JPS6243899B

PURPOSE:To enable the titled monitor used in a nuclear power generation plant or the like to ride over projecting bodies such as stairs smoothly by a method wherein the distance between the centers of track sprockets and idler wheels of track shoes can be changed. CONSTITUTION:The idler wheels 25c, 25d are connected by support members 27 rotatable respectively around the axles for the wheel sprockets 24c, 24d. The support members 2 are connected to hollow axles 30a, 30b which are rotated by motors 28a, 28b through worm reduction mechanism 29a, 29b, respectively. The track shoe 26a is driven by motors 32a, 23b, bevel gearings 33a, 33b and driving axles 31a, 31b to enable the monitor to travel. The support members 27 are respectively rotated by the motors 28a-28b so that track shoe type traveling parts 23a, 23b can be brought into a variety of configurations. In ascending a stairway, the balance of the monitor is kept by adapting the support members of the rear idler wheels to the inclination of the stairway. On the other hand, in descending a stairway, the front-side idler wheels are moved so as to conform to the inclination of the stairway. Accordingly, the monitor is enabled to ascned and decend stairways smoothly.