Patent Publication Number: US-10777341-B2

Title: Potentiometer toggle switch

Description:
TECHNICAL FIELD 
     The present disclosure relates to a toggle switch for an automobile. 
     BACKGROUND 
     Toggle switches may be utilized as an interface for various components. Toggle switches may be utilized in vehicles to activate various vehicle functions, such as climate functions, audio functions, driver settings, etc. Toggle switches may need to meet packaging requirements for vehicle interiors. Additionally, toggle switches may need to be reliable when activated. For example, when the switch is activated, it must respond to the corresponding vehicle function. Furthermore, there may be requirements for keeping costs low or to meet other various requirements of the vehicle. 
     SUMMARY 
     According to one embodiment, a vehicle toggle switch includes a toggle button body configured to move and to correspond to a toggle up position or a toggle down position, the toggle up position corresponds to activation of a first vehicle function, and the toggle down position corresponds to activation of a second vehicle function, a mating portion of the toggle button body that includes an end, and a potentiometer connected to the end of the mating portion and is configured to rotate in response to the movement of the toggle button body and to output a voltage in response to the rotation of the potentiometer. 
     According to the second embodiment, a vehicle toggle switch includes a toggle button body configured to toggle up position, the toggle button body including a mating portion that includes an end, wherein the end is configured to connect with a gear configured to rotate in response to movement of the toggle button body, a potentiometer connected to the gear and configured to output a potentiometer voltage in response to the rotation of the gear, and a processor in communication with the potentiometer, wherein the processor is configured to output a first activation signal for a first vehicle function when the potentiometer voltage exceeds an upper threshold. 
     According to the third embodiment, a vehicle toggle switch comprises a toggle head configured to move up and down, a toggle button body configured to move in response to movement of the toggle head, a rotary encoder configured to rotate in response to movement of the toggle button body and to output a voltage in response to the rotation of the rotary encoder, and a processor in communication with the rotary encoder, the processor is configured to output an activation signal for a vehicle function when the voltage exceeds an upper threshold. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  discloses a side perspective view of an embodiment of the toggle switch. 
         FIG. 2  discloses a bottom perspective view of an embodiment of the toggle switch. 
         FIG. 3  discloses a side perspective view of an embodiment of the toggle switch being activated. 
         FIG. 3A  discloses a bottom perspective view of an embodiment of the toggle switch being activated. 
         FIG. 4  discloses a side perspective view of an embodiment of the toggle switch, a top perspective view of the gear and potentiometer in a default state and in activation of the toggle switch. 
         FIG. 5  discloses a graph of the potentiometer output voltage as compared to an activation angle of the potentiometer. 
         FIG. 6  discloses a graph of the potentiometer voltage as compared with time during a default state, toggle up, and toggle down of the toggle switch. 
         FIG. 7A  discloses an example of a flagpole gear of one embodiment of the toggle switch. 
         FIG. 7B  discloses an example of a spoke gear of one embodiment of the toggle switch. 
         FIG. 7C  discloses an example of a bevel gear of one embodiment of the toggle switch. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
     A toggle switch with a low-cost structure that is capable of achieving a desirable haptic feeling and reliable activation may be desirable. Certain toggle switches may have a risk of mis-activation (early or late) due to the mechanical tolerance of the switch, thermal expansion, and a 2-way switch with only a binary on/off state. Other toggle switches (e.g. side-mounted dual-PCB designed) may minimize switch mis-activation, however, may have a higher-cost requirement because of requirement of two PCBs. A rocker switch design may also be useful to minimize mis-activation, however, require a larger packaging footprint in the “height direction” (H-direction e.g.  108  at  FIG. 1 ). The utilization of a potentiometer sensor may allow for a reliable activation due to a variable resistance measurement with thresholds to detect activation. Variable resistance measurement may also be able to account for the mechanical tolerance and thermal expansion. A combination of calibration and software logic may be used to accurately determine a toggle event for a toggle switch. Furthermore, it may be desirable to achieve a smaller packaging footprint in the H-direction as compared to other toggle button designs. 
