referring to fig1 a gas ignition glue gun according to the present invention is generally comprised of a gun body ( 1 ) having inserted therein a tubular insert ( ii ) for insertion therein of a glue stick ( 2 ), a grip ( 13 ) integrally extending downward from the body ( 1 ) for holding of hand , a feed control lever ( 12 ) at the upper front portion of the grip ( 13 ) to control the feeding of glue stick , a gas volume regulating lever ( 14 ) and an ignition trigger ( 151 ) respectively mounted thereon to project therefrom at one lateral side , a plurality of radiator holes ( 16 ) and ( 17 ) on the outer wall of the body ( 1 ), and a nozzle ( 18 ) at the front . referring to fig2 when the feed control lever ( 12 ) is pressed on , as the arrow indicates , the lower end of the resilient element ( 121 ) is pushed backward , therefore , the clamping element ( 122 ), which is fixedly connected to the top end of the resilient element ( 121 ) is pushed to drive the glue stick ( 2 ) to move forward . as soon as the feed control lever ( 12 ) is released , the resilient element ( 121 ) is immediately driven by a positioning spring ( 123 ) to return to the original position . because the glue stick ( 2 ) is controlled by the positioning spring ( 123 ), if the glue stick ( 2 ) is not completely melted , or the feed control lever ( 12 ) is idly pressed on , the internal mechanism of the device will not be damaged . a hook - like retainer ring ( 111 ) made of silicone rubber is set in the tubular insert ( 11 ) in the middle to firmly retain the glue stick ( 2 ). a spring ( 116 ) is mounted on the hook - like retainer ring ( 111 ) at the front end to firmly retain the hook - like retainer ring ( 111 ) so as to prevent the reverse flow of melted glue . the tubular insert ( 11 ) comprises a bevel front end ( 112 ) to which the nozzle ( 18 ) is connected . the nozzle ( 18 ) comprises an axial bore ( 183 ) having set therein a feeding device comprised of a ball ( 181 ) and a spring ( 182 ) to push melted glue out of the axial bore ( 183 ). the tubular insert ( 11 ) is comprised of a front half portion and a rear half portion and comprises a plurality of raised blocks ( 113 ), ( 114 ) and ( 115 ) integrally made at the front half portion . when the tubular insert ( 11 ) is inserted into the gun body ( 1 ), the raised blocks ( 113 ), ( 114 ) and ( 115 ) are respectively engaged with the projecting blocks ( 113 )&# 39 ;, ( 114 )&# 39 ; and ( 115 )&# 39 ; of the gun body ( 1 ), and the tubular insert ( 11 ) becomes firmly positioned in the gun body ( 1 ) with the rear end of the front half portion set in alignment with the rear half portion . a cutter ( 117 ) is set in the tubular insert ( 11 ) at the front end . it may be heated to cut the inserted glue stick ( 2 ) into two semi - circular parts to facilitate melting process . a gas tube ( 141 ) is set in the grip ( 13 ) to guide gas to a gear wheel ( 142 ). the gas volume regulating lever ( 14 ), a return spring ( 143 ) and a radiator fin ( 144 ) are respectively set at the front of the gear wheel ( 142 ). the gas from the gas guide tube ( 141 ) is , after passing through the gear wheel ( 142 ), guided to a lead hole ( 145 ) where the gas is mixed with air to heat a heating hole ( 118 ) and the cutter ( 117 ), by means of the cotton asbestos ( 146 ), so as to further melt the inserted glue stick ( 2 ). by means of the effect of the cotton asbestos ( 146 ), ejected gas is collected for complete burning to minimize the loss . according to the present invention , the igniter ( 15 ) is set at the inner bottom of the gun body ( 1 ). with respect to the ignition process of the present invention , please refer to fig3 and 4 . when the ignition trigger ( 151 ) is triggered to push the main rd ( 152 ) to move leftward , the front bevel edge ( 1521 ) of the main rod ( 152 ) is simultaneously driven to push the triggering rod ( 1531 ) to move forward to further trigger the igniter ( 153 ) to ignite sparks through the front ignition tube ( 1532 ). while the main rod ( 152 ) is pushed to move leftward , the rack portion ( 1522 ) simultaneously drives the gear wheel ( 142 ) to rotate along the direction the arrow indicates ( see fig4 ) to permit output of gas from the gas tube ( 141 ) for burning . after triggering , the ignition trigger ( 151 ) is immediately returned to original position , and the gear wheel ( 142 ) is simutaneously driven to turn to the original position . when the gas volume regulating lever ( 14 ) is pressed down , the two circular ends of the gas volume regulating lever ( 14 ) immediately squeeze the return spring ( 143 ) forward . at the time , a screw driver may be inserted through the hole ( 155 ) of the gun body ( 1 ) to screw in or out the regulating screw ( 154 ) so as to control the intensity of flame . as shown in fig3 the gas from the gas tube ( 141 ) is delivered through the lead hole ( 145 ), the jet ( 148 ) of the injection head ( 147 ), and into the cotton asbestos ( 146 ) for burning . in the present embodiment , the nozzle ( 18 ) has a conical front end and a hexagonal rear end to permit melted glue be ejected in a thread . in actual practice , the nozzle ( 18 ) may be alternatively replaced by any other type of nozzles according to requirement .