Provided is a lightweight crawler unit which is capable of swiveling, suitable for a trolley for bad roads, and used for transportation in muddy places such as snowy roads, sandy ground, and fields, and disaster sites. A crawler includes a plurality of inner attachments provided inside thereof toward a frame to have a band-shape, overhang edges 70 protruding in a left and right direction of a rail provided on a circumference of the frame, and overhang edges 34 protruding in a left and right direction of each of the inner attachments, in a space K enclosed between the overhang edges 34 facing each other, the overhang edges 70 are inserted, the overhang edges 34, 70 are set in a positional relation in which they overlap with each other in an up and down direction, and the crawler circulates around pulleys, while the inner attachments are restricted along the rail.

An improved hand truck having a stair navigator and brake system. The system includes a stair track, or stair navigator, having improved features allowing for the hand truck to navigate stairs more easily. The stair track is in connection with a brake, particularly a hydraulic brake system, allowing the user to stop movement of the belt of the stair climber while in use. The hand truck is an improved hand truck having an improved stair track, a brake system and a mechanism allowing for deployment and latching.

A self-propelled goods stair climber includes: first and second motorized tracks and an elongated configuration parallel to a straight forward travel direction; a loading surface implemented to tilt with respect to the tracks around a first transverse axis perpendicular to the tracks; an actuated stabilization member movable between an extracted position so that the weight of the stair climber is carried at least in part by the stabilization member and a retracted position in which the stabilization member is not loaded; a proximity or support sensor carried by the stabilization member to send a signal of approach or contact with a floor; an electronic control unit programmed to activate the first and second tracks on the basis of said signal when the stabilization member is extracted; and check an inclination of the loading surface to be maintained in a predefined angular range with respect to a horizontal direction.