US 5,035,678 AGranted

Energy-storing bicycle sprocket drive system

AssigneeTrilach Development Inc.

InventorMartin D. Hageman

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Abstract

The present invention is an energy-storing bicycle sprocket drive system which includes a crank which rotates a shaft about the shaft's longitudinal axis. The crank moves through a point of minimum applied leverage and a point of maximum applied leverage in each rotational cycle. Journalled to the shaft is a drive plate having an outer surface with at least one opening. Each opening has an inner surface with at least one end wall. Facing the drive plate is a wheel which rotates freely on the shaft. At least one drive peg is mounted to the wheel such that it is in a position parallel to the longitudinal axis of the shaft. The drive peg extends from the wheel and into the opening of the drive plate. A spring is mounted within the opening between the end wall and the drive peg. As the shaft rotates and the spring is in a compressed state, it stores energy while exerting a first force on the drive peg causing the wheel to revolve as the crank rotates 90 degrees from the point of maximum applied leverage. Whereby as the crank then rotates 90 degrees from the point of minimum applied leverage the spring releases energy, transforms into an extended state, and applies a second force on the drive peg which maintains the wheel's motion.

Claims12

Dependent claims

An energy-storing bicycle sprocket drive system comprising:

(a) a shaft having a longitudinal axis;
(b) a crank operatively arranged to rotate said shaft about the longitudinal axis,
said crank having a rotational cycle wherein said crank moves through a point of minimum applied leverage and a point of maximum applied leverage in the rotational cycle;
(c) a drive plate journalled to said shaft such that said drive plate rotates about said longitudinal axis,
said drive plate having an outer surface;
said outer surface having at least one opening;
said opening having an inner surface of the drive plate;
and
said inner surface having at least one end wall;
(d) a wheel facing the drive plate, freely rotatable about the longitudinal axis of the shaft;
(e) at least one drive peg mounted to said wheel such that said drive peg is positioned parallel to said longitudinal axis wherein said drive peg extends into the opening causing the wheel to interlock with the drive plate;
and
(f) a spring mounted within the opening between the end wall and the drive peg,
said spring having a compressed state and an extended state wherein in said compressed state the spring stores energy and exerts a first force on the drive peg causing the wheel to revolve as the crank passes through the point of maximum applied leverage;
and
whereby as the crank passes through the point of minimum applied leverage, the spring releases energy causing the spring to transform into the extended state while applying a second force on the drive peg.

13 more elements

Dependencies are inferred from the claim text.