       FIG. 1  discloses a side perspective view of an embodiment of the toggle switch  100 . The toggle switch  100  may include a toggle button cap  109  and a toggle button body  101  that is assembled to a front case  107 . The toggle button body  101  may include a mating feature to an additional gear part  104 . The gear part  104  may be relatively small. The gear part  104  may fit through a hole in the PCB  106  and mate with both the toggle button body and the potentiometer  105 . A rubber switch mat dome  103   a ,  103   b  may be mounted perpendicular to the PCB on both sides on the toggle body. 
     The toggle body  101  may be constrained translationally and rotationally in two directions. The toggle body  101  may move (e.g. rotate) in one direction during a push event. As the toggle body  101  moves or rotates, it may push the gear  104 , which causes the gear to rotate. During the rotation of the gear  104 , the small gear may rotate the potentiometer and change the resistance value. In addition to rotating the gear  104 , the toggle body  101  may also compress one of the rubber domes  103   a ,  103   b  to provide tactile feedback. A pivot  102  may be mounted onto the toggle button body  101 . The pivot may be used to allow the toggle button body  101  to rotate upon a toggle up or toggle down movement. 
     A potentiometer  105  may be mounted to a printed circuit board (PCB)  106 , for example, on a back-side of the PCB  106 . The potentiometer  105  is configured change a resistance value as it rotates. Thus, when the resistance changes, the potentiometer voltage output varies in turn. The potentiometer  105  may be mounted flat to the PCB  106  and have a hole through its center with a ring that is allowed to rotate. A shaft fits to the ring through the center of the potentiometer. As the shaft rotates, the potentiometer ring rotates as well. The potentiometer rotation moves an internal contact point to change the resistance value of the sensor. An electronic control unit (ECU) may record the changing resistance value of the potentiometer and be used to determine if an activation event occurred. A combination of establishing resistance thresholds and a change in resistance over time may be used to identify toggle activation. 
     The toggle switch  100  may be utilized to activate any number of vehicle functions. For example, the toggle switch  100  may be utilized to activate functions related to climate control, such as temperature controls (e.g. temperature up or temperature down), fan speed (e.g fan speed up/fan speed down), air recirculation, air conditioning (A/C) mode, etc. The toggle switch  100  may also be utilized for various audio functions. For example, the toggle switch  100  may be utilized to seek up/seek down, tune up/tune down, volume up/volume down, search a track list, etc. The toggle switch  100  may also be utilized to control various multimedia displays (e.g. navigation display, dashboard display, etc.) in the vehicle cabin. In sum, the vehicle functionality of the toggle switch is not limited to any specific vehicle function. 
     The toggle switch  100  may be equipped with a first dome switch  103   a  and a second dome switch  103   b . The first and second dome switches  103   a ,  103   b  may be utilized to provide a tactile feedback to a customer when a toggle up or toggle down action is conducted. The first and second dome  103   a ,  103   b  switch may be made of a plastic dome, silicon dome, metal dome, or any other suitable material. The first and second dome  103   a ,  103   b  may be depressed in response to a toggle up or toggle down movement, which in turn provides tactile feedback. A housing  107  feature of the toggle switch may be utilized to house various components of the toggle switch and to provide structural support for those components. The housing may be utilized to assemble multiple components together in a single-unit so that they can be simultaneously interacted in the vehicle. 
     The toggle switch with a potentiometer  105  may also reduce mis-activation based on thermal expansion. As thermal expansion occurs, the toggle switch may be capable of “re-zeroing” itself to adjust for some initial rotation of the potentiometer. While not shown in  FIG. 1 , a thermistor may also be utilized on the toggle switch  100 . The thermistor may be utilized to detect a temperature of the environment surrounding the toggle switch. The thermistor may record a temperature and output it to an ECU (e.g. processor or microprocessor) of the toggle switch. The temperature data output by the thermistor may be utilized to automatically calibrate adjustment of activation commands of the toggle switch. Thus, when the toggle switch is in a cold or hot environment, the ECU may account for changes in contraction/expansion of the rubber dome and adjust activation sequences accordingly. There may also be displacement between the PCB, gear, and the toggle body mating end. A look-up table may be stored in memory and be in communication with an ECU of the PCB to quantify the expected expansion based on a temperature of the vehicle cabin or outside the vehicle cabin. The look-up table may be configured to determine a true nominal position based on the expected expansion in response to the vehicle temperature. The toggle switch  100  may also utilize a thermistor or thermometer from another vehicle system to gauge temperature readings. For example, the toggle switch  100  may be in communication with the HVAC system with a thermistor to measure the temperature of the cabin. In another embodiment, the vehicle may be equipped with a thermometer configured to measure the temperature outside of the vehicle. 
