AUTOMATICALLY ADJUSTING A HANDLEBAR POSITION

TECHNICAL FIELD

The present invention relates to motorcycles, and in particular, although not exclusively, to road-going motorcycles.

BACKGROUND ART

Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of this application.

Many aspects of the design of a motorcycle involve compromise between competing requirements. For example, the ergonomics of a motorcycle typically represent a compromise between a rider position that allows for comfort over a long haul and a rider position that helps to maximise the dynamic potential of the motorcycle whilst negotiating corners and generally adopting a 'sporting' riding style. This is evident in touring motorcycles whereby the ergonomics of the motorcycle typically position the rider in a fairly comfortable upright stance. In comparison, sports motorcycles typically feature ergonomics that position the rider in a more crouched stance, whereby the rider's wrists are lower and further forward as compared to on a touring motorcycle. Such crouched riding positions are generally better suited to high speed corning, and the higher lean angles that this entails, but are also more likely to be uncomfortable, especially when riding for an extended period of time.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome, or substantially ameliorate, one or more of the disadvantages of the prior art, or to provide a useful alternative.

In one aspect of the present invention there is provided a kit for retrofitting onto a motorcycle, the kit including:

a member to which a handlebar is mountable; an actuator being operable to displace the member relative to a steerable component of the motorcycle; and

a user operable control for controlling the actuator such that, in use, a handlebar position is automatically adjustable.

Preferably the member includes at least one elongate cylindrical member defining a first end at which the handlebar is mountable and a second end to which the actuator is connectable.

Preferably the steerable component is a triple clamp defining at least one aperture sized to slidingly receive the at least one elongate cylindrical member.

Preferably the actuator is a linear actuator.

In one embodiment the member includes a pair of elongate cylindrical members extending parallel to each other, each of the elongate cylindrical members having a handlebar mounting clamp disposed at the first end, each of the elongate cylindrical members being attached to a bracket at the second end. In this embodiment the steerable component is a triple clamp defining a pair of apertures sized to slidingly receive the pair of elongate cylindrical members. Preferably the pair of apertures are respectively provided within a pair of sleeves and distal ends of the pair of sleeves are interconnected by a gusset member. In this embodiment the gusset member defines a cut out and, in use, the actuator extends through the cut out.

In one embodiment the handlebar position is adjustable in a direction that is parallel to a direction of suspension movement defined by a fork tube 37 of the motorcycle. In another embodiment the handlebar position is adjustable in a direction that is inclined toward a rider of the motorcycle relative to a direction of suspension movement defined by a fork tube 37 of the motorcycle.

In a second aspect of the present invention there is provided a motorcycle including: a member to which a handlebar is mounted;

an actuator being operable to displace the member relative to a steerable component of the motorcycle; and

a user operable control for controlling the actuator such that, in use, a handlebar position is automatically adjustable. Preferably the control is disposed on the handlebar such that the control is operable whilst the motorcycle is being ridden.

In an embodiment the motorcycle includes an electronic control unit for providing an output to control the actuator, the electronic control unit being configured to be responsive to an input indicative of a dynamic state of the motorcycle so to determine the output.

Preferably the input is indicative of any one or more of: application of the motorcycle's brake, an amount of throttle being used, a rotational speed of an engine of the motorcycle, an angle of lean of the motorcycle and/or a linear acceleration of the motorcycle.

In an embodiment in which the electronic control unit is configured to be responsive to an input that is indicative of an angle of lean of the motorcycle the electronic control unit is configured to only provide an output so as to adjust the handlebar position if the angle of lean of the motorcycle is less than a threshold angle.

Preferably the user operable control provides a first mode in which the user has control of the handlebar position and a second mode in which the electronic control unit automatically controls the handlebar position.

In another aspect of the present invention there is provided a method of operating a motorcycle including the steps of:

providing a motorcycle as described above;

riding the motorcycle with the handlebar in a first position relative to the steerable component;

operating the control whilst riding the motorcycle so as to automatically adjust the handlebar into a second position differing from the first position; and

continuing to ride the motorcycle with the handlebar in the second position.

