The present disclosure generally relates to a heating, ventilation, and/or air conditioning (HVAC) system and, more particularly, to an electronic door latch for the HVAC system.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
An HVAC system may include components that are accessible via doors for maintenance or configuration purposes. The doors may be secured by a lock to ensure that only appropriate people, such as service personnel or owners of the HVAC system, having keys to the lock may access the components. Because the doors may include inner portions that are exposed to the conditioned environment and outer portions that are exposed to an ambient, unconditioned environment, the doors may be insulated to prevent conditioned air from escaping from the conditioned environment to the ambient environment. However, because the locks may include metal parts that extend through the doors, such as cylinders, shafts, or lock bodies where the keys are inserted, these metal parts may create a thermal bridge from the conditioned environment to the ambient environment for conditioned air to escape, resulting in a loss of efficiency.
A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.
In one embodiment, a heating, ventilation, and air conditioning (HVAC) system includes a housing that contains components of the HVAC system and includes a door that enables access to the components of the HVAC system. The door includes an outer portion having a locking engagement device and an inner portion having a latching system. The latching system includes a latch that prevents the door from opening when engaged. The door also includes a conductor electrically coupling the locking engagement device to the latching system. The latching system disengages the latch in response to the locking engagement device being in a first position and engages the latch in response to the locking engagement device being in a second position.
In another embodiment, an electronic locking device of a door of an HVAC system includes a locking engagement device disposed on an outer portion of the door and a latching system disposed on an inner portion of the door. The latching system includes a latch and operates the latch to prevent the door from opening when the latch is engaged. The electronic locking device also includes a conductor electrically coupling the locking engagement device to the latching system. The latching system disengages the latch in response to the locking engagement device being in a first position and engages the latch in response to the locking engagement device being in a second position.
In yet another embodiment, a locking engagement device is disposed on an outer portion of a door of an HVAC system. The electronic locking device includes a receptacle that enables insertion of a key. The locking engagement device rotates in response to the key being inserted in the receptacle and rotated. The electronic locking device also includes a conductor that electrically couples the locking engagement device to a latching system disposed on an inner portion of the door. The locking engagement device sends a first indication of being in a first position to the latching system via the conductor in response to the locking engagement device being rotated into the first position. The locking engagement device also sends a second indication of being in a second position to the latching system via the conductor in response to the locking engagement device being rotated into the second position.
Various aspects of the present disclosure may be better understood upon reading the following detailed description and upon reference to the drawings, in which:
One or more specific embodiments of the present disclosure will be described below. These described embodiments are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but may nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment,” “an embodiment,” or some embodiments” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
An HVAC system may include components that are accessible via doors for maintenance or configuration purposes. For example, the HVAC system may include a rooftop unit cabinet that houses components used to provide conditioned air to a building or structure. The doors may be secured by a lock to ensure that only appropriate people, such as service personnel or owners of the HVAC system, having keys to the lock may access the components. Because the doors may include inner portions that are exposed to the conditioned environment and outer portions that are exposed to an ambient, unconditioned environment, the doors may be insulated to prevent conditioned air from escaping from the conditioned environment to the ambient environment. However, because the locks may include metal parts that extend through the doors, such as cylinders, shafts, or lock bodies where the keys are inserted, these metal parts may create a thermal bridge from the conditioned environment to the ambient environment for conditioned air to escape, resulting in a loss of efficiency. Moreover, when the ambient environment is sufficiently warm or humid compared to the conditioned environment, undesirable condensation may form, for example, on an outer portion of the door and/or on the lock engagement device. While the metal parts of the locks may be replaced with plastic or non-metal materials, using such replacements may not be practical due to the expense of manufacturing and/or molding the plastic or non-metal materials or lack durability.
Accordingly, the present disclosure provides systems and methods that operate a door latch electronically based on operating a locking engagement device. The locking engagement device may be disposed on an outer portion of a door, the latch may be part of a latching system disposed on an inner portion of the door, and the locking engagement device may transmit a signal indicating that the locking engagement device is in an open or closed position to the latching system via a conductor electronically coupling the locking engagement device and the latching system. In some embodiments, the locking engagement device may transmit a signal indicating that the locking engagement device is in an open or closed position to a controller, which may then instruct one or more latching systems to engage or disengage one or more latches based on receiving the signal.
