Back-pedal brake operator and braking system for multi-speed bicycles

A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having first brake means associated with the front wheel and second brake means associated with the rear wheel and having a pair of pedal crank arms on a crank shaft rotatably mounted in a bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction about its axis by the rider pedalling in the forward direction, said back-pedal brake operator comprising:

• a drive plate mounted for rotation about said axis with the pedal crank arms and crank shaft,
• said drive plate having a plurality of arcuate slots therein concentric about said axis of rotation,
• at least one chain sprocket for driving a chain for driving the rear wheel,
• a plurality of fastening means for mounting said sprocket onto said drive plate, said fastening means engaging said arcuate slots for holding said sprocket concentric about said axis of rotation and for permitting limited relative turning movement between said sprocket and said drive plate,
• a ratchet ring gear having multiple ratchet teeth,
• bearing means rotatably mounting said ratchet ring gear on said drive plate concentric about said axis of rotation,
• stop means engageable with the bicycle frame for preventing said ratchet ring gear from turning in the forward direction when the rider is pedalling in the forward direction,
• a brake actuator means connected to said ratchet ring gear, said brake actuator being adapted to be coupled to the first and second brake means for simultaneously applying braking action to both the front and rear wheels when the ratchet ring gear is turned in the reverse direction,
• a ratchet pawl pivotally connected to said drive plate and adapted to engage the ratchet teeth for turning said ratchet ring gear in the reverse direction when the drive plate is turned in the reverse direction by the rider back pedalling,
• spring means for urging said sprocket to turn a limited amount forwardly relative to said drive plate when the chain is unloaded and said spring means permitting said sprocket to turn a limited amount rearwardly relative to said drive plate as the rider is pedalling forwardly with the chain under load, and
• pawl control means operatively connected to said sprocket and engageable with said pawl for disengaging said pawl from said ratchet teeth in response to said limited relative turning movement occurring upon the rider pedalling forwardly with the chain under load and for causing said pawl to engage with said ratchet teeth as the rider back pedals for turning the ratchet ring gear in the reverse direction, thereby simultaneously to apply braking action to both the front and rear wheels when the rider back pedals.

A back-pedal brake operator assembly for use on a multi-speed bicycle of the chain derailer type having a plurality of chain sprockets and first brake means associated with the front wheel and second brake means associated with the rear wheel and having a pair of pedal crank arms on a crank shaft rotatably mounted in bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction about its axis by the rider pedalling in the forward direction, said back-pedal brake operator assembly comprising:

• a drive plate mounted for rotation about said axis with the pedal crank arms and crank shaft,
• said drive plate having a plurality of slots therein elongated concentric about said axis of rotation,
• a first of said chain sprockets being positioned outside of said drive plate and a second of said chain sprockets being positioned inside of said drive plate with said drive plate being compactly sandwiched between said first and second sprockets,
• a plurality of fastening means for rigidly interconnecting said sprockets for forming a sprocket assembly and for mounting said sprockets onto said drive plate, said fastening means extending between said first and second sprockets through said elongated slots for holding said sprockets concentric about said axis of rotation and for permitting limited relative rotational movement between said sprocket assembly and said drive plate,
• a ratchet ring gear having multiple ratchet teeth,
• bearing means rotatably mounting said ratchet ring gear on the inside of said drive plate concentric about said axis of rotation,
• stop means engageable with the bicycle frame for preventing said ratchet ring gear from turning in the forward direction when the rider is pedalling in the forward direction,
• brake actuator means connected to said ratchet ring gear, said brake actuator means being adapted to be coupled to the first and second brake means for simultaneously applying braking to both the front and rear wheels when the ratchet ring gear is turned in the reverse direction,
• at least one ratchet pawl pivotally connected to said drive plate and adapted to engage the ratchet teeth for turning said ratchet ring gear in the reverse direction when the drive plate is turned in the reverse direction by the rider back pedalling,
• spring means for urging said sprocket assembly to turn a limited amount forwardly relative to said drive plate when the chain is unloaded and said spring means permitting said sprocket assembly to turn a limited amount rearwardly relative to said drive plate as the rider is pedalling forwardly with the chain under load, and
• pawl control means operatively connected to said sprocket assembly and engageable with said pawl and responsive to the limited relative turning motion between said sprocket assembly and drive plate for disengaging said pawl from said ratchet teeth as the rider pedals forwardly with the chain under load and for engaging said pawl with said ratchet teeth as the rider back pedals, thereby simultaneously to brake the front and rear wheels as the rider back pedals.

