Patent ID: 8863621

Claim:
A power tong comprising: a stator frame having a rotor rotatably mounted to said frame, said rotor mounted to said frame for rotation of said rotor about an axis of rotation orthogonal to a plane of rotation of said rotor, and wherein said rotor includes a central opening of sufficient diameter to accommodate a tubular and includes a first slot lying in said plane of rotation, said first slot substantially intersecting said central opening and sized to allow radial passage of the tubular therethrough, a first drive cooperating between said frame and said rotor to selectively provide said rotation of said rotor relative to said frame, a grip mounted to said rotor, said grip actuable to clamp said grip on the tubular at said axis of rotation to thereby hold the tubular when the tubular is positioned substantially along said axis of rotation, a serpentine member cooperating with, so as to be, driven by a second drive, at least two stator sprockets rotatably mounted on said frame, and arrayed substantially around said rotor, said serpentine member mounted around so as to engage said at least two stator sprockets, at least two rotor sprockets rotatably mounted spaced apart on said rotor, said rotor sprockets positioned on said rotor to form a gap corresponding to said first slot at said intersection and sized to accept the tubular therethrough, wherein said serpentine member is reaved around said rotor sprockets between said stator sprockets so as to not obstruct said gap, and wherein at least one stator sprocket of said at least two stator sprockets is said driven by said second drive so as to drive said serpentine member and thereby transfer energy from said at least one stator sprocket to at least one rotor sprocket of said at least two rotor sprockets, a coupling mounted on said rotor and cooperating between said at least two rotor sprockets and said grip, wherein said energy is transferable from said serpentine member to said rotor sprockets, and said energy is transferable from said rotor sprockets to said grip, and wherein, as said rotor is rotated about said axis of rotation, continuous engagement is maintained between said serpentine member and said at least one rotor sprocket whereby said energy is transferable to said grip at any position of said rotor about said axis of rotation, and wherein said coupling includes a synchronizer synchronizing rotation of said at least two rotor sprockets.