Patent Publication Number: US-6666677-B1

Title: Piezoelectric gas lighter

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a piezoelectric gas lighter in which the fuel gas is discharged and ignited in response to depression of a depression means, and more particularly to a structure for improving controllability and stability of action of a lock mechanism for disabling the depression means from being depressed in the piezoelectric gas lighter. 
     2. Description of the Related Art 
     In a piezoelectric gas lighter in which a valve mechanism and a piezoelectric unit are actuated in response to depression of a depression means (a control cap) so that fuel gas discharged from a gas discharge nozzle is ignited by a spark generated by the piezoelectric unit, there have been known various lock mechanisms which disable the depression means from being depressed to lock the lighter when it is not used and enable the depression means to be depressed in response to a lock release action when the lighter is to be used. 
     For example, U.S. Pat. No. 5,145,358 (will be referred to as “the first prior art”, hereinbelow) discloses a lock mechanism in which a control cap is provided with a stopper member which is movable between its locking position where it prevents depression of the control cap and its releasing position where it permits depression of the control cap and is urged to the locking position, the stopper member being moved from the locking position to the releasing position by sliding an upper end portion thereof. 
     U.S. Pat. No. 5,885,069 (will be referred to as “the second prior art”, hereinbelow) discloses a lock mechanism in which the whole control cap is movable about a piezoelectric unit between the locking position and the releasing position and a resilient portion for urging the control cap to the locking position is provided integrally with the control cap. 
     Further, U.S. Pat. No. 5,833,448 (will be referred to as “the third prior art”, hereinbelow) discloses a lock mechanism in which a piezoelectric unit/control cap assembly is arranged to be rotatable between the locking position and the releasing position and the assembly is urged to the locking position by a separate resilient member. 
     However, the gas lighters provided with the lock mechanism in accordance with the first to third prior arts are disadvantageous in that the part for releasing the lock mechanism is small and hard to handle, the action of the lock mechanism is instable, or the control cap is moved to a direction different from the direction of depression of the control cap in response to the action of the lock mechanism, which makes it instable the ignition action, and that changes in components from the conventional volume products and incorporation of the components is complicated, which adds to the manufacturing cost of the lighters. 
     Specifically, in the lighter provided with the lock mechanism in accordance with the first prior art, since a lock member having a small control portion is provided to be slidable on a part of the surface of the control cap and the lock member is controlled, the lock releasing action is difficult and the normal ignition action is hard. Further, since a coiled spring for urging the lock member is disposed above the piezoelectric unit in the control cap, the position of the piezoelectric unit is changed from that in the conventional lighter without a lock mechanism, which results in many components to be changed and complicates incorporation of the spring. 
     In the lighter provided with the lock mechanism in accordance with the second prior art, since the whole control cap is moved about a piezoelectric unit between the locking position and the releasing position, depression of the control cap is apt to be instable and the engagement between the piezoelectric unit and the control cap becomes instable which weaken the integrality of the assembly. 
     In the lighter provided with the lock mechanism in accordance with the third prior art, since lock of the lighter is released by inclining the piezoelectric unit/control cap assembly, the position of the piezoelectric unit becomes assembly and the distance between the piezoelectric and the nozzle across which the spark is generated varies from ignition action to action, which deteriorates the igniting performance. Further, the structure exposes the gap between the control cap and the lighter body and permits foreign matters to enter the lighter body to obstruct the igniting action and the quenching action. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing observations and description, the primary object of the present invention is to provide a piezoelectric gas lighter which can be manufactured at low cost without deteriorating the controllability of the lock mechanism, the stability in action and the igniting performance and with a less number of components to be changed from the conventional components. 
