A joint device for providing hinged movement between a first and second arm member and for providing independent delivery of electrical power to the arm members, wherein said device includes a central portion for receiving at least two sets of electrical conductors and for delivering said at least one set of electrical conductors to each of said arm members, characterised in that upon hinged movement of the arm members about the central portion, the central portion maintains the conductors in a spaced apart relationship in a manner such that the structural integrity of said conductors is maintained for a predetermined minimum number of hinged movement cycles of said arm members.