Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
  • B62M9/00—Transmissions characterised by use of an endless chain, belt, or the like
  • B62M9/04—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio
  • B62M9/06—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like
  • B62M9/08—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
  • F16H55/32—Friction members
  • F16H55/52—Pulleys or friction discs of adjustable construction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
  • F16H55/32—Friction members
  • F16H55/52—Pulleys or friction discs of adjustable construction
  • F16H55/54—Pulleys or friction discs of adjustable construction of which the bearing parts are radially adjustable
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/02—Gearings for conveying rotary motion by endless flexible members with belts; with V-belts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H9/00—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members
  • F16H9/02—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion
  • F16H9/04—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes
  • F16H9/10—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley provided with radially-actuatable elements carrying the belt
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H9/00—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members
  • F16H9/02—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion
  • F16H9/04—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes
  • F16H9/12—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
  • F16H55/32—Friction members
  • F16H55/52—Pulleys or friction discs of adjustable construction
  • F16H55/56—Pulleys or friction discs of adjustable construction of which the bearing parts are relatively axially adjustable

Definitions

• the present invention generally relates to a transmission system.
• the present invention relates to a transmission system for a belt or pulley driven system.
• the present invention also relates to a pulley which can be used in the transmission system.
• Transmission systems are used in various vehicles to transfer power from a power source to an output, typically to a drive wheel to move the vehicle.
• a power source typically to a drive wheel to move the vehicle.
• One such vehicle which employs a drive train is a bicycle.
• the transmission system of a bicycle is typically in the form of a centrally located chain ring integrating two crank arms.
• a rider engages the crank arms to rotate the chain ring.
• the chain ring is spaced from a rear sprocket but is interconnected using a chain which spans between the chain ring and the sprocket.
• the rear sprocket is secured to the axle of the rear wheel of the bicycle such that as the rear sprocket rotates the rear wheel will simultaneously rotate.
• the transmission system of a bicycle will typically further comprise a gearing system to enable a rider to manipulate the effect the rotational force of the chain ring has on the rear wheel.
• This gear system general comprises a plurality of co-axially mounted rear sprockets of different diameter and a plurality of co-axially mounted chain rings (usually two or three) of different diameter.
• By activating a gear mechanism the rider can cause the chain to move to different sprockets or chain rings, enabling the rider to choose the gear ratio which best suits the conditions.
• Current drivetrains do, however, present disadvantages. This is particularly relevant to the field of competitive racing where a simple breakdown of equipment or inefficient gearing can cost the rider the race, or where a small reduction in bicycle weight can result in a win.
• a large gearing range is used for relatively flat terrain but inevitably leads to undesirable limitations when sections of the predominantly flat terrain lead uphill at a notable gradient, as these cannot be ridden with the preferred small gearing. This in turn leads to rider fatigue and a competitive disadvantage.
• a small gearing range is used for relatively steep uphill terrain but leads to undesirable limitations when riding downhill as large gearing to facilitate pedalling downhill at high speeds is not available. This leads to lower than possible speeds and hence a competitive disadvantage.
• Chain driven derailleur systems also feature inherent discontinuous securing when changing chain rings which result in the need to simultaneously change sprockets. This compounds the loss of momentum problem. It also presents a significant challenge to fatigued riders and frequently leads to inefficient riding.
• a second major issue for chain driven derailleur systems is that the process of changing gears results in a temporary loss of power transmission for the time it takes the chain to relocate from one chain ring or sprocket to another one. This results in notable loss of rider energy in particular when riding uphill at steep gradient, as the resulting loss of momentum during gear change requires additional effort to bring the bicycle back to the speed before the gear change. It also leads to a time delay in the opportunity to respond to another rider's sprint during a race situation, all of which constitutes a competitive disadvantage and may make the difference between winning or not winning a road race.
• Chain and derailleur driven bicycle drive trains have been refined over several decades but still feature unavoidable weight in their components, particularly the chain itself which can only practically be manufactured from heavy steel.
