Sealing rings for spool valves

摘要

Provision of constrictions imparts to a sealing ring for spool valves both needing flexibility and sufficient strength to remain undetached from the spool in the spool valves. The constrictions to impart flexibility are provided on the outside of the center of the band width of the sealing ring. The ring is of a greater axial thickness on a radially inner side thereof than at the constrictions so as to be firmly fitted in a groove of the spool.