GB339136A - Improvements in and relating to diaphragm devices operated by fluid pressure - Google Patents

Abstract

339,136. Barostat Co., (Assignees of Tigges, A. J.). Jan. 12, 1929, [Convention date]. Fluid-actuated valves.-A fluid-pressure-operated resilient diaphragm device, in which the diaphragm 12, Fig. 2, has a buckling or snap-over action from one extreme position to the other, is shown applied for regulating the pressure of a refrigerant which changes from a gas to a liquid, and vice versa, during a cycle, of operations; the diaphragm device is, however, applicable to other purposes. The diaphragm is backed by a pressure cushion 16, such as rubber, loaded by a spring 18 adjusted by a screwed sleeve 20 and acting through a hollow plunger 23 and a plate 22. The diaphragm 12 abuts below on a domed abutment 25 which is adjustable on the screwed end of the valve 27 by rotation of a shaft 40 accessible by removal of a cap 51. The shaft 40 is slotted at the top to engage the valve 27, and. it is prevented from moving axially by a flange or collar 48 on the upper side of the packing 44. In operation, when the valve 27 is open with the diaphragm in its uppermost position, the passage 61 is subject to a reduction of pressure which is communicated by passage 60 to one cooling element, and through the valve. 27 and chamber 11 by a connection (not shown) to a second cooling element. At a predetermined low pressure in the latter element and in the chamber 11, the diaphragm 12 snaps downwardly and closes the valve 27; the abutment 25 limits the downward buckling of the diaphragm to less than its full extent whilst a portion of the diaphragm is bowed, as shown, towards the medial position. Thereafter, as the temperature and pressure in the second cooling element rise to a predetermined degree, the pressure in the chamber 11 rises and allows the diaphragm 12 to snap upwardly and reopen the valve 27.