• Chain driven derailleur systems are sensitive to physical shocks to the bike, lack of mechanical calibration quality or other misalignment, componentry mismatch, and lack of sensible rider operation. If any of the above exceeds the limitation of their operational design, the chain will come off the chain ring or the sprocket and, in the worst case, the chain can break. Chain derailment is common in recreational cycling and even regularly occurs during professional road racing even though great care is taken to provide equipment in peak condition. Other mechanical failures for conventional chain drives include blockage of some of the gear ratios by dirt ingress or ice formation.
• Chain driven derailleur and also hub planetary gearing systems are subject to high wear rates between the two metallic surfaces interacting, i.e. either the steel chain and the teeth on a sprocket or chain ring, or the planetary gear sprockets in a hub. This reduces part life cycles and means the entire drive train needs regular replacement in order to provide efficient power transfer.
• 'cable' is used to describe a rope, a belt, a chain, webbing or any other rope-like device which may be used to assist in transmitting force from a pulley to another object.
• 'cable' can denote a single unitary cable, or a cable made from many smaller cables entwined or joined in an end to end arrangement.
• the present invention provides a transmission system, the transmission system comprising a first pulley and an output which is spaced therefrom, a cable extends between the first pulley and the output such that movement of the first pulley causes rotation of the output, the first pulley comprising: a first side assembly spaced from a second side assembly, the first side assembly and second side assembly are co-axially mounted and rotatably fixed together; a variable annular recess defined between the first side assembly and the second side assembly, the annular recess being adapted to receive the cable to support the first pulley at a first diameter; each of the first side assembly and the second side assembly comprising at least one ring, the at least one ring being laterally movable between a first position and a second position, the first position being spaced outwardly from the second position, the at least one ring being adapted to engage the cable wherein when the at least one ring of each side assembly is in the second position the cable is supported at a second diameter.
• the present invention further provides a transmission system, the transmission system comprising a first pulley and an output which is spaced therefrom, a cable extends between the first pulley and the output such that movement of the first pulley causes rotation of the output, the first pulley comprising: a first side assembly and a second side assembly spaced from each other, the first side assembly and second side assembly are co-axially mounted and rotatably fixed together; an annular recess between the first side assembly and second side assembly, the annular recess being adapted to receive the cable such that the cable is supported by the first pulley at a first diameter; each of the first side assembly and second side assembly comprising at least one ring, the at least one ring being laterally movable between at least a first position and a second position, the second position being spaced inwardly from the first position, the at least one ring being adapted to engage the cable wherein when the at least one ring of each side assembly is in the second position the cable is supported by the first pulle
• the first side assembly may be connected to the second side assembly.
• each of the at least one rings is in the first position the cable is supported by the first pulley at the first diameter.
• the first diameter is defined by the at least one ring of each of the first side assembly and second side assembly when in the first position.
• the cable is supported at a constantly increasing diameter.
• the cable is supported at a constantly decreasing diameter.
• the at least one ring has a plurality of projections extending laterally from the ring in a generally central direction. That is to say the projections extend towards a central plane of the first pulley wherein the central plane is substantially perpendicular to the pulleys axis of rotation.
• the plurality of projections may be spaced around the ring.
• Each projection may provide a supporting surface which is adapted to engage the cable.
• the projections of the at least one ring of the first side assembly are offset from the projections of the at least one ring of the second side assembly wherein movement of each of the at least one rings to the second position causes the projections of one ring to be received between the projections of the other ring.
• the rings effectively mesh together to provide a continuous groove/recess for supporting the cable.
• each of the first side assembly and second side assembly comprising a plurality of rings wherein the rings on the first side assembly are different diameters, and the rings on the second side assembly are different diameters, and the rings on the second side assembly have a corresponding ring on the first side assembly wherein corresponding rings move between at least a first position and a second position, the second position being spaced inwardly from the first position, corresponding rings being adapted to engage the cable wherein when the corresponding rings are in the second position the cable is supported by the first pulley at a different diameter to the diameter defined by the adjacent corresponding rings.
• the cable may connect the first pulley and the output.
• the cable may extend between the first pulley and the output such that the cable loops partially around the pulley and partially around the output.
• the cable may be in the form of a continuous belt which frictionally engages the first pulley.
• the cross section of the belt may be V-shaped, and may be truncated.
