Patent Application
20170208890
The present invention relates to a system for a shoe sole with at least one module comprising at least one piezoelectric element.
To many people, sport is an integral part of their life. For instance, people go running to improve their fitness and to live a healthy lifestyle. With the advent of smartphones, it has also become common to monitor one's training performance during or after the training for improving the training, and even for sharing the results with friends, for instance via social networks.
To this end, various approaches are known to obtain data, such as number of steps, distance travelled, cadence, pace, speed, and so on. For instance, smartphones provide apps which may be used for monitoring activities via integrated sensors such as GPS sensors and/or motion sensors in the smartphone.
Other approaches involve sensors which are placed somewhere on the person or the sports apparel, e.g., the shoes. Prior approaches involve sensors placed somewhere in the sole of a shoe to measure at least some of the above mentioned parameters. During or after the workout, the measured parameters may then be transferred to a monitoring device such as a smartphone.
Most of the above mentioned sensors include a battery to be able to measure the desired data. As a consequence, from time to time the battery becomes empty and needs to be replaced with new a new battery. For some sensor models, it may even be necessary to replace the complete device. It is apparent that these solutions pose a significant burden on the environment. Consequently, further approaches have been considered by the industry.
One example of other sensors involves piezoelectric elements for generating energy during an exercise which may be stored or used for operating the respective sensors.
For example, the U.S. Pat. Appl. Pub. No. 2013/0028368 relates to a pedometer for a shoe. An electromotive unit comprising a piezoelectric element produces an electric current in response to a pressure applied thereto when a user lands with his foot on the ground. The electric current is provided to an external pedometer unit to perform counting of steps.
Another solution is disclosed by the article “Insole Pedometer With Piezoelectric Energy Harvester and 2V Organic Circuits” by Ishida et al., published in IEEE Journal of solid-state circuits, Vol. 48, No. 1, January 2013. Ishida describes a shoe insole pedometer which consists of a piezoelectric energy harvester and includes a pseudo-CMOS 14-bit step counter that records the number of steps using the harvested power. Each time the insole is pressed by the foot during walking the piezoelectric energy harvester, which is a rolled polyvinylidene difluoride (PVDF) sheet, generates a pulse. Other PVDF rolls which are also included in the shoe sole may be used as power supply for the organic circuits.
The U.S. Pat. Appl. Pub. No. 2014/0088917 also discloses a step counter with energy scavenging functionality. To this end, a step-counter device detects and counts user steps. The device includes a transducer, which could be of the piezoelectric type, which is configured to generate an electrical transduction signal in response to user stepping. An energy-scavenging system is coupled to the transducer to generate a power supply voltage in response to the electrical transduction signal. A processing unit is powered by the power supply voltage. The processing unit is further configured to sense the electrical transduction signal and determine whether a user step has occurred and in response to that determination increment a step counter.
While the above approaches somewhat contribute towards a reduction of adverse effects on the environment, from a practical point of view they still have various disadvantages. For instance, such sensors are complex to manufacture, are relatively big and may not be practical to use in various conceivable situations. For example, it may not be possible to use the sensors or the obtained data when not using the shoe, e.g., during a short break or after the workout.
Objectives underlying the present invention include providing improved piezoelectric sensor systems to be used for monitoring various parameters, which are easy to produce, conveniently small to be placed internally of the shoe sole, and which provide a superior usability to the athlete.
These objectives are at least partly solved by a system for a shoe sole with at least one module, the module including at least one piezoelectric element adapted to produce an electrical signal upon mechanical deformation of the at least one piezo element (herein also referred to as piezoelectric element). The electrical signal is adapted to be used as signal for deriving at least one motion parameter of the shoe sole. The system further may include at least a first energy storage and a second energy storage, the at least first energy storage and second energy storage being adapted to store electrical energy obtained from the electrical signal, and the second energy storage is loaded only after the first energy storage reaches a first energy threshold.
The use of modules including piezoelectric elements offers various advantages such as avoiding the necessity of external power sources. Nevertheless, creating its own energy from scratch also means that in order to being able to use the modules and the system, a certain amount of initial motion of the wearer of the shoe is necessary, to create a minimum amount of energy that is required for operating the system and the modules. The reason is that only if sufficient energy is available, electric signals may be processed and parameters may be determined (and, e.g., locally stored) in the system.
