Bicycle crankset with radial effect and bicycle comprising the said bicycle crankset

Abstract

The present invention relates to a bicycle crankset (1) comprising a bottom bracket (2); an extendable right arm assembly (3), constituted by a right arm (31) in which is fixed one or more chain rings (32), and by a movable arm (33) which can slide over the said right arm (31); an extendable left arm assembly (4) consisting of a left arm (41) and a movable arm (42) that can slide over the said left arm (41); a right support assembly (5) including a stator (51) on which two rotors (52, 53) are mounted coupled to two unidirectional bearings (54, 55) with free rotation in a clockwise direction; a left support assembly (6) that includes a stator (61) on which two rotors (62, 63) are mounted coupled to two unidirectional bearings (64, 65) with free rotation in a counterclockwise direction; four link members (7, 8, 9, 10); and two stops (11, 12), one for each arm (41, 31). The invention also relates to a bicycle comprising the crankset. The invention belongs to the transport sector.

Description

[0001] DESCRIPTION

[0002] "BICYCLE CRANKSET WITH RADIAL EFFECT AND BICYCLE COMPRISING THE

[0003] SAID BICYCLE CRANKSET"

[0004] FIELD OF THE INVENTION

[0005] The present invention relates to a bicycle crankset that trans forms part of the radial component of cyclist ' s force into another tangential component adding, in this way, an extra torque to the torque produced in the conventional way . The invention also relates to a bicycle comprising the said bicycle crankset . The invention finds application in the transport sector, particularly in the field of production and commerciali zation of bicycles .

[0006] BACKGROUND OF THE INVENTION

[0007] The pedalling process involves trans forming the force exerted by the cyclist ' s legs into torque , which is then transmitted to the rear wheel of the bicycle via a chain . This torque is generated by the tangential component of said force , exerted on the pedal , which travels a circular traj ectory guaranteed by the attachment of said pedal to an arm which, in turn, is connected to the bottom bracket . With this crankset configuration, the radial component of said force is completely wasted, generating a reaction of equal magnitude on the bottom bracket that is fixed to the bicycle frame .

[0008] Therefore , a need exists to overcome the deficiencies noted in the prior art . BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following is a detailed description of the invention with reference to the attached drawings, in which:

[0010] Fig. 1 illustrates a schematic exploded view of an embodiment of the bicycle crankset of the present invention.

[0011] Fig. 2 illustrates a view from the right side of the crankset of Fig .1.

[0012] Fig. 3 illustrates a typical representation of the forces carried out on a complete cyclist pedal revolution.

[0013] SUMMARY OF THE INVENTION

[0014] The present invention relates to a bicycle crankset (1) comprising a bottom bracket (2) ; an extendable right arm assembly (3) , which is constituted by a right arm (31) , and by a movable arm (33) which is slidable over the said right arm (31) ; an extendable left arm assembly (4) consisting of a left arm (41) and a movable arm (42) that is slidable over the said left arm (41) ; a right support assembly (5) that includes a stator (51) on which two rotors (52, 53) are mounted coupled to two unidirectional bearings (54, 55) with free rotation in a clockwise direction; a left support assembly (6) that includes a stator (61) on which two rotors (62, 63) are mounted coupled to two unidirectional bearings (64, 65) with free rotation in a counterclockwise direction; four link members (7, 8, 9, 10) ; and two stops (11, 12) , wherein one stop (11) is mounted on the left arm (41) and the other stop (12) is mounted on the right arm (31) ; wherein the extendable right arm assembly (3) is fixed to one end of the bottom bracket (2) and the extendable left arm assembly (4) is fixed to the other end of the bottom bracket (2) , with the two support assemblies (5, 6) being configured to be fixed to a bicycle frame, and two link members (7, 8) connect the right movable arm (33) to the two rotors (52, 53) , and the other two link members (9, 10) connect the left movable arm (42) to the other two rotors (62, 63) .

[0015] In an embodiment the bicycle crankset (1) further comprises a slot (13) arranged in the movable arm (33) and another slot (14) arranged in the movable arm (42) , wherein each slot (13, 14) comprises a first stop zone (131, 141) and a second stop zone (132, 142) .

[0016] In a further embodiment the right arm (31) of the bicycle crankset (1) is connected to the movable arm (33) via a linear bearing (34) and the left arm (41) is connected to the other movable arm (42) via another linear bearing (43) ; or the right arm (31) and the left arm (41) are connected respectively to the movable arm (33) and the movable arm (42) via sliding adjustments.

[0017] Preferably, at least one chain ring (32) is fixed to the right arm (31) of the bicycle crankset (1) .

[0018] The invention also relates to a bicycle comprising a frame and the crankset (1) as above-defined.

[0019] In an embodiment of the bicycle, the two support assemblies (5, 6) of the bicycle crankset (1) are fixed to the bicycle frame at each side of the bottom bracket (2) .

[0020] DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention relates to a bicycle crankset with a radial effect which, in addition to producing torque in the conventional way, taking advantage of the tangential component (18) of the force (17) exerted on the pedals, transforms part of the radial component (19, 20) of said force (17) into another tangential component (18) adding, in this way, an extra torque to the torque produced in the conventional way. The invention finds application in the transport sector, particularly in the field of production and commercialization of bicycles.

