Patent Publication Number: US-7708554-B2

Title: Safety structure of a gas burner

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a gas burner and more specifically, to a safety structure of a gas burner. 
   2. Description of the Related Art 
   Following the movement of time, gas lighters are commonly used to make fire instead of matches. Further, handy gas burners, for example, hand gas torches are popularly accepted by consumers for the advantages of high mobility and ease of use. However, these handy gas burners must be kept away from reach of children. Because conventional handy gas burners can easily accidentally be triggered to make fire, they are not safe in use. There are numerous instances of fire accidents caused by children playing with gas burners. For easy use, the ignition switch of a conventional gas burner is not locked or can easily be unlocked, and a child may switch on the ignition switch accidentally when playing with the gas burner, thereby causing an accident. 
   Therefore, many countries have made relevant safety regulations stipulating installation of safety devices on gas burners, such as those disclosed in U.S. Pat. No. 6,293,782 (equivalent to Taiwan Patent Publication No. 446104), U.S. Pat. No. 6,296,476 (equivalent to Taiwan Patent Publication No. 449018), U.S. Pat. No. 6,527,543 (equivalent to Taiwan Patent Publication No. 525749), U.S. Pat. No. 6,688,879 (equivalent to Taiwan Patent Publication No. 534277), and Taiwan Patent Publication No. 582519. The aforesaid various patents are issued to the present inventor. According to these patents, when a gas burner is not in use, it is in a locked state. To use the gas burner, the safety device has to be released. The releasing operation is quite complicated, thereby making it relatively difficult for children to conduct. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the present invention, the safety structure of a gas rubber comprises a slide, the slide having a frame base accommodating a first spring means, a key from the frame base, two upright rods arranged in parallel at a top side of the frame base, a guide way defined between the upright rods, two transverse retaining grooves respectively formed on the upright rods at an inner side, and a pair of guide ribs respectively transversely provided at the upright rods at a bottom side; a stop device received in the sliding way of the slide, the stop device having a stop plate, a finger strip forwardly extending from the stop plate, a guide strip and a pin backwardly extending from the stop plate, two retaining blocks respectively extended from left and right sides of the stop plate for engaging the retaining grooves of the slide to lock the slide, two recessed portions respectively defined between the stop plate and the retaining blocks, and a third spring means mounted on the pin; and a housing formed of two cover shells, the housing having a longitudinal sliding slot and a guide way for the passing of the key and the finger strip respectively, a frame wall transversely disposed below the guide way and stopped against the third spring means, and a sliding slot cut through the frame wall for the passing of the guide strip. When the user presses the slide, the third spring will be compressed to lower the stop device and to further disengage the retaining blocks from the retaining grooves, thereby releasing the stop device from the constraint of the slide, and when the user keeps pressing the slide at this time, the retaining blocks will be moved to a bottom side of the guide ribs and the frame base will be forced to squeeze the first spring means to release the locked state. 
   According to another aspect of the present invention, the frame base of the slide has an extension wall backwardly extending one side thereof, a protruding rod perpendicularly extended from the extension wall, and a second spring means connected to the protruding rod; the housing has chamber accommodating the second spring means for enabling the second spring means to be compressed when the slide is moved. 
   According to still another aspect of the present invention, the safety structure further comprises a swinging member, the swinging member having a center pivot hole coupled to an axle inside the housing, a driving end coupled to a gas valve of a butane well, and a driven end connected to the slide, the swinging member being turned about the axle to lift open the gas valve when the slide is pressed. 
   According to still another aspect of the present invention, the safety structure further comprises a release-lock switch mounted in a hole on the housing, the release-lock switch having a front stop block movable from an unlocking position to a locking position above a protruding strip of the slide to prohibit upward movement of the slide and to lock the slide in the released state after the slide has pressed and the swinging member has been driven to open the gas valve. 
   According to still another aspect of the present invention, the safety structure further comprises a butane well holding a liquid fuel gas, the butane well having a top connector fastened to the housing, and a plurality of locating blocks protruded from the top connector and respectively engaged into respective retaining notches in a bottom cuff of the housing, a gas valve supported on an absorptive seat at a top side of the top connector, a flame adjustment wheel operable to regulate the flow rate of the fuel gas passing out of the butane well through the gas valve, and a handle fastened to the flame adjustment wheel and extended out of a hole of the housing for operation. 
