Operating mechanism for sequentially operating a fuel gas valve and an ignition means, and a gas powered appliance incorporating the operating mechanism

Abstract

A hot melt glue gun comprising a main housing ( 5 ) having a glue stick accommodating bore ( 8 ) extending therethrough and terminating in a dispensing nozzle ( 9 ) through which melted glue is dispensed. A catalytic combustion element ( 16 ) is located in a combustion chamber ( 15 ) for raising the temperature of the main housing ( 5 ) to an appropriate temperature for melting the glue stick. Fuel gas is supplied to the catalytic combustion element ( 16 ) through a fuel gas valve ( 20 ) having a spindle ( 40 ) extending therefrom. A piezo electric ignition unit ( 27 ) generates an EMF for generating a spark across a pair of electrodes ( 25 ) in the combustion chamber ( 15 ) for igniting the fuel gas to initially burn with flame combustion to raise the temperature of the catalytic element ( 16 ) to its ignition temperature. An operating member ( 51 ) and an integral camming member ( 52 ) are slideable in the direction of the arrow D from an inoperative state to an operative state for sequentially operating the fuel gas valve ( 20 ) from a closed to an open state, and then the piezo electric ignition unit ( 27 ) for igniting the fuel gas in the combustion chamber ( 15 ). An idle camming surface ( 55 ) of the camming member ( 52 ) engages a cam follower ( 53 ) of the spindle ( 40 ) of the fuel gas valve ( 20 ) with the fuel gas valve ( 20 ) in the closed state, and an operating camming surface ( 59 ) engages the cam follower ( 53 ) with the fuel gas valve ( 20 ) in the open state.

1 . An operating mechanism for sequentially operating a fuel gas valve ( 20 ) for delivering fuel gas to a fuel gas burner ( 16 ) and an ignition means ( 27 ) for igniting the fuel gas at the burner ( 16 ), characterised in that the operating mechanism ( 50 ) comprises a camming member ( 52 ) moveable between an inoperative state and an operative state, a cam follower ( 53 ) co-operable with the camming member ( 52 ) and with the fuel gas valve ( 20 ) for operating the fuel gas valve ( 20 ) from a closed state isolating the gas burner ( 16 ) from the fuel gas, to an open state for delivering fuel gas to the gas burner ( 16 ) in response to the camming member ( 52 ) being moved from the inoperative state to the operative state, and an activating member ( 60 ) associated with the camming member ( 52 ) and being co-operable with the ignition means ( 27 ) and being moveable with the camming member ( 52 ) for operating the ignition means ( 27 ) when the camming member ( 52 ) is in the operative state sequentially after the fuel gas valve ( 20 ) has been operated into the open state, for igniting the fuel gas at the gas burner ( 16 ).  
     
     
         2 . An operating mechanism as claimed in  claim 1  characterised in that the camming member ( 52 ) is moveable in the operative state after the fuel gas valve ( 20 ) has been operated into the open state for subsequently operating the ignition means ( 27 ).  
     
     
         3 . An operating mechanism as claimed in  claim 1  or  2  characterised in that the camming member ( 52 ) defines an activating camming surface ( 56 ) for co-operating with the cam follower ( 53 ) for operating the fuel gas valve ( 20 ) between the closed state and the open state.  
     
     
         4 . An operating mechanism as claimed in any preceding claim characterised in that the camming member ( 52 ) defines an operating camming surface ( 59 ) for co-operating with the cam follower ( 53 ) for retaining the fuel gas valve ( 20 ) in the open state.  
     
     
         5 . An operating mechanism as claimed in  claim 4  characterised in that the operating camming surface ( 59 ) is an elongated surface for facilitating further movement of the camming member ( 52 ) in the operative state for operating the ignition means ( 27 ) after the fuel gas valve ( 20 ) has been operated into its open state.  
     
     
         6 . An operating mechanism as claimed in  claim 5  characterised in that the activating member ( 60 ) co-operates with the ignition means ( 27 ) for operating the ignition means ( 27 ) during the further movement of the camming member ( 52 ) and the activating means when the camming member ( 52 ) is in the operative state.  
     
     
         7 . An operating mechanism as claimed in any of  claims 4  to  6  characterised in that the camming member ( 52 ) defines a detent ( 57 ) between the activating camming surface ( 56 ) and the operating camming surface ( 59 ) for releasably retaining the cam follower ( 53 ) in engagement with the operating camming surface ( 59 ).  
     
     
         8 . An operating mechanism as claimed in any of  claims 4  to  6  characterised in that the camming member ( 52 ) is an elongated member, the respective activating and operating camming surfaces ( 56 , 59 ) being sequentially defined longitudinally along the camming member ( 52 ).  
     