Preferably the first position is lower than the second position and the handlebars are in the first position whilst the motorcycle is negotiating a comparatively curved stretch of road and the handlebars are in the second position whilst the motorcycle is negotiating a comparatively straight stretch of road.

The features and advantages of the present invention will become further apparent from the following detailed description of preferred embodiments, provided by way of example only, together with the accompanying drawings. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 is a front view of a motorcycle steering assembly upon which an embodiment of the present invention has been retrofitted, with the handlebars in an elevated position;

Figure 2 from view of the motorcycle steering assembly of figure 1 , with the handlebars in a lowered position;

Figure 3 is a disassembled perspective view of the components of the motorcycle steering assembly of figure 1 ;

Figure 4 is a disassembled perspective view of a kit of parts in accordance with the preferred embodiment of the invention;

Figure 5 is an assembled front view of the kit of parts of figure 4;

Figure 6 is a disassembled side view of the kit of parts of figure 4;

Figure 7 is an assembled perspective view of the motorcycle steering assembly of figure 1 , with the handlebars in an elevated position; and

Figure 8 is an assembled perspective view of the motorcycle steering assembly of figure 1 , with the handlebars in a lowered position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

An embodiment of the present invention provides a kit 10 for retrofitting onto a motorcycle upon which it is desired to have adjustable handlebar positioning. Figures 1 and 7 show a motorcycle steering assembly in which the handlebars are adjusted to an elevated position. Figures 2 and 8 show a motorcycle steering assembly in which the handlebars are adjusted to a lowered position. This adjustability provides the rider with options to tailor some aspects of the motorcycle's ergonomics as desired. Indeed, it is believed that the additional comfort provided by the adjustability has the potential to improve rider safety by reducing fatigue on longer journeys. As shown for example in figures 4 to 6, the kit 10 includes a member 11 to which the motorcycle's original handlebar 12 is mountable. The member 11 includes a first elongate cylindrical member 13 and a second elongate cylindrical member 14 extending parallel to the first elongate cylindrical member 13. The handlebar 12 is mountable within a pair of bar clamps 15 and 16 that are respectively affixed to the first (i.e. upper) ends of each of the elongate cylindrical members 13 and 14 by bolts 17. Each of the second (i.e. lower) ends of the elongate cylindrical members 13 and 14 are interconnected by a bracket 18.

The kit 10 also includes a linear actuator 19, which, in use, is operable to linearly displace the member 11 relative to a steerable component of the motorcycle. Displacement of the member 11 displaces the bar clamps 15, which results in displacement of the handlebars 12 between the elevated position illustrated in figures 1 and 7 and the lowered position illustrated in figures 2 and 8. This provides the motorcycle rider with the option of positioning the handlebars 12 higher for comfortable touring-type ergonomics; or lower for a more sporting- type riding position. Optionally, the rider may choose to stop displacement of the handlebars 12 at any desired position intermediate of the elevated and lowered positions.

In one embodiment the linear actuator 19 is a model PA- 14 mini linear actuator, which is available from Progressive Automations, which has a distribution center at Unit 108, 11121 Horseshoe Way Richmond, BC V7A G7 Canada. This linear actuator can run at 12 volts, has a stroke length of approximately 50 mm and is capable of exerting a maximum force of approximately 665 Newtons. In another embodiment the linear actuator is a piezoelectric actuator and in another embodiment the linear actuator 1 is electro-mechanical. In yet another embodiment, the linear actuator 19 is hydraulic or pneumatic. The linear actuator 19 is powered via a control circuit that is connected to the motorcycle's battery.

The lower end 21 of the actuator 19 is connectable to an annular formation 21, which is centrally disposed on bracket 18. This connection is made by positioning the circular lower end 22 of the actuator 19 within the annular formation 21 and aligning the hole 23 on the lower end 22 with the two holes 24 that are provided on opposite sides of the annular formation 21 and inserting a fastener, such as a bolt or a split pin, through the holes 23 and 24.