• the belt may comprise a plurality of wedge shaped segments depending from a belt portion.
• the cross sectional profile of the belt changes between a tensioned state wherein the profile represents a narrow V-shape, and a relaxed state wherein the profile represents a broader V-shape.
• the belt may adopt the tensioned state when it spans between the pulley and the output.
• the belt may adopt the relaxed state when the belt engages the pulley and when the belt engages the output.
• the broader V-cross section presents a greater surface area to engage the annular recess of the pulley, and the output.
• the V-shape complements the annular recess.
• the narrower V- shape presents a reduced surface area such that the cross section is narrower than the cross section of the annular recess.
• the ratio of the friction between the belt and the pulley in the belt driving direction to the friction between the belt and the pulley in a direction at or near normal to the driving direction is as high as possible, being higher than 1 :1 , in that the driving direction friction is lower than the normal friction.
• friction between the belt and the pulley in the belt driven direction is high, and the friction between the belt and the pulley in a direction normal to the driven direction is low, power transmission is possible without belt slip. It also allows for feasible and practical shifting of gearing that otherwise would have to cope with high forces to overcome non-drive directional friction between belt and pulley.
• the surface of the belt and/or the surface of the pulley may comprise surface irregularities such as projections and/or knurls, to increase friction between the belt and the pulley.
• the surface of the belt and/or the surface of the pulley may comprise surface irregularities such as projections, knurls, grooves, and/or patterns to assist in increasing the ratio of the friction between the belt and the pulley in the belt driving direction to the friction between the belt and the pulley in a direction at or near normal to the driving direction.
• the cable may be in the form of a composite material.
• the cable may have a core.
• the core may be formed from a non-yielding material such as carbon fibre. While the core is flexible the length of the core, once formed into the belt, does not change.
• the output is in the form of a second pulley.
• the second pulley may be a smaller, or larger, version of the first pulley.
• the second pulley may comprise a first side assembly and a second side assembly spaced from each other, the first side assembly being connected to the second side assembly such that the first side assembly and second side assembly are co-axially mounted.
• each of the first side assembly and second side assembly of the second pulley comprise at least one ring,
• the first pulley comprises an activation means to cause movement of the at least one ring of each side assembly between the first position and the second position.
• the first pulley controls the position of the cable, effectively determining the gearing of the transmission system.
• the second pulley reacts to the movement of the at least one ring of each side assembly of the first pulley.
• the second pulley is a passive pulley.
• the at least one ring of each side assembly of the second pulley is preferably biased to its first position.
• the second pulley comprises an activation means to cause movement of the at least one ring of each side assembly between the first position and the second position.
• the second pulley controls the position of the cable, effectively determining the gearing of the transmission system.
• the first pulley reacts to the movement of the at least one ring of each side assembly of the second pulley.
• the activation means may comprise a biasing means wherein the biasing means biases the at least one ring towards the first position.
• the transmission system is arranged such that as the first pulley moves from the first diameter to the second diameter, the second pulley moves from the second diameter to the first diameter.
• the belt As the belt is fixed in length, the belt must move relative to the second pulley in order to compensate for movement of the belt relative to the first pulley. Therefore, as the belt is positioned to rotate about the larger second diameter of the first pulley, the belt is caused to move to rotate about the smaller first diameter of the second pulley or vice versa.
• the present invention provides a transmission system, the transmission system comprising a first pulley connected to an output by a cable such that movement of the first pulley causes rotation of the output, the first pulley comprising: an annular recess between a first side of the first pulley and a second side of the first pulley, the annular recess being adapted to receive the cable such that the cable is supported by the first pulley at a first diameter; at least one pair of rings located in the annular recess, the at least one pair of rings being moveable in a lateral direction relative to the sides of the pulley between a spaced condition, wherein the pair of rings do not engage the cable, and a meshed condition, wherein the pair of rings support the cable at a second diameter, the second diameter being larger than the first diameter.
• the present invention provides a variable diameter pulley, the pulley comprising: an annular recess for receiving a cable such that the cable is supported by the pulley at a first diameter of the pulley; at least one pair of rings located in the annular recess, the at least one pair of rings being moveable in a lateral direction between a spaced condition, wherein the pair of rings do not engage the cable, and a meshed condition, wherein the pair of rings support the cable at a second diameter, the second diameter being larger than the first diameter.