     In accordance with the present invention, there is provided a piezoelectric gas lighter comprising a lighter body in which fuel gas is stored, a fuel supply means which supplies the fuel gas in the lighter body to a nozzle through a valve mechanism, an actuator lever for opening and closing the valve mechanism, a spark ignition means which ignites the fuel gas discharged from the nozzle, and a depression means which actuates the actuator lever and the spark ignition means to open the valve mechanism and ignite the fuel gas discharged from the nozzle in response to depression of the depression means, wherein the improvement comprises that 
     the depression means comprises a control cap operatively connected to a piezoelectric unit, a stopper member which is movable between a locking position where a part of the stopper member is engaged with the lighter body to disable the control cap from being depressed and a releasing position where the stopper member is released from the lighter body to permit depression of the control cap and an urging member which urges the stopper member to the locking position, the stopper member is provided with a pair of sliding portions extending back and forth on opposite sides of the control cap and the sliding portions are slidably supported by the control cap so that the stopper member is movable downward together with the control cap and movable between the locking position and the releasing position, and the urging member comprises a pair of resilient pieces provided on opposite sides of the control cap so that they are engaged with the sliding portions of the stopper member to urge the stopper member in the locking position and the stopper member is moved from the locking position to the releasing position by urging the stopper member toward the control cap. 
     The urging member may be formed of a pair of resilient pieces of resin formed integrally with the control cap or may be formed of a pair of resilient pieces of resin or metal formed separately from the control cap. 
     The stopper member may comprise a peripheral wall which covers the opposite side surfaces and the rear surface of the control cap. Preferably, the stopper member is provided with a control portion which covers the upper surface of the control cap at least at a rear portion of the control cap. 
     Preferably, the control cap is provided with a hook portion which is engaged with a projection, which projects inward from the sliding portions of the stopper member, to limit the movement of the stopper member to the locking position. 
     In the gas lighter in accordance with the present invention, since the depression means is formed by a control cap, a stopper member and an urging member and the stopper member is provided with a pair of sliding portions which extend back and forth on opposite sides of the control cap and are slidably supported by the control cap so that the stopper member is movable downward together with the control cap and movable between the locking position and the releasing position, a part of the stopper member is in engagement with the lighter body to prevent depression of the control cap, thereby locking the lighter from being ignited, in the normal state where the stopper member is in the locking position, and when the stopper member is moved to the releasing position, the stopper member is disengaged from the lighter body to permit depression of the control cap. 
     After the gas lighter is ignited and the depression means is released, the depression means moves upward and at the same time, the stopper member is automatically moved to the locking position under the urging force of the urging member, thereby locking the lighter from being ignited. 
     Further, since the stopper member is separated from the control cap and the stopper member is moved relative to the control cap by virtue of the sliding portions and the resilient pieces, the lighter can be locked and released by a simple action of sliding the sliding portions back and forth relative to the nozzle, the locking action and the releasing action can be stabilized and the controllability of the lighter is improved. Further, by only changing the control cap of the conventional piezoelectric gas lighter without a lock mechanism, a piezoelectric gas lighter provided with a lock mechanism can be realized. That is, the lock mechanism can be incorporated in the conventional piezoelectric gas lighter without a lock mechanism without changing the relative positions between the components, such as the relative position between the piezoelectric unit and the nozzle, the manner of fixing the piezoelectric unit and the control cap and the movement of the piezoelectric. At the same time, the control cap is held stationery when the stopper member is moved between the locking position and the releasing position, and the piezoelectric unit and the control cap can be fixed together by fitting. Further, the control cap can be held by a windshield cap not to be drawn out in the vertical direction. Thus, a piezoelectric gas lighter with a lock mechanism which is stabilized in its igniting performance and igniting action can be manufactured at low cost. 
     Further, by disposing the resilient pieces on opposite sides of the control cap to be engaged with the stopper member and urge the same to the locking position, the lock mechanism can be incorporated without changing the relative position between the control cap and the piezoelectric unit, and the stopper member can be stably moved and urged to the locking position. Further, since the stopper member is moved from the locking position to the releasing position by urging the stopper member toward the control cap, lock releasing and ignition can be effected in a series of actions, which further improves controllability of the lighter. Especially when the urging member is formed by a pair of resilient pieces of resin formed integrally with the control cap or formed by a pair of resilient pieces of resin or metal formed separately from the control cap, incorporation of the depression means is facilitated and the manufacturing cost can be reduced. 
