Abstract: Provided is an apparatus for testing an associated tire. The apparatus may comprise a substantially transparent test platform. The test platform may comprise a low friction test surface. The low friction test surface may comprise a layer of lubricant. The layer may be less than 3 millimeters thick The apparatus may further comprise an optic or acoustic data acquisition system or appliance. The optic or acoustic data acquisition system or appliance may comprise either a camera positioned to view the test surface through the substantially transparent test platform, or ultrasonic equipment positioned to acquire data regarding the test surface through the substantially transparent test platform.

Abstract: A system for locating and tracking an object is provided. The system includes a measuring device configured to determine a property of a paving-related material, a locating device configured to determine a location of the measuring device, a tracking system configured to store tracking information associated with the measuring device and one or more properties determined by the measuring device, and a communications system configured to transfer, to a remote device, the location of the measuring device and the tracking information associated with the measuring device.

Abstract: Provided is a loading device that is provided in a tire testing machine including a testing station (30) provided with a spindle (31) attached with a tire (50) to be tested and feeds the tire (50) from a predetermined standby position to a testing position where the center of the spindle matches the center of the tire (50) in the testing station (30). The loading device includes: conveyors (1, 2) that convey the tire (50) from the standby position toward the testing position in a direction perpendicular to the axial direction of the tire; and positioning devices (6B, 20) that position the tire to be tested to a position, in which a front end of the tire in the feeding direction matches a point separated from the spindle by a predetermined distance, as the standby position. Setting of the standby position based on the position of the front end of the tire (50) in the feeding direction shortens the feeding distance and the feeding time and hence shortens the testing cycle time.

Abstract: A tire testing machine includes a tire and wheel assembly having a sensor configured to measure a parameter related to the tire and wheel assembly as it rotates on a rotating element. A holder supports the tire and wheel assembly. A processor is configured to receive an input at least based on the output signal from the sensor, and provide an output signal indicative of a parameter of a contact patch between a tire of the tire and wheel assembly and the rotating element. Controlled element(s) are configured to vary a parameter related to the contact patch and/or friction.

Abstract: A non-pneumatic tire may include a support structure having an inner circumferential portion configured to be associated with a hub. The tire may further include a tread portion associated with an outer circumferential portion of the support structure. The tire may also include at least one sensor associated with at least one of the support structure and the tread portion and configured to generate signals indicative of at least one characteristic associated with at least one of the support structure and the tread portion. The tire may further include a receiver associated with at least one of the support structure and the tread portion and configured to receive signals from the at least one sensor. The tire may also include a transmitter associated with at least one of the support structure and the tread portion and configured to transmit the signals to a location remote from the tire.

Abstract: A tire uniformity machine includes an apparatus for receiving and rotating a tire. The apparatus includes opposed spindles for receiving, inflating and rotating a tire, and a load wheel applied to the rotating tire to obtain tire test results. A spindle alignment assembly is associated with the opposed spindles to align the spindles with one another each time a tire is received. At least one characterizing device is associated with components of the apparatus to characterize forces of the opposed spindles and the characterized forces are used in adjusting tire test results.

Abstract: A device and a method for obtaining information about a wheel, the device including a penetrating body for at least partially inserting between a tire and a rim of a wheel, and a unit for acquiring the images, the unit being installed on a portion of the penetrating body which is designed to be positioned in an internal space between the tire and the rim.

Abstract: A road surface management system is capable of detecting road surface conditions that tend to damage dump trucks and displaying the positions of such road surfaces. When the traveling speed of the dump truck is higher than or equal to a preset threshold value, the server judges whether or not each of the pressures of suspensions of the dump truck detected by pressure sensors is within a reference range which has been set corresponding to each suspension. The server judges that the road surface at the position of a dump truck is in a poor condition if one of the pressures of the four suspensions of the dump truck is judged to be outside the reference range and the remaining three pressures are judged to be within the reference range. The positions of the road surfaces judged to be in the poor condition are displayed on an indicator.

Abstract: In order to improve general versatility that allows a user of a tire testing machine for testing a tire to flexibly change the contents of tests, a control mechanism for the tire testing machine is configured to include a tire testing controller for testing the tire according to a recipe, a changing test specification storage section for storing therein a changing test specification which is a program describing a criterion for determination of whether the order of next tests following the test described in the recipe is to be changed, as well as contents of changing of the order of the tests for the respective tests described in the recipe; and a changing determination section for determining whether the contents of the tests stored in the recipe are to be changed based on a measurement result given by the tire testing controller and the criterion for determination described in the changing test specification every time each test performed in the order described in the recipe is finished.