The illustrated embodiment is adapted for use with a motorcycle having the conventional or upside down telescopic fork tube type of front suspension. In this

embodiment the previously mentioned "steerable component" is in the form of upper triple clamp 20, which is provided as part of the kit 10 so as to replace the original upper triple clamp of the motorcycle. The replacement upper triple clamp 20 is manufactured specifically for the motorcycle onto which it is to be retrofitted. Typically, the intention when

manufacturing the replacement upper triple clamp 20 is to accurately replicate the geometry of the original upper triple clamp. Hence, the fork tube clamps 25, and the steering stem opening 26, are positioned on the replacement upper triple clamp 20 so as to replicate the positioning of those components on the original triple clamp. This ensures that the steering geometry is essentially unchanged when the original triple clamp is replaced by the replacement triple clamp 20.

The triple clamp 20 has a pair of sleeves 27, each having an aperture 28 sized to slidingly receive the elongate cylindrical members 13 and 14. The inner diameter of the apertures 28 are sized so as to closely match the outer diameter of the elongate cylindrical members 13 and 14 to within fairly fine tolerances, such as 0.1mm for example. This fine tolerance helps to ensure that the elongate cylindrical members 13 and 14 stay accurately aligned with the apertures 27 in the sleeves, which minimizes the risk of binding due to misalignment and helps to minimize friction as the elongate cylindrical members 13 and 14 slide through the sleeves 27. In another embodiment, each of the sleeves feature tubular bearings, which further minimize friction. Another embodiment makes use of the Simplicity ^® flange bearings that are available from PBC Linear at 6402 Rockton Road, Roscoe, IL 61073 United States of America and in particular one of the following models: DFPMR20,

DFPMR25 or DFPMR30.

The close tolerance between the apertures 28 and the elongate cylindrical members 13 and 14 helps to provide a solid feeling steering assembly from the rider's perspective. An excessive tolerance would allow the elongate cylindrical members 13 and 14 to move within the apertures 28 in response to acceleration, deceleration and cornering forces, which is likely to be disconcerting for the rider and it is likely to deprive the steering system of the 'feel' that is important when riding a motorcycle.

The distal (i.e. lower) ends of the pair of sleeves 27 are interconnected by a gusset member 29. This provides mechanical reinforcement to help ensure that the sleeves 27 are maintained parallel to each other. Additionally, the gusset member 29 defines a cut out in the form of centrally disposed slot 30. Upon assembly of the kit 10, a mid-portion of the body of the linear actuator 19 extends through the slot 30. The upper end 33 of the linear actuator 19 is positioned within a recess 34 that is provided in the lower side of the triple clamp 20. A U-shaped bracket 31 is affixed to the lower side of the gusset member 29 via a pair of fasteners 32 so as to retain the linear actuator 19 in position. Finally, a lock screw 36, which is threaded through the gusset member 29, is tightened, so as to maintain the upper end 33 of the linear actuator 19 in firm abutment with the recess 34.

The geometry of the triple clamp 20 when installed onto the motorcycle is such that the apertures 28 extend through the sleeves 27 in a direction that is parallel to the direction of suspension movement defined by the fork tubes 37 of the motorcycle. In other words, the axis of the fork tube clamps is parallel to the axis of the apertures 28. Hence, the cylindrical elongate members 13 slide through the apertures 28 in a direction that is parallel to the fork tubes 37. It therefore follows that the position of the handlebars 12 is adjustable so as to move in a direction that is parallel to the fork tubes 37. However, alternative embodiments make use of differing geometries such that the position of the handlebars 12 is adjustable so as to move in a direction that is inclined relative to the direction defined by the fork tubes 37. For example, in one alternative embodiment the position of the handlebars 12 is adjustable in a direction that is inclined by between 5° and 45° toward the rider relative to the direction defined by the fork tubes 37. Such inclination increases the horizontal component of movement of the handlebars 12, such that when the handlebars 12 are in the elevated position, they are also closer to the rider's body, and vice versa.