     When the stopper member is provided with a peripheral wall which covers the opposite side surfaces and the rear surface of the control cap, the stopper member is further stably moved between the locking position and the releasing position. When the stopper member is provided with a control portion which covers the upper surface of the control cap at least at a rear portion of the control cap, the area for operating the stopper member is enlarged and the operation of the stopper member is facilitated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary cross-sectional view of a piezoelectric gas lighter in accordance with a first embodiment of the present invention in a locked state, 
     FIG. 2 is a perspective view of the depression means in the state shown in FIG. 1, 
     FIG. 3 is an exploded perspective view of the depression means in the state shown in FIG. 2, 
     FIG. 4 is a fragmentary cross-sectional view of the gas lighter shown in FIG. 1 in an ignited state, 
     FIG. 5 is a perspective view of the depression means in the state shown in FIG. 4, 
     FIGS. 6A and 6B are a plan view and a side view, respectively, of the gas lighter shown in FIG. 1 when it is not being used, 
     FIGS. 7A and 7B are a plan view and a side view, respectively, of the gas lighter shown in FIG. 1 when lock is released, 
     FIGS. 8A and 8B are a plan view and a side view, respectively, of the gas lighter shown in FIG. 1 when it is being used, 
     FIGS. 9A and 9B are perspective views respectively showing modifications of the depression means, 
     FIGS. 10A to  10 C are perspective views respectively showing further modifications of the depression means, 
     FIG. 11 is a fragmentary cross-sectional view of a piezoelectric gas lighter in accordance with a second embodiment of the present invention in a locked state, 
     FIG. 12 is a perspective view of the depression means in the state shown in FIG. 11, 
     FIG. 13 is an exploded perspective view of the depression means in the state shown in FIG. 12, 
     FIG. 14 is a fragmentary cross-sectional view of the as lighter shown in FIG. 11 in an ignited state, 
     FIG. 15 is a perspective view of the depression means in the state shown in FIG. 13, and 
     FIG. 16 is a modification of the urging member in the state shown in FIG.  13 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A piezoelectric gas lighter in accordance with a first embodiment of the present invention will be described with reference to FIGS. 1 to  8 B, hereinbelow. In this specification, front and back (rear), and left and right are expressed with the left and the right as seen in FIG. 1 considered to be the front and the back. 
     In FIGS. 1 to  8 B, the gas lighter  1  of the first embodiment comprises a lighter body  2  in which fuel gas is stored, a fuel supply means  3  including a nozzle  31  for discharging the fuel gas and a valve mechanism  32 , an actuator lever  4  for opening and closing the valve mechanism  32 , a spark ignition means  5  having a piezoelectric unit  51 , and a depression means  6  which actuates the actuator lever  4  and the spark ignition means  5  to ignite the fuel gas discharged from the nozzle  31 . The depression means  6  comprises a control cap  7 , a stopper member  8  and an urging member  9 . The stopper member  8  and the urging member  8  form a lock mechanism. 
     Though not shown in detail, the lighter body  2  comprises a rectangular reservoir body  21  which is formed by molding of synthetic resin, an upper lid  22  which is fixed to the upper end of the reservoir body  21  in an air-tight fashion to form a fuel reservoir inside the reservoir body  21 , and an intermediate casing  23  which is fitted on the reservoir body  21 . 
     The valve mechanism  32  of the fuel supply means  3 , which controls the amount of fuel gas to be discharged through the nozzle  31 , is mounted on the upper lid  22  of the lighter body  2 . The nozzle  31  is provided with a nozzle tip at its upper end and projects upward at the center of the valve mechanism  32 . The actuator lever  4  is L-shaped and a groove  41  formed in one end portion of the actuator lever  4  is in engagement with the nozzle  31 . 
     The actuator lever  4  is provided with a pivot  42  at the bent portion thereof and is supported for rotation about the pivot  42  on the intermediate casing  23  of the lighter body  2  with an arm  43  extending obliquely downward. The nozzle  31  is lifted upward to open the valve mechanism  32  in response to rotation of the actuator lever  4 , whereby the fuel gas is discharged through the tip of the nozzle  31 . 
     The upper portion of the nozzle  31  is surrounded by a windshield cap  10 . Reference numeral  33  denotes a flame regulator ring  33  for regulating the amount of the fuel gas to be discharged through the nozzle  31 . 
