the chamber, and the additional member being shaped for having pressure applied thereto in view of the compressed gas flowing through the exit opening;
• means defining a gas leakage pathway located past the additional member for throttling the flow of gas from the exit opening past the additional member;
• whereby the moving means is acted upon to shift axially with respect to the chamber by a combination of gravity, the gas exiting through the nozzle, and the gas exiting through the exit opening applying pressure against the additional member and then exiting through the leakage pathway.