When the pressure increases in Bourdon tube 1, one end of which is fixed, the tube tends to straighten out, and member 2, attached to the movable end of the tube, turns segment gear 3 about fixed axis A. Segment gear 3 meshes with pinion 4, turning about fixed axis B, to which a hand is attached. Member 2 is not linked to segment gear 3. Thus, when the pressure drops and tube 1 returns to its initial position, segment gear 3 and the hand remain in the position they were in as a result of deformation of tube 1. The hand is returned to the zero position by retracting device 5. When the retracting button is pushed, it turns segment gear 3 by means of flat spring 6 an zeroes the hand.
$4058$EHP,M$