A mobile navigation device including a roller, a support, a plurality of
terminals, and a body. The roller including an insulated bushing and a
conductive ring. By matching the plurality of protrusions on an inner end
surface of the insulated bushing with a plurality of slots on one end of
the conductive ring, the conductive ring is plugged inside of the
insulated bushing. The support including two braces, wherein each of the
braces has a cantilever that is plugged into the conductive ring to
sustain the conductive ring and the insulated bushing. The plurality of
terminals are plugged into the conductive ring by prestress on the inner
surface of the conductive ring, and each terminal extends out of the
conductive ring to connect with a default circuit contact. The body
includes a plurality of fixture parts and a plurality of raised spots.
The whole structure is movable forward, backward, rightward, leftward,
and downward.