Patent ID: 7178708

Claim:
A tensioner for deploying an elongate member comprising: i) an endless track including a plurality of traction elements, each traction element comprising: (a) a base unit; (b) first and second arms mounted at respective opposite sides of the traction element and each including a gripping surface operatively disposed above the longitudinal axis of the member; and (c) third and fourth arms also mounted at respective opposite sides of the traction element and each including a gripping portion operatively disposed below the longitudinal axis of the member, each said arm being operatively moveable about a pivot axis between a first position in which the gripping surfaces are spaced from the member and a second position in which the gripping surfaces can contact the member; ii) drive means for driving the track so that the traction elements move along an endless path, said endless path including a path segment along which said gripping surfaces operatively contact the member; iii) guide means which operatively co-operates with the first and second arms to urge the first and second arms from said first position to said second position such that the first and second arms maintain said second position as the traction elements move along said path segment; and iv) a first linkage connecting the first arm and the fourth arm and a second linkage connecting the second arm and the third arm such that movement of the first and second arms between their first and second positions causes a corresponding movement of the third and fourth arms between their first and second positions.