Abstract: A tube joint for connecting a multi-walled tube assembly, typically a double-walled tube assembly, including a plurality of tubes defining a plurality of fluid passages to an object includes a joint body having a hole for inserting the tube assembly therein and as many passages as the number of the fluid passages. A tube connector mechanism is provided for engaging the tube assembly. A coupling has a rod for being fitted into the tube assembly and a passage for communicating the tube assembly with one of the passages of the joint body. The rod has on a distal end thereof a substantially spherical projection projecting radially outwardly for being fitted in an inner surface of the tube assembly to connect the tube assembly to the coupling. The inner surface of the tube assembly and the rod are slidable with respect to each other to prevent damage to the tube assembly when it is connected to and disconnected from the tube joint.

Abstract: An actuator driving system for driving a plurality of actuators operable by a fluid under pressure includes a plurality of tube joints connected respectively to the actuators for being coupled with a plurality of double-walled tubes each having a plurality of passages. Each of the tube joints includes a base member having passages communicating with respective fluid ports of one of the actuators and mounted on said one actuator, and a body member having a first cylindrical body mounted on the base member and a second cylindrical body having a hole for insertion of one of the double-walled tubes therein, to allow the passages of said one double-walled tube to communicate respectively with the passages of the base member, the first cylindrical body being angularly movable with respect to the base member.