     
         9 . An operating mechanism as claimed in any of  claims 4  to  6  characterised in that the camming member ( 52 ) defines an idle camming surface ( 55 ) for engaging the cam follower ( 53 ) when the camming member ( 52 ) is in the inoperative state.  
     
     
         10 . An operating mechanism as claimed in  claim 9  characterised in that the activating camming surface ( 56 ) is located between the operating camming surface ( 59 ) and the idle camming surface ( 55 ).  
     
     
         11 . An operating mechanism as claimed in  claim 9  or  10  characterised in that the respective idle camming surface ( 55 ), the activating camming surface ( 56 ) and the operating camming surface ( 59 ) define a single continuous camming surface.  
     
     
         12 . An operating mechanism as claimed in any of  claims 2  to  11  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable in one continuous movement between the inoperative state and the operative state, and in the operative state.  
     
     
         13 . An operating mechanism as claimed in any of  claims 2  to  12  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable from the inoperative state to the operative state, and in the operative state in one single direction, and are moveable from the operative state to the inoperative state in the reverse direction.  
     
     
         14 . An operating mechanism as claimed in any of  claims 2  to  13  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable between the inoperative state and the operative state, and in the operative state with linear motion.  
     
     
         15 . An operating mechanism as claimed in any of  claims 2  to  14  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable between the inoperative state and the operative state, and in the operative state with rectilinear motion.  
     
     
         16 . An operating mechanism as claimed in any of  claims 2  to  15  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are carried on an operating member ( 51 ), the operating member ( 51 ) being moveable between the inoperative state and the operative state, and in the operating state for in turn moving the camming member ( 52 ) and the activating member ( 60 ) between the inoperative and operative states, and in the operative state, respectively.  
     
     
         17 . An operating mechanism as claimed in  claim 16  characterised in that the operating member ( 51 ), the camming member ( 52 ) and the activating member ( 60 ) are formed as a single one-piece integral unit.  
     
     
         18 . An operating mechanism as claimed in  claim 16  or  17  characterised in that the operating member ( 51 ) is an elongated member, the camming member ( 52 ) extending longitudinally from one end thereof, and the activating member ( 60 ) extending transversely from the operating member ( 51 ) at the other end thereof.  
     
     
         19 . An operating mechanism as claimed in  claim 18  characterised in that the camming member ( 52 ) extends contiguously from the operating member ( 51 ).  
     
     
         20 . An operating mechanism as claimed in any of  claims 16  to  19  characterised in that a thumb engaging member ( 61 ) is provided on the operating member ( 51 ) for facilitating urging of the operating member ( 51 ) between the inoperative and operative states, and in the operative state for operating the ignition means ( 27 ).  
     
     
         21 . An operating mechanism as claimed in any preceding claim characterised in that the activating member ( 60 ) is adapted for operating an ignition means ( 27 ) provided by a piezo electric ignition unit.  
     
     
         22 . A gas powered appliance comprising a gas burner ( 16 ), a fuel gas valve ( 20 ) for supplying fuel gas to the gas burner ( 16 ), and an ignition means ( 27 ) for igniting the fuel gas at the fuel gas burner ( 16 ), characterised in that an operating mechanism ( 50 ) as claimed in any preceding claim is provided for sequentially operating the fuel gas valve ( 20 ) and the ignition means ( 27 ) for igniting the fuel gas at the gas burner ( 16 ).  
     
     
         23 . A gas powered appliance comprising a gas burner ( 16 ), a fuel gas valve ( 20 ) for supplying fuel gas to the gas burner ( 16 ), and an ignition means ( 27 ) for igniting fuel gas at the fuel gas burner ( 16 ), characterised in that an operating mechanism ( 50 ) is provided for sequentially operating the fuel gas valve ( 20 ) and the ignition means ( 27 ) for igniting the fuel gas at the gas burner ( 16 ), the operating mechanism ( 50 ) comprising a camming member ( 52 ) moveable between an inoperative state and an operative state, a cam follower ( 53 ) co-operable with the camming member ( 52 ) and with the fuel gas valve ( 20 ) for operating the fuel gas valve ( 20 ) from a closed state isolating the gas burner ( 16 ) from the fuel gas, to an open state for delivering fuel gas to the gas burner ( 16 ) in response to the camming member ( 52 ) being moved from the inoperative state to the operative state, and an activating member ( 60 ) associated with the camming member ( 52 ) and being co-operable with the ignition means ( 27 ) and being moveable with the camming member ( 52 ) for operating the ignition means ( 27 ) when the camming member ( 52 ) is in the operative state sequentially after the fuel gas valve ( 20 ) has been moved into the open state, for igniting the fuel gas at the gas burner ( 16 ).  
     
