Bicycle Drivetrain

Abstract

The pedal drivetrain includes an input interface, an output interface, and a power transmission belt. The power transmission belt engages the input interface and the output interface to transmit force from the input interface to the output interface. At least one of the input interface and the output interface includes a plurality of movable pins that engage the power transmission belt.

Description

[Background technology]

[0001] A bicycle is a vehicle that is powered by the rider's legs. There is a limit to the amount of force a human rider can transmit to the bicycle through the pedals and crankset. For this reason, many bicycles are equipped with drivetrains with different gear ratios to accommodate different terrains and road conditions.

[0002] The subject matter herein is not limited to embodiments that solve any disadvantages or that operate only in such environments. Rather, this background is provided only to illustrate one example technology area in which some embodiments described herein may be practiced. Summary of the Invention

[0003] In some embodiments, the pedal drivetrain includes an input interface, an output interface, and a power transmission belt. The power transmission belt is connected to the input interface and the output interface and transmits power from the input interface to the output interface. At least one of the input interface and the output interface includes a plurality of movable pins that engage the power transmission belt.

[0004] In some embodiments, the pedal drivetrain includes an input interface, an output interface, and a power transmission belt. The power transmission belt is connected to the input interface and the output interface and transmits power from the input interface to the output interface. The input interface and the output interface include a plurality of movable pins that engage the power transmission belt, the plurality of movable pins being arranged in a plurality of concentric circles around the axis of rotation.

[0005] This Summary is provided to introduce some concepts in a simplified form that are more fully described in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0006] Additional features and advantages will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the teachings herein. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Features of the disclosure will become more apparent from the following description and appended claims, or may be learned by the practice of the disclosure as set forth hereinafter.

[0007] To explain how the above-mentioned and other features of the present disclosure are obtained, a more particular description will be made by reference to specific embodiments that are illustrated in the accompanying drawings. For ease of understanding, like elements have been given like reference numerals in the various figures. Although some of the drawings may depict concepts in schematic or exaggerated form, at least some of the drawings may be drawn to scale. With the understanding that the drawings illustrate several exemplary embodiments, the embodiments will be described and explained with additional specificity and detail using the accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a bicycle with a gearless drivetrain in accordance with at least one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a side view of the bicycle of FIG. 1 with a gearless drivetrain in accordance with at least one embodiment of the present disclosure. [Diagram 3] FIG. 2 is a detailed view of a gearless drivetrain in a first ratio, in accordance with at least one embodiment of the present disclosure. [Figure 4]FIG. 4 is a detailed view of the gearless drivetrain of FIG. 3 in a second ratio, in accordance with at least one embodiment of the present disclosure. [Diagram 5] FIG. 5 is a detailed view of the gearless drivetrain of FIG. 4 in a third ratio, in accordance with at least one embodiment of the present disclosure. [Figure 6] FIG. 1 illustrates a cross-sectional view of a gearless drivetrain with a mechanically actuated pin in accordance with at least one embodiment of the present disclosure. [Figure 7] FIG. 1 is a cross-sectional view of a gearless drivetrain with an electromechanically actuated pin in accordance with at least one embodiment of the present disclosure. [Figure 8] FIG. 1 is a cross-sectional view of a gearless drivetrain with a piston actuated pin in accordance with at least one embodiment of the present disclosure. [Figure 9] FIG. 1 is a perspective view of a pin in accordance with at least one embodiment of the present disclosure. [Figure 10] FIG. 1 is a perspective view of a tapered pin in accordance with at least one embodiment of the present disclosure. [Figure 11] FIG. 1 is a perspective view of a conical pin in accordance with at least one embodiment of the present disclosure. [Figure 12] FIG. 1 is a perspective view of a frusto-conical pin in accordance with at least one embodiment of the present disclosure. [Figure 13] FIG. 1 is a perspective view of a semi-cylindrical pin in accordance with at least one embodiment of the present disclosure. [Figure 14] FIG. 13 is a side view of an input shaft interface illustrating rotational timing of actuation in accordance with at least one embodiment of the present disclosure. [Figure 15] FIG. 15-1 is a side view of an input shaft interface showing a tilt plate-like actuator mechanism according to at least one embodiment of the present disclosure, and FIG. 15-2 is a radial view of the input shaft interface of FIG. 15-1 according to at least one embodiment of the present disclosure. [Figure 16] FIG. 2 is a detailed view of a power transmission chain for use in any of the systems described herein, in accordance with at least one embodiment of the present disclosure. [Figure 17]FIG. 16 is a side view of a system including the power transmission chain of FIG. 15 in accordance with at least one embodiment of the present disclosure. [Figure 18] FIG. 1 is a perspective view of a drivetrain in accordance with at least one embodiment of the present disclosure. [Figure 19] FIG. 19-1 is a side view of the chain belt of FIG. 18 according to at least one embodiment of the present disclosure, and FIG. 19-2 is an end view of the chain belt of FIG. 19-1 according to at least one embodiment of the present disclosure. [Figure 20] FIG. 13 illustrates another chain belt contacting multiple pins in accordance with at least one embodiment of the present disclosure. [Figure 21] FIG. 21-1 is a side view of a high-definition input interface with a first engagement profile according to at least one embodiment of the present disclosure, FIG. 21-2 is a side view of the high-definition input interface of FIG. 21-1 with a second engagement profile according to at least one embodiment of the present disclosure, and FIG. 21-3 is a side view of the high-definition input interface of FIG. 21-1 with a third engagement profile according to at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] This disclosure relates generally to drivetrains including chains or cables for transmitting power from an input shaft to an output shaft. More particularly, this disclosure relates primarily or exclusively to pedal-powered and / or human-powered bicycle drivetrains, although drivetrain systems according to this disclosure may also be applied to electric or conventional internal combustion engine (ICE) drivetrains in various vehicles or devices.

[0010] FIG 1 is a perspective view of a bicycle 100. The bicycle 100 includes a drivetrain 102 that converts input torque about an input shaft 104 connected to crank arms 106 and pedals 108 to output torque about an output shaft 110 connected to a rear wheel 112. FIG 2 is a side view of the bicycle 100 of FIG 1. The drivetrain 102 includes an input interface 114 that connects the input shaft 104 to a belt 116, which is connected to an output interface 118 that is connected to the output shaft 110.

[0011] In some embodiments, a drivetrain according to the present disclosure transmits power from an input shaft to an output shaft at a variable ratio. With reference to FIG. 3, a drivetrain 102 according to some embodiments of the present disclosure includes an input shaft 104 and an output shaft 110 connected by a belt 116. The belt 116 transmits torque applied to the input shaft 104 through the belt 116 to the output shaft 110. In some embodiments, the input shaft 104 is a crankset, such as a bicycle or other pedal-driven device. In some embodiments, the input shaft 104 is a crankshaft, such as a motorcycle or other motor-driven device. In some embodiments, the output shaft 110 is a drive axle, such as a bicycle or other wheeled vehicle. In some embodiments, the output shaft 110 is another drive shaft, such as a propeller or other rotating device. In some embodiments, the output shaft 110 of the drivetrain 102 is an input shaft for another system or device. Drivetrain 102 allows for a variable ratio and provides a mechanical gain or translation between an input torque and speed at an input shaft 104 and an output torque and speed at an output shaft 110 .

