Field and Background of the Invention

[001] This invention relates to fire pits and gas burning grills, as well as related gas burning appliances for general household and personal use. More specifically, the invention relates to appliances which burn gas, at home mainly but also for commercial or industrial use, and which incorporate therein safety features and properties which may help to prevent or reduce accidents or damage that can result when the appliance malfunctions or otherwise releases flammable gasses with sometimes catastrophic consequences. The invention may include various sensors which cause the appliance to shut down or switch off when a given situation is detected, so as prevent further adverse consequences.

[002] A modem day fire pit is a sophisticated gas or wood burning structure which may be constructed from brick, metal, concrete or other materials. There are fire pits which include features and components whose main purpose is to prevent spreading of fire. These fire pits are used mainly as an outdoor leisure product. In order to ensure safe burning, these fire pits may use natural gas, propane gas or bio-methanol as the form of fuel. The fuel burns to heat, for example, glass pebbles or lava rock situated in the fire pit in order to produce an artificial effect of intense heat. Many homeowners today are using fire pits for warmth, entertainment and cooking, or simply as focal points for use and to create ambiance in an outdoor living space.

[003] The fire pits which are generally available may be operated either manually by using simple lighters or matches, or they may be more sophisticated in that they utilize auto ignition systems. However, no matter how they may be ignited, they come with plenty of potential problems. Lately, there have been instances of these fire pits causing severe burn injury and sometimes leading to a catastrophic disasters. These result mainly from the lack of safety protocols, or that the design of the fire pit does not include or encompass built in safety mechanisms. In many cases, fire pit accidents may could be due to the ignorance or even the carelessness of the end user, who may not be taking the appropriate precautions. Some of these disasters include or may result from gas leaks, gas explosions, or even flying lava rocks due to humidity or other atmospheric conditions.

Summary of the Invention

[004] One of the purposes of the present invention is to avoid and mitigate these types of accidents or disasters. The features of the invention may additionally be used to help the end user to operate the product safely in a more mindful and sophisticated way, and, furthermore, cater for situations where unexpected accidents may occur.

[005] The present invention therefore is configured with simplicity in mind as far as the end user is concerned with inclusion of safety features which are operative at all times and are designed to shut off the system, including flow of gas, at very early stages or potential problems and preferably before any major consequence can occur. Several key aspects of the operation of the fire pit are monitored continuously by the invention so that aberrant or unusual conditions which may arise at any one source can detected very soon and the system shut down to avoid further problems.

[006] The product of the invention may come pre-assembled with the base and ignition system. There may be provided a quick coupling valve or component for connecting to the gas tank or cylinder or other gas source at one point, and to the ignition system or burners of the fire pit, or other appliance, so as to integrate and effect a connection between the fuel source with the fire pit. The fuel source can be a propane gas tank, natural gas or bio-methanol, as examples, but are not limited to these sources or fuel types. After connecting to a fuel source using the quick coupling valve, or other type of valve or form of connection, a plurality of lava rocks are then placed on top of the ignition system where the fuel will be discharged and ignited. Now the product is ready for use. The lava rocks give character or ambiance or an atmosphere to the fire pit, as is the present case, and also retain heat from the burners so that such heat is more efficiently retained and spread more evenly to provide warmth and effect.

[007] One aspect of the invention provides that a firepit in accordance with the invention is designed in such a way that it encompasses and incorporates safety features and checks, and also provides the ability and components to control the firepit remotely using multiple forms of technology, as will be described.

[008] The firepit of the invention includes the provision of a controller which may be in the form of a microprocessor which has been programmed to receive various types of inputs in the form of a command which comprises but is not limited to voice and sound input, motion, light, and digital or analog signals from selected or preprogrammed sources. The status of the system and its operating components including the amount of fuel or its remaining level, the possible leakage of fuel, moisture where it would not be expected, to name a few examples but without being definitive, are in turn transmitted back through the controller so that alerts or status reports may be provided in order to take precautionary measure, as may be required in any given situation.

[009] The system can be operated either remotely using, for example, WiFi, Bluetooth™, cellular or radio frequency or infra-red devices. During the operation of the fire pit, the intensity of the heat can be adjusted again using the RF, cellular, infra-red or other suitable connections or devices. The controller or other components of the system may provide any selected output which maybe in the form of, for example, a blinking or stationary light, a sound or the like. The system may incorporate a reset capability as part of its properties.