Because the conductor may be provided without the presence of a cylinder, shaft, lock body, or any other structure that creates an excessive thermal bridge between the conditioned environment at the inner portion of the door to the ambient environment at the outer portion of the door, the presently disclose systems and methods may more effectively prevent conditioned air from escaping from the conditioned environment to the ambient environment, resulting in increased efficiency and performance. Moreover, the conductor may be provided without plastic or non-metal materials, thus avoiding the expense of manufacturing and/or molding the plastic or non-metal materials and avoiding the durability issues associated with the plastic or non-metal materials.
Turning now to the drawings,
The HVAC unit 12 may be an air cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. For example, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow from the building 10. After the air is conditioned, the HVAC unit 12 may supply the conditioned air to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or other sections of the building 10. In some embodiments, the HVAC unit 12 may include a heat pump that provides both heating and cooling to the building 10, for example, with one refrigeration circuit implemented to operate in multiple different modes. In other embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream.
A control device 16, one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device 16 also may be used to control the flow of air through the ductwork 14. For example, the control device 16 may be used to regulate operation of one or more components of the HVAC unit 12 or other equipment, such as dampers and fans, within the building 10 that may control flow of air through and/or from the ductwork 14. In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and/or the like. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10. In some embodiments, the HVAC unit 12 may operate in multiple zones of the building, and be coupled to multiple control devices that each control flow of air in a respective zone. For example, a first control device 16 may control the flow of air in a first zone 17 of the building, a second control device 18 may control the flow of air in a second zone 19 of the building, and a third control device 20 may control the flow of air in a third zone 21 of the building.
As shown in the illustrated embodiment of
The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers 28 and 30 may circulate refrigerant, such as R-410A, through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, conventional copper or aluminum tubing, and/or the like. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers 28 and 30 to produce heated and/or cooled air.
For example, the heat exchanger 28 may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger 30 may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit 12 may operate in a heat pump mode where the roles of the heat exchangers 28 and 30 may be reversed. That is, the heat exchanger 28 may function as an evaporator and the heat exchanger 30 may function as a condenser. In further embodiments, the HVAC unit 12 may include a furnace for heating the air stream that is supplied to the building 10. While the illustrated embodiment of
The heat exchanger 30 is located within a compartment 31 that separates the heat exchanger 30 from the heat exchanger 28. Fans 32 may draw air from the environment through the heat exchanger 28. As it flows through the heat exchanger 28, air may be heated or cooled before being released back to the environment surrounding the rooftop unit 12. Each fan 32 may be coupled to a blower assembly 34, which is powered by a respective motor 36, and may draw air through the heat exchanger 30 to heat or cool the air. Each motor 36 may be coupled to a respective variable frequency drive 37 that controls the speed of the motor 36 by adjusting the frequency of electrical power supplied to the respective motor 36.
The heated or cooled air may be directed to the building 10 by the ductwork 14, which may be connected to the HVAC unit 12. Before flowing through the heat exchanger 30, the conditioned air flows through one or more filters 38 that may remove particulates and contaminants from the air. In certain embodiments, the filters 38 may be disposed on the air intake side of the heat exchanger 30 to reduce likelihood of contaminants contacting the heat exchanger 30.
The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 may increase the pressure and/or temperature of the refrigerant before the refrigerant enters the heat exchanger 28. The compressors 42 may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors 42 may include a pair of hermetic direct drive compressors arranged in a dual stage configuration 44. However, in other embodiments, any number of the compressors 42 may be provided to achieve various stages of heating and/or cooling. As may be appreciated, additional equipment and/or devices may be included in the HVAC unit 12, such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things.
The HVAC unit 12 may receive electrical power via a terminal block 46. For example, a high voltage power source may be connected to the terminal block 46 to power the equipment. The terminal block 46 may be coupled to each variable frequency drive (VFD) 37 to provide power to the respective variable frequency drive 37. The operation of the HVAC unit 12 may be governed or regulated by a control board 48. The control board 48 may include control circuitry connected to a thermostat, a sensor, an alarm, and/or a variable frequency drive 37. One or more of these components may be referred to herein separately or collectively as the control device 16. The control circuitry may control operation of the equipment, provide alarms, and/or monitor safety switches. For example, as illustrated, the control board 48 is communicatively coupled to a VFD control unit 47 that may in turn be communicatively coupled to each controller of each variable frequency drive 37. As such, operation of each variable frequency drive 37 may be managed and/or configured via the VFD control unit 47. Wiring 49 may connect the control board 48 and the terminal block 46 to the equipment of the HVAC unit 12.