[0012] FIG. 3 illustrates a drivetrain 102 with a large ratio between the input and output interfaces. The drive ratio is determined by the ratio of the input radius of the input interface 114 to the output radius of the output interface 118. In some embodiments, the input interface 114 or the output interface 118 is of a fixed radius, such as a single gear. In some embodiments, either the input interface 114 or the output interface 118 includes a conventional derailleur, and the other interface includes multiple pins to provide a variable radius, as described herein. In the embodiment illustrated in FIG. 3, both the input interface 114 and the output interface 118 are variable radius interfaces using concentrically arranged pins 120. The shaded pins in the illustrated embodiment indicate actuated pins that engage between the first and second supports to interact with the belt 116.

[0013] In some embodiments, each of the concentric rings of the interface is actuable independently of the other rings. In some embodiments, the interface actuates all of the pins 120 inside the outermost actuation ring (i.e., closer to the axis of the interface). For example, in FIG. 3, the outermost ring of the input interface 114 is actuated, so all of the rings and all of the pins 120 of the input interface 114 are actuated. The output interface 118 has the second ring as its outermost actuation ring (in a radially outward direction from the axis), so the pins 120 of the second ring and the first ring are actuated, and the rings outside the second ring (the third, fourth, and fifth rings) are not actuated.

[0014] The pins 120 can be actuated directly or indirectly via one or more actuator mechanisms. In some embodiments, the pins 120 can be actuated individually. In some embodiments, the pins 120 can be actuated in batches of two or more, for example, the entire ring can be actuated simultaneously or substantially simultaneously. Substantially simultaneously means that the entire ring is actuated within one revolution of the ring about its axis.

[0015] FIG. 4 illustrates the drivetrain 102 of FIG. 3 with a reduced input radius. In some embodiments, the drivetrain 102 according to the present disclosure includes a variable radius input interface 114 between the input shaft 104 and the belt 116. Changing the input radius between the input shaft 104 and the belt 116 changes the linear velocity of the belt 116 and the force applied to the belt 116. The variable radius input interface 114 can change the radius in discrete steps by actuating a number of pins 120 arranged in concentric circles around the input shaft 104. The concentric circles are arranged at equal radial intervals, and the pins 120 of each ring are arranged at equal rotational intervals. In other words, the spacing between each pin 120 remains the same even as the radius of the input interface 114 is changed by actuating a pin 120 or a ring of pins 120.

[0016] In various embodiments, the pins 120 are actuated by one or more mechanical, electromechanical, magnetic, hydraulic, or pneumatic actuators, or combinations thereof. By actuating the pins 120 axially of the input shaft 104 and transversely to both the tension of the belt 116 and the radial direction of the input shaft 104, the pins 120 can transmit forces between the input interface 114 and the belt 116 without the actuator mechanism having to bear the transmitted forces.

[0017] FIG. 5 illustrates the drivetrain 102 of FIG. 3 with an increased output radius. In some embodiments, the drivetrain 102 according to the present disclosure includes a variable radius output interface 118 between the output shaft 110 and the belt 116. Changing the output radius between the output shaft 110 and the belt 116 changes the angular velocity of the output shaft 110 relative to the linear velocity of the belt 116 and the force that the belt 116 applies to the output shaft 110. The variable radius output interface 118 can change the radius in discrete steps by actuating a number of pins 120 arranged in concentric circles around the output shaft 110. The concentric circles are arranged at equal radial intervals, and the pins 120 of each ring are arranged at equal rotational intervals. In other words, the spacing between each pin 120 remains the same even as the radius of the output interface 118 is changed by actuating the pins 120 or the ring of pins 120.

[0018] In various embodiments, the pins 120 are actuated by one or more mechanical, electromechanical, magnetic, hydraulic, or pneumatic actuators, or combinations thereof. By actuating the pins 120 axially of the output shaft 110 and transversely to both the tension of the belt 116 and the radial direction of the output shaft 110, the pins 120 can transmit forces between the belt 116 and the output interface 118 without the actuator mechanism having to withstand the transmitted forces. In at least one embodiment, the drivetrain 102 includes both a variable radius input interface 114 and a variable radius output interface 118.

[0019] Thus, the ratio of the drivetrain 102 shown in FIG. 3 is high ratio since the input radius is larger than the output radius. FIG. 4 shows the embodiment of FIG. 3 in which the gear ratio is reduced by deactivating the rings of the input interface 114 (i.e., leaving the rings engaged or returning the rings to a deactivated state) to reduce the input radius. The output radius is constant, resulting in a lower drive ratio than the drivetrain 102 of FIG. 3. Similarly, FIG. 5 shows an embodiment of the drivetrain 102 of FIG. 3 in which all rings and pins are activated at both the input interface 114 and the output interface 118, resulting in equal input and output radii. In other words, the embodiment shown in FIG. 5 shows a 1:1 drive ratio. In some embodiments, the drivetrain 102 includes a tensioner 121 that provides a force to the belt 116 to maintain tension on the belt 116 as the radii of the input interface 114 and / or the output interface 118 change.

[0020] The belt 116 may include a flexible material, multiple hinged links, or a combination thereof. In some embodiments, the belt 116 is a continuous, endless belt including a flexible material such as rubber or other polymers, and is a continuous flexible belt. In some embodiments, the belt 116 is a continuous, endless chain including a series of rigid links movably connected to one another, such as, but not limited to, a conventional bicycle chain. In some embodiments, the belt 116 includes rigid links with flexible members between them, allowing the rigid links to move relative to one another.

[0021] The belt 116 may include a number of engagement features. The engagement features 122 may include protrusions, recesses, teeth, ridges, grooves, or other features on or in the surface of the belt, or features through the belt, such as holes. The engagement features 122 mechanically interface with complementary features of the input interface 114 and / or the output interface 118, such as the pins 120 described herein. For example, the belt 116 may include teeth protruding from an inner surface of the belt 116 to engage and / or fit between the pins 120 of the interface. In some embodiments, the belt 116 includes one or more longitudinal grooves that mate with or interact with grooves on the pins 120 to help keep the belt 116 longitudinally aligned with the drivetrain 102.

[0022] In some embodiments, the belt 116 is smooth on at least the longitudinal direction of its inner surface. The belt 116 can transmit forces between the input and / or output shafts and the belt by frictional engagement with the pins 120. The belt 116 can include a layer or coating on its inner surface that provides elastic and / or tensile strength to the belt 116 and has a higher coefficient of friction than the material of the belt body. In other examples, the belt 116 can be a rubber material that provides a relatively high coefficient of friction, while being reinforced with an internal material, such as a steel braid, to limit and / or prevent stretching of the belt 116 under load.