Abstract: A monitoring device and system for monitoring the conditions inside a pneumatic tire are disclosed. The monitoring device includes a sensor unit, a shell, and an encapsulant. The monitoring device is designed to roll on the inside of a tire or to float on a liquid inside of a tire.

Abstract: An automatic inspection system is provided for monitoring rail track for detecting and generating alerts for certain hazards to the operation of trains that may cause various safety concerns and even derailment. The monitoring is during normal railway service runs without interrupting the normal railway services. In one implementation, an imaging module is used on a passenger or freight train to capture video images of the rail track under the train in motion. In one implementation, the captured video images are automatically processed in a computer using a software module which is based on digital image processing techniques and algorithms to determine whether an irregularity is present on the rail track. In one implementation, video images containing detected irregularities on the rail track are transmitted to a control center for further analysis and possible alert.

Abstract: A touch-control tire pressure sensor device includes a housing holding an air nozzle at one side thereof, a circuit board accommodated in the housing and carrying a processor and memory unit having electrically coupled thereto a pressure sensor unit, a temperature sensor unit, an acceleration sensor unit, a LF transmission interface and a RF transmission interface for transmitting a sensed signal to an on-vehicle main unit, a battery pack providing the circuit board with the necessary working voltage, and a conducting plate having one end connected to the touch sensor IC and an opposite end kept in contact with the air nozzle.

Abstract: A tire testing machine of the present invention performs tests on a tire in a testing station, and prints a mark based on the test result in a predetermined mark position of the tire after undergoing the tests by means of a marking device. A controller of the tire testing machine previously stores therein the contents of the tests for performing the tests, and causes the testing machine to perform the tests according to a recipe. In order to freely set the marking setting conditions for marking in the marking device, the controller of the marking device previously stores therein a first marking setting condition as the recipe, and also stores therein a second marking setting condition different from the recipe by an input device as a script. Marking is performed according to the contents of the marking setting condition described in either the recipe or script selected.

Abstract: A marking device of the present invention includes a sequence of two belt conveyers for conveying a tire after undergoing a test by a tire testing machine, a pair of laser sensors each installed in a predetermined position in a conveyance direction of the tire by the belt conveyer, and adapted to detect an edge of the tire, and a controller for controlling a motor for driving the belt conveyer based on an output from the laser sensor. The controller is operable to convey the tire by a conveyance distance calculated based on a distance from an installing position of the laser sensor to a print position, an outer diameter of the tire and a predetermined mark position when the edge of the tire is detected by the laser sensor, and then to stop the tire, whereby the mark position of the tire is aligned with the print position.

Abstract: An external tire pressure sensing device includes from bottom to top along it axial direction a base, a sensor for detection of the internal pressure of tire, a circuit board for incorporating a control circuit therein, a button battery and a packaging suite.

Abstract: A tire pressure sensor device includes a tire pressure sensor including a housing and a mounting block defining a through portion in a coupling means thereof, and an air valve including an extension rod having a rod body rotatably inserted through the through portion and a stop block located at one end of the rod body and rotatable with the rod body between a first angular position where the stop block is kept in accurate alignment with the through portion and axially movable with the rod body through the through portion for allowing separation between the tire pressure sensor and the air valve and a second angular position where the stop block is stopped at the coupling means of the mounting block in a staggered manner relative to the through portion to prohibit separation between the tire pressure sensor and the air valve.

Abstract: To prevent occurrence of a slip between a tire and a drum and a flat spot on the tire and to reduce cycle time at a time of testing the tire, this tire testing method includes causing a control mechanism to control a motor to drive the tire to rotate at a predetermined rotational speed lower than a specified rotational speed if a linear sensor detects that the tire transported onto a center conveyor is sandwiched between an upper spindle and a lower spindle, and to control a moving mechanism to move a drum until the drum contacts the tire that rotates at the predetermined rotational speed. If a load cell detects the contact between the tire and the drum, then the control mechanism accelerates the rotation of the tire from the predetermined rotational speed to the specified rotational speed and increases a load applied to the tire by the drum, and the tire is tested.

