A crawler device for traversing in a confined environment, searching
victims or inspecting defections, comprises an elongated flexible drive
shaft extending along a central axis between a proximal end and a distal
end, a motor operatively connected to the drive shaft for turning the
drive shaft, and a plurality of segments disposed over the drive shaft.
Any two adjacent segments are joined by an articulate joint. Each segment
has a wheel assembly including drive wheels. At least two segments
further include a gear assembly operatively connecting the wheel assembly
to the drive shaft. Turning the drive shaft provides distributed traction
force to the drive wheels of the at least two segments, and thereby
drives the crawler device.