GB2640997A - Pedal for a bicycle, bicycle comprising a pedal, and a method of use of the pedal - Google Patents

Abstract

A pedal 10 for a bicycle comprises a pedal body 12, at least one load cell 14 located on or within the pedal body 12, a pedal top 16 and transmission means 68. The pedal top 16 defines an upper foot surface 60 and is connected to the pedal body 12 to permit movement relative to the pedal body 12 when a user applies a force to the surface 60. The at least one load cell 14 is configured to detect the said force applied to the pedal top 16. The transmission means 68 enable transmission of a measurement output by the at least one load cell 14 to an external device. The pedal may also comprise an accelerometer.

Description

Pedal For a Bicycle, Bicycle Comprising a Pedal, and a Method of Use of the Pedal The present invention relates to a bicycle pedal, as well as a bicycle comprising the same. The invention further relates to a method of use of the pedal.

In order to improve their cycling performance, cyclists need to obtain accurate measurements of their ability according to a range of performance metrics. Typically, monitored performance metrics include velocity, cadence and force. Cadence is the number of revolutions of the pedal per minute. Force applied by the user on the pedal gets converted into torque. Multiplying the cadence by the torque provides the power, another useful performance metric.

Force can be measured by placing a strain gauge on the crank arm. However, measuring the force away the source decreases the accuracy of the measurements.

To obtain the greatest accuracy, some cleated cycling pedals in the prior art are adapted to include means for measuring performance metrics, such as force, power and cadence. However, this requires specifically modified shoes which may not be suitable for walking. The measurement means may also add weight unnecessarily whilst the cost of such shoes may be prohibitive. For all these reasons, cleated shoes are not affordable to certain users and/or are undesirable.

An intermediate solution in the art is to provide a power pedal, which includes a strain gauge associated with the spindle of the pedal. As the user pushes down on the pedal, the spindle is deflected downward. The downward deflection is measured by the strain gauge which provides an estimation of the force applied. However, if a downward force is applied to the pedal spindle distally from the crank arm, the spindle may deform to a greater extent compared to a downward force applied proximally to the crank arm. In turn, the strain gauge accuracy varies with the location of application of the force. To maintain the accuracy of the strain gauge, the location of application of the force along the spindle needs to be consistent. This requires the foot position along the spindle to be constrained, which is achieved via the use of cleated shoes. Once again however, the need for cleated shoes restricts the accessibility of the sport to a range of users.

The present invention seeks to provide a solution to these problems.

According to a first aspect of the present invention, there is provided a pedal for a bicycle, the pedal comprising: a pedal body; at least one load cell located on or within the pedal body; a pedal top defining an upper rest surface, the pedal top being connected to the pedal body to permit movement relative to the pedal body when a user applies a force to the upper rest surface, the at least one load cell being configured to detect the said force applied to the pedal top; and transmission means for transmitting a measurement output by the at least one load cell to an external device.

The pedal has a movable top which enables an accurate measurement of a force applied to the pedal without requiring the user to wear cleated shoes during cycling. In other words, user can wear normal, non-cleated shoes when using a bicycle fitted with the pedal. This negates the need for the user to carry a pair of normal shoes in addition to cleated shoes. The ability to use the pedal with normal shoes also increases the range of scenarios in which the pedal can be used, for example, on a commute to work. Thus, the pedal is easier to use and universally compatible.

The pedal is an improvement over alternative crank based power meters because the pedal is compatible with nearly all bicycle crank arms.

The use of a movable pedal top and load cell enables an accurate measurement of the force of the user's foot, irrespective of where the foot applies the force. The transmission means enables data to be transmitted elsewhere, such as to a user's telecommunications device, for processing and/or for display. If the calculations of performance metrics are carried out remotely, this negates the need for calculation means to be included in the pedal. Calculation means within the pedal would be potentially exposed to shocks and forces, and accelerations upon rotation of the pedal, which might damage and/or shorten the lifespan of the electronics. Additionally, omission of calculation means from the pedal may enable the pedal to be lighter and/or more compact.

Preferably, the pedal may further comprise an accelerometer. The accelerometer 5 can measure acceleration of the pedal moving in a plane of action during pedalling.

Additionally, the accelerometer may be a three-axis accelerometer. The accelerometer can detect accelerations in all three dimensions. A three-axis accelerometer can detect pedal tilt angle. When the upper rest surface is rotated around the spindle to a first position away from being in a default, horizontal position, the pedal tilt angle is the deviation angle of the upper rest surface in the first position relative to the default position. Additionally, in the case of a non-stationary bicycle, a three-axis accelerometer can detect side movement of the pedal, such as when the bicycle is turning to the left or right.

Furthermore, the pedal may have a plurality of load cells. Preferably, the pedal may have four load cells. A plurality of spaced apart load cells may increase the accuracy of the force measurements, particularly if the force is applied away from the centre of the pedal top.