Abstract: A tire inspection apparatus for the optical inspection of a tire (4) comprises a housing with a support surface (3) for the tire (4) to be inspected; several measuring heads (7, 8, 9, 10; 12, 13, 14, 15, 16, 17), each of which comprises an optical measuring system, for inspecting the inside tread surface (11) and/or the external lateral surface (18) of the tire (4); and a positioning device (21, 22, 23, 24) for moving some or all of the measuring heads (7-10; 12-17) into a rest position and into a measuring position. To improve a tire inspection apparatus of this type, the measuring heads (7-10; 12-17) and the support surface (3) are installed without freedom of rotation.

Abstract: A cable depth gauge and method for determining the depth of a cable embedded in a sidewall of a tire, the cable depth gauge comprising an elongate body having a proximal end and a distal end, the proximal end having an indicator point set to reference a surface of the tire, the elongate body having a width to determine eligibility if the repair hole being examined meets the minimum size for the repair process and a first measuring region and a second measuring region located at the proximal end of the elongate body, the first measuring region and the second measuring region being at a known distance from the indicator point.

Abstract: This invention is directed to test devices and methods using subscale cylindrical laminates formed from general rubber composite plies as surrogates for full-size tires to predict how changes in the tire construction would impact tire cornering stiffness of the full-size tires.

Abstract: Disclosed is a multi-component force measurement spindle unit that accurately measures forces and moments applied to a tire in a tire testing machine. The multi-component force measurement spindle unit of a tire testing machine includes: a spindle shaft on which a tire can be mounted; an inner sleeve that rotatably supports the spindle shaft via a bearing part; an outer sleeve arranged on an outside of the inner sleeve along an axial center direction of the spindle shaft; a multi-component force measurement sensor that connects an end of the inner sleeve and an end of the outer sleeve to each other and is capable of measuring a load acting on the outer sleeve from the inner sleeve; and a cooling part that cools the inner sleeve.

Abstract: An apparatus and method for high voltage discharge testing of a tire is disclosed. In particular embodiments, a high voltage probe is maintained against the surface of a tire. The high voltage probe is energized and relative motion is provided between the surface of the tire and the high voltage probe. At the presence of an anomaly that penetrates the insulating material of the tire surface, an electrical discharge will occur between the conductive spring electrode and a reference electrode. The reference electrode is positioned adjacent the bead portion of the tire such that the electrical discharge will travel from the high voltage probe through the anomaly in the surface of the tire to one or more carcass plies in the tire. The carcass plies will carry the electrical discharge to the bead portion of the tire, where the electrical discharge will pass to the reference electrode.

Abstract: A tread wear indicator is affixed to a respective tire tread element. The indicator is constructed as a plurality of radially stacked sensor elements operatively configured and located to sequentially sacrificially abrade and change in electrical resistance responsive to a progressive tread wear of the respective tread element. The sensor elements are connected by circuitry that communicates a data signal from the sensor elements to a data processor indicative of a change in cumulative resistivity of the sensor elements. The data processor receives the data signal from the sensor elements and determines a radial wear level of the tread element based on the data signal. Multiple tread wear indicators may be mounted to respective tread lugs across the tread to derive a tread wear status based upon the tread wear profiles of the respective lugs.

Abstract: A method of installing a tread wear sensor in a tire includes configuring multiple tread wear indicators to each include a stack of sacrificial resistive sensor elements. The stacks of resistive sensor elements are affixed to respective selected tread lugs positioned at dispersed axial locations across a tire tread region. The resistive sensor elements sacrificially abrade and a change in resistance in each stack is measured. Connector assemblies within the tire carcass cavity are positioned radially opposite the selected tread lugs. A needle projection from each of the connector assemblies is inserted radially outward through the tire carrying leads which engage and establish electrical contact with a respective stack of resistive sensor elements.

Abstract: In a method for alerting to the wear of a tire that includes a tread strip equipped with at least one circumferential groove, the running noise made by the tire running along a ground is measured, from the measured running noise, a noise emitted in a predetermined range of frequencies close to a predetermined resonant frequency of a portion of the circumferential groove during running is isolated, the amplitude of the isolated noise is measured, and the measured amplitude is compared against a predetermined alert threshold.

