A device with a pivoting work arm (12) for carrying and positioning a tool which is moved by a modified Watts linkage (30) powered by a linear actuator (28) having a true straight line motion. The modified Watts linkage (30) has relatively short links resulting in the center (92) of the middle link (60, 62) following an arcuate path. The center (92) of the middle link (60, 62) is drivingly connected to the linear actuator (28) by a pivoting link or a cam (130). To provide shock absorption for the work arm (12) as it reaches its fully extended position, the modified Watts linkage (30) is coupled to a follower arm (104) yieldably biased by a spring (129). <IMAGE>