     
         24 . A gas powered appliance as claimed in  claim 23  characterised in that the camming member ( 52 ) is moveable in the operative state after the fuel gas valve ( 20 ) has been operated into the open state for subsequently operating the ignition means ( 27 ).  
     
     
         25 . A gas powered appliance as claimed in  claim 23  or  24  characterised in that the camming member ( 52 ) defines an activating camming surface ( 56 ) for co-operating with the cam follower ( 53 ) for operating the fuel gas valve ( 20 ) between the closed state and the open state.  
     
     
         26 . A gas powered appliance as claimed in any preceding claim characterised in that the camming member ( 52 ) defines an operating camming surface ( 59 ) for co-operating with the cam follower ( 53 ) for retaining the fuel gas valve ( 20 ) in the open state.  
     
     
         27 . A gas powered appliance as claimed in  claim 26  characterised in that the operating camming surface ( 59 ) is an elongated surface for facilitating further movement of the camming member ( 52 ) in the operative state for operating the ignition means ( 27 ) after the fuel gas valve ( 20 ) has been operated into its open state.  
     
     
         28 . A gas powered appliance as claimed in  claim 27  characterised in that the activating member ( 60 ) co-operates with the ignition means ( 27 ) for operating the ignition means ( 27 ) during the further movement of the camming member ( 52 ) and the activating means when the camming member ( 52 ) is in the operative state.  
     
     
         29 . A gas powered appliance as claimed in any of  claims 26  to  28  characterised in that the camming member ( 52 ) defines a detent ( 57 ) between the activating camming surface ( 56 ) and the operating camming surface ( 59 ) for releasably retaining the cam follower ( 53 ) in engagement with the operating camming surface ( 59 ).  
     
     
         30 . A gas powered appliance as claimed in any of  claims 26  to  29  characterised in that the camming member ( 52 ) is an elongated member, the respective activating and operating camming surfaces ( 56 , 59 ) being sequentially defined longitudinally along the camming member ( 52 ).  
     
     
         31 . A gas powered appliance as claimed in any of  claims 26  to  30  characterised in that the camming member ( 52 ) defines an idle camming surface ( 55 ) for engaging the cam follower ( 53 ) when the camming member ( 52 ) is in the inoperative state.  
     
     
         32 . A gas powered appliance as claimed in  claim 31  characterised in that the activating camming surface ( 56 ) is located between the operating camming surface ( 59 ) and the idle camming surface ( 55 ).  
     
     
         33 . A gas powered appliance as claimed in  claim 31  or  32  characterised in that the respective idle camming surface ( 55 ), the activating camming surface ( 56 ) and the operating camming surface ( 59 ) define a single continuous camming surface.  
     
     
         34 . A gas powered appliance as claimed in any of  claims 24  to  33  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable in one continuous movement between the inoperative state and the operative state, and in the operative state.  
     
     
         35 . A gas powered appliance as claimed in any of  claims 24  to  34  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable from the inoperative state to the operative state, and in the operative state in one single direction, and are moveable from the operative state to the inoperative state in the reverse direction.  
     
     
         36 . A gas powered appliance as claimed in any of  claims 24  to  35  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable between the inoperative state and the operative state, and in the operative state with linear motion.  
     
     
         37 . A gas powered appliance as claimed in any of  claims 24  to  36  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are moveable between the inoperative state and the operative state, and in the operative state with rectilinear motion.  
     
     
         38 . A gas powered appliance as claimed in any of  claims 24  to  37  characterised in that the camming member ( 52 ) and the activating member ( 60 ) are carried on an operating member ( 51 ), the operating member ( 51 ) being moveable between the inoperative state and the operative state, and in the operative state for in turn moving the camming member ( 52 ) and the activating member ( 60 ) between the inoperative and operative states, and in the operative state, respectively.  
     
     
         39 . A gas powered appliance as claimed in  claim 38  characterised in that the operating member ( 51 ), the camming member ( 52 ) and the activating member ( 60 ) are formed as a single one-piece integral unit.  
     
     
         40 . A gas powered appliance as claimed in  claim 38  or  39  characterised in that the operating member ( 51 ) is an elongated member, the camming member ( 52 ) extending longitudinally from one end thereof, and the activating member ( 60 ) extending transversely from the operating member ( 51 ) at the other end thereof.  
     
     
         41 . A gas powered appliance as claimed in  claim 40  characterised in that the camming member ( 52 ) extends contiguously from the operating member ( 51 ).  
     
     
         42 . A gas powered appliance as claimed in any of  claims 34  to  41  characterised in that a thumb engaging member ( 61 ) is provided on the operating member ( 51 ) for facilitating urging of the operating member ( 51 ) between the inoperative and operative states, and in the operative state for operating the ignition means ( 27 ).  
     