     Rather than utilizing a potentiometer, an encoder may be mounted in place of a potentiometer. The encoder may have two terminals that are used to acquire direction of the rotation. The encoder may have a certain angle of rotation is that required to activate the terminals in response to a toggle up or toggle down activation. For example, a 30° rotation may be required to activate an encoder in response to a toggle up or toggle down. Rather than utilizing a potentiometer, a rotary encoder may be mounted flat to a PCB. The rotary encoder may have a hole in its center that can rotate. A shaft may fit into the ring through the center of the rotary encoder. As the shaft rotates, the potentiometer ring of the PCB rotates as well. The encoder may have two sensors that are either on or off depending on where the center has rotated. The rotary encoder may either be an absolute encoder or incremental. 
       FIG. 2  discloses a bottom perspective view of an embodiment of the toggle switch. As shown, the toggle switch may include a potentiometer  105  that is mounted below a PCB  106 . A gear  104  may also fit through a hole of the PCB  106 , such as a center hole. The gear  104  may mate with the toggle button body and the potentiometer  105 . The gear  104  may be configured to react to movements of the toggle button body and in turn rotate the potentiometer  105 . 
       FIG. 3  discloses an example of a toggle switch being activated. As shown in  FIG. 3 , the toggle switch  100  may be pressed or moved by an orthogonal force  110  by an occupant of a vehicle. The orthogonal force  110  thus will force the toggle switch  100  to move. For example, if the orthogonal force  110  travels parallel from the right rubber mat dome  103   b  towards the left rubber mat dome  103   a , movement of the toggle switch  100  occurs. In such a scenario, the toggle button cap  109  may move towards the left rubber mat dome  103   a . However, the toggle button body  101  may move towards the right rubber mat dome  103   b . The toggle switch  100  may move until the toggle button body  101  becomes in contact with the right rubber mat dome  103   b . If the orthogonal force  110  travels in the opposite direction (e.g. from left rubber mat dome  103   a  towards right rubber mat tome  103   b ), the toggle button body  101  may move towards the left rubber mat dome  103   a  and the toggle switch will move toward the right rubber mat dome  103   b . The pivot  102  may be mounted onto the toggle button body  101  that is used to allow the toggle button body  101  to rotate upon a toggle up or toggle down movement. The pivot  102  may be used to translationally constrain the toggle body and constrain rotation in two direction. 
     Once there is movement of the toggle switch  100 , the mating feature of the toggle button body  101  may cause the gear  104  to rotate in either a clockwise or counter-clockwise direction by a certain angle. Because the toggle button body  101  is constrained translationally and rotationally in two directions, the toggle button body  101  may rotate in one dimension during a pushing event (e.g. around the pivot point  102 ). As the toggle button body  101  rotates, the body  101  pushes the small gear  104  that is configured to also rotate in response to the toggle button body. The gear  104  also rotates the potentiometer  105 , which causes the resistance value of the potentiometer to change. In addition to the rotation of the gear  104 , the toggle button body  101  also compresses one of the domes  103   a, b  to provide an appropriate tactile feedback to the customer. A housing  107  feature may be utilized to house various components of the toggle switch. 
       FIG. 3 a    discloses a bottom perspective view of an embodiment of the toggle switch being activated. As shown from the bottom perspective view, activation of the toggle switch  100  causes the gear  104  to rotate. The rotation of the gear  104  cause the potentiometer  105  to rotate. The potentiometer rotation  112  angle may be dependent on the rotation of the gear  104  as well as the type of mating feature utilized to connect the toggle button body  101  to the gear  104 . The ECU of the PCB  106  may in turn monitor and record data values of the resistance change and voltage change/output in response to the potentiometer  105  rotating. The rotation  112  of the potentiometer  105  may be opposite (e.g. counter-clockwise) of that shown in  FIG. 3A  if the orthogonal force  110  is coming from the opposite direction to activate the toggle switch  100 . 
