Renewable disc insert for gate valves or the like

Claim 1

IN A GATE VALVE COMPRISING A CASING WITH PORTS THERETHROUGH AND A VALVE CHAMBER HAVING OPPOSITELY DISPOSED WALLS BETWEEN THE PORTS, THE CHAMBER HAVING ITS OUTER LIMITS DEFINED BY OPPOSITELY DISPOSED VALVE SEAT MEANS, A RECIPROCALLY MOVABLE CLOSURE MEMBER FOR PREDETERMINED FLUID SEALING CONTACT WITH SAID SEAT MEANS, THE SAID CLOSURE MEMBER HAVING ON AT LEAST ONE FACE ADJOINING THE SAID SEAT MEANS A CUT-OUT SUBSTANTIALLY TRANSVERSELY EXTENDING SEGMENT OF OBLONG CONFIGURATION, THE SID SEGMENT BEING CONTINUOUS WITH OPEN ENDS AND EXTENDING IN A PLANE SUBSTANTIALLY AT RIGHT ANGLES TO THE VALVE VERTICL AXIS, A RELATIVELY THIN PLATE-LIKE INSERT SLIDABLY RECEIVED WITHIN THE CUT-OUT SEGMENT OF SUBSTANTIALLY THE SAME LENGTH AS THE CUT-OUT SEGEMENT, THE SAID SEGMENT CUT-OUT INCLUDING MEANS FOR RETAINING SAID PLATE-LIKE INSERT ON SAID CLOSURE MEMBER, THE OPPOSITELY DISPOSED WALLS OF THE CASING CHAMBER RESTRICTING THE SAID INSERT AGAINST SUBSTANTIAL ENDWISE SLIDING MOVEMENT RELATIVE TO THE CLOSURE MEMBER DURING THE MOVEMENT OF THE SAID CLOSURE MEMBER IN OPENING AND CLOSING THE VALVE, THE LENGTH OF SAID INERT BEING SUBSTANTIALLY DEFINED BY THE WIDTH OF SAID CLOSURE MEMBER.