Patent ID: 6041876
Filing Date: 2000-03-28
Classification: A61G,Y10S,Y10T

Abstract:
A wheelchair for use on a ground surface comprising:a frame;a seat received on the frame;a first arm pivotally connected to the frame;a driven wheel secured to a portion of the arm;at least one motor for powering the driven wheel;a plate attached to the rearward portion of the first arm;a dampener connected between the the frame and the plate, the dampener acting as a suspension for the driven wheel by exerting a first biasing force on the rearward portion of the first arm;a second arm extending from the plate and having a lower end with a smooth surface adapted to engage the ground surface, the second arm having at least two guide members extending through respective non-parallel slots in the plate for movement of the guide members in non-parallel directions within the slots to provide a predetermined range of movement of the second arm relative to the plate; anda biasing member having a first end secured to the plate and a second end secured to one of the pins for exerting a second biasing force on the second arm for urging the lower end of the second arm downwardly towards the ground surface, the first biasing force being greater than the second biasing force, whereby upon rearward tilting of the wheelchair, an initial anti-tipping force is provided by the biasing member until the second arm has substantially completed its predetermined range of movement, whereupon an additional anti-tipping force is provided by the dampener upon further rearward tilting of the wheelchair.