By providing a first energy storage which may be used to quickly operate the system, or at least the most important parts thereof, a proper function of the system may be ensured. The storage size of the first energy storage (e.g., capacitance) may be kept as small as possible so as to get the basic functionality (e.g., one or more control elements such as logic integrated circuit, or “IC” and/or regulator IC) to run. Having a small capacitance, the voltage in the capacitor will rise faster due to the relationship U=Q/C, where C is capacitance, Q is charge and U is voltage. However, the capacitance cannot be too small, because when the basic control elements start to work, they will take extra start up power/charge which causes a voltage drop in the capacitor. The step counting may then start in the control logic (e.g., in the logic IC). On the other hand, by additionally providing a second energy storage which is charged only when the first energy storage reaches a first energy threshold (and remains above that threshold), further functionality may be used. When the control elements (e.g., regulator IC and logic IC) are running, they will take certain amount of power/charge. The extra power/charge is loaded to the second energy storage (e.g., a capacitor). When the energy stored in the second energy storage (e.g., the capacitor voltage reaches certain level), the control element (e.g., logic IC) may allow to turn ON additional control elements such as a microcontroller or a controller for remote transmission (e.g., a Bluetooth Low Energy (BTLE), Bluetooth, Bluetooth Smart, IrDA, Near Field Communication (NFC), cellular network, ZigBee, Wifi, or other controller using suitable standards). These elements will draw a certain amount of power/charge and it is feed from first capacitor via another control element (e.g., a regulator IC). In one example, the second capacitor supports the first capacitor via a feedback diode, which may be a Schottky type diode.
The term sole as used in this document may refer to an insole or a midsole.
The system may also include a third energy storage being adapted to store electrical energy obtained from the electrical signal.
The capacity of the third energy storage may be larger than that of the first and the second energy storages so that when the athlete has to pause for a moment or even after the activity, data may be transferred from the system to an external and remote device, such as a smartphone, smartwatch, tablet computer, personal computer or another device. This is advantageous because it can be ensured that the time needed for getting the module ready is reduced by using the first energy storage without taking the risk that meanwhile the energy has been used for other, less necessary, aspects such as data transmission to a remote device, operation of LEDs and so on. It is therefore better to have separately controllable storage devices. As with the other capacitors, the type of third capacitor may be super cap, thin film lithium battery or similar. The leakage current in the third energy storage should be as small as possible to keep the charge several hours/days. For example, this may be achieved by suitable selection of the storage device, e.g., the capacitor. For instance, some capacitors may have lower leakage than other capacitors. In one example, the third energy storage may also be charged in the factory during manufacturing process. However, alternatively or in addition it may also be charged during use. In one example, the third energy storage is loaded only after the second energy storage has reached a threshold voltage.
The system may be provided so that the first energy storage is adapted to supply energy for processing the derived at least one motion parameter, wherein the second energy storage is adapted to supply energy for a control element and/or radio frequency functionality, and wherein the third energy storage is adapted to supply energy for transmitting the derived motion parameters. In one example, if three capacitors are used as energy storages, the capacities of the respective capacitors may be as follows: First capacitor: 40-100 μF; Second capacitor: 100-200 μF; Third capacitor: 2-15 mF.
The third energy storage may be adapted to supply energy for transmitting motion parameters (e.g., to a remote device), when the shoe sole is not moving and the piezoelectric elements are not deformed. As an example, the motion parameters determined can be transmitted to a remote device such as a smartphone, smartwatch, tablet computer, personal computer or another suitable device. It may be advantageous and convenient to monitor the obtained data at a remote device (e.g., during a short break or after the workout). Known solutions do not offer such convenient access to the data because the devices only generate energy that is available while using the device. There is no energy storage for providing energy during breaks or, at least for some time, after the workout that is sufficient for transferring the data from the module to the remote device. However, this concept may also be applied to the second energy storage.
The system may also comprise a control element, wherein the control element is adapted for controlling and/or monitoring the energy levels of the energy storages. The term control element used herein may refer to a microcontroller, a logic element, a programmable logic element, or other active IC component. In one example, the main control element in this system has a programmable logic. Control elements have advantageous properties for controlling the system and in particular the modules. For instance, the control element can control the energy flow in the system and in particular from the piezoelectric sensor to the various energy storages. It may also be configured to operate the RF device, e.g., the antenna. Data transmission via the RF device such as the antenna may occur periodically or aperiodically. For instance, in aperiodic transmission scenarios, data may only be transmitted when a buffer is full or upon specific user interaction (e.g., by pressing a button). The specific user interaction may also involve the reception of a request signal from the remote device (e.g., during or after the workout). This may be advantageous if it is not necessary to constantly monitor the measured parameters. Different control elements may be used for different purposes as will be explained in more detail below.
