Power transmission system particularly useful for bicycles
OwnerGabriel Philippinventor
Life of this patent
Estimating the term…
Abstract
A power transmission system particularly useful for a foot-operated bicycle comprises a pair of axle sections coaxially-mounted with respect to each other, each fixed to one of the crank arms and each rotatable independently of the other; and coupling mechanism between the pair of axle sections and the chain wheel effective to cause the angular velocity of one crank arm to decrease relative to the other for a portion of a rotary cycle, and then to increase relative to the other for the remaining portion of a rotary cycle, such that as the one crank arm approaches the lower dead-center position after completing a forceful downward stroke, the other crank arm has passed the upper dead-center position preparatory to starting another forceful downward stroke.
Claims19
A power transmission system, particularly useful for a foot-operated bicycle, including a frame and pair of crank arms rotatable with respect to said frame and coupled to a driven wheel which is rotated by rotation of the crank arms, characterized in that said transmission system comprises:
- a pair of axle sections coaxially-mounted with respect to each other, each fixed to one of said crank arms and each rotatable independently of the other;
- and coupling mechanism between said pair of axle sections and said driven wheel effective to cause the angular velocity of one crank arm to decrease relative to the other for a portion of a rotary cycle, and then to increase relative to the other for the remaining portion of a rotary cycle, such that as said one crank arm approaches a dead-center position on one side of the driven wheel after completing a forceful stroke, the other crank arm has passed the dead-center position on the other side of the driven wheel preparatory to starting another forceful stroke.
A bicycle comprising:
- a frame;
- a pair of foot pedals carried at the ends of a pair of crank arms rotatably mounted about a horizontal axis of the frame;
- a chain wheel driven by said crank arms and coupled by a chain to the rear bicycle wheel so as to rotate it upon rotation of the pair of foot pedals;
- and a power transmission system for transmitting the power from said pair of foot pedals to said chain wheel, comprising:
- a pair of axle sections coaxially-mounted with respect to said horizontal axis, each fixed to one of said crank arms and each rotatable independently of the other;
- and coupling mechanism between said pair of axle sections and said chain wheel effective to cause the angular velocity of one crank arm to decrease relative to the other for a minor portion of a rotary cycle, and then to increase relative to the other for the remaining portion of a rotary cycle, such that as said one crank arm approaches a lower dead-center position after completing a forceful downward stroke, the other crank arm has passed an upper dead-center position preparatory to starting another forceful downward stroke.
A bicycle comprising:
- a frame;
- a pair of foot pedals carried at the ends of a pair of crank arms rotatably mounted about a horizontal axis of the frame;
- a chain wheel driven by said crank arms and coupled by a chain to the rear bicycle wheel so as to rotate it upon rotation of the pair of foot pedals;
- and a power transmission system for transmitting the power from said pair of foot pedals to said chain wheel, comprising:
- a circular plate fixed to said frame eccentrically to said horizontal axis, said chain wheel being rotatably mounted on said eccentric circular plate;
- a pair of axle sections rotatably mounted with respect to said circular plate, and coaxially-mounted with respect to each other, each axle section being fixed to one of said crank arms and each rotatable independently of the other;
- and coupling mechanism between said pair of axle sections and said chain wheel effective to cause the angular velocity of one crank arm to decrease relative to the other for a portion of a rotary cycle, and then to increase relative to the other for the remaining portion of a rotary cycle, such that as said one crank arm approaches a lower dead-center position after completing a forceful downward stroke, the other crank arm has passed the an upper dead-center position preparatory to starting another forceful downward stroke.
Dependencies are inferred from the claim text.