Beneficially, the transmission means may include a near-field, preferably 20 Bluetooth (RTM), communications module. Bluetooth (RTM) communication enables the transmission of data to be wireless. Wired transmission is possible, however.

Additionally or alternatively, the transmission means may include an RF antenna. An RF antenna may enable transmission of data over a greater distance than 25 near-field communication.

Furthermore, the pedal may additionally comprise a controller. Beneficially, the controller may include a Printed Circuit Board. Advantageously, the controller may include an Analog to Digital Converter. A controller may be used to control other electronic components of the pedal. The Analog to Digital Converter may be able to estimate the force applied to the pedal top from the analogue deformation of the strain gauge of the or the plurality of load cells. The controller may even carry out the calculations of performance metrics locally. As such, the transmission means may only need to transmit the final results to the external device, rather than transmit large quantities of raw data.

Preferably, the pedal may further comprise an onboard power source. The electronic components of the pedal may be electrically energised.

Additionally, the power source may include a battery. There is no need for the power source to be provided within the bicycle. The battery may be rechargeable which is environmentally friendly. A battery may be small and light. If the battery is replaceable, the user can carry a spare battery to replace a used battery and be immediately on their way again. There is no need to wait for the battery to be recharged, unlike for rechargeable but non-replaceable batteries. It may even be envisioned that the spare battery may be replaceable and rechargeable such that it can be recharged whilst another battery is in use. The pedal may achieve superior battery life due to the intended use case, and ergonomic design. If the pedal utilises at least one and preferably two AAA batteries, the estimated battery life, assuming one hour per day of use, is expected to be about one year.

An alternative to a battery may include electrically energising the pedal via 20 induction and/or via a brush arrangement. These, however, may require a power source within the bicycle. A dynamo arrangement may even be provided in the pedal such that the user's pedalling also generates electricity.

Beneficially, the pedal may further comprise a force plate element positioned between the at least one load cell and the pedal top. The force plate element may provide protection to the at least one load cell. If a plurality of load cells is provided, the force plate element may be connected to all the load cells and distribute the force to the load cells.

Beneficially, the pedal top may have a dimension and/or a position relative to the at least one load cell so as to apply a pre-tensioning force to the at least one load cell. Pre-tensioning of the at least one load cell may enable calibration of the load cell.

Beneficially, the pedal may further comprise a foam pad. The foam pad may provide cushioning, moisture capture, gap tolerance accommodation, or any 5 combination thereof.

Preferably, the pedal body may further include a ground-facing portion. Optionally, the ground-facing portion may further include at least one strap-receiving aperture. Beneficially, the ground-facing portion may have a ground-facing surface and a pedal-orientation correcting protrusion extending from the ground-facing surface.

The pedal-orientation correcting protrusion may help ensure that the pedal top faces upwards to ensure the foot applies the force to the pedal top. In other words, the pedal-orientation correcting protrusion may act as a ballast or weight, so that the pedal is or is substantially gyroscopic. The pedal-orientation correcting protrusion may also be shaped and/or positioned so as to prevent or inhibit the user from being able to position their foot on the ground-facing portion.

Optionally, the pedal-orientation correcting protrusion may include at least one strap-receiving aperture. A strap may be received in or engaged with the strap-receiving aperture. If there are several strap-receiving apertures, the user may 20 have a choice of which strap-receiving aperture to use.

Advantageously, the pedal may further comprise a toe clip. The comfort of the user and/or ease of use of the pedal may be increased.

Additionally, the pedal may further comprise a strap. The user's shoe may be held by a strap which can increase the comfort of the user and/or ease of use of the 25 pedal whilst accommodate different types of shoes.

Beneficially, the toe clip may include a strap connector. The strap may be connected to both the toe clip and the strap-receiving aperture and be positioned thereby to form an extension of the toe clip and provide an enclosing structure for the user's foot, whilst accommodating all types of shoes.

Optionally, the pedal may be provided as a kit of parts. The pedal may be assembled and disassembled. Individual parts may be more easily replaceable.

According to a second aspect of the invention, there is provide a bicycle including a pedal preferably in accordance with the first aspect of the invention. A standard bicycle may be fitted or retrofitted with a pedal which can measure the force applied thereto. Optionally the bicycle may include two pedals in accordance with the first aspect of the invention, although only one pedal in accordance with the first aspect of the invention may be required and/or desired.

According to a third aspect of the invention, there is provided a method of use of a pedal, the method comprising the steps of: a] providing a bicycle having a crank arm to which a pedal, preferably in accordance with the first aspect, is mounted; b] applying a force to the upper rest surface and the load cell detecting the force applied to the upper rest surface; and c] the transmission means transmitting a measurement output by the at least one load cell to an external device. The pedal enables a force applied by the users to be detected without needed to detect any deflection of the pedal spindle.

