Abstract:
A clothes dryer including a cabinet, a drum rotatably mounted in the cabinet, ductwork connected to the drum for circulating air, a heating element for providing heat to the drum, and a control system for operating the clothes dryer. The control system includes a warning indicator and a control module. The control module monitors and tracks usage of the clothes dryer. The warning indicator provides first and second warnings to a user based on the usage. The first warning indicates that factory authorized service is required to clean inside the cabinet of the clothes dryer, and the second warning indicates that the heating element has been disabled until the factory authorized service occurs. Preferably, the control module is further operative to completely disable the clothes dryer based on the usage.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/303,897, filed Mar. 4, 2016, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The subject disclosure relates to safety mechanisms for clothes dryers, and more particularly to clothes dryer safety mechanisms that disable the heating element or operation when maintenance is overdue by a predetermined amount of cycles and/or runtime. 
         [0004]    2. Background of the Related Art 
         [0005]    Clothes dryer fires are common events, which often result in loss of property and endanger life. Typically, not only the vents and ductwork but everywhere inside the cabinet becomes clogged with lint. For example, factors such as design, installation, use and maintenance can result in lint accumulation near the heat sources such as the electric heating element and gas burners. Lint is an excellent fuel for fire so that when left in proximity to the heating element, fires often occur. External vents are typically fairly easy to clean with easy access and no required tools. However, the interior of the dryer is difficult to access without proper tools, training and strength to move the clothes dryer. Due to the close proximity to the heating element, it is the interior lint that is most likely to ignite. Further, cleaning of the interior may void the clothes dryer warranty if not performed by an authorized factory service representative, which is costly. As a result, the interior simply is not properly cleaned, if at all. 
         [0006]    Several attempts have been made to address clothes dryer fires. For example, U.S. Pat. No. 4,622,759 to Abe et al. issued on Nov. 18, 1986 discloses a clothes dryer with sensors and a control system that monitors temperature. Based on the sensors, power to heater may be shut off. In short, if the clothes dryer runs too hot, the heater is shut off. 
         [0007]    U.S. PGPUB. No. 2002/0184786 to Miller, II published on Dec. 12, 2002 discloses that dryer vent fires are a common hazard. When a fire is detected, the power to the dryer is disconnected and an extinguishing agent is applied to the area. 
       SUMMARY OF THE INVENTION 
       [0008]    In view of the above, a need exists for a system that insures proper maintenance of clothes dryers to prevent fires and the associated damage. 
         [0009]    The present disclosure is directed to a safety device for clothes dryers to prevent fires related to lint accumulation in hard to access places like inside the cabinet and ductwork. The additional components may simply be a small printed circuit board that operates to turn on one or more warning lights on the control panel of the clothes dryer after running a certain number of cycles. When the dryer is safe, the warning lights will be green or off. When the first warning comes up, the warning light turns yellow and may blink. The warning light signals that the dryer has to be professionally cleaned where the lint gathers at the rear of the drum, inside the cabinet, in the internal ductwork and/or other typical collection areas. After the yellow light goes on, the warning light turns red after another predetermined number of cycles. When the warning light turns red, the heating source becomes inoperable until the dryer is serviced and cleaned, at which time, the warning light is reset. Until servicing, the clothes dryer will still operate without heat, preventing lint fires by disconnecting the heat source. The lack of heat will still tumble dry the clothing but the poor performance will prompt the user to service their dryer. 
         [0010]    In another embodiment, the subject technology is a clothes dryer including a cabinet, a drum rotatably mounted in the cabinet, ductwork connected to the drum for circulating air, a heating element for providing heat to the drum, and a control system for operating the clothes dryer. The control system includes a warning indicator and a control module. The control module monitors and tracks usage of the clothes dryer. The warning indicator provides first and second warnings to a user based on the usage. The first warning indicates that factory authorized service is required to clean inside the cabinet of the clothes dryer, and the second warning indicates that the heating element has been disabled until the factory authorized service occurs. Preferably, the control module is further operative to completely disable the clothes dryer based on the usage. 