Further, the system may comprise at least one power valve for controlling the energy flow to the first and the second energy storages or, if present, between the first and the third energy storages and/or between the second and the third energy storages. Depending on the number of energy storages, the number of power valves may vary. For instance, there may be one dedicated power valve for each energy storage. The power valve may advantageously control when to use the first energy storage and when to use the second energy storage, or, more generically, when to use any of the energy storages. In this way, an improved operation and use of available resources can be obtained.
The energy storages can be capacitors, supercapacitors, thin film lithium batteries, or other types of suitable energy storages. Of course, various combinations of any of these types may be used. For instance, the first energy storage may be a capacitor, and the second energy storage may be a thin film lithium battery. In this way, different properties and advantages of the respective type of energy storage may be optimally used. As an example, an energy storage of a first type may quickly charge but cannot hold the stored energy for a longer time period. Another energy storage may need longer to charge but be able to store the energy for a longer time period.
The system may be operated by using only energy obtained from the electric signal of the piezoelectric elements. In this way, the system is self-sustained and completely independent from external energy sources. This allows for a hermetically sealed construction of the system because it is not required to provide access to any of the components or to maintain an external interface for plugs for charging or other purposes. By sealing the system, it is water proof and the mechanical construction becomes less complex because no openings (like battery covers) are needed. This way of construction also allows for a simpler construction of the sole. It is noted that every embodiment as described herein may be provided as a hermetically sealed construction.
The piezoelectric element may comprise at least two piezoelectric plates. By using more than only one plate of a piezoelectric element, it is possible to create more energy while exerting force. Since all of the plates of the piezoelectric elements may be deformed and thus create an electric signal, using two or more of them can be advantageous if more energy is needed than can be created by using a single-plated piezoelectric element.
Further, the system could comprise an antenna for transmitting data obtained from the electrical signal. The antenna could be integrated into the module, but it could also be provided external to the module. In one example, the antenna may be flexible and formed within the insole of the shoe. By having an external antenna, a better transmission of data may be realized.
The module may further comprise a rectifier for processing the electrical signal to be stored in one of the energy storages. The electric current from the piezoelectric elements is alternating current (AC), and the rectifier converts the AC current into a direct current (DC) to be provided to the energy storages. Consequently, the rectifier allows use the electric current and thus electrical energy resulting from deformation of the piezoelectric elements in both directions.
The system may comprise a radio frequency device, wherein the radio frequency device is adapted to transmit and/or receive data to and/or from an external and remote device. In one example, the data may be transmitted in accordance with the Bluetooth Low Energy (BTLE) standard. Other possible transmission standards may involve ZigBee, Near Field Communication (NFC), Bluetooth, Bluetooth Smart, IrDA, WiFi, cellular network standards or other suitable standards.
The system may comprise additional sensors to measure specific movements of the shoe, e.g. accelerometer(s) to get distance, speed, pace, movement time, gyroscope(s) to get orientation data, magnetometer(s) to get magnetic data, temperature sensor(s) to measure temperature, pressure sensor(s) to get pressure at specific points within the sole, GPS (or Galileo, GLONASS) to get position and performance data (speed, pace, distance, time). Different combinations of sensors may be used. A suitable control element may be provided which controls the operation of the respective sensors and may allow for selectively switching on and off of some or all of the sensors. For example, it may not be necessary to frequently measure the position or the temperature. Thus, in order to save energy, the respective control element may be adapted to control the operation of the corresponding sensors.
The system may comprise a memory which saves all measured and detected data. Memories to be used comprise RAM, ROM, flash memory and other types of memories generally known to the skilled person.
The system may comprise a battery which is be used together with the piezo element and may also be used as a fallback position if the energy which is created would not be efficient enough to detect the performance data or to transmit these data.