[0010] The fire pit using the controller can, in one form of the invention, be connected or connectable to a solar power source, or to an energy bank or to any power outlet including conventional AC or DC power sources, to charge the battery which may be required to operate and run the controller or the ignition system, or other components which may need power, intermittent or otherwise, in order to function.

[0011] The system may further include at least one gas sensor, such as a gas sensor 1 (MQ9-1) and gas sensor 2 (MQ9-2), and these may be connected serially, or in another manner, to the controller and ignition source. The gas sensor MQ9-1 may preferably be connected fairly close to the fuel source, while the gas sensor MQ9-2 maybe connected near the ignition source. In this way, the ability to sense gas at multiple locations, particularly locations where the first sign of unburned gas may be present or anticipated, on or in the system is provided so that the safety of the system as a whole is significantly improved as a result of such monitoring. The invention is not limited to the number of sensors. There may be only one sensor, or there may be more than two sensors.

[0012] If there should be any leaks in or from the fuel source or the fuel lines or at fuel connector locations, like for example the quick coupling valve or the gas hose or the gas connector, the gas sensor MQ9-1 will sense the presence of gas and send a signal to the controller relating to this situation. The controller may respond by immediately sending a signal to the ignition system to turn off the ignition, and/or close off all the gas supply lines and sources. At the same time, another signal may be sent to the output in the form of a sound through an associated speaker or as a blinking red or green light which is displayed. The invention may include the ability to send a text message or some other form of message or communication to any cellular device or portable electronic device or even a computer which may have been registered to this specific fire pit. Thus, a person will be alerted to the fact that a potentially dangerous or hazardous situation is present at the firepit, and that a safety inspection may be in order. The controller is also capable of storing these events with a date and time stamp for further evaluation, and for record purpose so that if these occur with some frequency, the owner may be alerted to a more fundamental problem in the system which may require a more comprehensive inspection. The data can be downloaded from the controller using for example a standard USB port, or by WiFi transmission, but the invention is not limited to these options. [0013] If the situation should arise where the system does not turn on as a result of an ignition problem, but the gas valve is however in the open position, the gas may well start to leak thereby creating a cloud of gas, which may develop into a very substantial cloud, over the fire pit. Since the density of gas is higher than ambient air, such a gas cloud is formed, and if and when ignited can cause a huge burst of flame resulting in severe burning and injury to person. Property in the vicinity may also be damaged if a fire is ignited and spreads. In order to avoid this situation, the gas sensor MQ9-2 is preferably connected near the ignition system. As the gas cloud is formed in the situation as described above, the gas sensor MQ9-2 will send a signal to the controller to shut off the ignition. The signal may also cause the controller to shut off all gas supply sources and close off gas supply lines. An immediate signal in the form of sound to a speaker or blinking red and green display of light on the fire pit may be activated, and a text or call may be initiated to the cellular device or other electronic device as mentioned above, and which has been registered to this specific fire pit. The existence of a hazardous condition is thereby relayed to a person in case no one is present at the fire pit when the dangerous condition arises, or the people present are not familiar with the action which may need to be taken in the circumstances.

[0014] In another form of the invention which incorporates a number of safety features and properties, if the product is burning and left unattended, there may be provided one or more proximity or motion sensors which may be mounted on the sides of the fire pit, or positioned elsewhere, even off the fire pit itself, and which may be able to detect the absence of any human motions and their presence. This type of detection may happen if one or more than one of the sensors senses the absence of human motions. In this situation, the system is able to trigger a message to turn off or reduce the flow of the gas or fuel supply. This in turn shuts of the fire. There is a timing for these sensors to trigger a message which is controlled by the controller. The sensors may first send a message to a preprogrammed phone or other device to give an operator the ability to override such a shutoff where it is not desired. The system may also be able to shut down gradually over a period of type during which no human presence or motions are detected. The system may also include wind sensors or moisture sensors which are able to shut down the gas supply and ignition when the ambient wind conditions may make it risky or dangerous for the fire pit to continue operating, or moisture from rain or other sources may douse the flames and cause gas leakage, so as to prevent damage from occurring in adverse weather conditions.

[0015] The present invention may also provide data regarding the health and condition of the product, or certain critical components thereof, and this may include alerts at the time for carrying out preventive maintenance, or at selected intervals between periodic maintenance where simple inspection or basic cleaning is recommended.