     The control cap  7  is disposed on the intermediate casing  23  of the lighter body  2  on the side opposite to the nozzle  31 . The control cap  7  can be depressed and is provided with a tubular portion. The piezoelectric unit  51  of the spark ignition means  5  is fitted in the tubular portion of the control cap  7 . The spark ignition means  5  comprises a discharge electrode  52  which is connected to the piezoelectric unit  51  and is disposed on the upper portion of the control cap  7 . A high voltage generated by the piezoelectric unit  51  is applied between the discharge electrode  51  and the nozzle  31  (nozzle tip) and a spark for igniting the fuel gas is generated. 
     The upper half of the piezoelectric unit  51  is moved downward in response to depression of the control cap  7 , and a lever pusher  53  which pushes the arm  43  of the actuator lever  4  to rotate the actuator lever  4  is provided on the upper half of the piezoelectric unit  51 . With this arrangement, the lever pusher  53  rotates the actuator lever  4  to open the valve mechanism  32  so that the fuel gas is discharged through the nozzle  31  in response to depression of the control cap  7 , and when the control cap  7  is further depressed, the piezoelectric unit  51  is actuated to generate a spark (FIG.  4 ). 
     The structure of the depression means  6  and the lock mechanism for the depression means  6  will be described, hereinbelow. The depression means  6  comprises the control cap  7  which holds the piezoelectric unit  51  and the stopper member  8  mounted on the control cap  7  to be movable between a locking position and a releasing position. The control cap  7  and the stopper member  8  are separately formed by plastic molding and the urging member  9  which urges the stopper member  9  to the locking position is formed integrally with the control cap  7 . 
     As shown in FIG. 3, the control cap  7  is provided with the aforesaid tubular portion into which the upper end portion of the piezoelectric unit  51  is inserted. The tubular portion is formed by side walls  71  and the rear wall  72 , and an upper wall  73  is formed above the tubular portion. A front portion of the top surface of the upper wall  73  forms a depressing portion  73   a  exposed upward. An engagement projection  74  (FIG. 1) extends downward from the lower surface of the upper wall  73  to be engaged with the upper end portion of the piezoelectric unit  51 . A sliding groove  75  is formed in the outer surface of each side wall  71  to extend back and forth. A substantially square opening  76  is connected to the sliding groove  75  from below at the center of the sliding grove  75 . A hook portion  77  is formed on the rear end of the portion of the sliding groove  75  on the front side of the opening  76  to project into the sliding groove  75 . 
     A resilient piece  91  (as the urging member  9 ) is provided in each of the opening  76  of the control cap  7 . The resilient piece  91  is formed integrally with the control cap  7  with its lower end portion connected to the front side wall of the opening  76 . The resilient piece  91  extends rearward from its lower end portion and is bent upward so that its upper end portion  91   a  is positioned in the sliding groove  75 . When the upper end portions  91   a  of the resilient pieces  91  are resiliently deformed back and forth, the stopper member  8  is urged. The upper end portions  91   a  of the resilient pieces  91  are also resiliently deformable inward. 
     A projecting portion  78  is provided in front of the depressing portion  73   a  slightly below the depressing portion  73   a . The projecting portion  78  is inserted into the windshield cap  10  to prevent the control cap  7  from being drawn out upward. The projecting portion  78  is provided with a cutaway portion  78   a  on the lower surface thereof. The aforesaid discharge electrode  52  is disposed in the cutaway portion  78   a . A recess  73   b  is formed on the rear side of the depressing portion  73   a , and the side walls  71  and the rear wall  72  are inside of the peripheral surface of the intermediate casing  23  of the lighter body  2 . 
     The stopper member  8  is U-shaped in plan and comprises a pair of sliding portions (opposite side walls)  81  and a rear wall  82 . An upper wall  83  is formed on a rear portion of the upper surfaces of the sliding portions  81 . The front portion of the upper wall  83  is cut away in a shape conforming to the depressing portion  73   a  of the control cap  7 . A releasing operation portion  84  in the form of a stepped surface is formed from a rear portion of the upper wall  83  to an upper end portion of the rear wall  82 , and an engagement shoulder  85  is formed from a lower end portion of the rear wall  82  to rear end portions of the sliding portions  81 . An engagement projection  86  extends downward from the lower end of the rear wall  82  at the center thereof. The lower halves of the sliding portions  81  and the rear wall  82  are shaped to be able to be inserted into the upper portion of the intermediate casing  23  of the lighter body  2 , and their upper halves are expanded outward so that when the stopper member  8  is moved back to the locking position, the engagement shoulder  85  is brought into engagement with the rear upper end portion of the intermediate casing  23 . Front and rear projections  87  and  88  are formed on the inner surface of an upper portion of each of the sliding portions  81 . The front end surface  87   a  of the front projection  87  is inclined. 