Preferably, in step a] the pedal may further comprise an accelerometer, the method may further comprise a step before, during or after step b] of c] estimating via the accelerometer the number of pedal revolutions per minute for estimating the cadence. The cadence, which is the number of revolutions per minute of the pedal, can be measured.

Advantageously, the method may comprise a further step of d] obtaining the force detected by the load cell and calculating the torque based on the length of the crank arm, obtaining the cadence, and multiplying the torque by the cadence to obtain the power. The power can be calculated based on the cadence and torque obtained by the user.

Furthermore, the method may comprise a further step prior to step a] of: mounting a pedal, preferably in accordance with the first aspect, to the crank arm of a bicycle. The pedal may be fitted or retrofitted to an existing bicycle.

Optionally, in step b] the force applied to the upper rest surface may be provided by the user standing on one or both pedals of the bicycle so that the at least one load cell detects a force corresponding to the weight or part thereof, for calculating the weight of the user. The user's weight can be measured. This negates the need of the user to own weighing scales to measure their weight. Weight measurement may also be useful for calibration purposes.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a perspective representation of an embodiment of a pedal in accordance with the first aspect of the invention, in an assembled condition, and an external device with which the pedal is communicable; Figure 2 is a side representation of the pedal of Figure 1, additionally showing a strap; Figure 3 illustrates the pedal of Figure 1 in an exploded condition; Figure 4 is a top plan representation of the pedal of Figure 1, with a pedal top, strap, and toe clip omitted for clarity; and part of a crank arm of a bicycle; 20 and Figure 5 is a flow diagram of the method of use of the pedal, in accordance with the third aspect of the invention.

Referring now to Figure 1, there is shown a pedal indicated generally at 10. The pedal 10 is adapted or configured for use with a bicycle. The pedal may thus be a bicycle pedal 10. The pedal 10 is configured or adapted to detect a force experienced by the pedal 10. The force detected may be used to calculate performance metrics, such as power in Watts and/or cadence in revolutions per minute or rpm. Thus, the pedal 10 may be referred to as a power pedal, a bike power pedal, a power meter, or a power sensor.

The pedal 10 may be provided as a kit of parts or in an assembled or part assembled condition. Optionally, the kit may further comprise a bicycle and/or an 5 external device 11.

The pedal 10 may be provided as part of or formed with the bicycle. Preferably, the bicycle is an indoor and/or stationary bicycle, but an outdoor and/or non-stationary bicycle may be envisioned. The bicycle may have a flywheel. The pedal 10 in-use is used to turn the cranks and thus, the wheel or wheels of the exercise bicycle. The wheel may be a fly wheel in the case of a stationary or exercise bicycle. The external device 11 is illustrated in Figure 1.

The pedal 10 has a pedal body 12, at least one load cell 14 a pedal top 16, a force plate element 18, a controller 20, a power source 22, a toe clip 24, a strap 26, but any of the above may be omitted and/or a plurality of any of the above may be provided. The strap 26 is shown in Figure 2. The pedal 10 may be formed at least in part of plastics, metal, wood, carbon fibre, glass fibre, fabrics, magnetic material, ferrous material, any further suitable material, and any combination thereof.

The pedal body 12 in-use provides a support for at least one and more preferably all other components of the pedal 10. The pedal body 12 may be referred to as a chassis. As most clearly shown in the exploded representation of Figure 3, the pedal body 12 includes a pedal-top-engagement portion 28, a top-facing portion 30 having a top-facing surface 30a, a ground-facing portion 32 having a ground-facing surface, one or more lateral walls 34 extending between the top-facing surface 30a and the ground-facing surface, a load-cell receiving recess 36, a spindle cavity 38, a spindle 40, a battery holder 42, and a foam pad 44, but any of the above may be omitted and/or a plurality of any of the above may be provided.

The pedal-top-engagement portion 28 in-use engages with the pedal top 16. The pedal-top-engagement portion 28 may guide or constrain the movement of the pedal top 16 to be linear or substantially linear away from and/or towards the pedal body 12. The flange cooperates with a corresponding body-engagement portion of the pedal top 16, not shown. In the shown embodiment, the pedal-topengagement portion 28 includes a flange element or flange. The flange is preferably upstanding from the top-facing portion 30.

The top-facing surface 30a and/or ground-facing surface may be planar, non-planar or part planar.

The load-cell receiving recess 36 is provided in the top-facing surface 30a and extends inwardly into the pedal body 12. The load-cell receiving recess 36 preferably also includes a ridge 46 for seating the load cell 14. More preferably, there are a plurality of load-cell receiving recesses 36. More preferably yet, there are as many recesses 36 as there are load cells 14 but fewer or more recesses than load cells may be envisioned.