     
         43 . A gas powered appliance as claimed in any of  claims 23  to  42  characterised in that the activating member ( 60 ) is adapted for operating an ignition means ( 27 ) provided by a piezo electric ignition unit.  
     
     
         44 . A gas powered appliance as claimed in any of  claims 23  to  43  characterised in that the ignition means ( 27 ) is a piezo electric ignition unit ( 27 ) comprising a piezo electric crystal for generating an EMF for in turn generating an ignition spark across a pair of electrodes ( 25 ) located adjacent the gas burner ( 16 ), and an operating plunger ( 31 ) urgeable into the ignition unit ( 27 ) for operably engaging the piezo electric crystal for generating the EMF, the activating member ( 60 ) being co-operable with the operating plunger ( 31 ) for urging the operating plunger ( 31 ) into the ignition unit ( 27 ) when the camming member ( 52 ) and the activating member ( 60 ) are in the operative state and are being further moved in the operative state, for in turn generating the EMF.  
     
     
         45 . A gas powered appliance as claimed in  claim 44  characterised in that the piezo electric ignition unit ( 27 ) is located adjacent the operating member ( 51 ) and is oriented so that the operating plunger ( 31 ) is urgeable into the piezo electric ignition unit ( 27 ) in a direction parallel to the direction of movement of the operating member ( 51 ) between the inoperative state and the operative state.  
     
     
         46 . A gas powered appliance as claimed in any of  claims 23  to  45  characterised in that the fuel gas valve ( 20 ) comprises a valve housing ( 21 ) and an operating spindle ( 40 ) extending therefrom for operating the fuel gas valve ( 20 ) between the closed and the open states, the operating spindle ( 40 ) being co-operable with the cam follower ( 53 ) and being moveable by the cam follower ( 53 ) from the closed state to the open state in response to the camming member ( 52 ) being moved from the inoperative state to the operative state.  
     
     
         47 . A gas powered appliance as claimed in  claim 46  characterised in that the operating spindle ( 40 ) is slideable in the valve housing ( 21 ) between the closed and the open states.  
     
     
         48 . A gas powered appliance as claimed in  claim 46  or  47  characterised in that the camming member ( 52 ) is slideably mounted relative to the valve housing ( 21 ), and the cam follower ( 53 ) is carried on the operating spindle ( 40 ).  
     
     
         49 . A gas powered appliance as claimed in any of  claims 46  to  48  characterised in that the operating spindle ( 40 ) extends transversely of and is moveable in a direction transversely of the direction of movement of the camming member ( 52 ) between the respective inoperative and operative states.  
     
     
         50 . A gas powered appliance as claimed in any of  claims 46  to  49  characterised in that the ignition means ( 27 ) is carried on a mounting bracket ( 28 ) extending from the valve housing ( 21 ) of the fuel gas valve ( 20 ).  
     
     
         51 . A gas powered appliance as claimed in any of  claims 23  to  50  characterised in that the fuel gas burner ( 16 ) comprises a combustion chamber ( 15 ) having a gas powered catalytic combustion element ( 16 ) located therein for converting the fuel gas to heat by flameless catalytic reaction, and a fuel gas nozzle ( 24 ) is located adjacent the combustion chamber ( 15 ) for delivering fuel gas into the combustion chamber ( 15 ), the fuel gas nozzle ( 24 ) being adapted for facilitating initial flame ignition of the fuel gas for raising the temperature of the gas catalytic combustion element ( 16 ) to its ignition temperature.  
     
     
         52 . A gas powered appliance as claimed in  claim 51  characterised in that the fuel gas nozzle ( 24 ) and the gas catalytic combustion element ( 16 ) are arranged so that as the gas catalytic combustion element ( 16 ) reaches its ignition temperature and commences to convert fuel gas to heat by flameless combustion, the flame is starved of fuel gas and extinguished.  
     
     
         53 . A gas powered appliance as claimed in any of  claims 23  to  52  characterised in that the gas powered appliance is a glue gun ( 1 ).  
     
     
         54 . A gas powered appliance as claimed in any of  claims 23  to  52  characterised in that the gas powered appliance is a soldering iron.  
     
     
         55 . A gas powered appliance as claimed in any of  claims 23  to  52  characterised in that the gas powered appliance is a hair dryer.  
     
     
         56 . A gas powered appliance as claimed in any of  claims 23  to  52  characterised in that the gas powered appliance is a hair curling tongs.  
     
     
         57 . A gas powered appliance as claimed in any of  claims 23  to  52  characterised in that the gas powered appliance is a sandwich maker.