초록 ▼

To enable an invalid\s wheelchair to negotiate stairways, it has a chassis frame equipped with ordinary motor-driven road wheels for level running and a pair of crawler belts for stair ascent or descent. Either the wheels or the belts may be selected, either to the exclusion of the other, as the mod

To enable an invalid\s wheelchair to negotiate stairways, it has a chassis frame equipped with ordinary motor-driven road wheels for level running and a pair of crawler belts for stair ascent or descent. Either the wheels or the belts may be selected, either to the exclusion of the other, as the mode of travel. A chair or like load carrier is movably mounted on the frame, and linkage is provided so the center of gravity of the load is adjusted to give the required stability for the selected travel mode.

대표청구항 ▼

Mobile apparatus comprising: a central support; a pair of side supports on respective side of the central support; means pivotally mounting the central support on each side support, respectively, said mounting means allowing the central support and each side support to move relative to each other; m

Mobile apparatus comprising: a central support; a pair of side supports on respective side of the central support; means pivotally mounting the central support on each side support, respectively, said mounting means allowing the central support and each side support to move relative to each other; means coupled with the supports for moving the side supports relative to the central support from first positions to second position and return; wheel means engageable with a supporting surface and coupled to the central support for supporting the same for movement over said surface when the side supports are in said first positions; means carried by the central support for driving said wheel means; an endless flexible track for each side support, respectively, each track being mounted on the respective side support and being movable into engagement with said surface for supporting said central support for movement over said surface when the side supports are in said second positions; and means coupled with each track, respectively, for moving the track relative to the respective side support, said tracks being out of engagement with the surface when the side supports are in the first positions and the wheel means being out of engagement with said surface when the side supports are in said second positions.