PRESSURE INDICATING AND LIMITING INSTRUMENT

摘要

A pressure gauge utilizes a Bourdon tube and associated mechanical linkage to indicate pressure on a calibrated dial between predetermined limits. High pressure and low pressure limit switches are fixedly secured to a carrier having lost motion connections with the Bourdon tube and said linkage. Adjustable high pressure and low pressure stops on the face of the instrument positively interrupt the movement of the instrument pointer and thereby lock said linkage. Continued expansion or contraction of the Bourdon tube utilizes said lost motion connections with said switch carrier to operate the high pressure and low pressure limit switches in proper sequence. The principle of operation is also adaptable to Bourdon tube temperature gauges.