US Patent 10022861 Two joint module and arm using same

A two joint module includes a housing and a pair of hollow rotary actuator assemblies. Each actuator assembly has an axis and a hollow shaft and the axes are arranged at an angle to each other. The pair of hollow rotary actuator assemblies are arranged back to back and attached to the housing such that cables can be fed from the outside of one of the pair of hollow rotary actuator assemblies to the inside thereof and to the inside of the other of the pair of hollow rotary actuator assemblies to the outside thereof. The disclosure also relates to a robotic arm. The robotic includes at least two two joint modules as described herein and at least a first link.