If provided, the spindle 40 is received or receivable within the spindle cavity 38. The spindle 40 and spindle cavity 38 cooperate to enable the pedal body 12 to be pivotable around the spindle 40. The spindle 40 may define a centre line of the pedal 10. The spindle 40 is connected or connectable to the bicycle, and more preferably a crank arm thereof. To enable cooperation between the spindle 40 and the spindle cavity 38 and/or to enable engagement of the spindle 40 and the crank arm, the pedal 10 may further comprise one or more suitable bearings and one or more seals. In the shown example, the pedal 10 includes a roller bearing seal 48a, a sealed bearing 48b, a roller bearing 48c; a locknut 48d, a spindle cap 48e, but any of the above may be omitted and/or a plurality of any of the above may be provided. Any further suitable joint or fastener may be considered. The locknut 48d is more preferably a steel locknut, and even more preferably a NutM7x1 Steel Locknut.

The ground-facing portion 32 has a pedal-orientation correcting protrusion 50 30 extending from the ground-facing surface and at least one strap-engaging portion 52, but either of the above may be omitted and/or a plurality of any of the above may be provided.

The pedal-orientation correcting protrusion 50 may also be referred to as a pedal orientation correction rib or protrusion for simplicity. The protrusion 50 may fulfil 5 in-use one or more functions. The protrusion 50 may help or cause the pedal body 12 to maintain a stable equilibrium or default orientation, such that the ground-facing portion 32 faces or substantially faces downward towards the ground. If the pedal body 12 is displaced from the stable equilibrium, the protrusion 50 may bias the pedal body 12 back into or toward the sable 10 equilibrium, at least in the absence of any interaction with the user. The protrusion 50 may be weighted, for example.

A second function of the protrusion 50 may be to prevent or inhibit the user from resting their foot on the ground-facing surface. In other words, the protrusion 50 may prevent or inhibit the user from placing their foot anywhere other than the pedal top 16. The protrusion 50 is preferably in the shape of a rib, lip or ledge 50a. The rib 50a is preferably provided at or adjacent where a lateral wall 34 meets the ground-facing surface but away therefrom may be an option. Preferably, there are two such ribs 50a. The ribs 50a may be spaced apart from each other.

The, each or at least one strap-engaging portion 52 in-use enables the or a said strap 26 to be associated with the pedal 10. Thus, the or each pedal-orientation correcting protrusion 50 may act as a guide for straps. Preferably, the strap-engaging portion 52 is an aperture 52a but any alternative to an aperture may be envisioned, such as a fastener, or a notch. If there are a plurality of strap- engaging portions 52, and more preferably a plurality of strap receiving apertures 52a, the user may have a choice of apertures 52a. The or at least one strap-engaging portion 52 is preferably provided in the pedal-orientation correcting protrusion 50. More preferably, there is a plurality of strap-engaging portions 52 per pedal-orientation correcting protrusion 50. As shown, there are three strap-receiving apertures 52a per protrusion 50.

The or each load cell 14 in-use detects a force applied to the pedal top 16 by the user. In the illustrated embodiment, there are four load cells 14 but any number, including one, two, three or at least five may be envisioned. The or each load cell 14 has a deflectable member 54 and a strain gauge 56.

The strain gauge 56 is arranged to detect if the deflectable member 54 is deflected. A strain gauge 56 is an analogue mechanism which typically detects a force via elongation or shortening of the electrical circuit upon deflection of the deflectable member 54. Elongation and shortening of the circuit in turn changes the electrical resistance of the electrical current within the strain gauge 56.

Preferably, the force detected on the, each or at least one said load cell 14 is linear. The force may also be sampled at a high frequency, for example, at 100 Hz. The load cell or cells 14 are calibrated before assembly and/or before use. Preferably, the load cells 14 are matched.

The, each or at least one load cell 14 is located on or within the pedal body 12, and more preferably, in or on the top-facing portion 30 thereof. As shown, the or each load cell 14 may be fully or at least partly received within the or a said load-cell receiving recess 36, although on the top-facing surface may be considered. Preferably each load cell 14 is received in a distinct load-cell receiving recess 36. Each load cell 14 is seated on the ridge 46 if provided. The ridge 46 enables the recess 36 to define a space into which the deflectable member 54 can be deflected.

The pedal top 16 in-use is the portion of the pedal 10 which is connected to the pedal body 12 to permit movement relative to the pedal body 12 when a user applies a force to the pedal top 16. The pedal top 16 may also be referred to as a top cover. The pedal top 16 may overlie or overlap at least partially with the pedal body 12. Preferably, the pedal top 16 completely overlaps with the pedal body 12. The pedal top 16 has a support 58 and the said body-engagement portion, not shown, but the latter may be omitted and/or a plurality may be provided. Preferably, the pedal top 16 has a dimension and/or a position relative to the at least one load cell 14 so as to apply a pre-tensioning force to the at least one load cell 14.

The support 58 defines a rest surface 60 upon which the user's foot is received. The rest surface 60 preferably faces upwards, away from the ground such that the rest surface 60 may be referred to as an upper rest surface. Alternative names for the rest surface include a foot receiving surface, and a foot engaging surface.