[0023] The drivetrain 102, and in particular the interface 114, 118 with the actuable pin 120, of the present disclosure allows the radius of the interface 114, 118 to be changed without moving the belt 116 laterally relative to the longitudinal direction of the belt 116. This is in contrast to the multiple gears or cogs of a conventional multi-speed bicycle drivetrain, in which the chain moves axially between fixed radius gears that are axially stacked on the crankset or drive axle. At the very end of the cassette, the chain may be cross-loaded or pinched within the drivetrain. Additionally, the cassette requires an increased width of the chainstays and drivetrain compared to drivetrain embodiments described herein. In some embodiments, the drivetrain 102 of the present disclosure may improve the aerodynamics, internal friction, weight, and reliability of the drivetrain compared to conventional systems that include cassettes and derailleurs.

[0024] FIG. 6 is a top view of the input interface 214 according to some embodiments of the present disclosure. Although the input interface 214 is described here, it should be understood that the description herein may also apply to the output interface. The input interface 214 has a fixed chain line. This means that the chain or other belt (not shown in FIG. 6) does not deflect laterally (i.e., perpendicular to the direction of the chain or belt while the chain or belt is moving). The ratio is changed by changing the actuator pin 220 inserted into the support of the input interface 214. In some embodiments, the translatable pin 220 is at least partially axially movable between the first support 224 and the second support 226, and when actuated, the pin 220 is supported in contact with both the first support 224 and the second support 226 with the belt 216 positioned between the first support 224 and the second support 226. This allows the first support 224 and the second support 226 to support the pin 220 when there is a load between the interface and the belt. Because the supports 224, 226 can withstand the force, the actuator only needs to move the pin 220 axially (perpendicular to the belt) when there is no load.

[0025] In some embodiments, the pins 220 are individually actuatable, such that at least some of the pins 220 are actuatable independently of the other pins. For example, each pin 220 may include an independent actuator 228 that moves only that pin 220. In other examples, the pins 220 are rotatable relative to the actuator 228 (e.g., about an input axis), such that a single actuator 228 can selectively actuate one or more pins 220.

[0026] In some embodiments, the actuator 228 is a mechanical actuator with one or more gears that move a rod, a ramp, or other surface toward the pin 220. For example, the actuator 228 can move axially to apply a force to the pin 220. In another example, the actuator 228 can have a ramp that moves radially toward or away from the axis of rotation of the shaft. The ramp can contact the pin 220 as the supports 224, 226 and / or the pin 220 rotate about the shaft, and the position of the ramp on the actuator 228 can determine which pin 220 the ramp contacts. The contact between the actuator 228 and the pin 220 biases the pin 220 axially toward the axis of rotation of the shaft. In some embodiments, the actuator 228 is electromagnetic, magnetic, pneumatic, hydraulic, or a combination thereof. For example, an electromagnet can selectively push the pin into the support to engage the belt, while a pneumatic cylinder can return the pin to a disengaged state. In another example, a mechanical actuator can selectively push the pin into the support to engage the belt, while a permanent magnet cylinder can return the pin to a disengaged state.

[0027] As shown in Figure 7, some embodiments of the interface 314 use an electromagnetic actuator 328 to apply a repulsive magnetic force to the pin 320 to move it into engagement with the supports 324, 326 and / or belt. In some embodiments, a spring or other biasing element 330 can return the pin 320 to a disengaged state. In some embodiments, as illustrated in Figure 8, an interface 414 according to the present disclosure can use a pneumatic actuator 428 to apply a mechanical force to the pin 420 to move it into engagement with the supports 424, 426 and / or belt, after which a spring or other biasing element 430 can return the pin 420 to a disengaged state.

[0028] The pins may have a variety of shapes to provide reliable actuation and efficient power transfer. FIG. 9 illustrates a first embodiment of a pin 420 according to the present disclosure. In some embodiments, the pin 420 is substantially cylindrical. For example, the pin 420 may be cylindrical across a contact portion 432 where the belt contacts the pin 420 when the pin 420 is actuated to engage the belt. In some embodiments, the cylindrical contact portion 432 may provide efficient power transfer from the pin to the belt or from the belt to the pin.

[0029] The tip 434 of the pin 420 can be rounded or pointed to ensure actuation through the first and / or second supports of the interface. For example, if the pin 420 is bent or not fully actuated before the belt contacts it, the tip 434 may become misaligned with respect to the hole in the support into which it is intended to be inserted. The rounded or pointed tip 434 allows the misaligned pin to enter the hole in the support and engage both the first and second supports to efficiently transfer power to and from the belt.

[0030] In some embodiments, such as illustrated in FIG. 10, the pin 520 has a tapered contact portion 532. The tapered contact portion 532 exerts a lateral force on the belt that urges the belt axially along the contact portion 532, keeping the belt in contact with the support and reducing belt vibration. Because belt vibration is a potential energy loss, keeping the belt in contact with the first support or the second support can more efficiently transfer power from the input shaft to the output shaft. In some embodiments, such as illustrated in FIG. 11, the pin 620 is conical with a tapered contact portion 632 and a pointed tip 634. In some embodiments, such as illustrated in FIG. 12, the pin is frustum-shaped with a tapered contact portion 732 and a blunt tip 734.

[0031] In some embodiments, the pins are rotationally symmetric about the pin axis, allowing the pins to rotate relative to the support without affecting the performance of the drivetrain. In some embodiments, the pins are rotationally fixed relative to the support. Some embodiments of pins according to the present disclosure may be semi-cylindrical for weight reduction, since only the radially outer surface of the pin relative to the axis of rotation of the support contacts the belt. Referring to FIG. 13, a semi-cylindrical pin 820 may have a shape with a portion of the contact portion 832 and / or tip 834 removed relative to the rotationally symmetric design of FIGS. 9-12. A semi-cylindrical pin may provide a similar contact surface for the belt to transmit power while reducing the overall mass of the drivetrain, particularly the rotational mass.

[0032] In some embodiments, multiple pins are actuated simultaneously. For example, a collective actuation can actuate an entire ring (e.g., multiple pins with equal radii from the axis of rotation) simultaneously. In other examples, collective actuation can actuate all pins in a ring (e.g., all pins within a radius from the axis of rotation) simultaneously. In some embodiments, the pins remain actuated throughout the rotation of the interface, such as while the rider is pedaling the bicycle. In some embodiments, the pins are actuated only for a portion of the rotational length (e.g., the arc length of the ring that is currently engaged with the belt). For example, each interface (input and output interfaces) of the drivetrain only engages the belt over about 50% of the interface area. At high ratios, the percentage of belt contact can be around 50%. The pins can be actuated only in a portion of the belt path where the belt contacts the interface. In some embodiments, the pins engage less than the entire circumference of the actuation ring in at least a portion of the belt path where the belt engages the interface.

[0033] 14 illustrates an input interface 914 with the belt 916 contacting the transmission portion 936 of the outer ring of the pins 920 of the interface 914 and the belt 916 not contacting the actuation portion 938 of the outer ring. Within the actuation portion 938, the pins 920 of the outer ring or other rings of the interface 914 can be actuated or deactuated to adjust the effective radius of the interface 914. In some embodiments, the transmission portion 936 is at least 40% (e.g., 144°) of the circumference of the actuated outer ring. In some embodiments, the transmission portion 936 is less than 60% (e.g., 216°) of the circumference of the actuated outer ring. Because the pins 920 may experience axial friction while in the transmission portion 936 of the interface 914, it may not be possible to actuate the pins 920 while in the transmission portion 936.

