Control devices

A control mechanism of the type employing a liquid therein, comprising:

• (a) a housing comprising upper and lower housing members of rigid material having a cavity;
• said cavity having a symmetrical configuration;
• (b) a generally symmetrically shaped diaphragm secured between said upper and lower housings, thereby dividing said cavity into at least a first and second chamber;
• the first chamber being adapted to receive therein the liquid;
• (c) a valve member formed in a central portion of said diaphragm;
• (d) a boss extending from within said first housing and forming a valve seat;
• said housing having a first conduit port extending through said boss for admitting the liquid into said first chamber;
• said valve member being in registry with said valve seat;
• valve seat having a substantially planar end for abutting said valve member to form said valve;
• said valve seat being so spaced from said diaphragm such that, upon said valve closing, said diaphragm being within its spring rate;
• said diaphragm having a plurality of concentric convolutions about said valve member;
• said valve member being coated with Teflon for sealing shut said valve;
• said valve being disposed substantially at the symmetrical center of said cavity;
• (e) said diaphragm, in combination with said housing wall, comprising means for entrapping within said first chamber and so disposed such that, upon a result of force being applied in a predetermined direction to said diaphragm and said valve closing, said entrapping means, as a result of the force, thereby entrapping at least a part of the liquid within said first chamber, so that the entrapped liquid prevents the diaphragm means from being damaged by the force, thereby entrapping at least a part of the liquid within said first chamber, so that the entrapped liquid provides a cushion and hydrostatic stop to prevent said diaphragm from being damaged by the force;
• (f) said housing having a second chamber port for communicating a substance through said second chamber to thereby move said diaphragm to thereby operate said valve;
• and
• (g) said housing having a bleed port at the periphery of said cavity and extending through said upper housing for filling liquid therein or removing air from said chamber.