The housing 13 of the HVAC unit 12 may include one or more doors 50 that enable access to any of the components of the HVAC unit 12 discussed above. For example, HVAC service personnel may open the one or more doors 50 to maintain, fix, replace components of, and/or change settings of the HVAC unit 12.
When the system shown in
The outdoor unit 58 may draw environmental air through the heat exchanger 60 using a fan 64 and expel the air above the outdoor unit 58. When operating in an air conditioner mode, the air heated by the heat exchanger 60 within the outdoor unit 58 exits the unit at a temperature higher than it entered. The indoor unit 56 includes a blower or fan 66 that directs air through or across the indoor heat exchanger 62, where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork 68 that directs the air to the residence 52.
The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the setpoint on the thermostat, or the setpoint plus a small amount, the residential heating and cooling system 51 may become operative to refrigerate or cool additional air for circulation through the residence 52. When the temperature reaches the setpoint, or the setpoint minus a small amount, the residential heating and cooling system 51 may stop the refrigeration cycle temporarily.
The residential heating and cooling system 51 may also operate in a heat pump mode. When operating in the heat pump mode, the roles of heat exchangers 60 and 62 may be reversed. That is, the heat exchanger 60 of the outdoor unit 58 may serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit 58 as the air passes over outdoor the heat exchanger 60. The indoor heat exchanger 62 may receive a stream of air blown over it and heat the air by condensing the refrigerant.
In some embodiments, the indoor unit 56 may include a furnace system 70. For example, the indoor unit 56 may include the furnace system 70 when the residential heating and cooling system 51 is not implemented to operate as a heat pump. The furnace system 70 may include a burner assembly and heat exchanger, among other components, inside the indoor unit 56. Fuel may be provided to the burner assembly of the furnace 70 where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger 62, such that air directed by the blower 66 passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system 70 to the ductwork 68 for heating the residence 52.
The description above with reference to
The actuator 122 is illustrated as a linear actuator, though any suitable actuator that may move the latch 120 into an engaged position to secure the door 50 and prevent unauthorized access to components of the HVAC system or unit and into a disengaged position is contemplated, including, for example, a rotating actuator. That is, the actuator 122 may rotate the latch 120 into an engaged position, such as into a latch receptacle of the housing 13 of the HVAC system or unit, to secure the door 50, and rotate the latch 120 into a disengaged position, such as out of the latch receptacle. Moreover, the actuator 122 may be powered by any suitable technique and, as such, the actuator 122 may be an electrical actuator, a pneumatic actuator, a hydraulic actuator, or a mechanical actuator.
In alternative or additional embodiments, the latch 120 may use any other suitable techniques to operate the locking engagement device 82. For example,
While the biasing element 152 is shown to couple the magnet 156 and the electromagnet 150 together, it should be understood that the biasing element 152 may couple together any suitable components that enable engagement and disengagement of the latch 120, such as the inner portion 128 of the door 50 and the latch 120. Moreover, while the magnet 156 is shown attached to the latch 120, in some embodiments, for example, at least a portion of the latch 120 may act as the magnet 156, such that there may be no separate magnet 156 attached to the latch 120. Additionally or alternatively, the biasing element 152 and the electromagnet 150 may perform the opposite functions as those shown in
The embodiments disclosed above include directly electrically coupling the latching system 118 to the locking engagement device 82, such that the indication, signal, or current sent by the locking engagement device 82 is received directly by the latching system 118 via the conductor 126, without an intermediate device receiving the indication, signal, or current sent from the locking engagement device 82 and forwarding the indication, signal, or current to the latching system 118. However, in some embodiments, a controller may receive the indication, signal, or current from the locking engagement device 82 and send the indication, signal, or current to the latching system 118. For example,
As illustrated, the control system 170 includes a controller 172 that may receive a signal, current, or indication of the position of the locking engagement device 82 via the conductor 126. The controller 172 may include a processor 174, which may include any type of processing circuitry, such as one or more processors, one or more general-purpose microprocessors, one or more special-purpose microprocessors, and/or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the processor 174 may include one or more reduced instruction set (RISC) processors. The controller 172 may also include a memory device 176. The memory device 176 may include any suitable type of memory that stores instructions (e.g., software) executable by the processor 174, such as a non-volatile and/or volatile memory. In particular, the memory device 176 may store instructions that, when executed by the processor 174, cause the processor 174 to receive the signal, current, or indication of the position of the locking engagement device 82 via the conductor 126, and operate the latching system 118 by, for example, engaging or disengaging the latch 120 of the latching system 118, based on the signal, current, or indication of the position of the locking engagement device 82.