[0016] The fire pit in accordance with the invention may be able to set a timer to turn the system ON or OFF, and run for a selected or a defined time interval. The system may also be programmed in a conservation manner such that as the time to shut off approaches and gets closer to the set time OFF, the fuel supply is adjusted accordingly by decreasing the flow so that unnecessary heat is not generated, which takes time to dissipate after the system is OFF. This helps to manage the fuel efficiently. There may be circumstances where the system fires up the heat in a gradual manner as well over a period of time, for the purposes of safety and conservation. Indicators may be provided, such as lights or sound emissions which display the progress of shutting down and firing up so alert the users as the changing conditions and output of the device.

[0017] In a further embodiment, heat sensors around the burners may be able to sense the ambient temperature and then increase or decrease gas flow to raise or lower the temperature output of the device incrementally in order to keep it fairly constant, and at a comfortable possibly preselected temperature which may be varied by programming.

[0018] In another embodiment of the invention, the firepit maybe smart enough to detect the fuel content in the tank, where the fuel source is a portable tank as opposed to a permanently installed fuel outlet. In this case, sensors may be able to warn the user such as with a signal showing different colors where the fuel level is full, % tank, 1/4 tank or close to empty, or anything in between. [0019] According to one aspect of the invention, there is provided a fire pit comprising: a fuel source connector; at least one fuel outlet; a fuel conduit for conveying fuel from the fuel source connector to the fuel outlet; at least one sensor for detecting the presence of unburned fuel outside the fuel conduit; and a fuel control mechanism for stopping or modulating the conveyance of fuel when the sensor detects the presence of unbumed fuel.

[0020] In one embodiment, the fuel outlet comprises a plurality of apertures formed in a recessed receptacle. The recessed receptacle may accommodate lava rocks positioned therein to be heated by burning fuel discharging at the plurality of apertures, and may be a generally circular shaped tray with the plurality of apertures located at or near a periphery thereof.

[0021] Preferably, the at least one sensor comprises a first sensor positioned at or near the fuel source connector and at least one second sensor positioned at or near the fuel outlet. Further, the fuel control mechanism may comprise a controller for receiving information from the at least one sensor, the controller being connected to the fuel source connector for effecting a stopping or modulating of the fuel flow from the fuel connector in programmed conditions.

[0022] In one embodiment, the sensor comprises at least one thermocouple for sensing temperature and transmitting temperature information to the fuel control mechanism, and an ignition switch located at or near a fuel outlet for igniting the fuel. The thermocouple may spaced from the fuel outlet by between about 10mm and about 12mm.

[0023] Preferably, at least one of the sensors comprises a MQ9 sensor for detecting the presence of gases including one or more of carbon monoxide, benzene, alcohol, NOx, NH3, smoke or a combination of two or more of such gases.

[0024] The fire pit may comprise a housing having a space for accommodating a fuel supply tank, sensors, electronics and other components, and a wherein the fuel outlet comprises a recessed tray at an upper portion of the housing, the recessed tray accommodating the fuel outlet and heatable material therein.

[0025] According to a further aspect of the invention, there is provided a heating device comprising: a fuel source connector; at least one fuel outlet; a fuel conduit for conveying fuel from the fuel source connector to the fuel outlet; at least one sensor for detecting the presence of unburned fuel outside the fuel conduit; and a fuel control mechanism for modulating the conveyance of fuel when the at least one sensor detects the presence of selected materials. The selected materials may comprise one or more of carbon monoxide, benzene, alcohol, NOx, NH3, smoke or a combination of two or more of such gases.

[0026] Preferably, the at least one sensor comprises a first sensor at or near the fuel source connector, a second sensor at or near the fuel outlet, and the fuel control mechanism comprises a controller receiving input from the first and second sensors, the controller being functionally connected to the fuel source connector so as to selectively modulate or cut off fuel supply to the fuel outlet in response to specified information received continuously in real time from the first and/or second sensors.

[0027] According to yet a further aspect of the invention, there is provided a method of making a fire pit comprising: providing a fuel source connector; providing at least one fuel outlet; connecting a fuel conduit for conveying fuel from the fuel source connector to the fuel outlet; locating at least one sensor for detecting the presence of unbumed fuel outside the fuel conduit; and providing a fuel control mechanism for stopping or modulating the conveyance of fuel when the sensor detects the presence of selected materials.