• the present invention provides a variable diameter pulley, the pulley comprising: an annular recess for receiving a cable at a first diameter of the pulley; the annular recess providing a support surface for supporting the cable, the support surface being movable between the first diameter and a second diameter; wherein the support surface is positionable at any diameter between the first diameter and the second diameter.
• the support surface presents a substantially continuous surface to the cable when received on the pulley.
• the cross sectional profile of the support surface may be complementary to the cross sectional shape of that portion of the cable which engages the support surface so that the cable is retained in the annular recess.
• the cable when supported thereon, remains in the same radial plane.
• the support surface is formed from a first set of support surface units and a second set of support surface units.
• the first set of support surface units and the second set of support surface units may mesh together or overlap with each other to form the support surface.
• the first set of support surface units and the second set of support surface units being moveable in a lateral direction between a spaced condition, wherein the cable may be supported at the first diameter, and a meshed condition, wherein the cable may be supported at the second diameter, whereby during movement of the set of support surface units between conditions the cable may be supported on the support surface which is changing diameter.
• Each set of set of support surface units may be arranged so that the support surface units define a plurality of rings.
• Each ring may comprise a hoop from which the support surface units of that ring project.
• Each ring of the plurality of rings of the first set of support surface units has a complementary ring of the plurality of rings of the second set of support surface units, whereby complementary rings are in a staggered relation to each other to provide a ring pair. Meshing of each ring pair provides the support surface.
• Each ring pair may move between a first position and a second position.
• the complementary rings of a ring pair may be spaced away from each other in the axial/lateral direction. In this position the cable cannot be supported by the ring pair.
• the complementary rings of the ring pair may be in the meshed condition to provide the support surface. In this position the cable is supported by the ring pair.
• Each ring pair may move to a third position which is between the first position and the second position.
• the plurality of rings of each set of support surface units may be arranged so that as a ring approaches the second position the adjacent upper/outer ring thereto commences moving towards the second position.
• the plurality of rings of each set of support surface units may be arranged so that as a ring approaches the first position the adjacent lower/inner ring thereto commences its movement towards the first position. [0059] The plurality of rings of each set of support surface units may be arranged so that as a ring of the first set of support surface units approaches the first position the adjacent lower/inner ring of the second set of support surface units moves to the third position.
• the plurality of rings of each set of support surface units may be arranged so that as a ring of the second set of support surface units approaches the first position the adjacent lower/inner ring of the first set of support surface units moves to the third position.
• Each support surface unit may be wedge shaped to provide a sloped surface which engages the cable.
• Each support surface unit of the first ring and last ring may be smaller than the support surface units of adjacent rings therebetween.
• the pulley may comprise a first side housing for housing the plurality of rings of the first set of support surface units.
• the pulley may comprise a second side housing for housing the plurality of rings of the second set of support surface units.
• the first side housing and the second side housing may be co-axially mounted with respect to each other to define the annular recess therebetween.
• the pulley may comprise activation means to cause movement of the ring pairs between the first position and the second position.
• the activation means may cause movement of the ring pairs between the first position, the second position and the third position.
• the activation means may comprise a biasing means wherein the biasing means biases each ring towards the first position.
• the biasing means may be provided by springs or magnets.
• the activation means may also comprise a plurality of actuator arms.
• Each actuator arm may be movable in a radial direction between a first position, central of the pulley and a second position, adjacent the outer diameter of the pulley.
• Each actuator arm may have a head adapted to cause movement of the ring pairs as the actuator arm moves between positions.
• a first set of actuator arms may be supported in recesses in the first side housing. The first set of actuator arms may be spaced radially in a spider web type arrangement.
• a second set of actuator arms may be supported in recesses in the second side housing.
• the second set of actuator arms may be spaced radially in a spider web type arrangement.
• each actuator arm may move to its third position.
• each actuator arm may move back to its first position.
• the activation means may be manually activated or automatically activated.
• the activation means may be activated mechanically as a result of an input force from an operator.
