Patent ID: 7766342

Claim:
An attachment for a manual wheelchair which has a pair of front caster wheels and a pair of main side wheels rearward of said front caster wheels, the attachment adapted to assist the wheelchair as the wheelchair descends from an upper surface to a lower surface, the attachment comprising: a damping unit adapted to mount on a wheelchair frame, said damping unit including a differential movement component; a rail adapted to mount on the wheelchair frame and adapted to slide along the wheelchair frame; wherein a first end of the rail is connected to the damping unit and a second end of the rail is connected to a front caster wheel on the wheelchair; a piston rod connected to the differential movement component of the damping unit and effective to eject the rail and front caster wheel from a first position to a second position such that the front caster wheel engages the lower surface when a latch adapted to maintain said rail in said first position is released; and a latch release mechanism having: a follower wheel support frame adapted for mounting on the wheelchair frame; a sliding member mounted on the follower wheel support frame and capable of sliding along the follower wheel support frame; and a follower wheel adapted for mounting on the sliding member, wherein when the front caster wheel of the wheelchair descends from the upper surface, the follower wheel engages the upper surface and temporarily supports the wheelchair and the sliding member slides along the follower wheel frame assembly releasing the latch and causing the rail connected to the front caster wheel and the damping unit to extend to the second position.