[0034] For example, as illustrated in FIGS. 15-1 and 15-2, the pin can be selectively actuated by contacting a movable ramp 1040 adjacent to the first support. As the pin 1020 rotates about the axis of rotation, the movable ramp 1040 contacts the base of the pin 1020. The ramp surface 1044 of the movable ramp 1040 is a ramp that urges the pin 1020 axially relative to the direction of rotation 1042, moving the pin 1020 from the first support 1024 toward the second support 1026. In some embodiments, the ramp surface 1044 moves the pin 1020 into an engaged position with the first support 1024 and the second support 1026, and the second surface 1046 holds the pin 1020 in the engaged position as it moves through an arcuate path about the axis of rotation. In some embodiments, the angled surface 1044 moves the pin 1020 into an engaged position with the first support 1024 and the second support 1026, and a catch, catch, stop, latch, or other mechanical retention mechanism holds the pin 1020 in the engaged position. For example, the angled surface 1044 can urge the pin 1020 toward the engaged position and a stop on the pin can engage the second support 1026 to hold the pin in the engaged position.

[0035] The pin 1020 can rotate through the rotary motion transmission while the pin in the transmission is actuated and in the engaged position. The power transmission belt 1016 or chain engages the pin 1020 in the transmission until the pin 1020 approaches the rotary motion actuation. In some embodiments, at the start of the actuation, the actuated pin 1020 may be disengaged and / or released and a different pin 1020 may be actuated by a ramp, motor, piston, magnet, etc., as described herein. In some embodiments, the actuated pin 1020 can remain in the engaged position until a ring of another pin is selected by the drive train. For example, a ramp or other engagement mechanism can urge the pin 1020 toward the engaged position, in which case the pin 1020 will remain in the engaged position until the ramp or other engagement mechanism selects a second ring (having a smaller or larger diameter than the currently actuated ring).

[0036] In some embodiments, the angular position of the engagement location 1048 (e.g., the start of the transmission, whether or not the pin remains engaged throughout the rotation) is relative to the transmission axis 1050 between the input and output shafts. It should be appreciated that the engagement location 1048 may change by changing the route of the chain or belt 1016 between the input interface 1014 and the output interface, such as via a driven pulley. In some embodiments, the angle that the engagement location 1048 makes with the transmission axis 1050 between the input and output shafts is approximately 90°. For example, if the selected pins 1020 or gears at the input and output interfaces have equal radii, the angle that the engagement location 1048 makes with the transmission axis 1050 (excluding chain slack) may be 90°. If the radii of the input and / or output interfaces change, the angular position of the engagement location 1048 may change due to the change in the angle of the chain or belt 1016.

[0037] In some embodiments, the angle that the engagement position 1048 of at least one of the input interface and the output interface makes with the transmission shaft 1050 is between 70° and 110°. In some embodiments, the angle that the engagement position 1048 of at least one of the input interface and the output interface makes with the transmission shaft 1050 is between 75° and 105°. In some embodiments, the angle that the engagement position 1048 of at least one of the input interface and the output interface makes with the transmission shaft 1050 is between 80° and 100°.

[0038] In some embodiments, the working area of ​​at least one of the input interface and the output interface is less than 180° of rotational movement of the input interface and the output interface, respectively. In some embodiments, the working area of ​​at least one of the input interface and the output interface is less than 160° of rotational movement of the input interface and the output interface, respectively. In some embodiments, the working area of ​​at least one of the input interface and the output interface is less than 140° of rotational movement of the input interface and the output interface, respectively. In some embodiments, the transmission of the input interface and / or the output interface is the remaining part of the rotational movement.

[0039] A pedal drivetrain according to the present disclosure can enable a single chainline between the input and output interfaces, reducing belt or chain wear and resistance and improving component life and drivetrain efficiency. In some embodiments, a pedal drivetrain according to the present disclosure can reduce weight and / or enable wireless actuation to further improve bicycle performance.

[0040] Because the belt or chain engages with lateral pins rather than radially arranged teeth, it may have different properties and configurations than a conventional bicycle chain. For example, a conventional belt or chain receives gear or cog teeth in openings or recesses between the pins of each link. In some embodiments according to the present disclosure, a bicycle chain for transmitting power between an input shaft and an output shaft includes teeth between the pins of each link that protrude laterally from at least one side of the link.

[0041] FIG. 16 is a side view of a portion of one embodiment of a chain belt 1116 according to the present disclosure. In some embodiments, the chain belt 1116 includes a plurality of outer links 1152 and inner links 1154 connected by hinges 1156. The hinges 1156 may include a pin inserted through the outer link 1152 and the inner link 1154 to connect the outer link 1152 and the inner link 1154 at the rotatable hinge 1156. In some embodiments, the links 1152, 1154 may be connected by press-fitting protrusions into detents. For example, the outer link 1152 may have a protrusion that fits into a detent on the inner link 1154, or the inner link 1154 may have a protrusion that fits into a detent on the outer link 1152.

[0042] In some embodiments, the chain belt 1116 includes a plurality of teeth 1158 for engaging between the pins on the chain belt 1116. FIG. 17 shows the teeth 1158 located on the inner side of the loop formed by the chain belt 1116 around the input and output shafts. The teeth 1158 are disposed longitudinally between the hinged connections of the links 1152, 1154. In some embodiments, each link of the chain belt 1116 includes at least one tooth 1158. In some embodiments, at least one link of the chain belt 1116 includes a plurality of teeth 1158. In some embodiments, at least one link has teeth 1158 on both the inner side 1160 of the chain belt 1116 and the outer side 1162 of the chain belt 1116. For example, some embodiments of a drivetrain according to the present disclosure may include a jockey wheel or idler pulley for directing the chain belt 1116 around the drivetrain while the suspension is moving or shifting. Teeth on both sides 1160, 1162 of the chain belt 1116 allow the chain belt 1116 to engage a jockey wheel or idler pulley and stay on the chain line and / or maintain tension.

[0043] In some embodiments, a flexible continuous belt with inverted teeth or projections can be used to transmit power from an input shaft to an output shaft. For example, a flexible continuous belt can provide a smooth exterior surface with fewer joints, limiting and / or preventing dirt ingress and wear. A flexible continuous belt can provide a smooth exterior surface that is less likely to pinch objects than a hinged chain, as well as improving safety.

[0044] 18 is a perspective view of another embodiment of a drive train 1200 according to the present disclosure. In FIG. 18, the drive train 1200 is shown with the pins 1220 of the input interface 1214 and the output interface 1218 disengaged, however, any number or combination of pins 1220 may be engaged to adjust the drive ratio between the input interface 1214 and the output interface 1218. In some embodiments, the chain belt 1216 includes a plurality of links 1252, 1254 that contact and engage the pins 1220 of the interfaces 1214, 1218. Each of the plurality of outer links 1252 and inner links 1254 has a recess 1222 located between the connecting hinges 1256.