Abstract: A subscale test cylinder for testing tire performance characteristics, wherein the cylinder comprises components found in a tire sidewall to be simulated, wherein the components consist of cords, sidewall compounds and beads.

Abstract: The invention provides a tread thickness measuring method for accurately measuring the tread thickness from a belt surface located in an outermost position in a tire to the tread surface by an ultrasonic measurement irrespective of the material of the belt. The method includes the steps of spraying the same liquid as the liquid pooled in a tank on the tread surface of the tire under inspection before immersing the tread surface in the liquid in the tank and measuring the depth of the belt located in the outermost position in the tire by emitting ultrasonic waves to the tread surface immersed in the liquid in the tank and receiving the reflected waves.

Abstract: One exemplary embodiment includes a method comprising providing a tire having a component constructed and arranged to cause at least one portion of the tire to have a first stiffness or resistance to force exerted thereon under a first condition and a second stiffness or resistance to force exerted thereon under a second condition and selectively causing the first or second condition to occur.

Abstract: Systems and methods for improving tire uniformity include identifying at least one candidate process harmonic and corresponding period. A set of uniformity waveforms is then collected for each test tire in a set of one or more test tires. To provide better data for analysis, the collection of waveforms may include multiple waveforms including measurements obtained before and/or after cure, in clockwise and/or counterclockwise rotational directions, and while the tire is loaded and/or unloaded. The uniformity waveforms may be re-indexed to the physical order of the at least one candidate process harmonic, and selected data points within the waveforms may optionally be deleted around a joint effect or other non-sinusoidal effect. The re-indexed, optionally partial, waveforms may then be analyzed to determine magnitude and azimuth estimates for the candidate process harmonics. Aspects of tire manufacture may then be modified in a variety of different ways to account for the estimated process harmonics.

Abstract: The invention relates to a method for estimating the dynamic load borne by a tire of a vehicle running along over a given period, whereby the pressure is measured during the period, at each pressure measurement point, the pressure, known as the reference pressure, of the same tire subjected to a load that is constant and known per time interval is determined, and the variation in load is calculated from the difference between the measured pressure and the pressure, known as the reference pressure, and from a model of the tire devised beforehand and that relates a variation in load to a variation in pressure. The invention also proposes a method for estimating the load borne by a tire.

Abstract: Provided is a method for testing a tire. The method may comprise performing a first stopping distance test on a tire of a first specification at a first inflation pressure and gathering data about the first stopping distance test. The method may further comprise performing a second stopping distance test on a tire of the first specification at a second inflation pressure and gathering data about the second stopping distance test. The method may further comprise performing a first traction test on a tire of the first specification at either the first inflation pressure or the second inflation pressure and gathering data about the first traction test.

Abstract: A method for detecting a wear condition of a tire utilizes tread pattern elements included on the tire. The elements are adapted to generate first and second acoustic footprint noises (BEA1, BEA2), with one of the first and second acoustic footprint noises being characteristic of the wear condition of the tire. According to the method, a parent frequency spectrum, which is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, and a child frequency spectrum, which is capable of forming a frequency spectrum of the other of the first and second acoustic footprint noises, are selected from a frequency spectrum of an acoustic signal acquired from the tire. Two detection confidence indices are determined. If each detection confidence index meets a predetermined condition, a warning is emitted indicating that tire wear has been detected.

Abstract: A tire-condition-ascertaining cartridge (100) comprising a scaffoyer structure which performs both scaffolding and fluid-foyer-forming functions. The scaffoyer (600) includes planks and/or derricks which properly posture a first fitting (200), a second fitting (300), an electronics assembly (400), and a power source (500) during cartridge construction. The scaffoyer (600) also forms a fluid foyer to the sensing site and this foyer can be tested for fluid integrity (e.g., leaks) prior to creating the housing capsule (800).

Abstract: Systems and methods of determining tire uniformity parameters from piezoelectric tire sensor output signals obtained while operating in the counter-deflection zone include establishing a transfer function that relates a tire uniformity parameter to the piezoelectric output signals. Piezoelectric output signals from two or more piezoelectric tire sensors are then monitored to measure the voltage change from each piezoelectric tire sensor while it is operating in the counter-deflection zone. These output signals are correlated, and an actual tire uniformity parameter value is determined by applying the measured and correlated piezoelectric output signal voltage change levels to the established transfer function. Actual tire uniformity values are ultimately provided as electronic output to a user.

