Pressure measuring devices of the electrical counterbalancing force balance type

Claim 1

A pressure measurement device comprising a measurement unit, a measurement bellows, two flexible diaphragms conveying the pressures to be compared to said measurement unit, a liquid filling the gap existing between said diaphragms and through which pressures are conveyed, a proof chamber filled up with liquid, delimited by the bellows and one of the two diaphragms, and electrical force balance set into said proof chamber, wherein said unit is formed of a magnetic piece of material punched with cylindrical holes in which are housed the variOus constituent parts, particularly a hole running through the unit, between the two diaphragms, in which is tightly secured a foot part of the measurement bellows the other closed tip thereof is connected to a balance lever, on one side of said bellows, a flat bottom blind hole in which is stuck the permanent magnet of the magnetic circuit of the balance counterbalancing motor, on the other side of the bellows, another blind hole in which is set, by means of a magnetic rest, a variation detector for said balance, and, set on either sides of the plane defined by the axis of the above holes, two additional blind holes wherein are respectively secured rests of a double part cross-tape joint, all the aforesaid holes being worked out on the same side of the unit and facing one of the two diaphragms, and finally a blind hole the axis thereof is at right angle with the axis of the other holes, inside of which is placed an helical spring for zero setting, one tip thereof being secured to the lever and the other tip secured to a nut allowed to be driven along a translation motion from outside, by means of a screw running tightly through the unit.