The at least one load cell 14 is configured to detect the said force applied to the pedal top 16, and more preferably to the upper rest surface 60. The upper rest surface 60 is preferably planar or substantially planar, but non-planar may be considered. The support 58 and/or the rest surface 60 is rectangular or generally rectangular in plan view, although non-rectangular may be an option.

Optionally, the support 58 may further have one or more grip-enhancing elements 62 for enhancing the engagement of the foot with the rest surface 60. The grip-enhancing elements 62 may take any form, such as protrusions, ribs, ridges, dimples, recesses, a friction enhancing material or coating, by way of examples only.

The force plate element 18 may also be referred to as a force plate or a spring plate. The force plate element 18 is in-use positioned between the at least one load cell 14 and the pedal top 16. If a plurality of load cells 14 is provided, the force plate element 18 connects all or at least a subset of the load cells 14 together. Preferably, the force applied to a said load cell 14 is equal to that applied to another said load cell 14. The force plate element 18 thereby distributes the force to the load cells 14 for example, if the force is not applied centrally to the pedal 10.

The combination of the force plate element 18 and the load cells 14 may even be adapted to measure metrics about the user's anatomy based on where the force is applied. For example, the pedal 10 may be able to detect if the user is flat footed or has a good arch and/or applies force with the ball of the foot or generally with the whole surface of their sole. The pedal 10 may even be able to detect unexpected deviations from the user's usual parameters and alert the user and/or a medical practitioner. For example, the user may have a recorded user profile whereby the whole foot normally contacts the pedal 10 during pedalling. If the user starts to only apply the ball of the foot, this could be indicative of an injury or pain felt in the heel of the foot, which could be detected by the pedal 10. Thus, the pedal 10 may have a therapeutic or diagnostic function. Preferably, the force plate element 18 applies the or a pre-tension force to the load cells 14.

Additionally, the force plate element 18 has a second function of securing the pedal top 16 to the pedal body 12. In other words, the force plate element 18 and the pedal top 16 may be connected to form an integral block, permitting a force applied to the pedal top 16 to be efficiently transmitted to the load cells 14 via the force plate element 18.

The force plate element 18 is preferably planar or at least extends in a plane. In 10 the plan view of Figure 4, the force plate element 18 may have a cross shape. As shown, the force plate element 18 has a core 64 and at least one, preferably a plurality of finger elements 66 extending from the core 64 to each load cell 14.

The core 64 is connected to the pedal body 12, and more preferably to the top-facing portion 30 thereof. Preferably, the core 64 is connected to the top-facing portion 30 on either, and more preferably both sides of the spindle cavity 38, although the force plate element 18 remains movable relative to the pedal body 12 even when connected thereto. Two connection points provide greater stability whilst their position means rotation of the pedal body 12 around the spindle 40 is not impeded.

All the finger elements 66 connecting centrally may have a balancing effect whilst also measuring the forces accurately at the corners, where the deflection may be the largest. The finger elements 66 may be linear, part linear or non-linear. Here, each finger element 66 has a linear extent 66a and a curved portion 66b but either may be omitted and/or a plurality of any of the above may be provided.

The linear extents 66a of the four load cells 14 extend in four different directions relative to each other. Each linear extent 66a may therefore have increased sensitivity to a force applied in a different direction and/or at a different location on the pedal top 16.

The controller 20 in-use may control other electronic components of the pedal 10. The controller 20 preferably includes transmission means 68, an accelerometer 70, a Printed Circuit Board (PCB) 72, an Analog to Digital Converter (ADC) 74, and a memory module 76, but any of the above may be omitted and/or a plurality of any of the above may be provided. When the controller 20 is assembled such that the ADC 74, accelerometer 70, memory module 76, transmission means 68 and accelerometer 70 are connected to the PCB 72, the PCB 72 may be referred to as a Printed Circuit Board Assembly or PCBA.

The transmission means 68 may also be referred to as a transmission module, element, or mechanism. The transmission means 68 in-use enables transmission of a measurement output by the at least one load cell 14 to an external device, not shown. The transmission is preferably wireless but wired transmission may be an option. The transmission may be one-way only, or two-way. The transmission means 68 may include at least one of: an emitter, a receiver, and a transceiver. The transmission means 68 preferably includes at least one of: a near-field communications module, such as a Bluetooth (RTM) communication module, an RF antenna, an ANT+ network module, a BLE/ANT+ module, a FTMS module, and an FE-C module; but any alternative or additional communication mechanism may be envisioned.

An example of an external device 11 is a user's telecommunications device, such as their computer, a smartphone or a smartwatch by way of examples. Preferably, the external device 11 may be a monitor screen on the bicycle. The external device 11 may be connected to the bicycle, such as between the handle bars. This may enable the user to visualise the outputs during a cycling session.