         [0011]    And yet another embodiment of the present disclosure includes a safety system for a clothes dryer with a specialized printed circuit board including memory storing an instruction set and data related to the clothes dryer and a first cycle count, and a processor in communication with the memory for running the instruction set. The processor is operative to monitor and track cycles of the clothes dryer, compare the cycles to the first cycle count to determine if the cycles is greater than the first cycle count, and provide a first warning signal to a user when the cycles is greater than the first cycle count, wherein the first warning signal indicates factory authorized service is required to clean inside a cabinet of the clothes dryer. Cleaning inside the cabinet includes cleaning ductwork and/or an area around a rotating drum. The memory may store a second cycle count so that the processor can compare the cycles to the second cycle count to determine if the usage total is greater than the second cycle count, and disable a heating element of the clothes dryer when the usage total is greater than the second cycle count. The memory may also store a third cycle count so that the processor can compare the cycles to the third cycle count to determine if the usage total is greater than the third cycle count, and disable the clothes dryer entirely when the usage total is greater than the third cycle count. In one version, the safety system includes a heating-element-on indicator light and a service required light, the lights being in communication with the processor so that the first warning signal turns the heating-element-on indicator light from green to yellow and the service required light illuminates when the clothes dryer is disabled entirely. 
         [0012]    Still another embodiment of the present disclosure includes a safety system for an appliance to monitor and track real time usage for providing warnings and controlling operation including a specialized printed circuit board having memory storing an instruction set and data related to the appliance, a first predefined criteria, and a second predefined criteria, and a processor in communication with the memory for running the instruction set. The processor can monitor and track usage of the appliance to record a usage total, compare the usage total to the first predefined criteria to determine if the usage total is greater than the first predefined criteria, provide a first warning signal to a user when the usage total is greater than the first predefined criteria, when the usage total is greater than the first predefined criteria, compare the usage total to the second predefined criteria to determine if the usage total is greater than the second predefined criteria, and disable a function of the appliance when the usage total is greater than the second predefined criteria. The appliance may be a clothes dryer, first criteria is a first number of cycles, the second criteria is a second number of cycles, and the function is providing heat from a heating element of the clothes dryer. A LED may be in communication with the processor, wherein the LED is green during normal operation, yellow as a result of the first warning signal, and red when the function is disabled. The first warning could also be a text message sent to a manufacturer and/or an owner of the appliance. The processor may also send a message to an agent of a manufacturer of the appliance based upon the function being disabled. 
         [0013]    It should be appreciated that the subject technology can be implemented and utilized in numerous ways, including without limitation as a process, an apparatus, a system, a device, a method for applications now known and later developed or a computer readable medium. These and other unique features of the system disclosed herein will become more readily apparent from the following description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    So that those having ordinary skill in the art to which the disclosed technology appertains will more readily understand how to make and use the same, reference may be had to the following drawings. 
           [0015]      FIG. 1  is a perspective view of a clothes dryer with the housing partially cutaway to illustrate interior components in accordance with the subject technology. 
           [0016]      FIG. 2  is a block diagram of a safety mechanism implemented in accordance with the subject technology. 
           [0017]      FIG. 3  is a flowchart depicting a process for operating a clothes dryer utilizing a safety process in accordance with the subject technology. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0018]    The subject technology overcomes many of the prior art problems associated with hazardous conditions in clothes dryers. The advantages, and other features of the technology disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present technology and wherein like reference numerals identify similar structural elements. 
         [0019]    In brief overview, the subject technology relates to appliance safety such as clothes dryer safety mechanisms that disable the appliance (e.g., disabling a heating element) or operation when maintenance is overdue by predetermined criteria (e.g., an amount of cycles and/or runtime). 
         [0020]    Referring now to the  FIG. 1 , there is shown a clothes dryer  100  in accordance with the subject disclosure. The clothes dryer  100  includes a cabinet  102 , which is shown in partial cutaway to illustrate interior components. A control panel  104  mounts on the cabinet  102  to allow users to selectively program operation of the clothes dryer  100 . The control panel  104  may have a selector dial, a plurality of selector buttons, switches and the like (not explicitly shown) as necessary to accomplish operation in accordance with the subject technology. A LED display  106  also mounts on the housing to provide visual indication to users of the status of the clothes dryer. In one embodiment, the LED display  106  includes three LEDs  118   a - c  to provide easy review of the status of the clothes dryer  100 . Commonly, the clothes dryer  100  also includes a start button  108  that is used to begin a drying cycle. 