Brief Description of the Drawings [0028] In the drawings:

[0029] Figure 1 is a top perspective view of a fire pit of the invention in one embodiment thereof;

[0030] Figure 2 is a perspective view of the fire pit shown in Figure 1 wherein the lava rocks are removed to show certain components and hardware of the fire pit;

[0031] Figure 3 is a perspective view of a fire pit which has a propane gas cylinder as the fuel source, with the propane tank in the uninstalled position;

[0032] Figure 4 is a view similar to that in Figure 3 wherein the propane gas tank has been inserted and is connectable within the housing of the fire pit;

[0033] Figure 5 is a further view showing in more detail the propane tank connected within the housing including the use of a conventional QCC connection device to the propane gas tank cylinder;

[0034] Figure 6 is a schematic perspective view from the top of a fire pit of the invention, showing a detail section with the positioning of an ignition pin and a thermocouple; and

[0035] Figure 7 is schematic flow chart and table showing safety features and structures associated with the controller used in a fire pit in accordance with the present invention.

Detailed Description of the Invention

[0036] Reference is now made to the accompanying drawings which shows a fire pit 10 in accordance with the present invention. Note that the invention is illustrated with reference to a fire pit but can be used in other appliances or devices where such systems may be necessary or desirable. The invention is therefore not one which is limited specifically to use on a fire pit.

[0037] In Figure 1 of the drawings, there is shown a fire pit 10 having a housing 12 with a base 14, side walls 16 and a top 18. One of the side walls 16A has a door 20 which can be opened or closed to provide access to the interior space 26 of the housing 12. The top 18 has a circular recessed area 30 (which may have shapes other than circular) having a floor wall 32. In use, the recessed area 30 is filled with lava rocks 36 or some other similar type of material. The lava rocks 36 are heated as will be described and give character and effect as well heat to the fire pit 10.

[0038] Figure 2 of the drawings is similar to that in Figure 1, but the lava rocks 36 have been removed to better show the recessed area 30 and its components. In this recessed area 30, there is provided a thermocouple 38 or other type of temperature sensor for measuring the temperature and amount of heat at its location. The thermocouple 38 will relay information to a controller 42 (such as shown in Figure 7 of the drawings) located within the housing 12 (or elsewhere), and the system will be programmed to react to information from the thermocouple 38 such as by shutting off gas supply when the heat exceeds a predetermined level.

[0039] Figure 2 also illustrates the presence of an ignitor and gas flow control 44. There is an ignitor 48 which will spark upon activation which will in turn light the gas discharged from the gas flow control 44. Also seen is an auto ignition switch 100 which may be operated by pushing it, in turn activating the spark from the ignitor 48. The recessed area 32 will preferably have a plurality of gas holes 52 as seen in Figure 6 of the drawings spaced around the circumference or periphery of the recessed area 30. Any configuration of gas holes 52 is possible in the invention and the invention is not limited to any one arrangement of such gas holes 52.

[0040] Figures 3 and 4 illustrate the insertion, or removal, process for a propane gas tank 60 in the interior space 26 of the housing 12. The door 20 is opened or removed depending on its form of attachment as seen in Figure 3, and the gas cylinder 60 placed on a receiving portion 62 of the base 14 inside the housing 12. A QCC quick coupling valve 64 is then connected to the outlet of the gas cylinder 60 and tightened appropriately. The valve 64 attaches to a hose 66 at one end thereof, and the hose 66 at its other end connects to gas conduit piping 68 which conveys gas from the gas cylinder 60 to the gas holes 52 in the recessed area 30, as described above. When the gas is flowing and is discharged from the gas holes 52, the gas will be ignited and burn in the recessed area 30, providing heat and heating the lava rocks 36 located in the recessed area 30. [0041] Once the gas cylinder 60 is installed and connected to the valve 64, the door 20 is closed or reconnected to close off the interior space 26 inside the housing 12.

[0042] Figure 5 of the drawings illustrates the propane cylinder 60 installed inside the housing 12. This figure also illustrates the position of gas sensor MQ9 #1 70 which senses for the presence of unburned gas at and around the connection between the valve 64 and gas cylinder 60. As will be described, this gas sensor 70 communicates with the controller 42, and if gas from a leak is detected by the gas sensor 70, shut down or remedial action to prevent or reduce the effects of a dangerous condition are set in motion, thereby alleviating the or removing the condition.