• the activation means may be activated by a motor wherein the motor is adapted to cause movement of the actuator arms.
• the motor may be an electric motor.
• the motor may be located in the pulley or a central hub/spindle between the first side housing and the second side housing.
• the motor may cause rotation of a gear system wherein the set of gears cause movement of the actuator arms.
• the motor may be reversed to cause movement of the actuator arms in the reverse direction.
• the motor may be powered by a power supply.
• the power supply may be located in the bicycle frame, the pulley, the crank arm and/or spindle.
• the power supply may be recharged through a charging socket located on the external surface of the bicycle frame, the pulley or the crank arm.
• the present invention provides a transmission system, the transmission system comprising a variable diameter pulley as herein before described connected to an output by a belt such that movement of the pulley causes rotation of the output, the activating means being activated by a motor wherein the motor is powered by a power supply located within the spatial foot print of the transmission system, such as for example, in the crank arm or inside the spindle.
• the power supply may be recharged through a charging socket, eliminating the need to remove the battery for re-charging.
• Figure 1 is a side view of a front pulley assembly of a transmission system of a bicycle according to a first embodiment of the invention
• Figure 2 is a cross sectional side view of figure 1 taken through line CC;
• Figure 3 is a perspective exploded view of figure 1 ;
• Figures 4, 5 and 6 are different views of figure 2 with the left hand side shown in an exploded condition and the right hand side in an assembled condition;
• Figure 7 is a perspective view of a plurality of rings of the present embodiment
• Figure 8 is a perspective view of the right hand side of figure 2 in an assembled condition
• Figure 9 is a perspective view of the left hand side of figure 2 in an assembled condition
• Figure 10 is a perspective view of an actuator means of the present embodiment
• Figure 1 1 is a side view of figure 10;
• Figure 12 is a part perspective view of figure 1 1 showing a cross section through a hub/spindle;
• Figure 13 is a front view of figure 12 without the crank
• Figure 14 is a perspective view of the motor and gear system
• Figure 15 is a schematic representation of part of the transmission system of the first embodiment when at the largest/highest gear ratio (one side of the pulleys being removed for illustrative purposes);
• Figure 16 is a schematic representation of the transmission system of the first embodiment when at the smallest/lowest gear ratio (one side of the pulleys being removed for illustrative purposes);
• Figure 17 is a perspective schematic representation of figure 15;
• Figure 18 is a front view of the front pulley of figure 17 without the cable
• Figure 19 is a cross section view of a section of the front pulley of figure 18;
• Figure 20 and 21 are schematic representations showing the position of the plurality of rings of the pulley of figure 18 when supporting the cable;
• Figure 22 is a perspective schematic representation of the transmission system of the first embodiment when moving from the largest gear ratio
• Figure 23 is a front view of the front pulley of figure 22 without the cable
• Figure 24 is a cross section view of a section of the front pulley of figure 23;
• Figure 25 and 26 are schematic representations showing the position of the plurality of rings of the pulley of figure 23 when supporting the cable;
• Figure 27 is a perspective schematic representation of the transmission system of the first embodiment when moving towards the smallest gear ratio
• Figure 28 is a front view of the front pulley of figure 27without the cable
• Figure 29 is a cross section view of a section of the front pulley of figure 28;
• Figure 30 and 31 are schematic representations showing the position of the plurality of rings of the pulley of figure 28 when supporting the cable;
• Figure 32 is a perspective schematic representation of figure 16
• Figure 33 is a front view of the front pulley of figure 32 without the cable
• Figure 34 is a cross section view of a section of the front pulley of figure 33.
• Figure 35 and 36 are schematic representations showing the position of the plurality of rings of the pulley of figure 33 when supporting the cable.
• the present invention according to a first embodiment of the invention is in the form of a transmission system 12 comprising a variable diameter pulley 1 1 .
• the pulley 1 1 is particularly adapted for use with a transmission system which functions in a similar/same manner as a continuously variable transmission (CVT).
• CVT continuously variable transmission
• the pulley of the present invention is configured to maintain a relatively narrow gauge. This enables the pulley and associated transmission system to be used in applications which have minimal space for a transmission system, such as, for example, bicycles including conventional bicycles, e-bicycles and pedelecs.