The at least one motion parameter may relate to one or more of: step count, cadence, acceleration, speed, pace, time, distance, or event detection (distinguishing between walking, jogging, running, standing still). The electrical signal may further used for determining a duration of use of the shoe. This can be achieved with a built-in timer which gets activated every time when a motion is detection. In another example, the activation time of at least one piezo element (or accelerometer/gyroscope/magnetometer) can be accumulated to determine the duration of used of the shoe. This allows an easy determination of activity relevant parameters by using the self-contained system exclusively based on the harvested energy.
The module may comprise at least one support ring for protecting the module. The support ring may limit movement of the cover to protect the components. In particular, the support ring may prevent over bending of the plates of the piezoelectric element.
The module may comprise at least one press bar for actuating the piezoelectric element. Providing such a press bar (or short “bar”) can help bending the plates of the piezoelectric elements while using the shoe. Of course, the bar can have different shapes such as a longitudinal shape, a cross shape, a circle shape and other types of shapes. It is also conceivable to have more than one bar, e.g., one on the top of the module and one on the bottom of the module to improve the bending. The shapes of the bars on top and on the bottom of the module may be different. The bar material can be made of different plastics, rubber, or other suitable materials. It may also be possible to have no bar at all and to use the piezo material as the activator.
The module may comprise at least one brass cover for conveying the electrical signal. Brass covers can serve different functions. On the one hand they may provide electrical connection between the piezoelectric element and other components of the module. These other components may be electronic components or an antenna. In this sense, the at least one brass cover may not only be used as protection, but also as conductive element. It is also conceivable to use a plastic cover or a rubber cover. If the cover material is non-conductive, an electrical connection may be provided via directly connecting a flexible conductive material (e.g., a wire or conductive tape) between the various components such as control elements, sensors and piezo elements. Moreover, it is conceivable to not use a cover. When not using a cover, a conductive adhesive may be used. For example, conductive adhesives may be provided by 3M company. Conductive tapes can be used to avoid conventional grounding means (screws or fasteners). Moreover, they provide increased flexibility.
The thickness of the at least one module may be less than 5 mm, preferably less than 3 mm. By providing a module having a thickness of less than 3 mm, it can easily be integrated into typical insoles without requirement of substantial reconstruction of the other parts of the shoe. It is also advantageous to have a thin module so as not to reduce the comfort of the shoe for the wearer.
The module may be integrated into a cavity or recess of an insole, a midsole or an outsole of a shoe. Depending on one or more of the needs of the athlete, the properties of the shoe and the number of modules, one or more of the modules can be integrated within different parts of the shoe or the shoe sole. For example, a first module can be provided in the insole, while a second module can be provided in the outsole or in the midsole.
The modules may be placed within the sole (e.g., the insole or the midsole) of the shoe so that they are exposed to maximum forces while treading onto the ground. The modules may be arranged in the heel area and/or the forefoot area of the sole. During use of the shoe and the shoe sole, respectively, there can be regions which are subject to more pressure than other parts of the shoe or the shoe sole. For example, the pressure in the heel region may be substantially higher than in the midfoot section. Also, the pressure in the forefoot region may be higher than in the midfoot region. Which region is subject to the highest pressure may also depend on the specific activity, e.g., it can make a difference whether the wearer is running or playing basketball. Therefore, by placing the modules in the shoe sole and taking into account these aspects, improved energy efficiency may be obtained.
The modules may be placed within the midsole of the shoe so that they are exposed to maximum forces while treading onto the ground. The modules may be arranged in the heel area and/or the forefoot area of the midsole. During use of the shoe and the shoe midsole, respectively, there can be regions which are subject to more pressure than other parts of the shoe or the shoe midsole. For example, the pressure in the heel region may be substantially higher than in the midfoot section. Also, the pressure in the forefoot region may be higher than in the midfoot region. Which region is subject to the highest pressure may also depend on the specific activity, e.g., it can make a difference whether the wearer is running or playing basketball. Therefore, by placing the modules in the shoe midsole and taking into account these aspects, improved energy efficiency may be obtained.
Possible embodiments of the present invention are further described in the following detailed description with reference to the following figures:
In the following, exemplary embodiments of the present invention will be described in further detail with respect to the figures. While some of the following examples are described for an “energy harvesting button,” it is to be noted that this is only an exemplary type of a module. The invention may also be implemented in other ways, e.g., wherein the module is provided as another type of “energy harvesting” module. Thus, it is to be understood that any reference to an “energy harvesting button” that is made herein is not to be understood to be limited to the specific shape of a button.