The controller 172 may be electrically coupled to the latching system 118 via, for example, a second conductor 177. As such, in response to receiving a signal, current, or indication of the position of the locking engagement device 82 via the conductor 126, the controller 172 may send an instruction or signal to the latching system 118 to engage or disengage the latch 120. For example, if the indication is associated with the locking engagement device 82 being in the open position, the controller 172 may instruct the latching system 118 to disengage a respective latch 188 via the second conductor 177, thus enabling the door 50 to be opened and enabling access to components contained in the housing 13 of the HVAC system or unit. If the indication is associated with the locking engagement device 82 being in the closed position, the controller 172 may instruct the latching system 118 to engage the respective latch 188 via the second conductor 177, thus preventing the door 50 from opening and preventing access to components contained in the housing 13 of the HVAC system or unit. Similar to the conductor 126, the second conductor 177 may be made of any suitable material that transmits the instruction or signal to the latching system 118 to engage or disengage the latch 120, such as copper, aluminum, and so on. In some embodiments, the second conductor 177 may be sheathed in any suitable insulation material to maintain the signal transmitted over the second conductor 177, such as a thermoplastic material or a thermoset material.
In some embodiments, the controller 172 may be communicatively coupled to a communication interface 178 that may enable communication with any suitable communication network, such as a wiring terminal, a cellular network, a WiFi network, a personal area network (PAN), a local area network (LAN), a wide area network (WAN), and/or the like. For example, the communication interface 178 may enable the controller 172 to communicatively couple to a second communication interface 180 of a second control system 182 via a suitable communication network. As such, the controller 172 may instruct a second controller 184 of the second control system 182 to operate a second latching system 186 by, for example, engaging or disengaging a second latch 188 of the second latching system 186, based on the signal, current, or indication of the position of the locking engagement device 82, via the communication interface 178 and the second communication interface 180. While a second control system 182 is shown in
In additional or alternative embodiments, a computing device 190 may be communicatively coupled to the control system 170. For example, the computing device 190 may include desktop computer, a personal computer, or a mobile computing device, such as a cell phone, a smartphone, a wearable device, a tablet, or a laptop. As illustrated, the computing device 190 may include a controller 192 that controls operations of the computing device 190. The controller 192 may include a processor 194 and a memory device 196. The processor 194 may include any suitable type of processing circuitry, such as one or more processors, one or more general-purpose microprocessors, one or more special-purpose microprocessors, and/or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the processor 194 may include one or more reduced instruction set (RISC) processors. The memory device 196 may include any suitable type of memory that stores instructions, such as in the form of software, executable by the processor 194, such as a non-volatile and/or volatile memory.
The controller 192 may be coupled to an electronic display 198 that enables a user to view information associated with the computing device 190. The display 198 may include a user interface 200 that enables a user to input information to the computing device 190. In alternative or additional embodiments, any suitable input device or technique may be used to receive input from a user, such as a keyboard, mousing device, trackpad, and so on.
The controller 192 may be coupled to a communication interface 202 that enables the computing device 190 to communicate with other electronic devices. For example, the communication interface 202 may enable the computing device 190 to communicate with any suitable communication network to communicatively couple to another electronic device. As such, the communication interface 202 may enable the computing device controller 192 to communicate with wireless networks, such as a mobile, WiFi, LAN, WAN, or Internet network, through which the computing device controller 192 may communicatively couple to the communication interface 178 of the control system 170. The communication interface 202 may also or alternatively enable the computing device controller 192 to communicatively couple to the communication interface 178 of the control system 170 through wire-based communication technology, such as Ethernet, RS-232, RS-485, UART, USART, or USB technology.
