Abstract: A method and apparatus are provided for controlling the movement of a surface traversing apparatus across a member which has an ordered array of openings in it's surface. Move control routines are provided, each of which instruct the traversing apparatus to move incrementally over the surface of the member by disengaging, incrementally moving, and re-engaging one of two stepping arms. Each routine operates to advance the apparatus an increment in one of a number of directions. Some of the routines move the apparatus parallel to lines or rows of openings. Others move the apparatus diagonally. Each routine senses the relative positioning of the two stepping arms to establish the sequence of operations and returns the stepping arm to its former position if it is unable to complete a step.

Abstract: An improved surface traversing apparatus has an anchor finger selectively movable laterally of another anchor finger into near or substantial alignment with an opening in a member for insertion thereinto and includes one or more of the fingers being mounted to a base portion of the platform by a mounting arrangement which allows one finger to be deflected laterally relative to another finger such that the finger being inserted may deflect into exact alignment with the receiving opening by lateral engagement with the sidewall of the opening. Each finger is resiliently mounted to a connecting member which is, in turn, connected to the base portion of the platform. The resilient mount for each finger normally centers the finger and allows both pivotal and translatory displacement of the finger relative to the connecting member.