The energy harvesting buttons comprising piezoelectric sensors and the electronic components may be arranged in the sole so that the maximum force is exerted onto the piezoelectric elements comprised in the energy harvesting buttons while the force exerted on the electronic components is kept as low as possible. In this way, it is possible to protect the electronic devices while ensuring an optimal energy gain from the bending of the piezoelectric elements.
The following
The invention allows to use the signal of the piezoelectric elements as both, sensor (e.g., as step counter), as well as for operating the electronic components of the energy harvesting button 500, including the transmission to a remote device. With this technique it is also possible to detect the time between two steps, which then could be used to detect the “air time” (e.g. to determine a jump), or to detect step frequency (e.g. steps/minute), or to detect different events during the movement, means to detect based on the time between at least two steps whether the wearer of the shoe is walking, running, jogging, sprinting, . . . , this can be easily done by comparing the signal with lookup-tables. This event classification as well as the steps, then can be saved in a memory and either transmitted (via Bluetooth Low Energy (BTLE), ZigBee, Near Field Communication (NFC), Bluetooth, Bluetooth Smart, IrDA, WiFi, cellular network standards, or other suitable standards) in real time or after a workout (or movement of the sole). It could be saved in the electronics that after a predefined time the data which is (at least temporally) saved in a memory is transmitted to a remote device. This remote device could be either a smartphone, smartwatch, tablet computer, personal computer or any other suitable device or a server/cloud device.
In this way, the piezoelectric element in the energy harvesting button 700 may be used for two different functions, namely for energy harvesting and step counting. However, also other types of motion parameters can be derived from the electric current such as cadence (time between two signals representing steps), velocity (e.g., when knowing the average step length and the number of steps, which could be either predefined or defined by the user, maybe with help of a mobile device which is connected (via Bluetooth Low Energy (BTLE), ZigBee, Near Field Communication (NFC), Bluetooth, Bluetooth Smart, IrDA, WiFi, cellular network standards or other suitable standards) to the electronics of the energy harvesting button 700) and many others, as described herein.
The term mobile device as used herein refers to portable handheld devices which are capable of communicating via one or more of the above mentioned standards. Mobile devices comprise smartphones, smartwatches, tablet PCs, mobile computers, wearable computers, personal digital assistants, game consoles, digital cameras, pagers, smartcards, cell phones, mobile phones, and music players. Mobile devices typically comprise a display, a (virtual) keyboard, a processor, and a memory. However, depending on the type of the mobile device, not all such components may be included. The energy harvesting button 700 of the present invention allows for a low cost solution compared to other solutions (e.g., accelerometer based step detection), it has a low current consumption, and its construction is very simple: For the step counting, the energy harvesting button 700 according to the above shown example requires two resistors and a MOSFET transistor, and for energy harvesting, the energy harvesting button 700 according to the above shown example requires a rectifier bridge (four diodes) and one or more capacitors for energy storage. Moreover, for controlling the components, a microcontroller and a logic IC are needed. The small and lightweight energy harvesting button 700 can easily be integrated into an insole of a shoe (or other parts of a shoe).
An embodiment of an energy harvesting button 900 of the present invention is shown in
A further example is shown in
The first energy storage is loaded first. When the voltage in the first energy storage exceeds a certain level, it will power the voltage regulator 1260 (DCDC converter/LDO regulator). Immediately after that the voltage regulator 1260 will power up power management logic (e.g., power management IC) 1270. The power logic management logic 1270 may manages power flow between energy storages (e.g., the capacitors) and may know voltage levels that are informed to the microcontroller 1280. The power management logic 1270 checks in one example every 200 ms the voltage level in the capacitors 1230 and 1235. Depending on the specific properties, other time intervals for checking the voltage level may also be applicable, such as every 50 ms, 100 ms, 300 ms or 500 ms.
The voltage level detection method can be used with the resistor bridge that is in series with load switch components, which are connected to capacitors. Also direct voltage measurement method can be used.
When the voltage level exceeds a certain limit (for example 4.2V), the power management logic 1270 detects the excess and it will open the power valve between capacitors.