[0022] In the context of this description, the term "comprising" should be understood as "including, among others". As such, said term should not be interpreted as "consisting only of".

[0023] In the context of the present invention, the term "torque" refers to the product of a force and the distance from the point of application of said force to an axis, and which causes rotation on that axis.

[0024] In the context of the present invention, the term "unidirectional bearing" refers to a device that allows rotation in only one direction while being blocked in the opposite direction .

[0025] The detailed description is provided herein making reference to Fig. 1 to 3 that should be construed as exemplificative and explanatory .

[0026] Making reference to Fig. 1 and 2, a bicycle crankset (1) in accordance with the present invention comprises:

[0027] • a bottom bracket (2) ;

[0028] • an extendable right arm assembly (3) which is constituted by a right arm (31) in which can be fixed one or more chain rings (32) and by a movable arm (33) which can slide over the said right arm ( 31 ) ; • an extendable left arm assembly (4) consisting of a left arm (41) and a movable arm (42) that can slide over the said left arm (41) ;

[0029] • a right support assembly (5) that includes a stator (51) on which two rotors (52, 53) are mounted coupled to two unidirectional bearings (54, 55) with free rotation in a clockwise direction;

[0030] • a left support assembly (6) that includes a stator (61) on which two rotors (62, 63) are mounted coupled to two unidirectional bearings (64, 65) with free rotation in a counterclockwise direction;

[0031] • four link members (7, 8, 9, 10) ;

[0032] • two stops (11, 12) , one stop (11) mounted on the left arm

[0033] (41) and the other stop (12) mounted on the right arm (31) ; wherein the extendable right arm assembly (3) is fixed to one end of the bottom bracket (2) and the extendable left arm assembly (4) is fixed to the other end of the bottom bracket (2) , with the two support assemblies (5, 6) being configured to be fixed to a bicycle frame, one at each side of the bottom bracket axle and in which two link members (7, 8) make the connection between the right movable arm (33) and two rotors (52, 53) and the other two link members (9, 10) make the connection between the left movable arm

[0034] (42) and the other two rotors (62, 63) .

[0035] Preferably, the slide path travelled by the movable arm (33, 42) , relatively to the arm (31, 41) in which is assembled, is limited through the stop (11) on the left arm (41) and to the stop (12) on the right arm (31) , wherein said stop (11, 12) works on a slot (13, 14) in the movable arm (33, 42) , each slot (13, 14) with a first stop zone (131, 141) for when the radial force has a negative direction (Z-) and another (second) stop zone (132, 142) for when the radial force has a positive direction (Z+) . Preferably, the right arm (31) is connected to the movable arm (33) via a linear bearing (34) and the left arm (41) is connected to the other movable arm (42) via another linear bearing (43) . This connection is also possible via a sliding adjustment.

[0036] The invention also relates to a bicycle described to comprise the bicycle crankset with radial effect.

[0037] Description of operation

[0038] Making reference to Fig. 3, the profile of the force (17) exerted on the pedal over the course of a complete pedal revolution has been extensively studied in the past. From the analysis of some studies carried out, it can be concluded that the direction of this force (17) is approximately the same, regardless of the cyclist, only its magnitude varies. It can be seen in Fig. 3 that, in relation to the radial component (19, 20) , its direction goes against the bottom bracket (2) (negative direction) in quadrants 1 and 4 (QI, Q4) and in the opposite direction (positive direction) in quadrants 2 and 3 (Q2, Q3) . Therefore, there is an alternating cyclical behaviour of the direction of the radial force between positive (19) and negative (20) , which is a crucial factor for the functioning of the invention.

[0039] Making reference to Fig. 2 and 3, analysing the right part of the bicycle crankset (1) with radial effect (on the left side the process is analogous) and starting at the beginning of quadrant QI, with the stop (12) of the right arm (31) positioned in the stop zone (131) of the movable arm (33) for when the radial force (20) has a negative direction ( Z-) , the said movable arm (33) is immobilized in relation to the right arm (31) with the unidirectional bearings (54, 55) allowing the rotation of the movable elements of the right part of the bicycle crankset (1) with radial effect, in a clockwise direction, all with the same angular speed. As soon as the direction of the radial force (19, 20) changes from negative (20) to positive (19) (approximately at the end of quadrant QI) , the movable arm (33) begins to slide over the right arm (31) and causes a change in the direction of the force transmitted through link member (8) to the rotor (52) to which said link member (8) is connected, blocking the respective unidirectional bearing (54) and thus allowing additional torque to be generated. When the movable arm (33) is immobilized by the action of the stop (12) placed on the right arm (31) which is positioned in the stop zone (132) for when the radial force (19) is in a positive direction (Z+) , the link member (8) transmits a force in the opposite direction to the rotor (52) , which thus unlocks the unidirectional bearing (54) allowing again the rotation of said rotor (52) . When the direction of the radial force (19, 20) changes back to negative (20) (approximately at the beginning of quadrant Q4) , the movable arm (33) begins to slide in the opposite direction and causes a change in the direction of the force transmitted through link member (7) to the rotor (53) to which said link member (7) is connected, blocking the respective unidirectional bearing (55) and thus allowing additional torque to be generated again. When the movable arm (33) is immobilized by the action of the stop (12) placed on the right arm (31) which is positioned in the stop zone (131) for when the radial force (20) is in a negative direction (Z-) , the link member (7) transmits a force in the opposite direction to the rotor (53) to which it is connected and thus unlocks the unidirectional bearing (55) , allowing said rotor (53) to rotate again. The movable arm (33) then returns to its initial position, leaving the system ready to restart the entire process. Reference Numbers