[0045] The recess 1222 is positioned to allow the pin 1220 to engage the link between the hinge 1256. For example, FIG. 19-1 shows a portion of the chain belt 1216 of FIG. 18. The outer link 1252 and the inner link 1254 are curved or arched to form a recess 1222 into which the pin 1220 fits. The hinge 1256 and the pin 1220 are aligned along the chain axis 1264 with the center of the pin 1220 located between the center of the hinge 1256. Aligning the pin 1220 with the hinge 1256 allows for more efficient power transfer between the interface and the chain belt 1216. Additionally, alignment of the pin 1220 with the hinge 1256 reduces wear on the chain belt 1216 because the force applied by the pin 1220 is aligned with the connection between the links 1252, 1254. To further align the chain belt at the interface, at least the outer link 1252 may taper from the outer surface 1262 to the inner surface 1260 as shown in FIG. 19-2. This taper may contact the first support 1224 and / or the outer guard 1226 to center the outer link 1252.

[0046] Reference is now made to Figure 20. Although the pins are described herein as round in shape, in some embodiments, the pins 1320 of the input and / or output interfaces may have other cross-sectional shapes, such as triangular, square, rectangular, oval, pentagonal, other regular polygonal, irregular polygonal, irregular curved shapes, or combinations thereof. The recesses 1322 and the pins 1320 may be complementary in shape to efficiently transfer power between the pins 1320 of the input and / or output interfaces and the links 1352, 1354.

[0047] In other embodiments, the high definition input interface and / or output interface includes a dense array 1466 of pins 1420, as shown in Figures 21-1, 21-2, and 21-3. The input interface 1414 includes a high density of pins 1420, such as less than 2.0 mm, less than 1.5 mm, or less than 1.0 mm in diameter. The array 1466 of pins 1420 is arranged such that the various engagement profiles 1468-1, 1468-2, 1468-3 can interact with a belt, such as a flexible belt or a chain belt as described herein. In some embodiments, the array 1466 of pins allows for a first engagement profile 1466-1 with a plurality of protrusions 1470 shaped complementary to recesses in the belt. The high definition array 1466 allows for the formation of various engagement profiles with different radii, allowing for a substantially continuously variable drive ratio for the input interface 1414 and / or the output interface. In some embodiments, the high definition array 1466 is altered in response to measurements from a torque sensor in the crank or input interface 1414. For example, the high definition array 1466 can alter the engagement profiles 1468-1, 1468-2, 1468-3 to compensate for variations in the user's input torque throughout the pedal stroke.

[0048] For example, FIG. 21-2 illustrates the input interface 1414 of FIG. 21-1 with a second engagement profile 1468-2. The second engagement profile 1468-2 has an elliptical profile and allows the input interface 1414 to vary the torque applied to the input shaft 1404 based on the position of the pedal in the rider's stroke. For example, when the crank arms are horizontal to the ground, the rider can apply a large force to the crank set, but when the crank arms are perpendicular to the ground, the rider can apply a small force to the crank set. The elliptical second engagement profile 1468-2 allows the torque applied to the input shaft 1404 to be varied by changing the lever arm to which the force is applied.

[0049] In other examples, the engagement profile has other shapes besides circular, for example, FIG. 21-3 shows the input interface 1414 of FIG. 21-1 with a third engagement profile 1468-3. The third engagement profile 1468-3 is circular about the input shaft 1404, but is eccentric. Again, because the force applied to the crankset by the rider's pedaling stroke may vary throughout the stroke, the eccentric third engagement profile 1468-3 can vary the torque applied to the input shaft 1404 by changing the lever arm to which the force is applied. [Industrial Applicability]

[0050] This disclosure relates generally to drivetrains including chains or cables for transmitting power from an input shaft to an output shaft. More particularly, this disclosure relates primarily or exclusively to pedal and / or human-powered bicycle drivetrains, although drivetrain systems according to this disclosure may also be applied to electric or conventional internal combustion engine (ICE) drivetrains in various vehicles or devices.

[0051] In some embodiments, the bicycle includes a drivetrain that converts an input torque about an input shaft connected to the crank arms and pedals to an output torque about an output shaft connected to the rear wheel, the drivetrain including an input interface connecting the input shaft to a belt, the belt connected to an output interface that is connected to the output shaft.

[0052] In some embodiments, a drivetrain according to the present disclosure transmits power from an input shaft to an output shaft at a variable ratio. A drivetrain according to some embodiments of the present disclosure includes an input shaft and an output shaft connected by a belt. The belt transmits torque applied to the input shaft through the belt and applies torque to the output shaft. In some embodiments, the input shaft is a crankset, such as a bicycle or other pedal-driven device. In some embodiments, the input shaft is a crankshaft, such as a motorcycle or other motor-driven device. In some embodiments, the output shaft is a drive axle, such as a bicycle or other wheeled vehicle. In some embodiments, the output shaft is another drive shaft, such as a propeller or other rotating device. In some embodiments, the output shaft of the drivetrain is an input shaft for another system or device. The drivetrain allows for a variable ratio and provides a mechanical gain or conversion between an input torque and speed at the input shaft and an output torque and speed at the output shaft.

[0053] The drive ratio is determined by the ratio of the input radius of the input interface to the output radius of the output interface. In some embodiments, the input interface or the output interface is of fixed radius, such as a single gear. In some embodiments, both the input and output interfaces are variable radius interfaces using concentrically arranged pins. The shaded pins in the illustrated embodiment indicate actuated pins that engage and interact with the belt between the first and second supports.

[0054] In some embodiments, each of the concentric rings of the interface is actuable independently of the other rings. In some embodiments, the interface actuates all pins inside the outermost actuation ring (i.e., closer to the axis of the interface). For example, when the outermost ring of the input interface is actuated, all rings and all pins of the input interface may be actuated. In another example, the output interface has a second ring as the outermost actuation ring (in a radially outward direction from the axis), so that the pins of the second ring and the first ring are actuated and the rings outside the second ring (the third, fourth, and fifth rings) are not actuated.

[0055] The pins can be actuated directly or indirectly via one or more actuator mechanisms. In some embodiments, the pins can be actuated individually. In some embodiments, the pins can be actuated in batches of two or more, for example, the entire ring can be actuated simultaneously or substantially simultaneously. Substantially simultaneously means that the entire ring is actuated within one revolution of the ring about its axis.

[0056] In some embodiments, the drivetrain according to the present disclosure includes a variable radius interface between the input shaft and the belt. Changing the input radius between the input shaft and the belt changes the linear velocity of the belt and the force applied to the belt. The variable radius input interface can change the radius in discrete steps by actuating a number of pins arranged concentrically around the input shaft. In various embodiments, the pins are actuated by one or more mechanical, electromechanical, magnetic, hydraulic, or pneumatic actuators, or combinations thereof. By actuating the pins in the axial direction of the input shaft and in a direction transverse to both the tension of the belt and the radial direction of the input shaft, the pins can transmit forces between the input interface and the belt without the actuator mechanism having to bear the transmitted forces.