     The stopper member  8  is mounted on the control cap  7  by fitting the stopper member  8  on the control cap  7  from the rear side with the front and rear projections  87  and  88  on the sliding portions  81  received in the sliding groove  75  so that the sliding portions  81  are held on the control cap  7  to be slidable back and forth between the locking position and the releasing position and to be movable downward together with the control cap  7  and so that the sliding portions  81  and the rear wall  82  surround the side surfaces and the rear surface of the control cap  7 . 
     When the front projection  87  is inserted into the sliding groove  75  from the rear side during mounting the stopper member  8  on the control cap  7 , the front projection  87  is caused to pass by the resilient piece  91  by deforming inward the resilient piece  91  by virtue of the inclined front end surface  87   a  of the front projection  87  and to pass by the hook portions  77  by deforming outward the sliding portions  81  at the opening  76 , and then is brought into engagement with the front portion of the sliding groove  75 . Thus the stopper member  8  is mounted on the control cap  7  to be movable back and forth relative to the control cap  7 . The rearmost position of the stopper member  8  relative to the control cap  7  is defined by abutment of the rear surfaces of the front projections  87  against the hook portions  77 . Further, when the front projections  87  is in abutment against the hook portions  77 , the rear projections  88  are in abutment against the upper portions  91   a  of the resilient pieces  91  with the resilient pieces  91  slightly deformed forward, whereby the stopper member  8  is urged rearward toward the locking position under the resiliency of the resilient pieces  91 . 
     The stopper member/control cap assembly thus formed is incorporated on the intermediate casing  23  of the lighter body  2  in the manner shown in FIG. 1, and then the windshield cap  10  is mounted. 
     A support column  24  is formed on each side of the intermediate casing  23  at an upper central portion thereof, and a partition plate  25  is held by the support columns  24  to separate the inside of the intermediate casing  23  into a nozzle side space and a piezoelectric unit side space. 
     Operation of the gas lighter  1  of this embodiment will be described, hereinbelow. In the locked state of the gas lighter  1  shown in FIGS. 1 and 2, the control cap  7  and the stopper member  8  are held in their uppermost positions under the force of a spring built in the piezoelectric unit  51 . Further, the stopper member  8  are held in the rearmost position under the resiliency of the resilient pieces  91  and a gap is formed between the rear wall  72  of the control cap  7  and the rear wall  82  of the stopper member  8 . In this state, the engagement shoulder  85  of the stopper member  8  is in engagement with the upper edge of the rear portion of the intermediate casing  23  with the engagement projection  86  in abutment against the inner surface of the peripheral wall of the intermediate casing  23  and accordingly, the control cap  7  and the stopper member  8  cannot be depressed, that is, the gas lighter is locked. The appearance of the gas lighter  1  in the locked state is shown in FIGS. 6A and 6B. 
     When the gas lighter  1  is to be used, the releasing operation portion  84  of the stopper member  8  is pushed forward to the releasing position and the stopper member  8  and the control cap  7  are depressed with the releasing operation portion  84  kept forward. That is, when the stopper member  8  is pushed forward toward the nozzle  31  overcoming the force of the resilient pieces  91 , the resilient pieces  91  are further deformed in response to the forward movement of the rear projections  88  and the rear wall  72  of the control cap  7  is moved toward the rear wall  82  of the stopper member  8 , whereby the engagement shoulder  85  is disengaged from the upper edge of the rear portion of the intermediate casing  23  to permit depression of the control cap  7  and the stopper member  8 , that is, the gas lighter  1  is released. The appearance of the gas lighter  1  in the released state is shown in FIGS. 7A and 7B. 