A back-pedal brake operator for use on a bicycle having a pedal crank, sprocket means, and brake means, said operator comprising:

• a drive plate adapted for connection with the pedal crank for rotation therewith about the axis of rotation of the pedal crank,
• a ratchet gear having a plurality of ratchet gear teeth,
• bearing means rotatably mounting said ratchet gear on said drive plate with said ratchet gear teeth extending around said axis concentric therewith,
• a brake actuator connected to said ratchet gear for movement therewith for actuating said brake means,
• means for preventing said brake actuator and ratchet gear from rotating in the forward direction when the operator pedals forwardly,
• at least one pawl pivotally mounted on said drive plate and engageable with and disengageable from said ratchet gear,
• pawl control means for moving each said pawl into engagement with said ratchet gear during back pedalling by the rider for turning said brake actuator in the reverse direction for actuating the brake means, and
• said pawl control means being adapted for connection to the sprocket for causing disengagement of said pawl from said ratchet gear upon forward pedalling of said pedal crank against a chain load on said sprocket.

A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake mechanism associated with a wheel and having a pair of pedal crank arms attached to a crank shaft rotatably mounted in a bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator comprising:

• a drive member rigidly affixed to the pedal crank shaft to turn with the crank shaft about the axis of rotation of the crank shaft,
• sprocket means associated with said pedal crank shaft and being rotatably mounted concentric about said axis for permitting rotational motion of said sprocket means relative to said drive member, said sprocket means being adapted to be engaged with a drive chain for driving the bicycle,
• brake actuator means mounted for free rotational motion about the axis of the pedal crank shaft, said brake actuator means including a ring member having a sufficiently large diameter to encircle said bearing housing and bearing means rotatably mounting said ring member upon said drive member in position to encircle said housing concentric about said axis, and a brake actuator member attached to said ring member, said brake actuator member being connectible to said brake mechanism for applying braking effort thereto,
• stop means for preventing said brake actuator means from rotating in the forward direction when the crank shaft is being pedalled in the forward direction,
• controlled unidirectional drive means operatively interposed between said drive member and said brake actuator means and responsive to limited relative motion of said sprocket means with respect to said drive member in one direction produced by chain loading for permitting free rotation of said drive member with respect to said brake actuator means whereby the brake actuator means does not apply braking effort during chain loading produced by forward pedalling or when the bicycle is wheeled backwards, and said controlled unidirectional drive means being responsive to limited relative motion of said sprocket means with respect to said drive member in the other direction produced by unloading of said chain for interconnection said drive member and said brake actuator means for applying braking effort when the bicycle rider back pedals.

A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake means associated with at least one wheel and having a pair of pedal crank arms attached to a crank shaft rotatable mounted in a bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator comprising:

• a drive plate adapted for mounting on the crank shaft between the bearing housing and one of the pedal crank arms for rotation with the crank shaft,
• a brake actuator assembly connectible to said brake means for applying braking effort thereto,
• bearing means rotatably mounting said brake actuator assembly upon said drive plate,
• means preventing said brake actuator assembly from turning in the forward direction as the rider pedals forward,
• sprocket means mounted upon the drive plate for limited rotational movement relative to said drive plate, said sprocket means being adapted for engagement with a drive chain,
• controlled unidirectional drive means including first and second engageable elements,
• one of said engageable elements being carried by said brake actuator assembly for motion therewith;
• the other of said engageable elements being carried by said drive plate for motion therewith,
• one of said engageable elements being movable between either of two positions in one of which positions said one engageable element is engaged with the other engageable element for preventing any relative rotation between said brake actuator assembly and said drive plate and in the other of which positions said one engageable element is retracted from the other engageable element for permitting said drive plate to rotate in the forward direction,
• control means for controlling the engagement and retraction of said one engageable element, said control means being actuated by the limited relative rotational motion between said drive plate and said sprocket means for retracting said one engageable element when the chain is under load and engaging said one engageable element with the other engageable element when the rider back pedals for moving said brake actuator to apply braking effort,
• said bearing means being a bearing ring of sufficiently large diameter to encircle said bearing housing,
• said bearing ring being attached to said drive plate in a position to encircle said bearing housing,
• said one engageable element included in said brake actuator assembly being a ratchet ring gear encircling said bearing ring, and said other engageable element being a controlled pawl pivotally mounted upon said drive plate, and
• said control means retracts said pawl away from said ratchet ring gear in response to said limited rotational motion in a first direction when said chain is under load and moves said pawl into engagement with said ratchet ring gear in response to said limited rotational motion in a second direction when said chain is unloaded as the rider back-pedals said crank shaft for applying braking effort to said brake means,
• whereby said back-pedal brake operator can be conveniently retrofitted on existing multi-speed bicycles as well as being installed on new bicycles being manufactured without structural modification of the bicycle frame or pedal crank bearing housing and bearings.