[0057] In some embodiments, a drivetrain according to the present disclosure includes a variable radius interface between the output shaft and the belt. Changing the output radius between the output shaft and the belt changes the angular velocity of the output shaft relative to the belt and the force the belt exerts on the output shaft. The variable radius output interface can change the radius in discrete steps by actuating a number of pins arranged concentrically around the output shaft. In various embodiments, the pins are actuated by one or more mechanical, electromechanical, magnetic, hydraulic, or pneumatic actuators, or combinations thereof. By actuating the pins in the axial direction of the output shaft and in a direction transverse to both the tension of the belt and the radial direction of the output shaft, the pins can transmit forces between the belt and the interface without the actuator mechanism having to bear the transmitted forces. In at least one embodiment, the drivetrain includes both a variable radius input interface and a variable radius output interface.

[0058] In some examples, when the input radius is greater than the output radius, the drivetrain has a high ratio. In some examples, when the input radius is reduced by deactivating a ring on the input interface (i.e., leaving the ring engaged or returning the ring to a deactivated state), the drivetrain has a low ratio. Similarly, the input and output radii can be equal if all rings and pins are activated on both the input and output interfaces. In other words, when the input and output rings have the same radius, the drivetrain has a 1:1 drive ratio.

[0059] The belt may comprise a flexible material, multiple hinged links, or a combination thereof. In some embodiments, the belt is a continuous, endless belt comprising a flexible material such as rubber or other polymers, a continuous flexible belt. In some embodiments, the belt is a continuous, endless chain including a series of rigid links movably connected to one another, such as, but not limited to, a conventional bicycle chain. In some embodiments, the belt comprises rigid links with flexible members between them, allowing the rigid links to move relative to one another.

[0060] The belt may include a number of engagement features. The engagement features may include protrusions, recesses, teeth, ridges, grooves, or other features on or at the surface of the belt, or features through the belt, such as holes, that mechanically interlock with complementary features of the interface, such as pins as described herein. For example, the belt may include teeth that protrude from an inner surface of the belt to engage and / or fit between pins of the interface. In some embodiments, the belt includes one or more longitudinal grooves that mate with or interact with grooves on the pins to help keep the belt longitudinally aligned with the drivetrain.

[0061] In some embodiments, the belt is smooth at least along the length of its inner surface. The belt can transmit forces between the input and / or output shafts and the belt by frictional engagement with the pins. The belt can include a layer or coating on its inner surface that provides elastic and / or tensile strength to the belt and has a higher coefficient of friction than the material of the belt body. In other examples, the belt can be a rubber material that provides a relatively high coefficient of friction, while being reinforced with an internal material, such as a steel braid, to limit and / or prevent stretching of the belt under load.

[0062] The drivetrain of the present disclosure, particularly the interface with the actuable pin, allows the radius of the interface to be changed without lateral movement of the belt. This is in contrast to the multiple gears or cogs of a conventional multi-speed bicycle drivetrain, in which the chain moves axially between fixed radius gears that are axially stacked on the crankset or drive axle. At the very end of the cassette (the stack of gears), the chain can be cross-loaded or pinched within the drivetrain. Additionally, the cassette requires an increase in the width of the chainstays and the drivetrain compared to the drivetrain embodiments described herein. In some embodiments, the drivetrain of the present disclosure can improve the aerodynamics, internal friction, weight, and reliability of the drivetrain compared to conventional systems that include a cassette and a derailleur.

[0063] In some embodiments, the input interface has a fixed chain line. This means that the chain or other belt does not deflect laterally (i.e., perpendicular to the direction of the chain or belt while it is moving). The ratio is changed by changing the actuator pin inserted into the support of the input interface. In some embodiments, the translatable pin is at least partially axially movable between the first and second supports, and when actuated, the pin is supported in contact with both the first and second supports with the belt positioned between the first and second supports. This allows the first and second supports to support the pin when there is a load between the interface and the belt. Since the support can withstand the force, the actuator only needs to move the pin axially (perpendicular to the belt) when there is no load.

[0064] In some embodiments, the pins are individually actuatable, with at least some pins being actuatable independently of the other pins. For example, each pin may have an independent actuator that moves only that pin. In other examples, the pins are rotatable (e.g., about an input axis) relative to the actuator, such that a single actuator can selectively actuate one or more pins.

[0065] In some embodiments, the actuator is a mechanical actuator with one or more gears that move a rod, a ramp, or other surface toward the pin. For example, the actuator can move axially to apply a force to the pin. In another example, the actuator can have a ramp that moves radially toward or away from the axis of rotation of the shaft. The ramp can contact the pin as the support and / or pin rotate around the shaft, and the position of the ramp can determine which pin the ramp contacts. Contact between the actuator and the pin biases the pin in the axial direction of the axis of rotation of the shaft. In some embodiments, the actuator is electromagnetic, magnetic, pneumatic, hydraulic, or a combination thereof. For example, an electromagnet can selectively push the pin into the support to engage the belt, while a pneumatic cylinder can return the pin to a disengaged state. In another example, a mechanical actuator can selectively push the pin into the support to engage the belt, while a permanent magnet cylinder returns the pin to a disengaged state.

[0066] In some embodiments, an electromagnetic actuator is used to apply a repulsive magnetic force to the pin to move it into engagement with the support and / or belt. In some embodiments, a spring or other biasing element can return the pin to a disengaged state. In some embodiments, a drivetrain according to the present disclosure uses a pneumatic actuator to apply a mechanical force to the pin to move it into engagement with the support and / or belt, after which a spring or other biasing element can return the pin to a disengaged state.

[0067] The pins may have a variety of shapes to provide reliable actuation and efficient power transfer. In some embodiments, the pins are substantially cylindrical. For example, the pins may be cylindrical across a contact area where the belt contacts the pin when the pin is actuated to engage the belt. In some embodiments, the cylindrical contact area allows for efficient power transfer from the pin to the belt or from the belt to the pin.

[0068] The tips of the pins can be rounded or pointed to ensure actuation through the first and / or second supports of the interface. For example, if the pin is bent or not fully actuated before the belt contacts it, the tip may become misaligned with respect to the hole in the support into which it is intended to be inserted. The rounded or pointed tip allows the misaligned pin to enter the hole in the support and engage both the first and second supports to efficiently transfer power to and from the belt.

[0069] In some embodiments, the pin has a tapered contact portion. The tapered contact portion provides a lateral force to the belt that urges the belt axially along the contact portion, keeping the belt in contact with the support and reducing belt vibration. Because belt vibration is a potential energy loss, keeping the belt in contact with the first support or the second support allows for more efficient power transfer from the input shaft to the output shaft. In some embodiments, the pin is conical with a tapered contact portion and a pointed tip. In some embodiments, the pin is frustum-shaped with a tapered contact portion and a blunt tip.

[0070] In some embodiments, the pins are rotationally symmetric about the pin axis, which allows the pins to rotate relative to the support without affecting the performance of the drivetrain. In some embodiments, the pins are rotationally fixed relative to the support. Some embodiments of pins according to the present disclosure may be semi-cylindrical for weight reduction, since only the radially outer surface of the pin relative to the axis of rotation of the support contacts the belt. In some embodiments, the semi-cylindrical pins may have a shape where a portion of the contact surface and / or tip is removed relative to a rotationally symmetric design. The semi-cylindrical pins may provide a similar contact surface for the belt to transmit power while reducing the overall mass of the drivetrain, especially the rotational mass.

