Stopcock with rotary and adjustable plug in the stopcock housing

A stopcock comprising in combination, a housing;

• a rotary and adjustable plug in said housing;
• a fixedly mounted liner of flexible material with a substantially smooth sliding surface at a bottom part of said housing;
• a shaft member displaceable for controlling the flow through said stopcock;
• a packing disk clamped at its outer edge to said housing and pressed tightly at its inner periphery to an upper surface of the said plug;
• a gasket located in a cylindrical annular space formed between said shaft member and a wall of said housing;
• a reset member projecting into the annular space, said reset member being reciprocably received in said annular space for resetting the stopcock, a reset force of said reset member acting via said gasket and packing disk on the stopcock bottom part for resetting in a conical seat in said liner;
• a fixed stop on said housing, a substantially rigid ring-shaped member movable reciprocably in said annular space in response to reciprocable movement of said reset member, said fixed stop limiting the reciprocable movement, said gasket being enclosed on all sides and acting onto said packing disk through said ring-shaped member;
• said ring-shaped member having a reciprocable path between said reset member and said plug limited in the reset direction by said fixed stop, said ring-shaped member transmitting reset forces to said plug, said ring-shaped member being stopped by said fixed stop when said liner has received a predetermined amount of wear, further reciprocation by said reset member compressing further said gasket.