Pedal-load lightening apparatus

Claim 1

A pedal-load lightening apparatus for reducing a necessary treadling force on a pedal, comprising: a support bracket including a pair of side plates and a top plate connecting the side plates; a horizontal support shaft extending between the side plates; a pedal arm supported, at the upper end portion thereof, on the support shaft so as to be rotatable around the shaft; a lever attached to the pedal arm so as to be rockable therewith; a torsion coil spring provided between the lever and the support bracket, and including at least one coil, a first end rockably supported by one side plate of the support bracket, and a second end anchored to the lever so as to apply an initial torsional moment to the coil, said torsion coil spring comprising means for urging the pedal arm to return to an initial position thereof before the arm reaches a critical position at a predetermined rotational angle to the initial position, and for urging the pedal arm in the direction of treadling action when the arm passes the critical position during movement from said initial position in the direction of treadling action, the second end of said torsion coil spring being located on one side of a line segment connecting the center of the support shaft and the first end when the pedal arm is in the initial position, and being located on a side opposite said one side, with respect to the line segment after the pedal arm has moved past said critical position during movement in the direction of treadling action; and an urging element positioned between the support bracket and the lever, and comprising second means for urging the pedal arm in the direction of treadling action thereof throughout substantially all of the predetermined rotational angle between the initial position and the critical position.