Patent ID: 7775307

Claim:
A power wheelchair comprising: a frame including a front, a rear and two pivot portions at opposite sides thereof; a pair of front wheel sets on the opposite sides of the front of the frame, wherein each of the front wheel sets includes a front wheel mount having a first connection portion, which is pivoted to the pivot portion of the frame, and a second connection portion, which is more distal to the frame than the first connection portion, and a front wheel connected to the second connection portion of the front wheel mount; a pair of middle wheel sets on the opposite sides of the frame between the front and the rear, wherein each of the middle wheel sets includes a middle wheel mount having a first connection portion, which is pivoted on the pivot portion of the frame, and a second connection portion, which is more distal to the frame than the first connection portion, and a middle wheel connected to the second connection portion of the middle wheel mount; a pair of rear wheel sets on the opposite sides of the rear of the frame; and a pair of elastic devices, each of which is provided between the front wheel mount and the middle wheel mount to cushion a swing of the front wheel set and the middle wheel set relative to the frame, wherein the middle wheel mount includes a frame base with a first hole portion to form the first connection portion and a transmission device, and each of the pivot portions of the frame is a tube through the first hole portion to be pivoted on the frame base and through the first connection portions of the front wheel sets to be pivoted on the front wheel mount respectively, and each of the transmission devices has a shaft to form the second connection portion for connection of the middle wheel respectively.