GB531744A - Improvements in pressure and vacuum alarm devices and the like - Google Patents

Abstract

531,744. Pressure gauges. STOKOE, C. L. Aug. 1, 1939, No. 22251. [Class 106 (ii)] Relates to pressure alarm devices in which a diaphragm b is enclosed in a two-part case a, c one side being exposed to the fluid pressure and the other to the load of a compression spring j which is distributed over the diaphragm by a disc f attached to a spindle g which passes through a movable member i guided by the case and provided with a pointer which registers on a scale m the pressure to which the spring is adjusted by a screw k the movement of the spindle g making or breaking contacts in the signal circuits, and consists in housing the electrical contacts and signal devices in a panel box attached to the casing. The panel box may be common to several diaphragm casings. A resilient member A fulcrummed at p carries a contact 1 and when the insulated knob h at the end of the spindle g moves downwards contact is made at 2 with a spring strip B and contact is broken at 3, 4 the latter contact being on a rigid member C. When contacts 1, 2 engage and pressure is normal a safety lamp a is lit. When the pressure falls to that shown by the pointer, the contacts 3, 4 engage and contact is broken at 1, 2 and a " danger " lamp t lights up. A bell or horn or relay may be in a parallel circuit to the " danger " circuit. Specification 435,133 is referred to.