       FIG. 4  discloses a side perspective view of an embodiment of the toggle switch and a top perspective view of the gear and potentiometer in a both a default state and in activation of the toggle switch. An imaginary vertical axis  113  may be utilized in  FIG. 4  to show movement of the toggle switch relative to various parts of the toggle switch  100 . During a toggle push, a toggle body rotation may lead to some rotation of the potentiometer through the small gear. The change in the potentiometer angle may lead directly to a measurable change in the potentiometer resistance. 
       FIG. 5  is an example graph of the output voltage in response to rotation of the potentiometer. The Y-axis may be the output voltage ratio (%). The X-axis may be the degrees of rotation of the potentiometer with a range of +/−160°. The potentiometer may provide a continuous output in the form of a resistance change. The resistance change may be measured as a output potentiometer voltage. The potentiometer may provide continuous output which can be taken advantage of to avoid mis-activation concerns involved with the binary output a typical two-way switch. Such mis-activation may be realized due to mechanical tolerances or thermal expansions of various parts in the toggle switch. Thus, while a typical two-way switch either provides a “one” or “zero” output voltage for activation/non-activation, the toggle switch that includes a potentiometer may allow flexibility in determining a threshold voltage for activation of the switch. The flexibility of the potentiometer may be utilized to mitigate or eliminate mechanical tolerances. As shown on the graph, the index point may be 50% of the output voltage. There may also be an error tolerance of +/−2%. That is, for a given rotation of the potentiometer, a potentiometer&#39;s output may have some tolerance of +/−2%. 
       FIG. 6  is an example of a graph charting an output voltage in relationship to activation of a toggle switch. Along the y-axis of the graph of  FIG. 6  is a voltage output of the potentiometer. Along the x-axis of the graph of  FIG. 6  is a time in seconds. The potentiometer may include an output voltage  201  charted on the graph of  FIG. 1 . When there is no toggle activation, the potentiometer or toggle switch may be in a default state with no activation. During such a time, there still may be a resistance and voltage that is output by the potentiometer. A default range  207  of the potentiometer may be utilized to define an upper threshold  203  and lower threshold  205  for no toggle activation. As opposed to a standard binary switch, the range may allow for some tolerance in the event of mis-activations or rapid-pressing of the toggle switch to define such slight changes in the output voltage  201  as not being a toggle activation. The default range  207  may be set and stored by the ECU and memory associated with the ECU of the PCB of the toggle switch. 
     As shown in the graph of  FIG. 6 , there may be a first toggle activation threshold  209  that activates a vehicle function when the potentiometer outputs a voltage above the first toggle activation threshold  209 . The first toggle activation threshold  209  may be above the upper default threshold  203 . When the output voltage  201  exceeds the first toggle activation threshold  209 , the ECU of the PCB may responsively activate a vehicle function associated with the toggle switch. The first toggle activation threshold  209  may be in response to the toggle switch moving either up or down, and in turn rotating the potentiometer clockwise or counterclockwise to increase the voltage output. In one scenario, a user may hold up the toggle switch which in turns allows the potentiometer to output a max voltage at a constant rate over time. The ECU of the PCB may associate a voltage above the toggle activation threshold  209  with a vehicle function. For example, when the voltage above the toggle activation threshold  209  is output, the ECU may identify an action to increase a temperature of the vehicle&#39;s heating, ventilation, and air conditioning (HVAC) system. 
     As shown in the graph of  FIG. 6 , there may be a second toggle activation threshold  211  that activates a vehicle function when the potentiometer outputs a voltage below the second toggle activation threshold  211 . The second toggle activation threshold  211  may be below the lower default threshold  205 . When the output voltage  201  is below the second toggle activation threshold  211 , the ECU of the PCB may responsively activate a vehicle function associated with the toggle switch. The second toggle activation threshold  211  may be in response to the toggle switch moving either up or down, and in turn rotating the potentiometer clockwise or counterclockwise to decrease the voltage output. In one scenario, a user may hold down on the toggle switch which in turns allows the potentiometer to output a minimum voltage at a constant rate over time. The ECU of the PCB may associate a voltage below the toggle activation threshold  211  with a vehicle function. For example, when the voltage below the toggle activation threshold  211  is output, the ECU may identify an action to decrease a temperature of the vehicle&#39;s HVAC system. 