         [0021]    A drum  110  is mounted for rotational movement in the cabinet  102 . Once clothes are placed in the drum  110  and a dry cycle is started, a heating element  112  raises the temperature inside the drum  110  to facilitate drying of the clothes. The clothes are placed and secured in the drum through a latching door mechanism (not shown). The heating element  112  may use electricity or natural gas to generate the heat. Ductwork  114  allows air to circulate through the drum  110 . Typically, the circulating air is driven through the clothes dryer  100  by an air handling unit  116 . As noted above, lint may collect inside the cabinet  102  and in the ductwork  114 . By the lint being in close proximity to the heating element  112 , a fire hazard exists. Operation of the clothes dryer  100  is controlled by a control module  200  (see  FIG. 2 ). 
         [0022]    Still referring to  FIG. 1 , various information (not shown) is silkscreened onto the cabinet so that users inherently understand the meaning of the LEDs  118   a - c . For example, LED  118   a  has the words “LINT FILTER” adjacent thereto and is typically off. A lint filter sensor (not shown) provides a signal to a control module  200  so that when cleaning of the lint filter is required, the LED  118   a  illuminates, preferably in a red color. 
         [0023]    The LED  118 B has the word “HEAT” adjacent thereto and is typically illuminated green. However, when service such as cleaning of the cabinet  102  and ductwork  114  is required, the LED  118   b  turns from green to yellow to provide indication of the required service. The LED  118   b  may also blink to further draw the users attention thereto. Once the criteria to disable the heating element  112  is reached, the LED  118   b  turns from yellow to red. Again, the LED  118   b  may blink to draw attention thereto as the criteria for disabling the clothes dryer  100  completely approaches. 
         [0024]    The LED  118   c  has the words “SERVICE REQUIRED” adjacent thereto and is typically off. However, when service by a factory technician becomes so overdue that operation of the clothes dryer  100  will be disabled, the LED  118   c  illuminates red and blinks to further draw the users attention thereto. Once the factory technician has performed the required maintenance, the LEDs  118   a - c  are reset. More particularly detail of the operation of the clothes dryer  100  is described below. The LED display  106  may alternatively be an LCD screen that provides messages, various images and the like to enhance operation of the clothes dryer  100  in accordance with the subject technology. 
         [0025]    Referring now to  FIG. 2 , a somewhat schematic block diagram of the control module  200  is shown. The control module  200  includes one or more digital data processing devices particularly suited to work in various embodiments of the subject technology. The control module  200  also interacts with the control panel  104 , the LED display  106 , and the start button  108 . Typically, the control module  200  is a specialized printed circuit board with components for receiving, processing, displaying, and/or transmitting digital and/or analog data. Although shown as a discrete singular element, the control module  200  may have separate components distributed throughout the clothes dryer  100 . 
         [0026]    The control module  200  includes a processor  220 , which is generally logic circuitry that responds to and processes instructions. The processor  220  can include, without limitation, a central processing unit, an arithmetic logic unit, an application specific integrated circuit, a task engine, and/or any combinations, arrangements, or multiples thereof. The processor  220  is in communication with memory  222 . Typical memory  222  includes random access memory (RAM), rewritable flash memory, read only memory (ROM), mechanisms and structures for performing I/O operations, and a storage medium such as a magnetic hard disk drive(s). The memory  222  may be a combination of integral and external memory. The memory  222  includes software  224  and a plurality of modules  226 ,  228 ,  230  as needed to perform the functions of the subject technology. 
         [0027]    For example, the software  224  may include an operating system for execution on the processor  220 . Software or code generally refers to computer instructions which, when executed on one or more digital data processing devices, cause interactions with operating parameters, sequence data/parameters, database entries, network connection parameters/data, variables, constants, software libraries, and/or any other elements needed for the proper execution of the instructions, within an execution environment in memory. A module is a functional aspect, which may include software and/or hardware. Typically, a module encompasses the necessary components to accomplish a task. It is envisioned that the same hardware (e.g., memory and processor) could implement a plurality of modules and portions of such hardware being available as needed to accomplish the task. 