A user operable control 35 is disposed on the handlebars 12 in a position that can be operated by the rider whist riding the motorcycle. Preferably it is disposed on the left hand side of the handlebars such that it is away from the throttle 38. It is electrically connected to the control circuit, which controls the operation of the actuator 19. In one embodiment the control 35 is in the form of a toggle switch having three positions: upper, middle and lower. When the toggle switch is in the middle position, the control circuit does not energize the actuator 19 and hence the position of the handlebars 12 remains constant. When the toggle switch is in the upper position, the control circuit energizes the linear actuator 19 so as to drive the handlebars 12 in an upwards direction. When the toggle switch is in the lower position, the control circuit energizes the actuator 19 so as to drive the handlebars 12 in a downwards direction. The control circuit is adapted to sense when the handlebar position has reached an upper or lower limit of range of motion and, once this has been sensed, the control circuit effectively ignores any attempt by the rider to operate the control 35 in an attempt to force the handlebar position beyond its intended range of motion.

In another embodiment the control is in the form of two buttons, with one button positioned above the other. When neither button is pressed, the linear actuator 19 is not energized and hence the handlebars remain stationary relative to the upper triple clamp 20. When the upper button is pressed, the control circuit energizes the linear actuator 19 so as to drive the handlebars 12 in an upwards direction. When the lower button is pressed, the control circuit energizes the actuator 19 so as to drive the handlebars 12 in a downwards direction. Hence, by operating the control 35, the handlebar position is automatically adjustable and the adjustment may take place whilst the motorcycle is moving.

In another embodiment the invention is not in the form of a kit 10 that may be retrofitted to a standard motorcycle; rather, the invention is in the form of a motorcycle that is manufactured in the first instance with automatically adjustable handlebar positioning. Such a motorcycle may be manufactured in the first instance with a steering assembly as depicted, for example, in figures 1 & 2 and 7 & 8. This motorcycle includes a member 1 1 to which the handlebars 12 are mounted, along with a linear actuator 19 that is operable to displace the member 11 relative to a steerable component of the motorcycle. A user operable control is disposed on the motorcycle to allow a rider to control the actuator 19 such that, in use, the handlebar 12 position is automatically adjustable.

When riding the motorcycle, the rider would typically operate the control 35 so as to position the handlebars 12 to a lower position (such as that illustrated in figures 2 and 8) when the rider is negotiating a comparatively curved stretch of road or wherever the rider intends to ride in a sporty manner. On the other hand, when the rider is negotiating a comparatively straight stretch of road, or when the rider wishes to cruise in a more relaxed manner, the rider would typically operate the control 35 so as to position the handlebars 12 in an elevated position (such as that illustrated in figures 1 and 7).

In the above described embodiments a linear actuator was used. However, in other embodiments other types of actuators, such as rotational actuators, may be utilized. Indeed, as used in this document, including in the claims, the term "actuator" is to be construed broadly so as to include any device that is capable of exerting a force sufficient to displace a member to which the handlebars are mounted relative to the steerable component. Some examples of such "actuators" include an electric motor driving a pinion gear that is meshed with a straight rack. Another example of such an actuator is an electric motor driving a worm gear, screw thread or other spiral track arrangement that gives rise to an appropriate displacement of the member 11 upon which the handlebars 12 is disposed. Some motorcycles feature fairings and/or brackets that are disposed close to the steering head and which may preclude use of the arrangement illustrated in figures 1 to 8. Hence, to accommodate such motorcycles, it is desirable to have a variety of differing options for actuators and for the geometry of the arrangement by which the actuator displaces the handlebars 12.

The arrangement illustrated in figures 1 to 8 keeps a majority of the weight of the components that are added to the motorcycle in a position that is close to the steering axis of the motorcycle. This advantageously avoids an excessive increase of the overall moment of inertia of the steering assembly, which helps to avoid or at least minimize any undesirable effects on the steering of the motorcycle.

Whilst the above embodiments have been described with reference to motorcycles having conventional or upside down telescopic fork tube-type front suspension, it will be appreciated by those skilled in the art that the invention may be readily modified to accommodate alternative front suspension systems, such as the Hossack/Fior suspension system, the Saxon-Motodd suspension system, single-sided front swing arm suspension systems and the like.