     When the stopper member  8  and the control cap  7  are subsequently depressed, the lever pusher  53  is brought into abutment against the arm  43  of the actuator lever  4  to rotate the actuator lever  4 , whereby the nozzle  31  of the fuel supply means  3  is lifted to open the valve mechanism  32  and the piezoelectric unit  51  is operated to ignite fuel gas discharged from the nozzle  31  as shown in FIGS. 4 and 5. The control cap  7  can be depressed by pushing downward the releasing operation portion  84  of the stopper member  8  instead of pushing downward the depressing portion  73   a  of the control cap  7  since the lower surface of the upper wall  83  of the stopper member  8  is in abutment against the recess  73   b  of the control cap  7 . The appearance of the gas lighter  1  in the ignited state is shown in FIGS. 8A and 8B. 
     When the control cap  7  and the stopper member  8  are released, the control cap  7  is returned to the original position under the force of the spring built in the piezoelectric unit  51  and the like, and the valve mechanism  32  is closed, whereby the flame is quenched. At the same time, the stopper member  8  is returned to the locking position under the force of the resilient pieces  91  and the lighter  1  comes to be locked where depression of the control cap  7  is prevented. 
     FIGS. 9A and 9B and  10 A to  10 C show modifications of the depression means  6 . In the modification shown in FIG. 9A, the upper wall  83  of the stopper member  8  is extended forward halfway to the front end of the sliding portions  81 . In the modification shown in FIG. 9B, the upper wall  83  of the stopper member  8  is extended forward to the front end of the sliding portions  81  and covers the entire upper surface of the control cap  7 . In the modification shown in FIG. 10A, the upper wall  83  of the stopper member  8  is extended forward halfway to the front end of the sliding portions  81  and a transverse slit  83   a  is formed in the upper wall  83 . In the modification shown in FIG. 10B, the upper wall  83  of the stopper member  8  is extended forward to the front end of the sliding portions  81  and a pair of longitudinal slits  83   b  are formed from the front end of the sliding portions  81  halfway to the rear end of the same on opposite sides of the stopper member  8 . In the modification shown in FIG. 10C, the upper wall  83  of the stopper member  8  is extended forward to the front end of the sliding portions  81  and a pair of longitudinal slits  83   b  are formed from the front end of the sliding portions  81  to the rear end of the same on opposite sides of the stopper member  8 . Depending on the shape of the upper wall  83  of the stopper member  8 , the shape of the upper surface of the upper wall  73  of the control cap  7  is changed so that the area of the depressing portion  73   a  exposed upward becomes as small as possible. 
     A piezoelectric gas lighter  100  in accordance with a first embodiment of the present invention will be described with reference to FIGS. 11 to  15 , hereinbelow. The gas lighter  100  of this embodiment differs from that of the first embodiment mainly in that the depression means  6  is separated into a control cap  17 , a stopper member  18  and an urging member  19 , and accordingly, the elements analogous to those of the first embodiment are given the same reference numerals and will not be described here. 
     In this embodiment, the depression means  6  comprises three separate components formed by plastic molding, a control cap  17  which holds the piezoelectric unit  51 , a stopper member  18  which is mounted on the control cap  17  to be movable between the locking position and the releasing position, and an urging member  19  which urges the stopper member  18  to the locking position. 
     The control cap  7  is provided with a tubular portion into which the upper end portion of the piezoelectric unit  51  is inserted. The tubular portion is formed by side walls  171  and the rear wall  172 , and an upper wall  173  is formed above the tubular portion. A front portion of the top surface of the upper wall  173  forms a depressing portion  173   a  exposed upward. A sliding groove  175  is formed in the outer surface of each side wall  171  to extend back and forth. The part of the side wall  171  below the sliding groove  175  is substantially equal to the intermediate casing  23  of the lighter body  2  in width and can be fitted in the intermediate casing  23 . An insertion groove  176  is formed in the part of the si de wall  171  below the sliding groove  175  to extend up and down and open at the upper and lower end. The upper wall  173  is smaller than the side walls  171  in width. A hook portion  177  projects into the sliding groove  175  at an intermediate portion thereof, and the rear end surface  177   a  of the hook portion  177  is inclined. A vertical groove  179  is formed in the rear wall  172  at the center thereof. An engagement portion  173   c  extends rearward from the rear end of the upper wall  173  at the center thereof. A recess  173   b  is formed on the upper wall  173  on the rear side of the depressing portion  173   a . A projecting portion  178  is provided in front of the depressing portion  173   a  slightly below the depressing portion  173   a . The projecting portion  178  is inserted into the windshield cap  10  to prevent the control cap  17  from being drawn out upward. 