         [0028]    For example, a database module  226  creates, stores, and maintains data and multiple databases necessary for the proper operation of the subject technology. A program module  228  stores an instruction set to allow the operator to program operation of the control module  200  and, in turn, the operation of the clothes dryer  100  by using the control panel  104 . An algorithm module  230  stores an instruction set to allow the processor to apply one or more algorithms for operation of the clothes dryer  100 . 
         [0029]    The control module  200  also includes various other circuitry  236  (not drawn distinctly) as needed for proper operation. For example, the circuitry  236  may include a power module, control circuitry, circuitry for processing logical operations, integral A/D conversion circuitry, an integral display driver, a peripheral eeprom (non-volatile rewriteable memory for storing user settings and the like), an external flash memory chip (for in-field software updates), and an external WIFI radio which includes built-in IP stack and WIFI encryption functionality. 
         [0030]    Still referring to  FIG. 2 , the control module  200  also includes a WiFi module  238  and/or wired communication channels  240  to facilitate communication with external devices such as a cellular telephone, home network, other devices and the like. The control module  200  also has a connector sections  204  for interacting with the other components such as the drum  110 , heating element  112 , and air handling unit  116 . Although drawn as part of the processor  220 , the WiFi module  238  may be separate or otherwise incorporated into the clothes dryer  100 . 
         [0031]    Those of ordinary skill will recognize that the hardware, software, modules, sensors, elements, devices and various processes discussed herein are merely exemplary of the functionality performed by the disclosed technology and thus such hardware and processes (and/or their equivalents) may be implemented in commercial embodiments in various combinations without materially affecting the operation of the disclosed technology. It is also envisioned that the control module  200  may interact with a comprehensive home/site controller that controls the operation of additional systems (e.g., air conditioning) along with additional components and sensors (e.g., smoke detectors etc.) and the like. 
         [0032]    The following flow charts herein illustrate the structure or the logic of the present technology, possibly as embodied in program software for execution on the processor  220  of the control module  200 . Those skilled in the art will appreciate that the flow charts illustrate the structures of the program software or code elements, which may include logic circuits on an integrated circuit and/or printed circuit board, that function according to the present technology. As such, the present technology may be practiced by a specialized machine component that renders the program software in a form that instructs a processor to perform a sequence of function steps corresponding to those shown in the flow charts and equivalents. 
         [0033]    Referring now to  FIG. 3 , there is illustrated a flowchart depicting a process  300  for preventing normal operation of the clothes dryer  100  when maintenance such as cleaning the cabinet  102  for lint is overdue in accordance with the subject technology. Initially, the process  300  begins under ongoing operation circumstances as opposed to an initial start-up condition when power is applied to the clothes dryer. At step  302 , the process  300  begins by initiating the main program function loop. 
         [0034]    At step  304 , the process  300  sets up the internals for the processor  220  such as initiating the registers and the like. At steps  306  and  308 , the necessary data is loaded from the memory  222 . Such data may include pre-defined criteria for when to provide indication (i.e., warning) to the user and when to take further action such as disabling the heating element  112 . Such criteria are programmed into the memory  222  and kept in non-volatile memory storage. 
         [0035]    At step  310 , the main programming loop is entered. In step  312 , an interrupt is driven by an internal timer so that a live variable is updated. The live variable is the elapsed (live) time. At step  314 , the process  300  checks the inputs to determine if a service switch change is required. For example, the processor  220  can compare a number of cycles of use of the clothes dryer  100  against a predetermined criteria so that when the number of cycles exceeds the predetermined criteria, an indication of service being recommended is provided. As noted above, the processor  220  changes the state of the LED  118   b  from green to yellow to indicate that service is required. 
         [0036]    At step  316 , the process  300  prepares to save the updated data by collecting a snapshot of all the relevant data. At step  318 , the relevant data is loaded into temporary registers as the active registers continue to update. The relevant data is then loaded into non-volatile RAM memory at step  320 . 
