Gas pressure regulators

Claim 1

A gas pressure regulator comprising a gas inlet, a gas outlet, a regulator valve, said regulator valve having a regulator valve closure member and an orifice closable thereby, a cutoff valve, said cutoff valve being disposed in series with an upstream of said regulator valve and having a cutoff valve closure member and an orifice closable thereby, control mechanism, said control mechanism having a flexible diaphragm movable by gas pressure acting against a yieldable force, a connection between said diaphragm and an operating lever for controlling said regulator valve closure member and said cutoff valve closure member, an operating spinDle forming part of said connection and having mounted coaxially thereon said regulator valve closure member and said cutoff valve closure member, said connection also including a linkage able to ''''break'''' said connection by overcenter trip action, said linkage including a link and an operating lever, said link being pivotally connected at one end near said diaphragm and said operating lever having an operative end able to act upon a free end of said operating spindle to move said regulator valve closure member towards and away from said regulator valve orifice, and said operating lever being fulcrummed at a point near said operative end a short way removed from the axis of said operating spindle but remote from a free end of said operating lever, said connection also including a trip lever and a spring, said trip lever being connected to said flexible diaphragm and being pivoted to said operating lever, said spring extending from an anchor point on said operating lever to an anchor point on said trip lever, the arrangement being such that in normal operating conditions a straight line between the two anchor points lies on one side of the pivot common to the operating lever and the trip lever, and the two levers move as one so that over a range of pressures said connection causes opening movement of the regulator valve upon decrease in gas pressure and closing movement upon increase in gas pressure, and such that when said gas pressure exceeds a predetermined upper limit the trip lever pivots relative to the operating lever so that the line between the two anchor points moves to the other side of said common pivot to trip the lever so that said linkage ''''breaks'''' to cause closing movement of the cutoff valve.