Abstract: Provided is a tire testing machine including: a spindle shaft that rotatably attaches a tire as an inspection target thereto; a tire outer shape measurement sensor that moves close to the tire or moves away from the tire and detects a deformation amount of an outer shape and a diameter of the tire attached to the spindle shaft; and a collision preventing sensor that includes a probe formed in a linear material and a contact detecting portion detecting a state where the probe contacts the tire in order to prevent the tire outer shape measurement sensor from colliding with the tire, wherein the probe has a bent or divided shape in order to ensure a wider contact detecting range contacting the tire.

Abstract: Frames of data are received. Each frame includes at least a sensor identifier and a changeable data field and is sent from one of a plurality of sensors. Each of the plurality of sensors is associated with a respective one of a plurality of sensor identifiers. The changeable data field includes, in some of the frames, data representing a sensed condition and, in others of the frames, counter data. The counter data is analyzed to determine whether any of the sensor identifiers can be associated with one of a plurality of sensor locations.

Abstract: A simple method and apparatus for accurately estimating the contact patch shape of a moving tire. The vibration waveforms of a tire (20) with sipe rows (25A, 25B) formed at the respective pitches (Pa, Pb) in the left and right shoulder lands (24a, 24b) are detected by an acceleration sensor attached to a knuckle of the vehicle. Rotational order spectrums are obtained by performing a rotational order analysis on the vibration waveforms. The peak height (Za) of the rotational order (na) corresponding to the pitch (Pa) and the peak height (Zb) of the rotational order (nb) corresponding to the pitch (Pb) are extracted from the rotational order spectrums.

Abstract: A method for determining a load exerted on a tire, fitted on a vehicle, during running of the vehicle on a rolling surface, is disclosed. The method includes acquiring a first signal comprising a first signal portion representative of a radial deformation; measuring an amplitude of the radial deformation in the first signal portion; estimating a rotation speed of the tire corresponding to the radial deformation; estimating an inflation pressure of the tire corresponding to the radial deformation; and deriving the load exerted on the tire from the amplitude, the rotation speed, and the inflation pressure. The first signal portion is representative of the radial deformation to which a first tread area portion of the tire is subjected during passage of the first tread area portion through a contact region between the tire and the rolling surface. A system for determining the load exerted on the tire is also disclosed.

Abstract: A vehicle wheel service apparatus, in particular a wheel balancer or a tyre changer, comprising a load means for applying a predetermined load onto a peripheral surface of a wheel/tyre assembly, a sensor device arranged to determine forces acting between the peripheral surface of the wheel/tyre assembly and the load means, wherein the forces comprise at least a first force acting in a radial direction of the wheel/tyre assembly and a second force acting in a circumferential direction of the wheel/tyre assembly, and an evaluation device arranged to determine a rolling resistance coefficient of the tyre on the basis of the first and second forces.

Abstract: An attachment support, which is designed for attaching a module to a wall (101) of a tyre (100), includes a substantially flexible body (11) of substantially elongate shape. The body (11) includes a connecting surface (26) capable of being placed substantially permanently against an internal wall (101) of the tyre (100), a second, free surface (28) opposite to the connecting surface (26), and at least one substantially cylindrical housing (20). The housing (20) has an axis at right angles to the second, free surface (28) of the body (11) and is open on the second, free surface (28). The housing (20) includes a first substantially cylindrical portion (22) extended by a chamber (21) of substantially cylindrical shape and coaxial with the first portion (22). The chamber (21) has a diameter greater than the diameter of the first portion (22) of the housing (20).

Abstract: There is provided a warning device for detecting attachment integrity issues of a wheel assembly of a vehicle while the vehicle is in motion, the system comprising: a rigid body having: a first side and a second side to define an axis there between; a plurality of circumferentially distributed apertures extending axially between the first side and the second side, such that a spatial distribution of the plurality of circumferentially distributed apertures corresponds to a spatial distribution of wheel hub studs configured to receive a rim of the wheel; a plurality of wheel nut mounting locations positioned about each of the plurality of circumferentially distributed apertures on the first side, each of the plurality of wheel nut mounting locations having a mating surface for mating with an underside of a respective wheel nut; one or more rim mounting surfaces on the second side for mating with an outwardly facing exterior surface of the rim; and a plurality of indicators positioned adjacent to each of the plu

