Adjustable Straight-Line Linkages—Possible Legged-Vehicle Applications Available to Purchase

The stimulus for this paper is the expressed need in proposals for legged vehicles both to propel the vehicle in rectilinear translation parallel to the mean ground-profile beneath it and to allow the chassis-height to be adjustable. Energy considerations point toward having a single propulsion-actuator on each leg-linkage rather than adopting the less economical option of simultaneous actuation at two or more serially connected leg-joints. Of the linkages whose kinematics are here studied some relate more closely to legged vehicles than others do; the paper should be viewed in a general rather than a specific context. Exact and approximate straight-line planar linkages are covered. Derivatives of Richard Roberts’s linkage are put forward as those that are the most promising adjustable linkages whose joints are all turning pairs.