On a bottom cover 18, which is mounted on bottom surface of a valve body 6 of selector valves 1A and 1B for the purpose of covering unnecessary holes, engaging sectors 28 are formed, and by engaging the engaging sectors 28 with engaging edges 4b and 4b of a rail 4, the selector valves 1A and 1B are mounted...http://www.google.se/patents/US5529088?utm_source=gb-gplus-sharePatent US5529088 - Rail-mounted aggregate valve
