Adjustable bore gauge

Claim 1

A BORE GAUGE COMPRISING IN COMBINATION A TUBULAR STEM AND AN ASSOCIATED PLUNGER MOUNTED THEREIN, AND ADAPTED TO MOVE ALONG A LONGITUDINAL AXIS THEREOF, AN EQUALIZING HEAD ASSEMBLY OPERATIVELY CONNECTED TO ONE END OF SAID TUBULAR STEM AND ADAPTED FOR INSERTION INTO A BORE OPENING TO BE MEASURED, A DIAL INDICATOR OPERATIVELY CONNECTED TO THE OPPOSITE END OF SAID TUBULAR STEM FOR ACTUATION BY SAID PLUNGER, A GAUGING HEAD MOUNTED WITHIN SAID EQUALIZING HEAD ASSEMBLY, SAID GAUGING HEAD INCLUDING A HOLLOW GAUGING PIN COMPRISING A FIRST MEASURING CONTACT AND BEING MOVABLE THEREIN, A RANGE EXTENSION HAVING A LENGTH SUBSTANTIALLY EQUAL TO THE DIMENSION OF SAID EQUALIZING HEAD TRANSVERSE TO SAID LONGITUDINAL AXIS, SAID GAUGING HEAD HAVING AN OPENING TRANSVERSE TO SAID LONGITUDINAL AXIS AND ADAPTED TO ACCOMMODATE SAID HOLLOW GAUGING PIN AND SAID RANGE EXTENSION WHEN ADJUSTABLY POSITIONED THEREIN, SAID GAUGING PIN AND SAID RANGE EXTENSION BEING ADAPTED TO TELESCOPE DURING CERTAIN BORE MEASUREMENTS, AND MEANS FOR TRANSLATING THE MOTION OF SAID HOLLOW GAUGING PIN TO SAID PLUNGER.