Pressure control valve

A pressure control valve for adjusting the pressure of fluid flowing in a conduit comprising:

• (a) first and second plates mounted together in superposed relationship on a common base;
• (b) an inflatable sac interposed between said plates;
• (c) a pivotal support connecting said plates together and providing pivotal movement for said first plate relative to said second plate in response to inflation and deflation of said sac;
• (d) a fluid passageway incorporated in said second plate remote from said pivotal support and having an axis perpendicular to a plane containing said second plate and providing a fluid inlet for coupling to a conduit having a pressurized flowing fluid and a fluid outlet;
• (e) means provided by said first plate to control fluid flow from said outlet by opening and closing said outlet in said second plate in response to pivotal movement of said first plate with respect to said second plate;
• (f) a branch duct formed integrally with second plate and interconnecting said fluid passageway and said inflatable sac so that pressurized fluid from the pressurized flowing fluid can be transferred therebetween;
• and
• (g) pressure setting control means acting on said first plate for adjusting the pivotal movement of the first plate and thereby adjusting the opening and closing of said fluid outlet to control the pressure of the pressurized flowing fluid, said pressure setting control means comprising a follower slidable with respect to a spiral cam surface, said spiral cam surface being located on a face of said common base facing said first plate, and said follower being connected to a rotatable shaft extending from the opposite face of said base wherein adjustment of the position of said follower on said spiral cam adjusts the amount said first plate is pivotable relative to said second plate.