• Previous CVT's comprise relatively thick front and/or rear pulley arrangements which could not be readily applied in applications which have limited space to house the pulley arrangement. For example, these CVTs could not be applied to bicycles as it would impede the pedal action, not provide a sufficient range in gear ratios, place significant stress on the chain and/or is too heavy.
• the relatively narrow pulley of the present invention provides the transmission system with a practical and efficient drive train geometry. When applied to a bicycle the thickness of the pulley of the present invention is similar to the thickness of a chain ring of a conventional bicycle wherein the chain ring comprises two sprockets.
• the present invention also allows the diameter of the pulley to be increased with minimal or no change in the width of the pulley. This provides for a large range of gear ratios. This further enhances the vast array of applications the present invention is suited.
• the pulley 1 1 is adapted to support two crank arms 13 to which peddles/clips 15 are secured.
• a rider (not shown) can engage the peddles 15 to cause the pulley 1 1 to rotate, as is well known.
• the pulley 1 1 comprises a first side housing 17 and a second side housing 19.
• the first side housing 17 and the second side housing 19 are co-axially mounted and secured to each other via a shaft 21 .
• the pulley 1 1 is secured to a frame of the bicycle (not shown) so that the pulley 1 1 is located adjacent the frame.
• crank arms 13a is connected to a shaft which passes through a spindle/hub 23 of the bicycle frame before being secured relative to the second side housing 19.
• the second crank arm 13b is secured directly to an outer surface of the first side housing 17.
• the first side housing 17 and the second side housing 19 are spaced a distance from each other to define an annular recess 25 therebetween.
• the first side housing 17 houses nine rings 27 of different diameters.
• Each ring 27 comprises a hoop 29 which has a plurality of wedged shaped projections 31 projecting therefrom in a spaced apart arrangement to define a gap 33 therebetween.
• Each projection 31 provides a support surface 35 for reasons which will be discussed below.
• the projections 31 are arranged so that projections 31 on one ring are offset relative to the projections 31 on adjacent rings 27.
• the projections 31 on each ring 27 are spaced apart to define a gap 33.
• the gaps are sized so that projections 31 of adjacent rings 27 can be received in the gaps 33 so that adjacent rings 27, when assembled, can nestle together, as represented by the second side housing 19 shown in at least figure 4, 5 and 6.
• the projections 31 a on the first ring 27a are approximately half the size of the projections 31 on the ring adjacent thereto.
• the first ring 27a has the smallest diameter.
• the last ring 27i also comprises a second set of projections 32i which are approximately half the size of the projections 31 i.
• the projections 32i may be located between projections 31 i on the rings adjacent these two rings 27a, 27i.
• the last ring 27i has the largest diameter.
• Each ring 27 is movable in a lateral direction relative to the first side housing 17. With the exception of the first ring 27a, each ring 27 is movable between a first position, as shown in figure 9, wherein each ring is adjacent to an inner side 37 of the first side housing 17, and a second position, wherein the ring 27 is spaced away from the inner side 37. In this embodiment each ring 27, with the exception of the last ring 27i, is also movable to a third position which is located laterally between the first position and the second position.
• the transmission system 12 also comprises an activation means 39.
• the activation means 39 co-operates with the pulley 1 1 to cause movement of each ring 27 between the first position, the second position and the third position.
• the activation means 39 comprises a biasing means, which in this embodiment is in the form of a set of magnets 41 , which bias each ring to the first position.
• the magnets co-operate with a set of metal pins 43 retained in each ring 27.
• the biasing means can be in the form of springs.
• the activation means 39 also comprise a plurality of actuator arms 45 supported in recesses 47, wherein a first set of the actuator arms 45 are located on the inner side 37 of the first side housing 17, and a second set of the actuator arms 45 are located on the inner side of the second side housing 19.
• the actuator arms 45 are spaced radially in a spider web type arrangement.
• Each actuator arm 45 is movable along its recess 47 in a radial direction (as indicated by the arrows in figure 1 1 ) between an innermost position, central of the first side housing 17, as shown in figure 1 1 , and an outermost position, adjacent the outer diameter of the first side housing 17.