Abstract: A system for monitoring the pressure in the tires of a plurality of wheels of a motor vehicle comprises a first sensor module that comprises at least one sensor measuring the angular velocity of at least part of the plurality of wheels of the motor vehicle. A means is provided for determining, from the angular velocity of at least part of the plurality of wheels of the motor vehicle, a signal indicative of a first value of the heading of the motor vehicle. A second sensor module generates a signal indicative of a second value of the heading of the motor vehicle, and an abnormal situation with the pressure in at least one of the tires is determined when the first value of the heading of the motor vehicle and the second value of the heading of the motor vehicle are not consistent with one another.

Abstract: A tire performance indicator for a tire includes at least one tread wear indicator region structured and arranged in a tread region of the tire and at least one performance symbol guide structured and arranged approximate a sidewall region of the tire.

Abstract: In a method for checking vehicle tires, wheel sensor signals of at least one wheel of the vehicle are recorded over a time period, and a comparative value is determined to indicate a travel distance of the wheel. A reference travel distance covered by the vehicle in the time period is determined independently of the wheel sensor signals, and an individual ratio value of the wheel is formed from the wheel travel distance and the reference travel distance. The behavior of the ratio value over time is determined, and a determination is made concerning changes to the tire of the wheel.

Abstract: A dynamic load estimation system is provided including: a vehicle load bearing tire; at least one tire sensor mounted to the tire, the sensor operable to measure a tire deformation of the one tire and generate a raw load-indicating signal conveying measured deformation data; road roughness estimation means for determining a road roughness estimation; filtering means for filtering the measured deformation data by the road roughness estimation; and load estimation means for estimating an estimated load on the one tire from filtered measured deformation data. A road profile estimate is fused with the static load estimate in order to obtain an instantaneous tire load estimate.

Abstract: A system for predicting tire casing life remaining for a casing in a tire, the system including: a tire condition measurement unit that measures one characteristic value including tire internal pressure information indicating at least one of a tire condition and a vehicle running condition; a temperature history estimation unit that estimates a temperature history of at least one location in at least one casing structural member based on the characteristic value; a member physical property calculation unit that calculates at least one current physical property value of the at least one casing structural member that degrades due to tire internal air temperature based on at least the tire internal pressure information and the temperature history; and a remaining drivable distance prediction unit that predicts a drivable distance of the tire until the current physical property value reaches a physical property value limit set in advance.

Abstract: A tire shape inspection method executes the following steps: first, as a teaching operation step, boundary lines of the bulge and dent marks are detected in a sample source image of a sample tire, a mask image is generated which denotes the boundary lines, regions are removed from the sample source image which correspond to the boundary lines which are denoted in the mask image, and a height offset image is generated which represents the heights of the remaining regions with one or more offset values. Next, as an inspection operation step, the height offset image is subtracted from an inspection image of the inspection tire, the boundary regions which the mask image represents are removed, and, on the basis of the obtained bulge/dent removal image, shape defects of the sidewall surfaces of the inspection tire are inspected.

Abstract: A tyre changer, comprising: a mounting device for receiving at least a wheel rim of a wheel/tyre assembly, the mounting device having an axis (S), a load belt apparatus being able to contact a peripheral surface of the wheel/tyre assembly and to apply a predetermined force to the peripheral surface of the wheel/tyre assembly, a control device for controlling the predetermined force applied by the load belt apparatus during a rotation of the wheel/tyre assembly about the axis (S) of the mounting device and a sensor device for measuring force variations acting between the peripheral surface of the wheel/tyre assembly and the load belt apparatus, wherein supports of the load belt apparatus and of the mounting device are designed for a relative movement of the load belt apparatus and of the mounting device towards each other to apply the predetermined force to the peripheral surface of the wheel/tyre assembly.

Abstract: Systems and techniques are provided for managing an interface between a machine or work vehicle and a surface that the machine/work vehicle travels on in order to provide an optimum work performance level that balances fuel efficiency and surface adversity. Fleet management and reporting capabilities pertaining to such interface management are also provided.

Abstract: An energy harvesting system and method includes a rotatable member with an electrically conductive coil mounted to the rotatable member and adapted to move with the rotatable member such that the movement of the coil through a magnetic field induces a voltage in the coil. An energy storage device is coupled to the coil.