Hydraulic reaction type control valve for hydrovacs and air-paks

Claim 1

IN A REACTION PRODUCING STRUCTURE: A BODY MEMBER HAVING A STEPPED CHAMBER THEREIN FORMING A FIRST SHOULDER BETWEEN GENERALLY AXIALLY ALIGNED LARGE DIAMETER AND SMALL DIAMETER CHAMBER PORTIONS, A CLOSURE MEMBER FOR SAID LARGE DIAMETER PORTION OF SAID CHAMBER, A BLOCK OF ELASTOMERIC MATERIAL POSITIONED AGAINST SAID SHOULDER AND SUBSTANTIALLY FILLING SAID LARGE DIAMETER PORTION, A CONTROL MEMBER HAVING AN END PORTION IN SAID SMALL DIAMETER CHAMBER PORTION FOR ABUTMENT BY SAID DEFORMABLE BLOCK, FIRST MEANS COMMUNICATING FLUID PRESSURE TO SAID LARGE DIAMETER PORTION TO BIAS SAID BLOCK AGAINST SAID SHOULDER, SAID BLOCK OF ELASTOMERIC MATERIAL BEING CONSTRUCTED AND ARRANGED TO BE DEFORMED HYDROSTATICALLY BY SAID HYDRAULIC PRESSURE TO MAINTAIN A SEAL AGAINST SAID SHOULDER AND SIDEWALLS OF SAID CHAMBER AND ALSO TRANSMIT FORCE TO SAID CONTROL MEMBER, SAID BLOCK RETURNING TO ITS ORIGINAL SHAPE WHEN HYDRAULIC PRESSURE IS REMOVED FROM SAID BLOCK, STATIONARY ABUTMENT MEANS FOR CONFINING THE PERIPHERY OF SAID BLOCK AGAINST SAID SHOULDER WHEN PRESSURE IS REMOVED FROM SAID BLOCK AND SAID BLOCK RETURNS TO ITS ORIGINAL SHAPE, AND MEANS REGULATED BY SAID CONTROL MEMBER FOR INCREASING PRESSURE SUPPLIED BY SAID FIRST MEANS AGAINST SAID BLOCK AS SAID CONTROL MEMBER IS MOVED TOWARD SAID BLOCK OF ELASTOMERIC MATERIAL.