   According to still another aspect of the present invention, the safety structure further comprises a burner. The burner comprises a flexible gas tube connected to the gas valve 3 , a gas nozzle connected between one end of the flexible gas tube remote from the gas valve and a mixing tube that is fixedly mounted in a positioning hole of a top neck of the housing and has at least one air hole for receiving outside air for mixing with discharged fuel gas for combustion, a flame nozzle connected to the mixing tube, and a heat insulative ring mounted around the flame nozzle for protection. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention can be more fully understood by referring to the following description and accompanying drawings, in which: 
       FIG. 1  is an exploded view of a gas burner embodying the present invention. 
       FIGS. 2   a ˜ 2   c  are sectional views explaining the release and release lock operation procedure of the present invention. 
       FIG. 3  is a sectional view of the present invention, showing the positioning of the butane well in the housing. 
       FIG. 4  is a schematic sectional view showing the structure of the gas burner according to the present invention. 
       FIG. 5  is an exploded view of a gas burner constructed according to one example of the present invention. 
       FIG. 6  is an elevational assembly view of  FIG. 5 . 
       FIG. 7  is an exploded view of a gas burner constructed according to another example of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1 and 2   a ˜ 2   c , a safety structure of a gas burner in accordance with the present invention is shown comprising a slide  1  and a stop device  2 . The slide  1  and the stop device  2  are mounted in a housing  3 . 
   The slide  1  has a frame base  13  mounted inside the housing  3 , a shank  12  extended from one side of the frame base  13  through a longitudinal sliding slot  311  on the housing  3 , and a substantially L-shaped key  11  fixedly connected to the free end of the shank  12  and supported on the outside wall of the housing  3  and movable along the longitudinal sliding slot  311 . The frame base  13  defines a space that accommodates a first spring means  15 , for example, a piezoelectric device, which automatically returns the slide  1  to the locked state when the slide  1  is released after each operation. The frame base  13  has two upright rods  131  arranged in parallel at the top, a guide way  132  defined between the upright rods  131  for receiving the stop device  2  and allowing transverse movement of the stop device  2  in the guide way  132 , two transverse retaining grooves  133  respectively formed on the upright rods  131  at an inner side, and a pair of guide ribs  134  respectively transversely provided at the upright rods  131  at a bottom side for stopping the stop device  2 . 
   For allowing the slide  1  to move relative to the housing  3  smoothly, the frame base  13  has two guide rails  135  longitudinally arranged in parallel at the left and right sides and respectively movably attached to a respective longitudinal track  32  inside the housing  3 . 
   Further, the frame base  13  has an extension wall  14  backwardly extending at one side, a protruding rod  141  perpendicularly extended from the extension wall  14  and pressed on a second spring means  16 , for example, a coil spring. The second spring means  16  imparts an upward pressure to the slide  1  such that a young child will not easily press the slide  1  to trigger the ignition system, i.e., the piezoelectric device. The slide  1  further has a protruding strip  142  at the back. When the user holds the slide  1  in the pressed position and moves a release status lock switch  5 , the slide  1  is locked in the released state. 
   Further, an actuating member  143 , for example, a bevel face is formed on the rear bottom side of the extension wall  14  for moving a swinging member  4  to pull open the gas valve  63  of a butane well  6 , thereby supply fuel gas to a burner  7 . 
   The stop device  2  is a key member bent into shape, having a stop plate  21 , a finger strip  22  forwardly extending from the front side of the stop plate  21 , a guide strip  23  backwardly extending from the back side of the stop plate  21  below the elevation of the finger strip  21 , two retaining blocks  24  respectively transversely protruded from the left and right sides of guide strip  23 , two recessed portions  25  respectively defined between the retaining blocks  24  and the stop plate  21 , a pin  26  backwardly extending from the stop plate  21  above the guide strip  23 , a third spring means  27 , for example, a coil spring mounted on the pin  26 . The stop device  2  is mounted in the guide way  132  with the two retaining blocks  24  respectively engaged into the two transverse retaining grooves  133  and the third spring means  27  stopped against a transversely extending frame wall  35  in the housing  3 . The frame wall  35  has a sliding slot  351  for the passing of the guide strip  23 . The guide strip  23  is movable with the stop device  2  along the guide strip  23 , causing the third spring means  27  to be compressed or released. 