     There may also be a range between the upper default threshold  203  and the first toggle activation threshold  209  that will also lead to activation of a first vehicle function. There may also be a range between the lower default threshold and the second activation threshold that will also lead to activation of a second vehicle function. In some embodiments, the upper default threshold  203  and the first activation threshold  209  may be the same voltage. In another embodiment, the lower default threshold  203  and the second activation threshold  209  may be the same voltage. 
     When the toggle switch is originally installed, a calibration may be run to determine a nominal reading of the toggle switch. When the toggle switch is first pressed up, an upper target point for activation may be set. The toggle may be pressed down to set the lower target point for activation. This may account for any tolerance deviation which causes the potentiometer to start outside of its nominal position. The calibration may be done automatically or manually. Software may be utilized that allows a customer or dealership to make adjustments utilizing a human-machine interface (HMI) of the vehicle. Such adjustments may be made based on the owner&#39;s environment of the vehicle. Such considerations may include the climate, season, altitude, or etc. of the vehicle. Each of the considerations may affect the thermal expansion and mechanical tolerances of the toggle switch. 
     The toggle switch may also reduce mis-activation based on velocity recognition of the toggle switch with a potentiometer. Because the recognition of activation is not binary, velocity recognition may be utilized for switch activation. During a toggle stroke, the resistance of the potentiometer may change at a greater rate during the rubber dome snap down event. This increased change in slope may be recognized through software and used to determine activation. In another example, a range can float at various areas of activation threshold to be dependent on the environment of the vehicle. 
     The potentiometer or the processor in communication with the potentiometer may be constantly recording the voltage for monitoring. The data of the potentiometer voltage that is output may provide indications of habits that occur over time. For example, a large slope up of the potentiometer voltage can be correlated to a toggle up position. In another example, a large slope down of the potentiometer voltage can be correlated to a toggle down position. 
       FIG. 7A  discloses an example of a flagpole gear of one embodiment of the toggle switch. As explained above, a gear  104  may be utilized to connect the potentiometer to the mating feature of the toggle switch. The gear  104  may be any type of gear utilized. Different mating shapes can be used to maximize the amount of potentiometer rotation. The larger the potentiometer rotation, the larger the change in resistance. The larger change in resistance may allow the software of the ECU to check for a toggle push. For example, 4° is an approximate nominal toggle push rotation based on a position of the left rubber dome  103   a  and right rubber dome  103   b . A flagpole gear is one type of gear  104  that may be utilized. In one example, the flagpole gear may have a toggle rotation angle (θ) at 4°. In response to the toggle rotation of the gear  104 , the potentiometer may have a potentiometer rotation (α) of 20°. As the potentiometer rotation α increases towards the 20° angle, the voltage output by the potentiometer may increase more dramatically based on the potentiometer&#39;s resistance change. 
       FIG. 7B  discloses an example of a spoke gear of one embodiment of the toggle switch. The spoke gear may require a different mating feature of the toggle button body. For example, a spoke gear may require the mating feature to have one or more plurality of arms to rotate the gear. As shown in  FIG. 7B , the mating feature of the toggle button body may have 5 arms. The spoke gear may allow for a larger potentiometer rotation than a flagpole gear shown in  FIG. 7A . In one example, the spoke gear may have a toggle rotation angle θ at 4°. In response to the toggle rotation of the gear  104 , the potentiometer may have a potentiometer rotation α of 21.7°. As the potentiometer rotation α increases towards the 21.7° angle, the voltage output by the potentiometer may increase or decrease more dramatically based on the potentiometer&#39;s resistance change. 
       FIG. 7C  discloses an example of a bevel gear of one embodiment of the toggle switch. The bevel gear may require a different mating feature of the toggle button body. For example, a bevel gear may require the mating feature to have one or more plurality of teeth within the gear to rotate and to interlock with the gear&#39;s corresponding grooves. The bevel gear shown in  FIG. 7C  may have a ratio of 6:1. As shown in  FIG. 7C , the mating feature of the toggle button body may have a pair of interlocking gears. The bevel gear may allow for a larger potentiometer rotation than a flagpole gear shown in  FIG. 7A . In one example, the spoke gear may have a toggle rotation angle θ at 4°. In response to the toggle rotation of the gear  104 , the potentiometer may have a potentiometer rotation α of 24°. As the potentiometer rotation α increases towards the 24° angle, the voltage output by the potentiometer may increase or decrease more dramatically based on the potentiometer&#39;s resistance change. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life-cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.