Diaphragm valve

Claim 1

A DIAPHRAGM VALVE COMPRISING A BODY INCLUDING A FLUID PASSAGE THERETHROUGH, A VALVE SEAT IN SAID BODY A BONNET INCLUDING A CIRCULAR FLANGE, A FLANGE ON SAID BODY COOPERATING WITH THE FLANGE ON SAID BONNET, A SPINDLE MOUNTED FOR LONGITUDINAL MOVEMENT RELATIVE TO THE AXIS THEREOF IN SAID BONNET FOR MOVEMENT IN A DIRECTION GENERALLY PERPENDICULAR TO THE PASSAGE THROUGH SAID BODY, A MOVABLE GATE MEMBER MOUNTED FOR MOVEMENT BY SAID SPINDLE IN A POSITION TO ENTER SAID PASSAGE AND CONTROL THE FLOW THERETHROUGH, A DEFORMABLE DIAPHRAGM HAVING ITS OUTER PERIPHERY SECURED BETWEEN SAID BODY AND SAID BONNET AND ITS INNER PERIPHERY ENGAGING THE GATE MEMBER FOR MOVEMENT THEREWITH, SAID DIAPHRAGM PRESENTING AN ANNULAR PORTION BETWEEN THE OUTER PERIPHERY AND THE GATE MEMBER HAVING A CROSS SECTION SUBSTANTIALLY IN THE FORM OF A PAIR OF INVERTED U''S FOR ALL POSITIONS OF THE GATE MEMBER, A GUIDE MEMBER COUPLED FOR MOVEMENT ALONG WITH SAID GATE MEMBER AT A MODIFIED RATE OF MOVEMENT WHICH FOLLOWS THE NATURAL DEFORMATION OF THE DIAPHRAGM WHEN THE GATE MEMBER IS MOVED, A SHAPED DIAPHRAGM FOLLOWER GUIDE AFFIXED TO THE GUIDE MEMBER FOR MOVEMENT THEREWITH HAVING A GENERALLY INVERTED U-SHAPE SURFACE OF REVOLUTION DEFINING AN ARCUATE SURFACE CONTINUOUSLY ENGAGING THE ANNULAR PORTION OF THE DIAPHRAGM IN ROLLING CONTACT, SAID SHAPED FOLLOWER GUIDE EXTENDING BETWEEN AND CONTACTING THE DIAPHRAGM AND THE GATE MEMBER AND OVERLAPPING ANY SPACE INTRODUCED BETWEEN THE RELATIVELY MOVABLE GUIDE AND GATE MEMBERS THROUGHOUT ALL POSITIONS TO PREVENT FRICTIONAL CONTACT BETWEEN THE GATE MEMBER AND THE DIAPHRAGM.