• Each actuator arm 45 has a head 49 adapted to cause movement of the ring pairs as the actuator arm 45 moves between positions.
• each head 49 provide a sloping upper face 51 for engaging a sloping lower face 151 of the rings 27.
• Each head 49 also comprises a sloping lower face 52 for engaging a sloping upper face 152 of the rings 27 for reasons which will be described below.
• the activation means 39 is activated by an electric motor 53 which cooperates with a gearing system 55 to move the actuator arms 45 along the recesses 47 so that the actuator arms 45 are caused to move outwardly or inwardly.
• the activation means 39 is also able to hold the actuator arms 45 at any location between their innermost position and outermost position. This is achieved by controlling the electric motor 53 accordingly.
• the configuration of the second side assembly 19 is largely identical to that of the first side assembly 17.
• the second side assembly 19 comprises an activation means which has the same components as those of the first side assembly 17.
• the activation means and its features are numbered the same for the second side assembly 19 as those of the first side assembly 17.
• the activation means of the second side assembly 19 is activated by the electric motor 53 and the gearing system 55 such that the activation means of the second side assembly 19 operates simultaneously with that of the first side assembly 17.
• the second side assembly 19 also comprises an identical set of nine rings 27.
• the set of nine rings 27 and their features are numbered the same as those of the first side assembly 17.
• each of the rings of the second side assembly 19 has a corresponding ring 27 on the first side assembly 17 to provide a ring pair.
• the corresponding rings of the ring pair are the same as each other but when the pulley is assembled the corresponding rings are offset to each other.
• the corresponding rings are offset, when the corresponding rings move from the first position to the second position the projections 31 from the ring of the first side assembly are received in the gaps 33 of the corresponding ring of the second side assembly 19 such that in the second position the ring pair are meshed together, as best shown in figure 18.
• the first side assembly 17 and second side assembly 19 define the annular recess 25 therebetween.
• the annular recess is adapted to receive a cable in the form of a V-shaped belt 59.
• actuation arms 45 can be set at any position between their innermost position and outermost position the location of the belt 59 can be supported by the pulley at any diameter between the smallest diameter and the largest diameter.
• variable diameter pulley 1 1 can be combined with a second variable diameter pulley 1 1 1 to complete the transmission system 12.
• the belt 56 which is a continuous loop, extends between the two pulleys 1 1 , 1 1 1 to transfer movement from the first pulley 1 1 to the second pulley 1 1 1 .
• the second pulley 1 1 1 acts as a slave pulley whereby it reacts to changes of the first pulley 1 1 .
• the second pulley 1 1 1 is a smaller version of the first pulley 1 1 without the need to incorporate an activation means 39, electric motor 53 and gearing system 55 in the second pulley 1 1 1 .
• FIG. 17 to 36 show various views of the transmission system.
• the transmission system 12 comprises the first variable diameter pulley 1 1 , and second variable diameter 1 1 1 interconnected by the belt 59.
• the various views show the belt 59 at various positions of the transmission system 12 wherein the various positions correspond to various gear positions of a conventional bicycle chain driven derailleur system.
• the transmission system 12 is shown at a position relating to the largest/highest gear ratio wherein the actuator arms 45 are at their outermost position, whereby the sloping upper face 51 of actuator head 49 engages the sloping lower face 151 of the ring 27i.
• the last set of rings 27i of the first side assembly 17 of the first pulley 1 1 , and the last set of rings 27i of the second side assembly 19 of the first pulley 1 1 are each in their second position to support the belt 59 at the largest diameter.
• the remaining rings of the first pulley 1 1 are in their third position.
• the belt 59 is supported by the first pulley 1 1 in the largest diameter, the belt 59 is supported by the second pulley 1 1 1 in the smallest diameter, as shown in figure 17.
• the second pulley 1 1 1 is a reactionary pulley wherein the operation of the second pulley 1 1 1 is dictated by the operation of the first pulley 1 1 .
• the change in tension in the belt 59 causes the second pulley 1 1 1 to react to support the belt 59 in a new position.
• the transmission system 12 is shown at a first intermediary position.