A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake means associated with at least one wheel and having a pair of pedal crank arms attached to a crank shaft rotatably mounted in a bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator comprising:

• a drive plate adapted for mounting on the crank shaft between the bearing housing and one of the pedal crank arms for rotation with the crank shaft,
• a brake actuator assembly connectible to said brake means for applying braking effort thereto,
• bearing means rotatably mounting said brake actuator assembly upon said drive plate,
• means preventing said brake actuator assembly from turning in the forward direction as the rider pedals forward,
• sprocket means mounted upon the drive plate for limited rotational movement relative to said drive plate, said sprocket means being adapted for engagement with a drive chain,
• controlled unidirectional drive means including first and second engageable elements,
• one of said engageable elements being carried by said brake actuator assembly for motion therewith,
• the other of said engageable elements being carried by said drive plate for motion therewith,
• one of said engageable elements being movable between either of two positions in one of which positions said one engageable element is engaged with the other engageable element for preventing any relative rotation between said brake actuator assembly and said drive plate and in the other of which positions said one engageable element is retracted from the other engageable element for permitting said drive plate to rotate in the forward direction,
• control means for controlling the engagement and retraction of said one engageable element, said control means being actuated by the limited relative rotational motion between said drive plate and said sprocket means for retracting said one engageable element when the chain is under load and engaging said one engageable element with the other engageable element when the rider back pedals for moving said brake actuator to apply braking effort,
• said sprocket means including a plurality of sprockets in spaced parallel relationship concentric about the axis of said pedal crank shaft,
• said drive plate being sandwiched between a pair of said sprockets,
• a plurality of fastening means extending between said pair of sprockets, and
• said drive plate having a plurality of circumferentially elongated openings therein and said fastening means extending through respective ones of said elongated openings for mounting said sprockets upon said drive plate while providing for limited rotational movement relative to said drive plate,
• whereby said back-pedal brake operator can be conveniently retrofitted on existing multi-speed bicycles as well as being installed on new bicycles being manufactured without structural modification of the bicycle frame or pedal crank bearing housing and bearings.

A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake mechanism associated with a wheel and having a pair of pedal crank arms attached to a crank shaft rotatably mounted in a bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator comprising:

• drive member means for coupling to the pedal crank shaft to turn with the crank shaft about the axis of rotation of the crank shaft,
• sprocket means associated with said pedal crank shaft and being mounted in encircling relationship about the axis of said crank shaft and being movable for permitting limited relative rotational motion of said sprocket means with respect to said drive member means, said sprocket means being adapted to be engaged with a drive chain for driving the bicycle,
• a brake actuator assembly mounted for free rotational motion about the axis of the pedal crank shaft, said brake actuator assembly including a ring member having a sufficiently large diameter to encircle said bearing housing on the bicycle frame,
• bearing means rotatably mounting said ring member upon said drive member means in position to encircle said housing concentric about said axis, whereby said brake operator can be conveniently retrofitted on such multi-speed bicycles as well as being installable on new bicycles being manufactured without structural modification of the bicycle frame, pedal crank bearing housing, bearings or pedal crank,
• a ratchet gear associated with said ring member, said ratchet gear having a plurality of teeth extending concentrically about said axis,
• a brake actuator member attached to said ring member, said brake actuator member being connectible to said brake mechanism for applying braking effort thereto,
• stop means for preventing said brake actuator assembly from rotating in the forward direction when the crank shaft is being pedalled in the forward direction,
• controlled unidirectional drive means operatively interposed between said drive member means and said brake actuator assembly and responsive to limited relative motion of said sprocket means with respect to said drive member means in one direction produced by chain loading for permitting free rotation of said drive member means with respect to said brake actuator assembly, whereby the brake actuator assembly does not rotate during chain loading produced by forward pedalling or when the bicycle is wheeled backwards, and said controlled unidirectional drive means being responsive to limited relative motion of said sprocket means with respect to said drive member means in the other direction produced by unloading of said chain for interconnecting said drive member means and said brake actuator assembly for applying braking effort when the bicycle rider back pedals, said controlled unidirectional drive means including:
• a controlled pawl pivotally mounted upon one of said drive member means and said sprocket means, and
• a control element mounted upon the other of said means and responsive to said limited relative rotation between the sprocket means and drive member means for causing said pawl to move into engagement with said ratchet gear upon back pedalling and for retracting said pawl away from said ratchet gear during chain loading produced by forward pedalling and during chain loading produced by wheeling the bicycle backwards.