   The housing  3  is formed of two cover shells  31  that are abutted against each other, having the aforesaid longitudinal sliding slot  311  and guide way  312  for the passing of the shank  12  and the finger strip  22  respectively. The two longitudinal tracks  32  of the housing  3  are provided for receiving the guide rails  135  of the frame base  13  of the slide  1 . A chamber  33  is provided below one longitudinal track  32  to accommodate the second spring means  16 , keeping one end of the second spring means  16  stopped against the protruding rod  141  of the slide  1 . The housing  3  further has an axle  34  suspending on the inside near the butane well  6  for supporting the swinging member  4  such that the swinging member  4  is turnable about the axle  34  to pull open the gas valve  63  of the butane well  6 . The frame wall  35  of the housing  3  is transversely disposed below the guide way  312  to support the third spring means  27 . As indicated above, the frame wall  35  has a sliding slot  351  for the passing of the guide strip  23 . The frame wall  35  further has two ribs  352  bilaterally disposed below the sliding slot  351  and extending in longitudinal direction to a predetermined depth to enhance the structural strength of the sliding slot  351 . Further, a guard  36  is protruding from the front side of the housing  3  for the resting of the forefinger when operating the gas burner. 
   During operation, the thumb is pressed on the stop device  2  to lower the retaining blocks  24  and to further disengage the retaining blocks  24  from the retaining grooves  133 , thereby releasing the stop device  2  from the locked state. At this time, keep pressing the thumb downwards to move the against the L-shaped key  11  of the slide  1 , causing the guide rails  135  of the frame base  13  of the slide  1  to move along the two longitudinal tracks  32  of the housing  3  so that the retaining blocks  24  are moved to the bottom side of guide ribs  134 . During this action, the frame base  13  and the protruding rod  141  are respectively forced against the first spring means  15  and the second spring means  16 , causing one electrode  151  of the ignition system (piezoelectric device) to produce sparks that burn the fuel gas ejected out of the burner  7  to produce a flame. 
   When released the slide  1 , the first spring means  15  and the second spring means  16  are respectively returned to their former shape and to push the frame base  13  and the protruding rod  141 , thereby moving the slide  1  upwards. When the retaining grooves  133  are moved to the top side of the retaining blocks  24 , the third spring member  27  extends out to force the retaining blocks  24  into engagement with the retaining grooves  133  again, and therefore the finger strip  22  is forced out of the housing  3  and the stop plate  21  is stopped against the inside wall of the housing  3 , i.e., the safety structure is in the locked state. 
   To form a gas burner, the housing  3  has a bottom cuff  37 , a serrated rib  371  protruding from the inner side of the bottom cuff  37 , at least one pair of retaining notches  372  formed on the serrated rib  371  for securing the butane well  6 , a top neck  38  upwardly extending from the center of the top side, a positioning hole  381  defining in the top neck  38  for securing the burner  7 , and an outer thread  382  extending around the top neck  38  for fastening to an external apparatus (this will be discussed further). 
   The swinging member  4  is a lever, having a center pivot hole  41  coupled to the axle  34  such that the swinging member  4  is turnable about the axle  34 . The swinging member  4  is a L-shaped member having one end, namely, the driving end  43  coupled to the gas valve  63  of the butane well  6 , and the other end, namely, the driven end  42  disposed in contact with the an actuating member  143  of the extension wall  14  of the slide  1 . When the user lowers the slide  1  relative to the housing  3 , the actuating member  143  moves the driven end  42  of the swinging member  4 , thereby causing the driving end  43  of the swinging member to lift the gas valve  63  of the butane well  6  from the close position to the open position to discharge butane (fuel gas). The driving end  43  has a coupling hole  431  for receiving the gas valve  63 . The driven end  42  has a protrusion  421  disposed in close contact with the actuating member  143 . 
   The release status lock switch  5  is mounted in a hole  313  on the housing  3  near the front side, having a stop block  51 . When the slide  1  is pressed and the swinging member  4  is driven to open the gas valve  63 , the user can operate the release status lock switch  5  from an unlocking position to a locking position where the stop block  51  is moved to the top side of the protruding strip  142  to prohibit upward movement of the protruding strip  142 , and therefore the slide  1  is locked in the released state, and fuel gas is been continuously supplied to the burner  7 . 
