Patent ID: 7490683

Claim:
A power wheelchair comprising: a. a frame; b. a seat supported by said frame; c. a pair of drive wheels positioned below a central portion of said seat on opposite sides of said frame and supported thereon, said drive wheels rotatable about transverse axes; d. drive means for causing rotation of said drive wheels, said drive means being operatively connected to said frame rearward of said front portion of said frame; e. power means for supplying power to said drive means to move the wheelchair; f. control means for controlling the rotation of said drive wheels by said drive means; g. at least one idler wheel operatively connected to said frame and positioned behind said drive wheels and rearward of the back of said seat, said idler wheel mounted for rotation about a horizontal axis and supported for rotational movement about a vertical axis; h. at least one anti-tip device operatively connected to said frame and positioned forward of said drive wheels and said frame, said anti-tip device being operatively connected to said drive means and being positioned off the ground when said drive wheels and said rear idler wheel are in their normal ground-engaging position on level ground; and i. a resilient suspension supporting said forward anti-tip device for resisting upward arcuate movement of said anti-tip device, said resilient suspension comprising a first assembly and a first member, said first assembly being operatively attached to said drive means at a first location rearward of the front portion of said frame and said first member being pivotally attached to said frame at a second location, said first member comprising a substantially upright portion and a substantially transverse portion having an angle therebetween, said first assembly being pivotally attached to said substantially upright portion of said first member at a third location rearward of the front portion of said frame, and the substantially transverse portion of said first member being operatively attached to said anti-tip device.