[0071] In some embodiments, multiple pins are actuated simultaneously. For example, a collective actuation can actuate an entire ring (e.g., multiple pins with equal radii from the axis of rotation) simultaneously. In other examples, collective actuation can actuate all pins in a ring (e.g., all pins within a radius from the axis of rotation) simultaneously. In some embodiments, the pins remain actuated throughout the rotation of the interface, such as while a rider is pedaling the bicycle. In some embodiments, the pins are actuated only for a portion of the rotational length of the interface (e.g., the arc length of the ring that is currently engaged with the belt). For example, each interface (input and output interfaces) of the drivetrain may only engage the belt over about 50% of the interface area. At high ratios, the percentage of belt contact may be around 50%. The pins can be actuated only in the portion of the belt path where the belt contacts the interface. In some embodiments, the pins engage less than the entire circumference of the actuation ring in at least a portion of the belt path where the belt engages the interface.

[0072] In some embodiments, within the actuation section, pins of the outer ring or other rings of the interface can be actuated or deactuated to adjust the effective radius of the interface. In some embodiments, the transmission section is at least 40% (e.g., 144°) of the circumference of the actuated outer ring. In some embodiments, the transmission section is less than 60% (e.g., 216°) of the circumference of the actuated outer ring. It may not be possible to actuate the pins while they are in the transmission section of the interface, as the pins may experience axial friction while in the transmission section of the interface.

[0073] For example, the pin can be selectively actuated by contacting a movable ramp (ramp) proximate to the first support. As the pin rotates about the axis of rotation, the movable ramp contacts the base of the pin. The ramp surface of the movable ramp is a ramp that urges the pin laterally relative to the direction of rotation, moving the pin from the first support toward the second support. In some embodiments, the ramp surface moves the pin into an engagement position with the first and second supports, and the second surface holds the pin in the engagement position as the pin moves through an arcuate path about the axis of rotation. In some embodiments, the ramp surface moves the pin into an engagement position with the first and second supports, and a catch, catch, latch, or other mechanical retention mechanism holds the pin in the engagement position. For example, the ramp surface can urge the pin toward the engagement position, and a catch on the pin can engage the second support to hold the pin in the engagement position.

[0074] The pins can rotate through the transmission of the rotary motion while the pins in the transmission are actuated and in the engaged position. A power transmission belt or chain engages the pins in the transmission until the pins approach the actuated part of the rotary motion. In some embodiments, at the start of the actuated part, the actuated pins can be disengaged and / or released to actuate a different pin by a ramp, motor, piston, magnet, etc., as described herein. In some embodiments, the actuated pins can remain in the engaged position until a ring of another pin is selected by the drive train. For example, a ramp or other engagement mechanism can urge the pins toward the engaged position, in which case the pins will remain in the engaged position until the ramp or other engagement mechanism selects a second ring (having a smaller or larger diameter than the currently actuated ring).

[0075] In some embodiments, the angular position of the engagement position (e.g., the start position of the transmission, whether the pin remains engaged throughout the rotation) is relative to the axis between the input and output shafts. It should be understood that the engagement position may change by rerouting the chain or belt between the input and output interfaces, such as via a driven pulley. In some embodiments, the angle that the engagement position makes with the transmission axis between the input and output shafts is approximately 90°. For example, if the selected pins or gears at the input and output interfaces have equal radii, the angle that the engagement position 1048 makes with the transmission axis 1050 (excluding chain slack) may be 90°. If the radii of the input and / or output interfaces change, the angular position of the engagement position may change due to the change in the angle of the chain or belt.

[0076] In some embodiments, the angle between the engagement position of at least one of the input interface and the output interface and the transmission shaft is between 70° and 110°. In some embodiments, the angle between the engagement position of at least one of the input interface and the output interface and the transmission shaft is between 75° and 105°. In some embodiments, the angle between the engagement position of at least one of the input interface and the output interface and the transmission shaft is between 80° and 100°.

[0077] In some embodiments, the working area of ​​at least one of the input interface and the output interface is less than 180° of rotational movement of the input interface and the output interface, respectively. In some embodiments, the working area of ​​at least one of the input interface and the output interface is less than 160° of rotational movement of the input interface and the output interface, respectively. In some embodiments, the working area of ​​at least one of the input interface and the output interface is less than 140° of rotational movement of the input interface and the output interface, respectively. In some embodiments, the transmission of the input interface and / or the output interface is the remaining part of the rotational movement.

[0078] A pedal drivetrain according to the present disclosure can enable a single chainline between the input and output interfaces, reducing belt or chain wear and resistance and improving component life and drivetrain efficiency. In some embodiments, a pedal drivetrain according to the present disclosure can reduce weight and / or enable wireless actuation to further improve bicycle performance.

[0079] Because the belt or chain engages with lateral pins rather than radially arranged teeth, it may have different properties and configurations than a conventional bicycle chain. For example, a conventional belt or chain receives gears or gear teeth in openings or recesses between the pins of each link. In some embodiments according to the present disclosure, a bicycle chain for transmitting power between an input shaft and an output shaft includes teeth between the pins of each link that protrude laterally from at least one side of the link.

[0080] In some embodiments, the chain includes a plurality of outer links and inner links connected by a hinge. The hinge may include a pin inserted through the outer link and the inner link to connect the outer link and the inner link with a rotatable hinge. In some embodiments, the links may be connected by press-fitting a protrusion into a detent. For example, the outer link may have a protrusion that fits into a detent on the inner link, or the inner link may have a protrusion that fits into a detent on the outer link.

[0081] In some embodiments, the chain includes a plurality of teeth for engaging between the pins on the chain. In some embodiments, the teeth are longitudinally disposed between the hinged connections of the links. In some embodiments, each link of the chain includes at least one tooth. In some embodiments, at least one link of the chain includes a plurality of teeth. In some embodiments, at least one link has teeth on both the inner side of the chain and the outer side of the chain. For example, some embodiments of a drivetrain according to the present disclosure may include a jockey wheel or idler pulley for directing the chain around the drivetrain while the suspension is moving or shifting. Teeth on both sides of the chain allow the chain to engage the jockey wheel or idler pulley and stay on the chainline and / or maintain tension.

[0082] In some embodiments, a flexible belt with inverted teeth or projections can be used to transmit power from the input shaft to the output shaft. For example, the flexible belt can provide a smooth exterior surface with fewer connection points, limiting and / or preventing dirt ingress and wear. The flexible belt can provide a smooth exterior surface, making it less likely for objects to get caught in the belt than a hinged chain, as well as improving safety.

[0083] In some embodiments, the chain belt includes a plurality of links that contact and engage the pins of the interface, the plurality of outer links and the inner links each having a recess located between the connecting hinges.

[0084] The recess is positioned to allow the pin to engage the link between the hinge. The outer link and the inner link may be curved or arcuate with a recess formed therein for the pin to fit into. The hinge and pin are aligned along the chain axis with the center of the pin located between the centers of the hinge. Aligning the pin and hinge may allow for more efficient power transfer between the interface and the chain belt. Additionally, alignment of the pin and hinge may reduce wear on the chain belt since the force applied by the pin is aligned with the connection between the links. To further align the chain belt at the interface, at least the outer link may be tapered from the outer surface to the inner surface. This tapered portion may contact the first support and / or the outer guard to center the outer link.

