referring to fig1 to fig6 , the present invention comprises a main body 10 , an air blower 20 , an ignition device 30 , a nozzle 40 , a switch set 50 and a safety switch 60 ; the main body 10 further consists of a barrel 11 and a handle 12 , a heating chamber 111 is inside the barrel 11 , a gas can 122 is inside the handle 12 , users can press the switch set 50 to start the safety switch 60 and have the gas of the gas can 122 spray out from the nozzle 40 into the heating chamber 111 , the ignition device 30 ignites the gas inside the heating chamber 111 to generate heat source , the air blower 20 blows the hot air inside the heating chamber 111 externally to the main body 10 . the main body 10 comprises of a barrel 11 , a handle 12 , an intake 13 and a exhalation hole 14 ; a heating chamber 111 and a mixing chamber 112 are on the inner front of the barrel 11 , a daisy shape metal slice 113 and a catalyst 114 are inside the heating chamber 111 , the metal slice 113 is installed inside the heating chamber 111 near the front side of the barrel 11 , the catalyst 114 is installed near the end of the barrel 11 ; a burning chamber 115 is inside the metal slice 113 , the mixing chamber 112 in installed on the barrel 11 that is opposite to the location of the heating chamber 111 ; a shrink 116 near the metal slice 113 is formed on one end of the mixing chamber 112 , the shrink 116 is interlinked to the burning chamber 115 of the metal slice 113 ; several air inhalation holes 117 are around the mixing chamber 112 , a passages 118 is between the metal slice 113 and the barrel 11 ; a tube shape metal net 119 to control the mixing air flow is installed between the burning chamber 115 of the metal slice 113 and the shrink 116 of the mixing chamber 112 , a thicker metal net 120 with smaller net holes near the exhalation hole 14 is on one side of the metal net 119 . the handle 12 is connected to and beneath the barrel 11 , a first container 123 and a second container 124 are inside the handle 12 , a battery set 121 and a gas can 122 are inside the first and the second container 123 , 124 respectively , the gas can 122 contains burnable fluid , usually is liquid gas ; a movable cover 125 is on the bottom of the handle 12 to cover the first and the second container 123 , 124 . the intake 13 is installed on the end of the barrel 11 for air to flow into the barrel 11 ; several protective grids 131 are on the intake 13 to prevent users from inserting their fingers in . the exhalation hole 14 is on the front of the barrel 11 to expel air from the barrel 11 . the air blower 20 in installed internally on the end of the barrel 11 to draw air from the intake 13 into the barrel 11 , a dc motor is applied in this application , the blower 20 further comprises a motor 21 , a fan blade 22 and a temperature sensor 23 ; the motor 21 locates near one side of the exhalation hole 14 , the fan blade 22 is installed on the motor 21 and near one side of the intake 13 to be driven by the motor 21 ; the temperature sensor 23 is installed around the barrel 11 near the heating chamber 111 , the temperature sensor 23 controls the motor 20 , after end of application and when the temperature of the heating chamber 111 below certain temperature , the temperature sensor 23 stops the motor 21 from turning . the ignition device 30 is installed inside the metal slice 113 of the heating chamber 111 to ignite the mixed gas in the heating chamber 111 ; the ignition device 30 is installed inside the burning chamber 115 of the metal slice 113 in this application . the nozzle 40 is installed inside the barrel 11 of the main body 10 and located between the blower 20 and the mixing chamber 112 ; one end of the nozzle 40 is connected to the gas can 122 . the switch set 50 is installed inside the handle 12 of the main body 10 near the barrel 11 ; the switch set 50 further comprises of a power switch 51 , a control rod 52 , an ignition switch 53 and a regulation valve 54 ; the control rod 52 controls open and close of the gas can 122 , the ignition switch 53 connects to the ignition device 30 with electrical wires ; the regulation valve 53 is installed on the gas can 122 to control the gas flow amount of the gas can 122 . the safety switch 60 connects to the power switch 51 , the safety switch 60 also connects to the motor 21 , the temperature sensor 23 of the blower 20 , the battery set 121 on the handle 12 and the control rod 52 of the switch set 50 , all these components are controlled by the safety switch 60 to turn on and off . referring to fig4 , when the power switch 51 is pressed on , the safety switch 60 is activated , the safety switch 60 turns on the control rod 52 to open the gas can 122 , the gas sprays out from the nozzle 40 ; at the same time , the safety switch 60 activates the blower 20 blow air from the intake 13 into the mixing chamber 112 to mix the gas and the air blown in ; when the mix gas passes the shrink 116 , with the shrinking diameter of the shrink 116 , the mixed gas is compressed , the mixed air spays out the shrink 116 at a faster speed , the high speed injected mixed air entering the burning chamber 115 of the metal slice 113 flows to the tube shape metal net 119 that guides the flow direction of the mixed gas ( referring to fig5 ), with the two blocks by the thicker metal net 120 on