Patent Application
20200370331
This document relates generally to the motor vehicle and autonomous vehicle fields and, more particularly, to a new and improved apparatus for heating a door latch assembly and ensuring proper operation of that door latch assembly in inclement winter weather conditions and sub-freezing temperatures.
During inclement winter weather conditions with sub-freezing temperatures a door latch assembly may not operate as intended due to freezing water or condensation in the latch assembly.
This document relates to a new and improved apparatus especially configured or adapted to prevent a latch assembly from freezing during inclement winter weather conditions with sub-freezing temperatures.
In accordance with the purposes and benefits described herein, a new and improved apparatus is provided for heating a latch assembly and, more particularly, a door latch assembly on a motor vehicle or an autonomous vehicle. Advantageously the apparatus ensures proper operation of the latch assembly in inclement winter weather conditions including sub-freezing temperatures.
The apparatus comprises a latch assembly including a housing and a latch carried in the housing, a heating feature at least partially carried on the housing and a rechargeable battery connected to the heating feature.
In one particularly useful embodiment, the heating feature includes a thermoelectric cooler controller and a resistive heating element. That resistive heating element may be a heater film molded to a face of the housing of the latch assembly.
The apparatus may further include a control module adapted or configured for controlling the operation of the heating feature. That control module may include a controller having control logic configured to activate and deactivate the heating feature. Further, the control module may include a latch assembly temperature sensor providing current latch assembly temperature data to the controller as well as an ambient air temperature sensor providing ambient air temperature data to the controller.
More particularly, the control logic may be configured to activate the heating feature in response to the current latch assembly temperature data indicating a first current latch assembly temperature below a first threshold latch assembly temperature. That threshold latch assembly temperature may be, for example, 0 degrees C., 1 degree C., 2 degrees C., or any other temperature appropriate for indicating a potential latch assembly freezing condition.
Further, the control logic may be configured to deactivate the heating feature in response to the current latch assembly temperature data indicating a second current latch assembly temperature above a second threshold latch assembly temperature. That second threshold latch assembly temperature may be, for example, 3 degrees C., 4 degrees C., 5 degrees C. or other temperature above 0 degrees C.
In one possible embodiment the first threshold latch assembly temperature is lower than the second threshold latch assembly temperature. In another possible embodiment the first threshold latch assembly temperature is equal to the second threshold latch assembly temperature.
The control logic of the controller may also be configured to activate the heating feature in response to the current outside ambient air temperature data indicating a current outside ambient air temperature below a predetermined outside ambient threshold temperature such as, for example, 0 degrees C.
In addition, the control logic may be configured to activate the heating feature in response to a remote start signal received by the controller from a remote start actuator for the vehicle in which the apparatus is incorporated.
In accordance with an additional aspect, the apparatus comprises a latch assembly, including a housing and a latch carried in the housing, and a heating feature including a thermoelectric cooler controller and a resistive heating element. More particularly, the resistive heating element may be a heater film molded to a face of the housing. In such an embodiment the housing may include an inner face oriented toward the latch and an outer face oriented away from the latch. The heater film may be molded to the outer face.
In accordance with yet an additional aspect, the apparatus may comprise a latch assembly, including a housing and a latch carried in the housing, and a heating feature including a thermoelectric cooler controller and a resistive heating element wherein the resistive heating element is carried on a face of the housing. The resistance heating element may be a heater film molded to a face of the housing. Further, the apparatus may include a control module controlling operation of the heating feature. Such a control module may include a controller having control logic configured to activate and deactivate the heating feature in response to changes in current ambient air temperature and changes in current latch assembly temperature.
In the following description, there are shown and described several preferred embodiments of the apparatus. As it should be realized, the apparatus is capable of other, different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the apparatus as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.
The accompanying drawing figures incorporated herein and forming a part of the specification, illustrate several aspects of the apparatus and together with the description serve to explain certain principles thereof.
Reference will now be made in detail to the present preferred embodiments of the apparatus, examples of which are illustrated in the accompanying drawing figures.
Reference is now made to
As illustrated in schematically in
Referring back to
The ambient air temperature sensor 38 is of a type known in the art that is adapted to detect current ambient air temperature and provide current ambient air temperature data to the controller 36. The latch assembly temperature sensor 40 is also of a type known in the art and adapted to detect the current latch assembly temperature and provide data with respect to the current latch assembly temperature to the controller 36.
As additionally shown in
The control module 34 controls operation of the resistive heating element 28 carried on the housing 20 of the latch assembly 12. More particularly, the controller 36 of the control module 34 has control logic configured to activate and deactivate the heating feature 14. In at least one of the many possible embodiments of the apparatus 10, the control logic of the controller 36 is configured to activate the heating feature 14 in response to the current latch assembly temperature data received from the current latch assembly temperature sensor 40 indicating a first current latch assembly temperature below a first threshold latch assembly temperature. Further, the control logic of the controller 36 may be configured to deactivate the heating feature 14 in response to the current latch assembly temperature data received from the current latch assembly temperature sensor 40 indicating a second current latch assembly temperature above a second threshold latch assembly temperature. In many embodiments, the first threshold latch assembly temperature is lower than the second threshold latch assembly temperature but in some embodiments the first and second threshold latch assembly temperatures may be equal.
Typically, the first latch assembly temperature is indicative of a potential freezing condition wherein a moisture in the latch assembly 12 freezes and potentially prevents proper operation thereof. Thus, the first threshold latch assembly temperature may be, for example, 0 degrees C., 1 degree C., 2 degrees C., 3 degrees C., 4 degrees C. or 5 degrees C. Typically the second threshold latch assembly temperature is 2 or more degrees above the first threshold latch assembly temperature.
The control logic of the controller 36 may also be configured to activate the heating feature 14 in response to current outside ambient temperature data received from the current ambient air temperature sensor 38 indicating a current outside ambient air temperature below a predetermined outside ambient threshold temperature. That outside ambient threshold temperature may be, for example, the temperature at which water freezes, 0 degrees C., or within a few degrees above that temperature.
In still other embodiments, the control logic of the controller 36 is configured to activate the heating feature 14 in response to the remote start signal 44 being received at the receiver 42 and thereby by the controller 36 when the remote start actuator 48 on the key fob 46 is depressed.
Reference is now made to
The control logic flow diagram 50 also illustrates the backup system that may be operated periodically or at a predetermined selected time by the motor vehicle user (e.g. at a particular time of day before the user leaves for work in the morning). Thus, the backup system periodically verifies the current latch assembly temperature at box 70 based upon data provided by the latch assembly temperature sensor 40. If the current latch assembly temperature is below freezing (see box 72) the system is activated at box 74 so that power from the battery 16 is delivered to the thermoelectric cooler controller 26 which in turn initiates heating of the latch assembly 12 by application of current through the resistive heating element 28 at box 64. The controller 36 continues to monitor the current temperature of the latch assembly at box 66. So long as that temperature remains below the threshold value heating continues. However, once the current latch assembly temperature is above the threshold value heating is terminated at box 68. This action ensures that the latch assembly 12 is maintained at a temperature that prevents function failure due to winter temperature extremes that might otherwise cause a freezing condition.
The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