The measurement output may be measurement data. Measurement data may include one or more raw values of electrical resistance, voltage and/or intensity of an electrical current through the load cell and/or accelerations from the accelerometer 70. Measurement data may include data calculated from raw values. The calculated data may relate to performance metrics. Examples of calculated data may include the value of a force, the average power, the maximum power, by way of examples only.

The accelerometer 70 in-use measures accelerations experienced by the pedal 10 during pedalling. Thus, the accelerometer 70 is beneficial to be able to estimate rotational force, velocity and revolutions per minute. Preferably, the accelerometer 70 is a three-axis accelerometer but this is optional, as the pedal 10 moves in a two-dimensional plane. However, if the bicycle during use turns to the left or right, the pedal 10 would correspondingly experience accelerations perpendicular to the plane, hence the benefit of a three-axis accelerometer. Furthermore, the ability to measure the pedal tilt angle may be useful during calibration and/or to calculate a force accurately, for example, if the force is not applied perpendicularly to the upper rest surface 60 and/or perpendicularly to the load cells 14. The accelerometer 70, especially a three-axis accelerometer, may enable the pedal tilt angle to be estimated. Preferably, the accelerometer 70 is mounted in close proximity to the spindle 40 and/or central line of the pedal 10.

The power source 22 in-use enables the electronic components of the pedal 10 to be electrically energised or energisable. Preferably, the power source 22 includes at least one battery. The battery may be removably received within the pedal body 12, such as within the battery holder 42. The battery may be rechargeable. As illustrated, there are two batteries. The batteries may be AA or AAA. AA or AAA batteries are small and easily sourced.

The foam body or pad 44 may fulfil one or more of the following functions. Firstly, the foam pad 44 may accommodate any tolerance between the pedal body 12 and the toe clip 24. Secondly, the foam pad 44 may capture moisture within the pedal body 12. Moisture capture may reduce the risk of damage to internal components of the pedal body 12 such as the electronics. The risk of a short circuit may be reduced. Thirdly, the foam pad 4 may provide a shock absorbing or cushioning effect for internal components of the pedal body 12.

The toe clip 24 in-use encloses or surrounds the front of the user's foot. This may increase the user's comfort. The toe clip 24 may further facilitate cycling for the user by maintaining the user's foot in the general vicinity of the pedal 10. Thus, if the user's foot becomes disengaged from the upper rest surface 60, the user does not need to look down and/or think about where to spatially position their foot to reconnect with the upper rest surface 60 as the toe clip 24 may automatically guide the foot towards the upper rest surface 60. In the case of an outdoor bicycle, the toe clip 24 may have a secondary function of shielding the foot, for example against wind, rain or mud, particularly if the user does not want their shoes dirtied. The toe clip 24 has a generally curved body 78 and at least one, and preferably two strap connectors 80.

The curved body 78 defines a toe clip volume 82 and terminates at a terminal end region 84. The terminal end region 84 overlies at least in part the upper rest surface 60.

One or more said straps 26 can be connected to one, both or each strap connector 80.

In-use, the user obtains at least one power pedal 10 and a bicycle, as per Step S100 in Figure 5. The bicycle may be fitted with two power pedals 10 but this is optional. For instance, the bicycle may have one power pedal 10 and one non-15 power pedal.

If the or at least one of the two power pedals 10 is provided in a disassembled condition such as in a kit of parts or in a part disassembled condition, the user may need to assemble the pedal 10 first by carrying out some or all of the following steps.

In no particular order, any or all of: the power source 22, the controller 20, the foam pad 44, and the or each load cell 14 are inserted into the pedal body 12. The force plate element 18 is connected to the or each load cell 14. The pedal top 16 is engaged with the pedal body 12.

If provided, the toe clip 24 is connected to the pedal body 12 and/or to the pedal 25 top 16, such as via a fastener 86 which may be a pair of screws in the illustrated embodiment.

The, each or a said strap 26 may be connected to the, each or a said strap connector 80 and strap-receiving aperture 52a.

The spindle 40 is received in the spindle cavity 38. The pedal 10 may be fitted or retrofitted to the bicycle, for instance by connecting the crank arm and the spindle 40, if the spindle is not already integrally formed with the crank arm. The pedal 10 may use standard size threads, such as 15 mm. This may enable the pedal 10 to be fitted to any or virtually any crank arm 90 without fouling the bicycle frame and/or body. The pedal 10 can be installed in seconds, such as using a 15 mm spanner. Part of a crank arm 90 of a bicycle 92 is shown in Figure 4.

Thus, a bicycle 92 is provided having a crank arm to which a pedal 10 is mounted, the pedal 10 being adapted to detect a force applied by the user.

The user positions their feet on the pedals 10 of the bicycle. If required, the pedal 10 may need to be calibrated first. Calibration may be carried out by the controller 20 if provided. Alternatively, or additionally, calibration may be carried out by the external device communicable with the pedal 10 via the transmission means 68.

Calibration may require knowledge of the user's morphology and/or weight, such 15 as their whole body weight or at least the weight of the user's legs.

