An off-axis rotary joint (20) for selectively enabling communication of a
signal (i.e., electrical and/or optical) between a housing (21) mounted
for rotation about an axis (y-y) relative to a hollow shaft assembly (22)
at all permissible relative angular displacements (e.g., 0.degree.,
180.degree., 360.degree., 540.degree., 720.degree., etc.) between the
housing and shaft assembly, broadly includes: a first conductor (23)
having an first end mounted on the second member and having a second end
mounted on the first member, the first conductor being adapted to convey
a signal between its ends; a first motor (24) operatively arranged to
selectively rotate the first conductor first end through a desired
angular displacement relative to the second member; a second conductor
(25) having an first end mounted on the second member and having a second
end mounted on the first member, the second conductor being adapted to
convey a signal between its ends; a second motor (26) operatively
arranged to selectively rotate the second conductor second end through a
desired angular displacement relative to the first second member; an
encoder (28) for monitoring the angular displacement of the first member
relative to the second member; a first divider/combiner (29)
communicating with the second end of each of the conductors; a second
divider/combiner (30); a first connector (31) mounted on the first member
for selectively communicating the first and second divider/combiners
through the first conductor; a second connector (32) mounted on the first
member for selectively communicating the first and second
divider/combiners through the second conductor; and a controller (33) for
selectively operating the first and second motors and the first and
second connectors; whereby a signal may be conveyed though the joint at
all permissible angular displacements of the housing relative to the
shaft assembly.