A Pneumatic Piston-Ring Gage for Radial-Pressure Measurement

This paper describes an instrument for indicating the radial pressure distribution of piston rings. The piston ring is supported at eighteen equally spaced points by flat-faced pins located around the circumference of a circle of the same size as the engine cylinder. The force exerted on each pin by the ring is measured by a self-balancing pneumatic device which simultaneously indicates all the forces on a row of eighteen manometers. The rapidity with which the measurements can be made makes the instrument suitable for production inspection.