     The urging member  19  comprises a pair of side frame portions  192  extending along the side walls  171  of the control cap  17  and a rear frame portion  193  which connects the rear ends of the side frame portions  192 . A support portion  194  extends upward from the front end of each side frame portion  192 . A resilient piece  191  is connected to the rear face of the support portion  194 . The resilient piece  191  is connected to the rear face of the support portion  194  at its lower end and extends rearward curving upward to its upper end portion  191   a  which is higher than the upper end of the support portion  194  and is resiliently deformable back and forth. The rear top corner of the upper end of the upper end portion  191   a  is chamfered. A boss  195  extends upward from each of the side frame portions  192  near the rear end thereof, and the bosses  195  are inserted into the bottom of the control cap  17 , whereby the urging member  19  is mounted on the control cap  17 . At this time, the support portions  194  and the resilient pieces  191  of the urging member  19  are inserted into the insertion groove  176  of the control cap  17  from below so that the upper end portions  191   a  of the resilient pieces  191  project into the sliding grooves  175 . The front portions of the upper ends of the support portions  194  project forward in engagement with the upper ends of the front ends portions of the insertion grooves  176 . 
     The stopper member  18  comprises a pair of sliding portions  181  extending along the opposite sides of the control cap  17  and an upper wall  183  formed to connect the rear portions of the sliding portions  181 . The sliding portions  181  an the upper wall  183  are formed to cover the upper peripheral edge of the control cap  17 . The front portion of the upper wall  183  is cut away in a shape conforming to the depressing portion  173   a  of the control cap  17 . A rear wall  182  extends downward from the lower surface of the upper wall  183  at the center of the rear end thereof. The rear wall  182  is of such a width that permits the rear wall  182  to be inserted into the vertical groove  179  on the rear side of the control cap  17 . The lower end face of the rear wall  182  forms an engagement shoulder  185  and an engagement projection  186  extends downward inward from the lower end face of the rear wall  182 . A releasing operation portion  184  in the form of a stepped surface is formed on the upper surface of the upper wall  183 . A recess  183   a  on which the engagement portion  173   c  extending from the rear end of the upper wall  173  slides is formed below the rear end portion of the lower surface of the upper wall  183  as shown in FIG.  11 . 
     Front and rear projections  187  and  188  (FIG. 11) are formed on the inner surface of each of the sliding portions  181  on opposite sides of the position to be inserted into the sliding groove  175  of the control cap  17 . The front end surface  187   a  of the front projection  187  is inclined and the front lower edge of the rear projection  188  is chamfered. 
     The stopper member  18  is mounted on the control cap  17  by fitting the stopper member  18  on the control cap  17  from the rear side with the front and rear projections  187  and  188  on the sliding portions  181  received in the sliding groove  175  so that the sliding portions  181  are held on the control cap  17  to be slidable back and forth between the locking position and the releasing position and to be movable downward together with the control cap  17  and so that the rear wall  182  is inserted into the vertical groove  179  of the control cap  17 . 
     When the front projection  187  is inserted into the sliding groove  175  from the rear side during mounting the stopper member  18  on the control cap  17 , the front projection  187  is caused to pass by the hook portion  77  by deforming outward the sliding portions  181  by virtue of the inclined front end face  187   a , and then is brought into engagement with the front portion of the sliding groove  175 . Thus the stopper member  18  is mounted on the control cap  17  to be movable back and forth relative to the control cap  17 . The rearmost position of the stopper member  18  relative to the control cap  17  is defined by abutment of the rear surfaces of the front projections  187  against the hook portions  177 . Further, the rear projection  188  is in the rear portion of the sliding groove  175 . 
     Then the urging member  19  is mounted on the control cap  17  from below. That is, the support portions  194  and the resilient pieces  191  are inserted into the insertion grooves  176  of the control cap  17  from below so that the chamfered rear upper edges of the upper end portions  191   a  of the resilient pieces  191  are brought into abutment against the chamfered front lower edges of the rear projections  188  and the resilient pieces  191  are slightly deformed forward and so that the front portions of the upper ends of the support portions  194  are brought into engagement with the upper front ends of the insertion grooves  176  and the bosses  195  are fitted in the bottom of the control cap  17 . The stopper member  18  is urged rearward toward the locking position under the resiliency of the resilient pieces  191  with the front projections  187  in abutment against the hook portions  177 . 