For example, when the voltage limit is exceed in the first energy storage 1230, the power management logic 1270 will open the power valve between the first energy storage 1230 and second power storage 1235. When power valve is opened, a current will flow to the second energy storage 1235. At the same time the voltage drops in the first power storage 1230, and as soon as it is below a certain threshold (for example 4.2V), the power valve is closed. The same will happen also between the second energy storage 1035 and the third energy storage 1240.
When the voltage level in the second energy storage 1235 rises high enough, the power management logic 1270 detects it and it will give allowance to power up the microcontroller. When the microcontroller is powered up, the voltage levels in the first energy storage 1230 and the second energy storage 1235 starts to drop. When the levels are below a certain threshold, which may be measured by power management logic 1270, a control signal is send to the microcontroller, which initiates a sleep/low power mode. The power control can also be done in other ways, for example the microcontroller may keep itself in on-state for a certain time period, when it exactly knows how much charge is consumed from the energy storages (e.g., capacitors).
When the microcontroller is in on-state, the current flow continues via the voltage regulator 1260 from the first power storage 1030. When voltage level in the first power storage 1230 is lower than that of the second power storage 1035 minus the threshold level of power feedback element 1245 (e.g., a Schottky diode), the current flow also comes from the second energy storage 1235 which supports the first energy storage 1230.
The microcontroller 1280 may also operate the antenna 1290 for subsequent data transmission. In accordance with the examples described herein, the data transmission can be done in two ways: The first one is that a mobile device is carried by the user during the exercise. The data from the energy harvesting button 1200 is sent time to time to the mobile device. For example, the data may be sent in real time or in intervals such as 50 ms, 500 ms, 1s, 5 s, 10 s, 30 s, only when the memory is full, or upon request by the user. A second way for data transmission may be realized when the energy harvesting button 1200 is used without the mobile device. Data is collected to a memory which is connected or combined with the energy harvesting button 1200 (e.g. RAM, ROM, flash memory, FRAM memory or similar other suitable memory types). After the exercise, which means after a certain amount of time the energy harvesting button 1200 or the sensors do not produce or receive a signal, the recording stops. The energy harvesting button 1200 connects via a transmitter or transceiver (e.g. Bluetooth Low Energy (BTLE), ZigBee, Near Field Communication (NFC), Bluetooth, Bluetooth Smart, IrDA, WiFi, cellular network standards or other suitable standards) to a router, a server computer, a computer, a mobile device as defined above, or any other suitable medium and transmits the recorded data which was collected during the exercise. One example how it could work in such case may, that the microcontroller detects the transmitter/transceiver signal and opens the valve between the third energy storage 1040 and the power feedback element 1250. By that way it will give enough power for data transmission. The power from the third energy storage 1240 may flow via the power feedback element 1250 to the first energy storage 1230.
In addition, the power from the third energy storage 1240 can be also used for other purposes, like fast start-up of the system. In this way, the energy harvesting button 1200 may manage itself based on self-harvested energy. Nevertheless, the energy harvesting button 1200 is designed to have a very low power consumption. The power storages mentioned above may be one or more of a capacitor, super capacitor, thin film Lithium battery or other suitable types of energy storages (e.g. any battery) which has a lower power leakage and small dimensions. The firmware of the microcontroller and the antenna may be designed in a way that they are in sleep mode when they are not used. This allows for a lower power consumption and a more efficient use of energy.
It is pointed out that the various sensors discussed herein, e.g., with respect to
While the foregoing has been described with respect to piezoelectric elements, it is noted that also other types of elements capable of creating electric current from mechanical strain can be used to realize the invention. Thus, the objective of providing a self-sustaining energy harvesting button comprising one or more sensors wherein the created electric energy is used as both, sensor signal and energy for operating the system may also be realized by such other types of elements (e. g. of an electromagnetic type comprising a body, with permanent magnetization, configured to move within a coil, wherein the movement is created by exerting pressure on the element).
Embodiments have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.
The foregoing description of the specific embodiments of the system described with reference to the figures will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention.
While various embodiments of the present invention have been described above, they have been presented by way of example only, and not limitation. It should be apparent that adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It therefore will be apparent to one skilled in the art that various changes in form and detail can be made to the embodiments disclosed herein without departing from the spirit and scope of the present invention. The elements of the embodiments presented above are not necessarily mutually exclusive, but may be interchanged to meet various needs as would be appreciated by one of skill in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102016201152.9 | Jan 2016 | DE | national |