the front of the tube shape metal net 119 and the tube shape metal net 119 itself , since the net holes of the thicker metal net 120 is smaller , the mixed gas is blocked effectively to have most of the mixed gas spays out in all directions . when the ignition switch 53 is pressed , the ignition device 30 ignites the mixed gas and generates flame , the flame expands several tongue of flames from the burning chamber 115 to surround the metal slice 113 and have the temperature of the metal slice 113 rise gradually that forms the first burning ; with the better heat exchange rate of the metal slice 113 , when the air flow sent by the blower 20 passes through the passage 118 of the metal slice 113 , air flow can bring the heat on the metal slice 113 to generate hot air ; when the hot air passes through the catalyst 114 , the catalyst 114 burns the small quantity left - over gas to reduce the quantity of carbon mono - oxide ( co ) that forms the second burning ; after two times of burning , the air temperature is higher , the air is safer , the catalyst 114 avoids the burning flame in the metal slice 113 from coming out of the exhalation hole 14 . the mixed gas needs to have a good ratio of fresh air and gas to be properly burnt , when oxygen contained is too low in the mixed gas , the inhalation holes 117 around the burning chamber 115 offers fresh air ; the diameter of the shrink 116 of the mixing chamber shrinks 112 gradually , fresh air is sucked in , mixed with gas and enters the burning chamber 115 to be burnt stably ; the quantity of gas can also be controlled by the regulation valve 54 ; since the metal slice 113 inside the heating chamber 111 has very good heat conductivity , the temperature of the metal slice 113 is lifted rapidly after the ignition inside the burning chamber 115 ; if the gas in the heating chamber 111 is not burnt properly , the toxic carbon mono - oxide is generated and is harmful to human body ; in order to achieve complete burning , the catalyst 114 can achieve such purpose , the catalyst 114 reacts with the burning gas and generates non - toxic carbon di - oxide , the catalyst 114 can also prevent the flame from coming out of the exhalation hole 14 . when following situations happen , the safety switch 60 elaborates the proper function ; when power switch 51 is on without flame or gas burning stops , the temperature sensor 23 installed on the barrel 11 near the heating chamber 111 detects the temperature did not reach the expected temperature , the safety switch 60 stops all the signals to make the motor 21 stop , the control rod 52 break away to stop the gas . at normal operation , when the temperature sensor 23 detects abnormal high temperature , the safety switch 60 have the control rod 52 stop the gas and have the motor 21 turn on to blow air until temperature drop and then stop . when temperature sensor 23 detects the temperature remain high after the power switch 51 is off , the safety switch 60 have the nozzle 40 stop spraying gas and turn on the blower 20 , the blower 20 keeps blowing fresh air to cool the temperature of the heating chamber 111 , the metal slice 113 absorbs the cold fresh air to lower the temperature of the heating chamber with the good heat conductivity , when the temperature sensor 23 detects the temperature of the heating chamber 111 reach low temperature , the blower 20 is turned off ; such design makes the present invention easier to carry without the danger of burn . referring to fig6 , when the safety switch 60 detects the battery set 121 in low battery condition or gas can 122 has insufficient gas to introduce the burning temperature drop , the safety switch 60 blocks all the signals to stop all operations ; either battery set 121 or gas can 122 is out , new battery set 121 or gas can 122 can be replaced ; the replacement is very convenient , users only need to lift the movable cover 125 and take the battery set 121 or gas can 122 out from the first or the second container 123 , 124 respectively and do the replacement ; the gas can 122 can be re - fill type can ; the present invention applies gas to generate high temperature to avoid the troublesome of power cord and reduce the space , users are very convenient to carry the present invention around . while a preferred embodiment of the invention has been shown and described in detail , it will be readily understood and appreciated that numerous omissions , changes and additions may be made without departing from the spirit and scope of the invention .
a gas hot air gun includes a main body , an ignition device , a switch set and a safety switch . the main body includes a blower , a nozzle , a barrel and a handle . a heating chamber and a mixing chamber are on the inner front of the barrel . a gas can is inside the handle . one end of the nozzle is connected to the gas can . the switch set includes a power switch , with the safety switch closing power of the battery set or gas flow of the gas can under some pre - set conditions . users press the power switch and have gas spray out from the nozzle into the heating chamber to generate heat . the blower sends hot air in the heating chamber out of the main body . a metal slice regulating the direction of air and a catalyst for avoiding flame extending out of the nozzle area are inside the heating chamber .