[0040] 1 - bicycle crankset;

[0041] 2 - bottom bracket;

[0042] 3 - extendable right arm assembly;

[0043] 31 - right arm of the extendable right arm assembly;

[0044] 32 - chain ring;

[0045] 33 - movable arm;

[0046] 34 - linear bearing;

[0047] 4 - extendable left arm assembly;

[0048] 41 - left arm of the extendable left arm assembly;

[0049] 42 - movable arm;

[0050] 43 - linear bearing;

[0051] 5 - right support assembly;

[0052] 51 - stator;

[0053] 52 - rotor;

[0054] 53 - rotor;

[0055] 54 - unidirectional bearing;

[0056] 55 - unidirectional bearing;

[0057] 6 - left support assembly;

[0058] 61 - stator;

[0059] 62 - rotor;

[0060] 63 - rotor;

[0061] 64 - unidirectional bearing;

[0062] 65 - unidirectional bearing;

[0063] 7 - link member;

[0064] 8 - link member;

[0065] 9 - link member;

[0066] 10 - link member;

[0067] 11 - left stop;

[0068] 12 - right stop;

[0069] 13 - right slot; 131 - first right slot stop zone;

[0070] 132 - second right slot stop zone;

[0071] 14 - left slot ;

[0072] 141 - first left slot stop zone;

[0073] 142 - second left slot stop zone ;

[0074] 15 - right bottom bracket cup ;

[0075] 16 - left bottom bracket cup ;

[0076] 17 - cyclist force ;

[0077] 18 - tangential component of the cyclist force ;

[0078] 19 - positive radial component of the cyclist force ;

[0079] 20 - negative radial component of the cyclist force .

[0080] The description presented herein should be understood as exemplary and not limiting the scope of the present invention, which is defined in the attached claims .

[0081] It should be noted that although the present invention has been described with reference to its preferred embodiments , many modi fications and alternatives can be made by a person skilled in the art without departing from the scope of the invention, which is defined by the claims .

Claims

CLAIMS1. A bicycle crankset (1) , characterized in that it comprises:• a bottom bracket (2) ;• an extendable right arm assembly (3) , which is constituted by a right arm (31) , and by a movable arm (33) which is slidable over the said right arm (31) ;• an extendable left arm assembly (4) consisting of a left arm (41) and a movable arm (42) that is slidable over the said left arm (41) ;• a right support assembly (5) that includes a stator (51) on which two rotors (52, 53) are mounted coupled to two unidirectional bearings (54, 55) with free rotation in a clockwise direction;• a left support assembly (6) that includes a stator (61) on which two rotors (62, 63) are mounted coupled to two unidirectional bearings (64, 65) with free rotation in a counterclockwise direction;• four link members (7, 8, 9, 10) ; and• two stops (11, 12) , wherein one stop (11) is mounted on the left arm (41) and the other stop (12) is mounted on the right arm ( 31 ) ; wherein the extendable right arm assembly (3) is fixed to one end of the bottom bracket (2) and the extendable left arm assembly (4) is fixed to the other end of the bottom bracket (2) , with the two support assemblies (5, 6) being configured to be fixed to a bicycle frame, and two link members (7, 8) connect the right movable arm (33) to the two rotors (52, 53) , and the other two link members (9, 10) connect the left movable arm (42) to the other two rotors (62, 63) .

2. The bicycle crankset (1) according to claim 1, characterized in that it further comprises a slot (13) arranged in the movable arm (33) and another slot (14) arranged in the movable arm (42) , wherein each slot (13, 14) comprises a first stop zone (131, 141) and a second stop zone (132, 142) .

3. The bicycle crankset (1) according to claim 1 or 2, characterized in that the right arm (31) is connected to the movable arm (33) via a linear bearing (34) and the left arm (41) is connected to the other movable arm (42) via another linear bearing (43) .

4. The bicycle crankset (1) according to claim 1 or 2, characterized in that the right arm (31) and the left arm (41) are connected respectively to the movable arm (33) and the movable arm (42) via sliding adjustments.

5. The bicycle crankset (1) according to any of the preceding claims, characterized in that at least one chain ring (32) is fixed to the right arm (31) .

6. A bicycle comprising a frame and the bicycle crankset (1) as claimed in any of preceding claims 1 to 5.

7. The bicycle according to claim 6, characterized in that the two support assemblies (5, 6) of the bicycle crankset (1) are fixed to the bicycle frame at each side of the bottom bracket

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