A robot arm includes a drive assembly and an articulated arm assembly
pivotally connected to the drive assembly. The articulated arm includes a
pivoting base link system, a wrist link system, and a first elbow link
system rotatably connected to the base link system by a pair of upper
arms and connected to the wrist link system by a pair of forearms, a
second elbow link system rotatably connected to the base link system by
another at least one upper arm and connected to the wrist link system by
another at least one forearm, wherein the drive assembly is connected to
at least one of the upper arms and the base link system to provide three
degrees of freedom by driving the at least one of the upper arms and
pivoting the pivoting base link system to position the wrist link system
at a given location with a predetermined skew relative to an axis of
translation.