The pedal 10 can be used to weigh the user and/or weigh the user's leg. For the whole body weight, the user may need to stand on one or both pedals 10 simultaneously. The at least one load cell 14 detects a force corresponding to the weight or part thereof, for calculating the weight of the user. If the user puts all their weight on a single pedal 10 adapted to detect force, the pedal 10 measures the force corresponding to the whole weight. On the other hand, if the user stands on both pedals 10, each pedal 10 will measure only pad of the force, typically around half. The transmission means 68 of the pedals 10 may be communicable with each other. Communication between the pedals 10 allows the total force measured across both pedals 10 to be summed.

The weight of the or each leg can be similarly measured by the pedal or pedals 10 if the user is seated and resting their legs on the pedals 10.

When the user wishes to use the bicycle, for example, to exercise, the user sits on the seat of the bicycle and applies a force to the upper rest surface 60 of the or each pedal 10 by pedalling. This is Step S200 in Figure 5.

There is no need for the user to have cleated shoes. In fact, cleated shoes may 5 not even be able to safely and/or stably engage with the pedal 10 due to the shoes having cleats. The cleats may be damaged and/or risk causing injury to the user.

The application of the force causes the pedal top 16 to move towards the pedal body 12. The pedal top 16 results in deflection of the deflectable member 54, directly or indirectly via the force plate element 18. If the force is applied away from the centre of the pedal top 16, the force plate element 18 may be enable the force to be detected wherever it is applied and/or with greater accuracy. In either case, the at least one load cell 14 detects the force applied to the upper rest surface 60.

Preferably, the load cell or cells 14 are pre-tensioned by the pedal top 16 and/or force plate element 18. This may aid in calibrating the load cells 14. Pre-tensioning may aid in reducing and/or preventing material fatigue of the load cells 14, which may otherwise cause the load cells 14 to provide incorrect readings over time.

If the pedal 10 further comprises an accelerometer 70, the accelerometer 70 measures the accelerations experienced by the pedal 10. Based on the accelerations, the number of pedal revolutions per minute can be estimated to provide the cadence. The force detected by the or the plurality of load cells 14 is used to calculate the torque. This may require knowledge of the length of the crank arm 90. Multiplying the torque by the cadence provides an estimate of the power.

If the controller 20 is provided within the pedal 10, the controller 20 may carry out the calculations to convert raw measurements such as from the load cells 14 and/or the accelerometer 70 into calculated data, such as one or more performance metrics, as per Step S300.

The transmission means 68 transmits a measurement output received from the at least one load cell 14 and/or from the to an external device 11 such as the 5 user's phone, computer or smartwatch, in Step S400. The measurement output may be raw data and/or calculated data.

The external device 11 displays the measurement output which may include raw data and/or calculated data, as per Step S500. For example, the external device 11 may display graphs of the force displayed, as illustrated in Figure 1. The external device 11 may show, optionally in real time, the user's power output while exercising. The data, whether raw and/or calculated, may be recorded by the memory module 76 and/or by a remote memory module, such as on a smartphone.

Optionally, the external device 11 may carry out the calculations, in addition to or 15 instead of the controller 20. The external device 11 may calculate further data, such as performance metrics. The performance metrics may be cadence, velocity, average and/or maximum power by way of examples.

When the user has finished, the pedal 10 may automatically shut down into a deep sleep mode after a specified period of time of no-detected movement and/ or, for example, when the pedal is rotated beyond a 90° angle, in other words, when the pedal tilt angle may be 90°. The rest surface 60 in this configuration may be vertical or substantially vertical. Deep sleep mode may save battery life.

Furthermore, the batteries may only activate under certain conditions, such as if the accelerometer 70 detects rotation, or if turned on by the user. The user may 25 be able to control the pedal 10 via interacting with the controller 20 and/or via the external device 11.

Whilst in the above embodiment, the pedal is preferably retrofitted to a bicycle, it may be alternatively considered that the pedal may already be provided connected to or integrally formed with a bicycle.

In an alternative embodiment, it may be envisioned that the pedal top may be the force plate element such that there is no distinct force plate element.

The cross-shape of the force plate element is beneficial as decreasing the amount of material required during manufacture and/or due to physical properties 5 of the geometry. However, the force plate element may have a non-cross shape. Any suitable shape may be envisioned, such as a square or rectangle.

In an alternative embodiment, the controller or any part thereof, such as the accelerometer, may be provided in or on the bicycle such as the crank arm thereof.

Any of the features and caveats that apply to one of the embodiments may easily be provided or applicable to any of the other embodiments.

Whilst a preferred shape may have been specified for any of the above-described features, any alternative shape may be envisioned in any of transverse or lateral cross-section, longitudinal cross-section, in side view, or in plan view. The shape may be any or any combination of: curved, part curved, non-curved, linear, part linear, non-linear, a broken line, any polygon, whether regular or irregular, having one or more chamfered and/or rounded corners, a triangle, a quadrilateral, such as a square, a rectangle, a trapezium, a trapezoid, a pentagon, a hexagon, a heptagon, an octagon, or any other polygon, a cross, an ellipse, a circle, part circular, an oval, or any abstract shape.

