Patent ID: 7823899

Claim:
A propulsion assembly for a bicycle having a frame with a top having a seat post with seat extending therefrom, a bottom opposite the top, a front with a front wheel rotatably connected thereto at the bottom, and a rear opposite the front with a rear wheel rotatably connected thereto at the bottom, the assembly comprising: a support member extending from the frame, away from the seat post and towards the rear of the frame, to a distal end of the support member, the distal end being spaced-apart from the rear wheel and comprising a support housing; a rear axle axially connected to the rear wheel and rotatably mounted on the frame, a rear sprocket radially extending from the rear axle at one end of the rear axle, the rear sprocket being axially connected to the rear wheel for transmitting motion thereto; a drive axle rotatably received in part within the support housing, a rotatable drive sprocket radially extending from the drive axle at one end of the drive axle, the drive sprocket being spaced-apart from the seat post, the drive sprocket having an axis of rotation; an endless chain operatively connecting the rear sprocket to the drive sprocket; a pair of ratchets connected by opposed ends of the drive axle and axially aligning with the axis of rotation of the drive sprocket, the drive sprocket being between the pair of ratchets; a pair of rigid elongate members operatively connected to the drive sprocket and extending from the pair of ratchets in planes parallel with the frame to a pair of pedals positioned between the rear wheel and the front wheel of the bicycle, the pair of pedals being movable in the planes from an upper position to a lower position for transmitting one-way rotational power to the drive sprocket; and means for selectively returning the pair of rigid elongate members from the lower position to the upper position, the means for selectively returning the pair of elongate members from the lower position to the upper position including a first piston and a second piston, the first piston being operatively connected to the frame, the first piston engaging one of the pair of elongate members in the lower position and being compressed thereby, and the second piston being operatively connected to the frame, the second piston engaging another of the pair of elongate members in the lower position and being compressed thereby, whereby upon being engaged, the first piston and the second piston are retractable and biased towards the upper position for returning the pair of elongate members to the upper position thereby.