     The control cap  17  mounted with the stopper member  18  and the urging member  19  is incorporated on the intermediate casing  23  of the lighter body  2  in the manner shown in FIG. 11, and then the windshield cap  10  is mounted. 
     Operation of the gas lighter  100  of this embodiment will be described, hereinbelow. In the locked state of the gas lighter  1  shown in FIGS. 11 and 12, the control cap  17  and the stopper member  18  are held in their uppermost positions under the force of a spring built in the piezoelectric unit  51 . Further, the stopper member  18  are held in the rearmost position under the resiliency of the resilient pieces  191 . In this state, the engagement shoulder  185  of the stopper member  18  is in engagement with the upper edge of the rear portion of the intermediate casing  23  with the engagement projection  186  in abutment against the inner surface of the peripheral wall of the intermediate casing  23  and accordingly, the control cap  17  and the stopper member  18  cannot be depressed, that is, the gas lighter is locked. 
     When the gas lighter  100  is to be used, the releasing operation portion  184  of the stopper member  18  is pushed forward to the releasing position and the stopper member  18  and the control cap  17  are depressed with the releasing operation portion  184  kept forward. That is, when the stopper member  18  is pushed forward toward the nozzle  31 , the resilient pieces  191  are further deformed in response to the forward movement of the rear projections  188  and the engagement shoulder  185  is disengaged from the upper edge of the rear portion of the intermediate casing  23  to permit depression of the control cap  17  and the stopper member  18 , that is, the gas lighter  1  is released. 
     When the stopper member  18  and the control cap  17  are subsequently depressed, the lever pusher  53  is brought into abutment against the arm  43  of the actuator lever  4  to rotate the actuator lever  4 , whereby the nozzle  31  of the fuel supply means  3  is lifted to open the valve mechanism  32  and the piezoelectric unit  51  is operated to ignite fuel gas discharged from the nozzle  31  as shown in FIGS. 14 and 15. 
     When the control cap  17  and the stopper member  18  are released, the control cap  17  is returned to the original position under the force of the spring built in the piezoelectric unit  51  and the like, and the valve mechanism  32  is closed, whereby the flame is quenched. At the same time, the stopper member  18  is returned to the locking position under the force of the resilient pieces  191  and the lighter  100  comes to be locked where depression of the control cap  17  is prevented. 
     Also in this embodiment, the upper wall  183  of the stopper member  18  may be modified as described above in conjunction with FIGS. 9A to  10 C. 
     FIG. 16 shows a modification of the urging member  19  shown in FIG.  13 . The modification is formed by stamping press of a metal plate (metal spring). The basic shape of the urging member shown in FIG. 16 is the same as that shown in FIG. 13, and the analogous parts are given the same reference numerals. 
     That is, the urging member  19  formed of a metal plate comprises a pair of side frame portions  192  which extends back and forth at a lower portion of the urging member  19  and a rear frame portion  193  which connects the rear ends of the side frame portions  192 . A support portion  194  extends upward from the front end of each side frame portion  192 . A resilient piece  191  is erected upward from an intermediate portion of each side frame portion  192 . The resilient piece  191  is connected to the side frame portion  192  at its lower end and extends upward to its upper end portion  191   a  which is higher than the upper end of the support portion  194  and is resiliently deformable back and forth. A projection  195  extends upward from the middle of the rear frame portion  193 , and the projection  195  is inserted into the bottom of the control cap  17 , whereby the urging member  19  is mounted on the control cap  17 . The urging member  19  shown in FIG. 16 is mounted on the control cap  17  in the similar manner to that shown in FIG.  13 . The resilient pieces  191  are resiliently deformed by the rear projections  188  of the stopper member  18  and the stopper member  18  is urged to the locking position under the force generated by the resilient deformation of the resilient pieces  191 . 
     In addition, all of the contents of Japanese Patent Application No. 11(1999)-323770 are incorporated into this specification by reference.