Electric propulsion system for a bicycle

A control system for operating two electric motors selectively in series, parallel, or individually, including:

• first, second, and third relays having first, second, and third normally open relay contacts;
• a power circuit comprising said first, second, and third normally open contacts connected in series between an electrical supply and ground;
• a first one of said motors connected between said electrical supply and a circuit point between said second and third relay contacts;
• a second one of said motors connected between ground and a circuit point between said first and second relay contacts;
• selector switch means for operating said second relay to cause said second relay contacts to connect said first and second motors in electrical series, and for operating said first and third relays simultaneously to cause said first and third relay contacts to connect said first and second motors in parallel relationship;
• and
• means for operating said first and third relays alternately to cause said first and third relay contacts to close alternately and connect said second and first motors, respectively, to operate alternately.

An electric propulsion system for a bicycle, including:

• a pair of electric motors having output shafts joined to a common drive roller, the output shafts being rigidly secured together for rotation in common;
• and
• motor mounting means for mounting the pair of electric motors to a frame portion of the bicycle;
• wherein a torque of the motors creates a reaction force to cause impingement of the drive roller on the tire, and wherein when the drive roller impinges on the tire, the torque of the motors further urges the drive roller into greater frictional engagement with the tire.

An electric propulsion system for a bicycle, including:

• a pair of electric motors having output shafts joined to a common drive roller, each of the pair of electric motors including means for accommodating a misalignment between the output shafts;
• and
• motor mounting means for mounting the electric motors to a frame portion of the bicycle;
• wherein a torque of the motors creates a reaction force to cause impingement of the drive roller on the tire, and wherein when the drive roller impinges on the tire, the torque of the motors further urges the drive roller into greater frictional engagement with the tire.

An electric propulsion system for a bicycle, including:

• at least one electric motor having an output shaft joined to a drive roller;
• motor mounting means for mounting the at least one electric motor to a frame portion of the bicycle;
• and
• a support plate secured to the motor mounting means for supporting a distal end portion of the output shaft of the at least one electric motor, the support plate including means for permitting movement of the axis of the output shaft with respect to the support plate;
• wherein a torque of the at least one motor creates a reaction force to cause impingement of the drive roller on the tire, and wherein when the drive roller impinges on the tire, the torque of the at least one motor further urges the drive roller into greater frictional engagement with the tire.

An electric propulsion system for a bicycle, including:

• at least one electric motor having an output shaft joined to a drive roller;
• and
• motor mounting means for pivotally mounting the at least one electric motor to a frame portion of a bicycle, the motor mounting means including a damped torsional spring for applying a damped resilient restoring force to the at least one electric motor to urge the drive roller toward engagement with a tire of the bicycle;
• wherein a torque of the at least one motor creates a reaction force to cause impingement of the drive roller on the tire, and wherein when the drive roller impinges on the tire, the torque of the at least one motor further urges the drive roller into greater frictional engagement with the tire.

An electric propulsion system for a bicycle, including:

• a pair of electric motors having output shafts joined to a common drive roller;
• motor mounting means for mounting the pair of electric motors to a frame portion of the bicycle;
• and
• control means for actuating the pair of electric motors individually and alternately each for a predetermined period of time;
• wherein a torque of the motors creates a reaction force to cause impingement of the drive roller on the tire, and wherein when the drive roller impinges on the tire, the torque of the motors further urges the drive roller into greater frictional engagement with the tire.

An electric propulsion system for a bicycle, including:

• at least one electric motor having an output shaft joined to a drive roller;
• motor mounting means for mounting the at least one electric motor to a frame portion of the bicycle;
• and
• suspension means for suspending a power source for the at least one electric motor under tension between a crossbar, a seat tube, and a down tube of the bicycle;
• wherein a torque of the at least one motor creates a reaction force to cause impingement of the drive roller on the tire, and wherein when the drive roller impinges on the tire, the torque of the at least one motor further urges the drive roller into greater frictional engagement with the tire.