GB587479A - Improvements in indicating or recording diaphragm instruments or diaphragm relays - Google Patents

Abstract

587,479. Pressure gauges. BAILEY METERS & CONTROLS, Ltd., and HOWE, T. H. June 2, 1944, No. 10633. [Classes 106 (ii) and 106 (iv)] A pressure gauge comprising a unit including a flexible diaphragm and an arm fixedly positioned at one end and acted on at an intermediate point by the diaphragm so as to affect indicating or recording mechanism, has its zero or normal indication adjustable by rocking the unit about a pivot. The halves 6, 7 of a casing, Fig. 4, are separated by an elongated diaphragm 1 supporting dished plates 12, 13, movements of which are limited by-adjustable screws 16, 17, 18. In the embodiment shown in Figs. 1 and 4, the diaphragm is subjected to atmospheric pressureon the one side and on the other side to a pressure or suction led into the chamber 8 through a pipe 78, and a long link 15<1> transmits movement of the diaphragm to a spring strip 20. The effective length of the strip and therefore the magnification of the movement is varied by a screw 31, the setting being fixed by a screw 30. A rigid extension 21 is secured to the strip 20 and its further end is secured to a tape wound round a drum 59, whereby movements of the diaphragm are indicated by a lever 64 moving over a scale 55, the lever being biassed by its own weight or by a counterweight 65 in one or other direction. The zero or normal position of the indicating mechanism is adjusted by rotating the diaphragm assembly unit about its hinge 34 by adjustment of a screw 41. In Fig. 3 (not shown) and Fig. 4, the diaphragm is subjected to pressures from two sources and a space 70 normally accommodating the link 15<1> is closed by a plate 80. A short link 15 rocks a lever 82 pivotally mounted in a diaphragm 81 excluding the atmosphere from the space 9. A link 83 transmits the movement of the lever 82 to the strip 20.