• the transmission system 12 is shown at a second intermediary position. In these sets of figures the transmission system 12 moves away from the largest/highest gear ratio. This is achieved by activating the activation means 39 to cause the actuator arms 45 to move inwardly towards their innermost position.
• the transmission system 12 is shown at a position relating to the smallest/lowest gear ratio wherein the actuator arms 45 are at their innermost position, whereby the sloping upper face 51 of actuator head 49 engages the sloping lower face 151 of the ring 27a.
• the first ring 27a of the first side assembly 17 of the first pulley 1 1 , and the first ring 27a of the second side assembly 19 of the first pulley 1 1 are each in their second position.
• the remaining rings of the first pulley 1 1 are in their first position.
• the transmission system 12 presents a substantially continuous support surface on both the first pulley 1 1 and the second pulley 1 1 1 as the transmission system moves between the largest/highest gear ratio and the smallest/lowest gear ratio.
• the activation means 39 is operable such that the actuator arms 45 may be positioned anywhere between their lowermost and outermost position (inclusive) and may be held in that position. As such the surface which supports the belts can be at any diameter between the largest diameter and smallest diameter.
• the reason why this malfunction or failure is possible is due to the design and construction of prior art derailleur driven cassette and chain ring systems which do not physically force the chain to be retained in place.
• the present invention is designed such that it is relatively impossible for the belt to come off the front or rear pulleys because no jockey wheels are in use and the edge perimeters of the pulleys physically constrain the belt under any load including shocks induced by road conditions. This increases the safety for the ride and, in competition, levels the playing field.
• the present invention mitigates loss of power during gear ratio changes as it provides continuous power transmission during those gear ratio changes. This does not apply to derailleur systems of prior art bicycles which suffer from loss of momentum during gear (chain ring or sprocket) changes
• Loss of momentum is particularly significant for prior art derailleur systems when changing between chain rings requiring associated multiple sprocket (typically 3- 4) changes in the cassette at the same time in order to avoid excessive gear ratio adjustments from the current setting.
• the present embodiment can be activated by single trigger up or down shifting (using existing handle bar mounted shifter hardware) on the front crank set.
• the rear wheel gearing adjusts automatically to the crank setting through belt pretension and a spring-like mechanism.
• Prior art derailleur drive trains require the rider to separately coordinate shifting of rear sprockets as well as front chain rings to achieve continuous gearing during up or down shifts which is not only inefficient as it leads to loss of momentum as between 3 and 4 gears have to be traversed when chain rings are changed, but it also places a strain on the riders in a state of fatigue or needing to respond to race situations without warning.
• the present embodiment removes the manual coordination requirement of rear (cassette) and front (chain ring) changes making shifting much simpler. This is particularly desirable when riders are fatigued.
• the present embodiment also removes gear ratio duplication which exists in all prior art chain ring and cassette combinations, thereby simplifying the system further.
• the present embodiment eliminates the need for drivetrain lubrication which reduces maintenance and does not compromise drive efficiency.
• the gearing ratio of the present embodiment combines existing standard and compact gearing ratios of prior art systems so that there is no need to swap chain rings and or cassettes from race day to race day which is currently the case. This further reduces maintenance.
• the present embodiment also expands on the largest as well as the smallest gear ratios available from prior art derailleur systems.
• the efficiency of the present embodiment is superior to that of the prior art systems as traditional systems suffer from inefficiencies when using smallest sprockets and when using cross chain gear settings.
• the efficiency of the present embodiment ensures more rider energy input at the crank set arrive at the rear wheel.
• the present invention provides a transmission system having a relatively narrow, fixed width, pulley which is capable of being designed to have near unlimited gear ratios. This is in contrast to current CVT systems which must increase in width as gear ratios increase.
• Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
• first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
• Spatially relative terms such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

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• 2016
  • 2016-10-26 WO PCT/AU2016/051006 patent/WO2017070736A1/en active Application Filing
  • 2016-10-26 EP EP16858500.8A patent/EP3368793A4/en not_active Withdrawn
  • 2016-10-26 AU AU2016345061A patent/AU2016345061A1/en not_active Abandoned
  • 2016-10-26 TW TW105134621A patent/TW201718333A/zh unknown

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