         [0037]    Still referring to  FIG. 3 , at step  322 , the process  300  evaluates the relevant data to determine if any of the limits have been exceeded. Based upon the evaluation of the relevant data, the processor  220  takes control action (e.g., disabling the heating element  112 ) and change of state for the LEDs  118   a - c  as needed at step  324 . Once the user has been warned and/or the necessary protection against hazard has been accomplished, the process  300  proceeds to step  330 . At step  330 , the process  300  checks to see if the clothes dryer  100  is running or in an idle state. If in an idle state, the control module  200  can enter an idle state as well, preferably a sleep mode to conserve power. The process  300  will loop through steps  310 - 330  to insure that the user is protected and hazards are avoided. 
         [0038]    Optionally, the factory technician or other user may utilize diagnostic functions in the process  300  at steps  326 - 328 . At step  326 , the process  300  can display a visual of the run time, cycles, maintenance history and the like. The technician may have to utilize a diagnostic tool to access the reading or use the LED display  106 . At step  328 , the process  300  can calculate the run time and otherwise tabulate relevant maintenance data for presentation at step  326 . 
         [0039]    As can be seen from review of the above, the subject technology provides a safety device for clothes dryers to prevent fires related to lint accumulation in hard to access places like inside the cabinet and ductwork. The additional components may simply be a small printed. circuit board and warning light(s). The warning lights not only provide warnings to the consumer but indicate various states of operation based upon run-time or other usage. The states of operation can include operation without heat, completely disabled and the like. 
         [0040]    In one embodiment, the predefined criteria can be an amount of calendar time such as 18 months. As such, an 18 month interval without servicing can start a grace period (e.g., 6 months) of still normal operation in which a single warning light is yellow. At the end of the grace period, the heating element is disabled and the warning light turns red. The disabled heating element period can also be set to a temporal limit such as another 6 months. As the end of the disabled heating element period approaches, the warning light blinks to indicate that the clothes dryer will become completely disabled soon unless proper service is performed. Once the disabled heating element period ends without service, the clothes dryer is disabled and can only be reset by a technician, who would need to clean the clothes dryer and reset the warning system. Preferably, the disabling of the clothes dryer may be a general overall disablement or a locking of the door. 
         [0041]    In one embodiment, the criteria is a number of cycles. A cycle could be defined as simply starting a drying cycle, 1 hour of run-time, and variations thereof. Preferably, when a cycle is a full drying cycle, the caution yellow LED is illuminated after a criteria selected from 416, 520 or 624 cycles. After another 50 cycles, the red LED illuminates with the clothes dryer still cycling but disabling of the heating element  112 . Blinking could occur for 5 cycles as transition between the periods approaches. For another example, the clothes dryer could modify operation and provide warning based on usage recorded in an hour-meter off the hours of operation of the heating element, rotation of the drum, and/or running of the air handling unit. Such run-time could also be converted into cycles such as by equating 1 hour of operation being counted as 1 cycle. Additionally, the WiFi module can email the same warnings and relevant status information to the manufacturer or a service provider, who can in turn contact homeowner to schedule a service appointment when the product has been registered. 
         [0042]    Although the subject technology has been described with respect to clothes dryers, it is envisioned that the subject technology would be equally applicable to other fields and applications such as on refrigerator icemakers, dishwashers, water treatment systems such as reverse osmosis filters and UV light sanitizing modules, stovetop vents or any appliance that may need periodic maintenance such as filter changing or cleaning. The subject technology can also be formed as a retrofit kit for use on existing appliances such as clothes dryers. 
         [0043]    It will be appreciated by those of ordinary skill in the pertinent art that the functions of several elements may, in alternative embodiments, be carried out by fewer elements, or a single element. Similarly, in some embodiments, any functional element may perform fewer, or different, operations than those described with respect to the illustrated embodiment. Also, functional elements (e.g., modules, processors, memory, printed circuit boards, light emitting diodes, databases, interfaces and the like) shown as distinct for purposes of illustration may be incorporated within other functional elements in a particular implementation. 
         [0044]    All patents, patent applications and other references disclosed herein are hereby expressly incorporated in their entireties by reference. While the subject technology has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the subject technology without departing from the spirit or scope of the invention as defined by the appended claims. For example, each claim may depend from any or all claims in a multiple dependent manner even though such has not been originally claimed.