In the above embodiments the handlebars 12 are constructed from a single length of tubular material. However, in other embodiments, the invention may be adapted to function with other types of handlebars, such as clip-on handlebars and the like. For example, to accommodate clip-on handlebars, the bar clamps 15 would not be included. Rather, the clip- on handlebars would clamp directly onto the upper end of each of the elongate cylindrical members 13 and 14.

The components of the present invention may be manufactured from various materials having appropriate properties, such as stainless steel, aluminum, titanium, mild carbon steel metals, carbon fibre, etc.

In the above-described embodiments the height of the handlebar 12 is adjustable solely in response to user operation of the control 35. However, in an alternative embodiment, the adjustment of the handlebar's height can also be automatically controlled by an electronic control unit (ECU) that is electrically connected to the linear actuator 19. In this embodiment the user operable control 35 allows the user to select a first mode in which the user has control of the handlebar position (as described above) and a second mode (as described in more detail below) in which the electronic control unit automatically controls the handlebar position.

The ECU adjusts the handlebar height by providing an output in the form of a positive voltage to the linear actuator 19 to cause the linear actuator to raise the handlebars 12. If the ECU provides an output in the form of a negative voltage to the linear actuator 19, this causes the linear actuator to lower the handlebars 12. If the ECU provides an output in the form of a zero voltage to the linear actuator 19, this causes the linear actuator to maintain the current position of the handlebars 12.

One or more sensors are disposed on the motorcycle so as to sense information about the dynamic state of the motorcycle and to feed that information to the ECU. These sensors may be native to the motorcycle and/or retrofitted. The ECU has electronics that are responsive to that input so to determine the output that is provided to the linear actuator 19.

In one embodiment the input indicates to the ECU when the motorcycle's brakes are, and are not, being applied. When the brakes are being applied, a small proportion of the voltage of the brake light system is sent as the input signal to the electronics of the ECU. Other options for providing this input signal include the use of a switch that is toggled when the brake lever is being used or making use of a switch that resides within the hydraulic brake line. In any event, when the ECU receives an input signal indicating that the motorcycle's brakes are being applied the ECU is configured to respond by providing an output in the form of a positive voltage causing the linear actuator 19 to raise the handlebars 12. This is achieved within the ECU with the use of electronics such as a transistor, a relay, a processor, or the like. Whilst braking occurs, the ECU causes the actuator to raise the handlebars 12 until such time as the uppermost handlebar position is attained. At this stage the linear actuator 19 is physically restrained from raising the handlebars 12 any further and an over voltage is experienced by the linear actuator 19. This over voltage is sensed by the ECU and in response the ECU ceases to provide the output to the actuator, thereby maintaining the handlebars 12 in the raised position. Hence, the ECU automatically raises the handlebar position, or maintains the handlebars at the uppermost position, whilst the rider is braking the motorcycle. This has a tendency to help counter the normal dipping of the handlebar caused by compression of the front suspension due to the braking of the motorcycle.

Once the rider ceases braking, the ECU no longer receives the input indicating that the brakes are being used and the ECU is configured to respond by providing an output in the form of a negative voltage, which causes the linear actuator 19 to lower the handlebars 12. Assuming that the brakes are not immediately re-applied, the lowering of the handlebars 12 continues until the lowermost handlebar position is attained. At this point the ECU is responsive to the over voltage of the linear actuator 19 by ceasing to provide the output, thereby maintaining the handlebars 12 at the lowermost position until such time as the rider applies the brakes. Hence, the ECU automatically lowers the handlebar position, or maintains the handlebars at the lowermost position, whilst the rider is not braking the motorcycle.

In another embodiment the input is associated with the throttle of the motorcycle. In this embodiment a throttle position sensor provides the input, which is indicative of the amount of throttle that is currently being used by the rider. The ECU includes a processor that is configured to continuously calculate an average amount of throttle being used over the immediately preceding 30 second window of time. The processor then compares this average amount to a threshold value, such as 50% for example. If the average amount is less than the 50% threshold, then the processor is configured to provide an output so as to raise the handlebar position and then so as to maintain the handlebar at the uppermost position. Hence, periods of riding in which the rider uses lower average throttle openings are associated with a raised handlebar position, which is suited to a relaxed cruising riding style.