It is therefore possible to provide a pedal which can accurately estimate the force applied thereto by any user, including casual cyclists. No cleated-shoe is required, which allows the user to wear normal, non-cleated shoes. This is achieved by the pedal having a pedal body and a pedal top that can be moved relative to the pedal body, with one or more load cells positioned between the pedal top and the pedal body, independently of the pedal spindle. There is preferably no detection of the deflection of the spindle relative to the crank arm in the present invention. The pedal can easily be retrofitted to an existing standard bicycle. The transmission means enables one or more cycling metrics to be calculated remotely such that it is not required to include electronic calculating means inside the pedal, nor connections to electronic calculating means within the bicycle. Live performance data can also be displayed to the user.

It is also possible to provide a bicycle fitted with a pedal adapted to detect and 5 measure a force applied thereto. It is also possible to provide a method of use of the pedal to measure a force applied thereto.

The words 'comprises/comprising' and the words 'having/including' when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims (25)

1. Claims 1. A pedal for a bicycle, the pedal comprising: a pedal body; at least one load cell located on or within the pedal body; a pedal top defining an upper rest surface, the pedal top being connected to the pedal body to permit movement relative to the pedal body when a user applies a force to the upper rest surface, the at least one load cell being configured to detect the said force applied to the pedal top; and transmission means for transmitting a measurement output by the at least one load cell to an external device.
2. 2. A pedal as claimed in claim 1, further comprising an accelerometer.
3. 3. A pedal as claimed in claim 2, wherein the accelerometer is a three-axis accelerometer.
4. 4. A pedal as claimed in any one of the preceding claims, wherein the pedal has four load cells.
5. 5. A pedal as claimed in any one of the preceding claims, wherein the transmission means includes a near-field communications module.
6. 6. A pedal as claimed in any one of the preceding claims, wherein the transmission means includes an RF antenna.
7. 7. A pedal as claimed in any one of the preceding claims, further comprising a controller.
8. 8. A pedal as claimed in claim 7, wherein the controller including a Printed Circuit Board and/or an Analog to Digital Converter.
9. 9. A pedal as claimed in any one of the preceding claims, further comprising an onboard power source.
10. 10.A pedal as claimed in claim 9, wherein the power source includes a battery.
11. 11.A pedal as claimed in any one of the preceding claims, further comprising a force plate element positioned between the at least one load cell and the pedal top.
12. 12.A pedal as claimed in any one of the preceding claims, further the pedal top has a dimension and/or a position relative to the at least one load cell so as to apply a pre-tensioning force to the at least one load cell.
13. 13.A pedal as claimed in any one of the preceding claims, further comprising a foam pad.
14. 14.A pedal as claimed in any one of the preceding claims, wherein the pedal body further includes a ground-facing portion, having a ground-facing surface and a pedal-orientation correcting protrusion extending from the ground-facing surface.
15. 15.A pedal as claimed in claim 14, wherein the pedal-orientation correcting protrusion includes at least one strap-receiving aperture.
16. 16.A pedal as claimed in any one of the preceding claims, further comprising a toe clip.
17. 17.A pedal as claimed in claim 16, wherein the toe clip includes a strap connector.
18. 18.A pedal as claimed in any one of the preceding claims, further comprising a strap.
19. 19.A pedal as claimed in any one of the preceding claims provided as a kit of parts.
20. 20.A bicycle including a pedal as claimed in any one of the preceding claims.
21. 21. Method of use of a pedal, the method comprising the steps of a] providing a bicycle having a crank arm to which a pedal as claimed in any one of claims 1 to 18 is mounted; b] applying a force to the upper rest surface of the pedal and the load cell detecting the force applied to the upper rest surface; and c] the transmission means transmitting a measurement output by the at least one load cell to an external device.
22. 22. Method as claimed in claim 21, wherein in step a] the pedal further comprises an accelerometer, the method comprising a further step before, during or after step b] of c] estimating via the accelerometer the number of pedal revolutions per minute for estimating the cadence.
23. 23. Method as claimed in claim 22, comprising a further step of d] obtaining the force detected by the load cell and calculating the torque based on the length of the crank arm, obtaining the cadence, and multiplying the torque by the cadence to obtain the power.
24. 24. Method as claimed in any one of claims 21 to 23, comprising a further step prior to step a] of: mounting a pedal as claimed in any one of claims 1 to 18 to the crank arm of a bicycle.
25. 25. Method as claimed in any one of claims 21 to 24, wherein in step b] the force applied to the upper rest surface is provided by the user standing on one or both pedals of the bicycle so that the at least one load cell detects a force corresponding to the weight or part thereof, for calculating the weight of the user.