As such, the communication interface 202 may enable the computing device 190 to operate the latching system 118 by, for example, engaging or disengaging the latch 120 of the latching system 118, based on the signal, current, or indication of the position of the locking engagement device 82 via the controller 172 and the communication interface 178. In particular, the user interface 200 may display controls, such as buttons or switches, which are associated with engaging or disengaging the latch 120 of the latching system 118. The computing device controller 192 may receive an indication or signal from user interface 200 as to whether a control is placed in an open (or first) or closed (or second) position. The computing device controller 192 may then instruct the controller 172 of the control system 170 to engage or disengage the latch 120 via the communication interface 202 and the communication interface 178. As such, the user interface 200 may enable, for example, a user, to engage or disengage the latch 120 via the computing device 190. In such an embodiment, the outer door portion 84 may or may not include the locking engagement device 82, as it may be superfluous, but could still be used as a redundant way to engage or disengage the latch 120. The user interface 200 may be referred to as a virtual lock, and thus may use security techniques, such as appropriate login and password information, biometric information, and so on, to enable use of the user interface 200 to engage or disengage the latch 120.
With the foregoing in mind,
As illustrated, the processor 174 receives, at process block 212, an indication that a locking engagement device 82 is in an open (or first) or closed (or second) position. In particular, a user may place or rotate the locking engagement device 82 into the open or closed position. In response to the locking engagement device 82 being placed or rotated into the open or closed position, the locking engagement device 82 may send an indication of or a signal associated with the position via the conductor 126 to the processor 174.
In process block 214, the processor 174 instructs one or more latching systems 118 to engage or disengage one or more latches 188 of the one or more latching systems 118 based on the indication. For example, if the indication is associated with the locking engagement device 82 being in the open position, the processor 174 may instruct a latching system 118 to disengage a respective latch 188, thus enabling the door 50 to be opened and enabling access to components contained in the housing 13 of the HVAC system or unit. If the indication is associated with the locking engagement device 82 being in the closed position, the processor 174 may instruct the latching system 118 to engage the respective latch 188, thus preventing the door 50 from opening and preventing access to components contained in the housing 13 of the HVAC system or unit. In some embodiments, the processor 174 may be directly and electrically coupled to the latching system 118 via, for example, the second conductor 177 of
In some cases, the processor 174 may control other components of the HVAC system or unit, such as other components contained in the housing 13 of the HVAC system or unit, based on engaging or disengaging the one or more latches 188 of the one or more latching systems 118 and/or opening or closing the one or more doors 50 of the housing 13. For example, an HVAC system may include ultraviolet lights that reduce microbial growth in a portion (e.g., an evaporator section) of the HVAC system. However, it may be undesirable for a human (e.g., service personnel or owners of the HVAC system) to be exposed to the ultraviolet lights. As such, the processor 174 may be communicatively coupled to a switch (e.g., an interlock switch) that controls operation of the ultraviolet lights, such that when the processor 174 disengages the one or more latches 188 (and/or receives an indication or determines that the one or more doors 50 are opened), the processor 174 may switch or turn off ultraviolet lights associated with the one or more doors 50 (and/or other nearby doors) corresponding to the one or more latches 188.
Additionally or alternatively, the processor 174 may override the presently disclosed control schemes of the latches 188 (e.g., the process 210) in certain circumstances. For example, if the interlock switch that controls the operation of the ultraviolet lights described above fails to switch or turn off the ultraviolet lights, the processor 174 may override disengagement of the latches 188 (and/or prevent the one or more doors 50 from being opened) to ensure that the service personnel or owners of the HVAC system are not exposed to the ultraviolet lights.
The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).
The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.
This is a continuation application of U.S. patent application Ser. No. 16/380,810, entitled “SYSTEMS AND METHODS FOR ELECTRONICALLY LOCKING HVAC DOORS,” filed Apr. 10, 2019, which claims priority from and the benefit of U.S. Provisional Application No. 62/821,870, entitled “SYSTEMS AND METHODS FOR ELECTRONICALLY LOCKING HVAC DOORS,” filed Mar. 21, 2019, each of which is hereby incorporated by reference in its entirety for all purposes.
Number | Date | Country | |
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62821870 | Mar 2019 | US |
Number | Date | Country | |
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Parent | 16380810 | Apr 2019 | US |
Child | 17892993 | US |