[0085] Although the pins are described herein as round in shape, in some embodiments the pins of the input and / or output interfaces may have other cross-sectional shapes, such as triangular, square, rectangular, oval, pentagonal, other regular polygonal, irregular polygonal, irregular curved shapes, or combinations thereof. The recesses and pins may be complementary in shape to efficiently transfer power between the pins of the input and / or output interfaces and the links.

[0086] In other embodiments, the high definition input interface and / or output interface includes a dense array of pins. The input interface includes a high density of pins, such as pins with diameters of less than 2.0 mm, less than 1.5 mm, or less than 1.0 mm. The array of pins is arranged to allow a variety of engagement profiles to interact with a belt, such as a flexible belt or a chain belt as described herein. In some embodiments, the array of pins allows for a first engagement profile with a plurality of protrusions shaped complementary to recesses in the belt. The high definition array allows for the formation of a variety of engagement profiles with different radii, allowing for a substantially continuously variable drive ratio for the input interface and / or output interface.

[0087] The second engagement profile can have an elliptical profile and allows the input interface to vary the torque applied to the input shaft based on the position of the pedal in the rider's stroke. For example, when the crank arms are horizontal to the ground, the rider can apply a large force to the crankset, but when the crank arms are perpendicular to the ground, the rider can apply a small force to the crankset. The elliptical second engagement profile can vary the torque applied to the input shaft by changing the lever arm to which the force is applied.

[0088] In other examples, the engagement profile has a shape other than circular. The third engagement profile may be circular about the input shaft, but is eccentric. Again, because the force applied to the crankset by the rider's pedaling stroke may vary throughout the stroke, an eccentric third engagement profile may vary the torque applied to the input shaft by changing the lever arm to which the force is applied.

[0089] The articles "a," "an," and "the" are intended to mean that there is one or more of the elements in the preceding description. The terms "comprising," "including," and "having" are used in an inclusive sense to mean that there may be additional elements other than the listed elements. Furthermore, it should be understood that references to "an embodiment" or "embodiments" in this disclosure are not intended to be interpreted as excluding the existence of additional embodiments incorporating the described features. For example, elements described in connection with an embodiment described herein can be combined with elements of any other embodiment described herein. Any numerical value, percentage, ratio, or other value described herein is intended to include that value, and values ​​that are "about" or "approximately" the described value, as would be understood by one of ordinary skill in the art to be included in the embodiments of the present disclosure. Thus, the specified value should be interpreted broadly enough to encompass values ​​that are at least sufficiently close to the specified value to perform the desired function or achieve the desired result. The specified value includes at least the expected variation of a reasonable manufacturing or production process, and may include values ​​within 5%, 1%, 0.1%, or 0.01% of the specified value.

[0090] Those skilled in the art will appreciate from this disclosure that equivalent structures do not depart from the spirit and scope of the disclosure, and that various changes, substitutions, and modifications can be made to the embodiments disclosed herein without departing from the spirit and scope of the disclosure. Equivalent structures, including functional "means-plus-function" clauses, are intended to cover structures described herein as performing the described functions, including both structural equivalents that operate in the same manner, and equivalent structures that provide the same function. It is the express intent of the applicants not to apply means-plus-function or other functional claims to any claim, except where the word "means" appears with the relevant function. Additions, deletions, and modifications to the embodiments that come within the meaning and scope of the claims are intended to be included within the scope of the claims.

[0091] It should be understood that the orientations or frames of reference in the foregoing description are purely relative orientations or movements. For example, the terms "front" and "back", "up" and "down", "left" and "right" are merely intended to describe the relative positions or movements of the associated elements.

[0092] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are illustrative and should not be considered limiting. The scope of the present disclosure is therefore indicated by the appended claims, rather than the above description. All changes that come within the meaning and range of equivalency of the claims are encompassed within their scope.

Claims

1. An input interface; An output interface; a power transmission belt engaging the input interface and the output interface to transmit force from the input interface to the output interface; A pedal drivetrain, wherein at least one of the input interface and the output interface includes a plurality of moveable pins that engage the power transmission belt.

2. The pedal drive train according to claim 1 , wherein the plurality of movable pins are arranged in a plurality of concentric circles around the rotation axis.

3. the first concentric ring has a first radius and a first inter-pin rotational spacing; the second concentric ring has a second radius and a second inter-pin rotational spacing; 3. The pedal drivetrain of claim 2, wherein the first radius and the second radius are different and the first inter-pin rotational spacing and the second inter-pin rotational spacing are equal.

4. The pedal drivetrain of claim 1 , further comprising an actuator for moving at least one of the plurality of movable pins from a disengaged state to an engaged state.

5. The pedal drivetrain of claim 4 , wherein the actuator is a mechanical actuator.

6. The pedal drivetrain of claim 4 , wherein the actuator is an electromagnetic actuator.

7. The pedal drivetrain of claim 4 , wherein the actuator is a pneumatic actuator.

8. The pedal drivetrain of claim 4 , wherein the actuator includes an angled surface that contacts and moves the at least one pin.

9. The pedal drivetrain of claim 1 , wherein at least one of the input interface and the output interface includes a first support and a second support.

10. 9. The pedal drivetrain of claim 8, wherein at least one pin of the plurality of pins is movable between an engaged state and a disengaged state, and in the engaged state, the at least one pin is positioned through the first support and the second support.

11. The pedal drivetrain of claim 1 , wherein at least one of the plurality of movable pins has a tapered contact portion.

12. The pedal drivetrain of claim 1 , wherein at least one of the plurality of movable pins has a rounded tip.

13. The pedal drivetrain of claim 1 , wherein at least one of the plurality of movable pins has an engagement mechanism that holds the at least one pin in an engaged state.

14. The pedal drivetrain of claim 1 , wherein the power transmission belt includes a plurality of links.

15. An input interface; An output interface; a power transmission belt engaging the input interface and the output interface to transmit force from the input interface to the output interface; A pedal drivetrain, wherein the input interface and the output interface include a plurality of movable pins that engage the power transmission belt, the plurality of movable pins being arranged in a plurality of concentric circles around an axis of rotation.

16. 16. The pedal drivetrain of claim 15, further comprising a belt tensioner that applies a force to the power transmission belt.

17. 16. The pedal drivetrain of claim 15, wherein the power transmission belt is a chain belt including a plurality of links, at least one link including teeth longitudinally between hinge connections.

18. 16. The pedal drivetrain of claim 15, wherein the power transmission belt is a flexible continuous belt.

19. An input interface; a crankset connected to the input interface for transmitting torque from the pedals to the input interface; An output interface; a power transmission belt engaging the input interface and the output interface to transmit force from the input interface to the output interface; A pedal drivetrain, wherein the input interface and the output interface include a plurality of movable pins that engage with the power transmission belt, the plurality of movable pins being arranged in a plurality of concentric circles around a rotation axis.

20. 20. The pedal drivetrain of claim 19, wherein the input interface has a transmission portion and an actuation portion, and the actuator is configured to actuate at least one of the plurality of movable pins when the at least one pin is located in the actuation portion.

Images