Measuring instrument for a pressure gauge

摘要

The measuring instrument for a pressure gauge comprises an indicator unit with two plates that bear rotatably an indicator shaft carrying a pinion and that furthermore bear a gear segment. The measuring instrument furthermore comprises a metal Bourdon tube bent into an arc shape, which is soldered on one end to a spring carrier and on the other to a spring end-piece. The spring end-piece is connected to the gear segment such that the displacement of the spring end-piece because of the measurement pressure is transferred to the gear segment. The spring end-piece constitutes a part that is rigidly attached to one of the two plates prior to the Bourdon tube being soldered to the spring end-piece and that is separated from this plate once the Bourdon tube has been soldered to the spring end-piece. During the course of the manufacture of this measuring instrument, the spring end-piece is produced as a part that is securely joined to the two plates. The Bourdon tube is soldered to the spring end-piece while the latter is still rigidly affixed to the plate. It is not until thereafter that the spring end-piece is separated form the plate. Preferably the spring carrier is integral to or attached to one of the two plates. The spring end-piece assumes its target position with greater accuracy with respect to the indicator unit.