[0043] Figure 6 of the drawings shows the fire pit 10 of the invention in a top perspective view and a detail showing the position of the ignitor 48 and thermocouple 38. Also shown are the plurality of gas holes 52, through which gas from the gas cylinder 60 is discharged and ignited to create the heat for the fire pit 10 while burning. Figure 6 also illustrates the gas sensor MQ9 #2 80, which is positioned at or near the ignitor 48 and in the region of the gas holes 52. The gas sensor 80 is able to detect the presence of unburned gas in the area that may be leaking from the gas holes 52 without being ignited, a potentially dangerous condition, since the build up of unburned gas is liable to explode and also, since it may near odorless and invisible, hazardous to those breathing the air in the vicinity of the fire pit.

[0044] Figure 6 also shows one preferred embodiment where the distance between the thermocouple 38 and the gas hole is about 10mm to about 12mm. Note that this distance is not absolute, and can vary according to design and intended usage of the fire pit 10. Note, too, that there maybe a plurality of gas sensors 80 arranged in a selected configuration at or near gas holes to have the capability of very local leak or unbumed gas detection, adding safety to the system.

[0045] There maybe additional sensors arranged in various locations between the gas connection to the propane tank and the discharge gas holes 52, in order to improve gas leak detection. Further, there may be sensors arranged around the fire pit in certain positions to detect the presence of unburned gas which may not necessarily have been detected or which are present along the gas feed line. Sensors outside the housing of the fire pit may be included in this embodiment.

[0046] Figure 7 is a chart or table showing the electronics and operational steps of the safety systems built into the fire pit 10 of the invention. The controller 42 is programmed to control these features, and receives input from the gas sensors 70 and 80. The system may be shut down in response to signals from these sensors regarding the presence of unbumed gas, when exceeding levels not considered to be safe.

[0047] The controller 42 also manages the indicator lights 84 for the fire pit 10 system. These may be red, green and blue, or another combination of different colors. The light illumination information and options are provided in the box 86, although these may vary based on model and level of sophistication which may be desired. Different lighting options provide information as to the charging status, system “in order” status, as well an option which indicates that there is a problem which has been detected and which requires either manual or automatic shut down to preserve safety in the region of the fire pit.

[0048] The controller 42 also monitors the valve 64 which may be opened and closed through the use of a switch 88 or other hardware. The controller 42 may also connect to the IOT at 90. Further, information as to temperature is received from the thermocouple 38 so that appropriate action can be taken when temperatures reach unacceptable levels which may create dangerous conditions.

[0049] The controller 42 maybe powered by one or a combination of sources, such as a battery 92 which can be powered from several different sources. [0050] The system may include an auto ignition switch 100 for use by the owner to generate a spark at the point of exit of the gas, at the gas holes 52, to initiate the burning of gas and heating process.

[0051] Note that the controller may also be programmed to send messages, such as through a Bluetooth connected device or through an internet Wi-Fi connection to a remote electronic device such as a smart phone to warn users or owners or others about the condition of the fire pit 10 when monitors detect a dangerous condition evolving.

[0052] Various input devices to the controller 42 are illustrated, including power bank, adapter, solar energy connector and USB plug or port.

[0053] According to one aspect of the invention, there is provided a fire pit comprising a housing, a source of gas, a burn recess area where gas is ignited and burned, and safety devices and monitors to monitor levels of heat and unburned gas.

[0054] Preferably, the burn recess area is filled or partially filled with lava rock or other heat retaining material.

[0055] The safety devices may include gas sensors. These gas sensors are preferably located at the point where a gas connection connects to a source of gas in the housing, and the point or points where gas is discharged into the burn recess area. A plurality of gas holes may be positioned in the burn recess area through which such gas is discharged. In one embodiment, the source of gas is a propane gas tank which is located in the housing and can be removed and replaced when the gas in the gas tank has been depleted. [0056] The safety devices may further include a thermocouple, preferably place near gas holes, to monitor temperate and take appropriate action when temperature levels increase to undesirable or dangerous readings.

[0057] The fire pit of the invention further may comprise a controller for receiving information from the system including the safety devices, and which can take action in certain circumstances to mitigate danger, provide audible or visual warnings on conditions, or send messages to remote electronic devices to warn others who may not be in the vicinity of the fire pit that a hazardous situation is developing or has been reached.

[0058] Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements maybe combined in other ways to accomplish the same objectives. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments.

[0059] As used herein, “plurality” means two or more. As used herein, a “set” of items may include one or more of such items. As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’, respectively, are closed or semi-closed transitional phrases with respect to claims. Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.