Valves

Claim 1

A VALVE, PARTICULARLY FOR CONTROL OF LIQUIDS HAVING A HIGH CONTENT OF RELATIVELY COARSE SOLID PARTICLES CARRIED THEREBY, AND COMPRISING A MOVABLE VALVE BODY AND A STATIONARY SEAT PROVIDED WITH CO-OPERATING SEALING SURFACES, IN WHICH VALVE THAT PORTION OF THE VALVE BODY AND OF THE SEAT WHICH CARRIES THE PORTION OF THE RESPECTIVE SEALING SURFACES LOCATED CLOSEST TO THE AXIS OF SYMMETRY OF SAID VALVE BODY IS MADE OF AN INELASTIC MATERIAL WHILE THAT PORTION OF THE VALVE BODY AND OF THE SEAT, TOO, WHICH CARRIES THE ADJACENT PERIPHERAL PORTION OF SAID SEALING SURFACES IF MADE OF AN ELASTIC MATERIAL, THE COOPERATING SEALING SURFACES OF THE VALVE BDOY AND OF THE SEAT BEING OR DOUBLE FRUSTO-CONICAL SHAPE, THE CONICAL SURFACES LOCATED CLOSEST TO THE AXIS OF SYMMETRY OF THE VALVE BODY HAVING A LARGE TOP ANGLE WHILE THE ADJACENT CONICAL SURFACES HAVE A SMALLER TOP ANGLE, THE DIVIDING LINE BETWEEN THE TWO CONICAL SURFACES OF SAID VALVE BODY BEING DISPOSED ON THE PORTION OF SAID VALVE BODY MADE OF ELASTIC MATERIAL AND SAID DIVIDING LINE OF SAID BODY BEING LOCATED ON THE CORRESPONDING LEVEL OF THE SEAT WHEN CLOSED SO THAT ANY SOLID PARTICLES WHICH ARE PRESENT BETWEEN THE SEALING SURFACES OF THE VALVE BODY AND THE SEAT ON CLOSING OF THE VALVE ARE EITHER EMBEDDED INTO THE ELASTIC MATERIAL OR CAUSE A LIMITED TILTING OF THE VALVE BODY RELATIVELY TO THE SEAT, IN WHICH LATTER CASE A SATISFACTORY SEALING OF THE VALVE IS STILL ENSURED BY THE ELASTIC MATERIAL.