Dial instrument

Claim 1

A DIAL INSTRUMENT COMPRISING: (A) A HOUSING, (B) A POINTER MEANS MOUNTED ON SAID HOUSING, (C) A PRESSURE RESPONSIVE CAPSULE MEANS MOUNTED WITHIN SAID HOUSING, SAID CAPSULE MEANS BEING ADAPTED TO EXPAND AND CONTRACT IN RESPONSE TO PRESSURE VARIATIONS, (D) A CONDUIT CONNECTING THE INTERIOR OF SAID CAPSULE TO A PRESSURE SOURCE EXTERIORLY OF SAID HOUSING, (E) A VALVE MEANS FOR VENTING SAID CAPSULE MEANS, (F) SAID VALVE MEANS INCLUDING A VALVE BODY CONNECTED IN COMMUNICATION WITH SAID CONDUIT AND THE INTERIOR OF SAID CAPSULE MEANS, (G) SAID VALVE BODY HAVING AN EXHAUST PORT DEFINED BY A VALVE SEAT OPENING TO THE INTERIOR OF SAID HOUSING, (H) A VALVING MEMBER INCLUDING A VALVE HEAD AND EXTENDING VALVE STEM FOR VALVING SAID PORT, (I) A RESILIENT SPRING NORMALLY BIASING SAID VALVE HEAD IN SEATING POSITION ON SAID VALVE SEAT TO CLOSE SAID PORT, (J) AND A DRIVE MEANS OPERATIVELY CONNECTING SAID CAPSULE MEANS IN DRIVING RELATIONSHIP TO SAID POINTER MEANS WHEREBY THE LATTER IS ACTUATED IN RESPONSE TO THE DEFLECTION OF SAID CAPSULE MEANS, (K) SAID DRIVE MEANS INCLUDING A LINKING MEANS CONNECTED TO SAID CAPSULE MEANS, SAID LINKAGE MEANS HAVING AN OPENING THEREIN FOR RECEIVING THE FREE END OF SAID VALVE STEM, (L) SAID OPENING BEING LARGER THAN THE DIAMETER OF SAID VALVE STEM SO THAT SAID CAPSULE MEANS AND CONNECTED LINKAGE HAS A LIMITED FREE MOVEMENT BEFORE THE PERIPHERY OF SAID OPENING ENGAGES THE VALVE STEM EXTENDING THERETHROUGH WHEREBY SAID DEFLECTION CAUSES SAID PORT TO BE OPENED TO EXHAUST SAID CAPSULE TO RELIEVE ANY EXCESSIVE PRESSURE WITHIN SAID CAPSULE, (M) SAID FREE END OF SAID VALVE STEM VARYING IN WIDTH, AND MEANS FOR ADJUSTING SAID VALVE STEM WITH RESPECT TO SAID OPENING FOR ADJUSTING THE PRESSURE AT WHICH SAID VALVE IS ACTUATED.