A restriction engaging system includes, a restriction engager, one or more restrictions, and at least one counter configured to permit or prevent passage of a restriction engager through one of the one or more restrictions.
申请公布号
US2012097265(A1)
申请公布日期
2012.04.26
申请号
US201113340939
申请日期
2011.12.30
申请人
GERRARD DAVID P.;XU YANG;BAKER HUGHES INCORPORATED