   Referring to  FIGS. 1 and 3 , the butane well  6  is a container holding a liquid fuel gas, having a top connector  61  fastened to the bottom cuff  37  of the housing  3 , and a plurality of locating blocks  62  protruded from the top connector  61  and respectively engaged into the retaining notches  372 . The gas valve  63  is supported on an absorptive seat  64  at the top side of the top connector  61 . A flame adjustment wheel  64  is provided and operable to regulate the flow rate of fuel gas passing out of the gas valve  63 . A handle  641  is fastened to the flame adjustment wheel  64  and extended out of a hole  314  of the housing  3  for operation by the user to rotate the flame adjustment wheel  64  with less effort. The filling valve  65  is provided at the bottom side of the butane well  6 , having a relatively longer filling tube  651  and a relatively shorter exhaust tube  652  concentrically arranged inside the butane well  6  for filling fuel gas into the butane well  6  and for overpressure protection. Because the structure of the filling valve  65  is of the known art, further detailed description in this regard is not necessary. 
   Referring to  FIGS. 1 and 5 , the burner  7  is a known product, comprising a flexible gas tube  71  connected to the gas valve  63 , a gas nozzle  72  connected between one end of the flexible gas tube  71  remote from the gas valve  63  and a mixing tube  73  that is fixedly mounted in the positioning hole  381  of the top neck  38  of the housing  3  and has at least one air hole  731  for receiving outside air for mixing with discharged fuel gas for combustion, a flame nozzle  74  connected to the mixing tube  73 . 
   The flame nozzle  74  is comprised of a gear holder  741 , a flame gear  742  mounted in the gear holder  741 , a lock pin  743  inserted through the center of the flame gear  742  and fastened to the gear holder  741  to affix the flame gear  742  to the gear holder  741 . Further, a heat insulative ring  75  is provided around the flame nozzle  74  for protection. A discharging electrode  751  is mounted on the heat insulative ring  75 . During operation of the gas burner, a high voltage is transmitted through the gas nozzle  72  and the mixing tube  73  to the flame nozzle  74  and then discharged out of the discharging electrode  751 , thereby producing sparks to burn discharged fuel gas around the flame nozzle  74 . 
   Further, a sleeve  76  is sleeved onto the heat insulative ring  75  and a lock ring  77  is fastened with its inner thread  711  to the outer thread  382  of the top neck  38  to lock the sleeve  74  and the flame nozzle  74 . The sleeve  76  has an air hole  761  corresponding to the air hole  731  of the mixing tube  73  for guiding in air. The stop device  2  is released from the locked state, the slide  1  is pressed to compress the first spring means  15 , i.e., the piezoelectric device, causing the electrode  151  to contact the gas nozzle  72 . Thus, a high voltage goes through the mixing tube  73  and the flame nozzle  74 , thereby causing sparks to be produced between the discharging electrode  751  and the flame nozzle  74  to burn discharged fuel gas. Referring to  FIG. 4 , a metal contact member  152  is provided in the positioning hole  381  for the contact of the sleeve  76 , and a lead wire  153  is connected between the metal contact member  152  and the first spring means  15 , i.e., the piezoelectric, thereby forming a loop. 
   Further, an iron tip  78  is provided at the front side of the sleeve  76 , having a heating member  781  and a locating ring  782  provided on the inside. During burning of discharged fuel gas, the iron tip  78  is heated. Thus, the gas burner is sued as a gas iron as shown in  FIGS. 5 and 6 . 
   Referring to  FIG. 7 , the heat plate holder  79  may be used to substitute for the aforesaid iron tip  78  and affixed to the top side of the sleeve  76  to hold a heat plate  79 . 
   By means of the application of the present invention, the slide and the stop device constitute a double-safety switch, preventing a child playing the gas burner for fun from triggering the gas burner. When released the slide or unlock the release-lock switch, all the parts are returned to their former position to cut off the supply of fuel gas and to extinguish the flame. The auto-locking design of the present invention is a design of human technology. Further, during operation of the gas burner, the user must overcome the resisting force of the first and second spring means. A young child is not easy to overcome the resisting force of the first and second spring means, preventing triggering of the ignition system accidentally. Further, the parts of the invention are of modularized design, convenient for installation. According to the present invention, the gas burner can be made in any of a variety of forms for different applications. 
   While only one embodiment of the present invention has been shown and described, it will be understood that various modifications and changes could be made thereunto without departing from the spirit and scope of the invention disclosed.