GB449827A - Improvements in or relating to fluid pressure gauges - Google Patents

Abstract

449,827. Bourdon gauges. DEWRANCE, SIR J., 165, Great Dover Street, Southwark, London. March 28, 1935, No. 9678. [Class 106 (ii)] One or more of the walls of the tube containing compartment remote from the dial plate are constituted by, or include, frangible or deformable closure elements which yield and release pressure on the tube bursting, thus preventing damage to the dial plate and front glass. The casing 6 between the back plate 6a and front plate 12 carrying the dial 11 is provided with an inwardly projecting flange 7 on the rear side of which bears a frangible or deformable diaphragm 8 held in place by a spring strip 16 engaging the front side of the flange and clamped at the centre to the diaphragm by a bolt 9. The spindle of the indicating needle passes through the dial plate with small clearance. If the tube 10 bursts, the pressure will build up behind the plate 12 and cause the diaphragm to yield or break, the gas escaping through holes 5 to the atmosphere. In a modification, where the gauge is supported on the connection to the source of fluid pressure, the casing ends at the flange 7, the diaphragm itself constituting the back plate. In a modification of this form, the disc 8 is connected at the centre to the internal mechanism of the gauge and the spring 16 dispensed with.