| 摘要 |
An improved surface traversing apparatus is provided in which one anchor or group of anchors is connected with one base, another anchor or group of anchors is connected with another base, each anchor group is movable en bloc transversely of its respective base for lateral movement across the surface of a member to be traversed, and the two bases are movable relative to one another in a direction which moves one finger group alternately toward and away from engagement with a member engaged by the other finger group. The anchors may be selectively expandable fingers which are longitudinally insertable into and retractable from openings in a steam generator tube sheet to provide the engagement therewith. The anchor fingers in each group are fixed longitudinally to their respective bases and an actuator, such as a piston and cylinder combination, is oppositely connected to the two bases for varying the spacing therebetween longitudinally of the fingers to alternately move the two finger groups respectively en bloc alternately toward and away from the tube sheet. |