When the ECU's processor determines that the average amount of throttle is greater than the 50% threshold, the processor provides an output that lowers the handlebar position and then maintains it at the lowermost position. Hence, periods of riding in which the rider uses higher average throttle openings are associated with a lowered handlebar position, which is suited to a sportier riding style.

In another embodiment the input is associated with the rotational speed (i.e. RPM) of the engine of the motorcycle. This input signal is provided to the ECU's processor from either the motorcycle's ignition system or from the motorcycle's tachometer. The ECU's processor is configured to calculate an average RPM being used over the preceding 30 second time period. This average value is compared with a threshold value, such as 50% of the maximum available RPM of the engine. When the processor determines that the average RPM is less than the 50% threshold, it provides an output that raises the handlebar position and then maintains it at the uppermost position. Hence, lower average RPM, which generally indicates a more moderate riding style, is associated with a raised handlebar position.

When the average RPM level is greater than the 50% threshold the processor is configured to provide an output that lowers the handlebar position and then that maintains it at the lowermost position. Hence, when the processor determines that the rider is more aggressively using the engine, it causes the handlebars to be lowered to suit a sportier riding style.

In another embodiment the input is indicative of an angle of lean of the motorcycle. A tilt sensor or a gyroscope is disposed on the motorcycle and it is used to provide the input to the ECU. As the rider negotiates a set of bends, the ECU's processor is configured to calculate an average angle of lean that is being used over a period of time, such as the immediately preceding 30 seconds, for example. The ECU is configured to cause the actuator to raise and then maintain a raised handlebar position when the average angle of lean is less than a threshold, such as 20° from vertical, for example. The relatively mild average angle of lean indicates that the rider is cruising and therefore a higher handlebar position is maintained. However, the ECU causes the actuator to lower the handlebars and then maintain a lowered handlebar position when the average angle of lean is greater than the 20° threshold. Hence, when the rider is cornering with the use of higher angles of lean, a lower handlebar position is maintained.

In yet another embodiment the input is indicative of a linear acceleration of the motorcycle. In this embodiment an accelerometer is disposed on the motorcycle. It provides a measurement of the linear acceleration of the motorcycle, which is provided to the ECU as the input. The ECU's processor is configured to calculate an average linear acceleration being used over a period of time, such as the immediately preceding 30 seconds. The ECU causes the actuator 19 to raise the handlebars 12, and then to maintain a raised handlebar position, when the average linear acceleration is less than a threshold, such as 0.5g. The ECU causes the actuator to lower the handlebars, and then to maintain a lowered handlebar position, when the average rate of linear acceleration is greater than the 0.5g threshold. This has a tendency to help counter the natural rearward rotation that the rider's upper body is exposed to due to the acceleration.

As a safety precaution in some contexts it may be preferable to ensure that the height of the handlebars remains fixed whenever the motorcycle is leaning beyond a threshold angle of lean. To address this issue, an embodiment has an ECU that is configured to be responsive to an input that is indicative of the current angle of lean of the motorcycle. This input is provided by a tilt sensor that is disposed on the motorcycle. Whilst the input from the tilt sensor indicates that the motorcycle is relatively upright (i.e. it is leaning at an angle that is less than a threshold, such as 5° for example), then the ECU is configured to be capable of providing outputs to the actuator 19 that can change the height of the handlebars 12.

However, whilst the input from the tilt sensor indicates that the motorcycle is currently at an angle of lean that exceeds the 5° threshold, then the ECU is configured to cease providing any such output. Hence, whilst the angle of lean exceeds the threshold, the handlebar height remains constant.

In another embodiment the ECU is configured to receive an input from the motorcycle's control circuitry that is indicative of a power mode and/or a traction control mode that the rider has selected for the motorcycle. The ECU is configured to select some or all of the various thresholds mentioned above (such as the acceleration threshold, the lean angle threshold, etc.) in response thereto. For example, the ECU may be configured to select higher thresholds in response to selection by the rider of more aggressive power and/or traction control modes.

While a number of preferred embodiments have been described, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.