Patent Publication Number: US-6663382-B2

Title: Safety lighter

Description:
CROSS REFERENCE OF RELATED APPLICATION 
     This is an improved non-provisional application of another non-provisional application, U.S. Pat. No. 5,913,674, issued on Jun. 22, 1999, assigned to the applicant of the present invention. 
    
    
     BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to disposable lighter, and more particularly to a safety lighter for preventing the minor to ignite the lighter so as to guarantee the safety of children. 
     2. Description of Related Arts 
     The traditional disposable lighters are popular because they are easy to ignite and operate. 
     However, for protecting the safety and benefit of children, starting from 1993 to 1994, the U.S. Consumer Product Safety Commission declared that it should stop selling the traditional disposable lighter. In view of protecting the safety of children, it is absolutely necessary and reasonable to do so. Therefore, the U.S. Consumer Product Safety Commission imposed an important regulation that “Child below 4 years old cannot light the lighter”. 
     Accordingly, various kinds of disposable lighter having switching mechanism for rendering the lighter being child resistant are developed. Typical examples include the U.S. Pat. No. 5,096,414 issued to Zellweger and the U.S. Pat. No. 5,547,370 issued to Hwang. In order to improve the drawbacks of both the Zellweger&#39;s and Hwang&#39;s patents, a safety lighter was invented, U.S. Pat. No. 5,913,674, which was issued on Jun. 22, 1999 and assigned to the applicant of the present invention. 
     According to the disclosure of the U.S. Pat. No. 5,913,674, the driving wheels are arranged loosely rotatable around the driven bodies when the driving wheels have not been depressed. When a depressing force is applied downwardly to the driving wheels, the driving grooves are pressed to engage with the driven spurs of the two driven bodies. Therefore, when the driving wheels are depressed and turned, the two driven bodies are driven to strike the spark wheel against the flint. However, since the driving holes of the driving wheels must be larger than the driven bodies so as to render the driving wheels being loosely rotatable around the driven bodies normally. In other words, the driving wheels are loosely put on the driven bodies, so that laterally movement may be occurred for the unstable driving wheels during the rotation around the smaller driven bodies that may adversely affect the ignition operation of the lighter. 
     SUMMARY OF THE PRESENT INVENTION 
     A main object of the present invention is to provide a safety lighter that can prevent the minor, especially under 4 years old, to ignite the lighter so as to guarantee the safety of children, wherein the driving wheels are better supported in a stable and a free rotatable manner that can guide the rotation of the driving wheels effectively. 
     Another object of the present invention is to provide a safety lighter having two positioning discs provided on two outer sides of two driving wheels respectively, so as to prevent lateral movements of the two driving wheels with respect to the wheel axles and ensure the spark wheel being driven by the driving wheels. 
     Another object of the present invention is to provide a safety lighter wherein the spark wheel can be easily mounted on a central position between the two supporting walls. Since the spark wheel is supported by the two wheel axles on both sides respectively, the two wheel axles can substantially prevent the spark wheel to move aside, so that the spark wheel can permanently remain in a central position, between the two wheel axles. 
     Another object of the present invention is to provide a safety lighter, which does not require incorporating with any additional element in order to provide safety feature for preventing the children to ignite the lighter. Moreover, the assemble of the spark wheel and the two wheel axles are as simple and easy as studding two inner ends of the two wheel axles to the two side holes of the spark wheel respectively. Therefore, the manufacturing cost and process of the present invention can thus be remained as usual. 
     Accordingly, in order to accomplish the above objects, the present invention provides a safety lighter, comprising: 
     a supporting frame disposed on a gas reservoir having a valve which is actuated by a gas lever pivotally mounted on the supporting frame for actuating the valve to release gas within the gas reservoir therefrom, wherein the supporting frame comprises two supporting walls parallelly protruded on opposite sides of the gas lever and each of the supporting walls has a supporting hole provided thereon; and 
     an ignition means comprising: 
     a flint supported by a resilient element; 
     a spark wheel which is rotatably mounted on the supporting frame and has a striking surface in contact with the flint, wherein the flint is retained urging against the striking surface of the spark wheel by means of the resilient element for generating sparks directed toward the valve when the striking surface is driven to strike against, and that two sides of the spark wheel each has an axle hole, a periphery of each of the axle holes having a plurality of evenly spaced engaging indentions; 
     two wheel axles, each having a round supporting axle for rotatably inserting into one of the supporting holes, a driving axle for inserting into one of the axle holes of the spark wheel, wherein a periphery of the driving axle has a plurality of evenly spaced protrusions adapted for firmly engaging with the engaging indentions of the axle hole of the spark wheel, and-a round driven body integrally formed between the supporting axle and the driving axle, wherein a plurality of axial driven spurs are evenly spaced and protruded on an outer circular surface of the driven body; 
     two driving wheels, which are supported by the two driven bodies of the two wheel axles respectively, each having an outer knurling surface, a central driving hole having a diameter larger than that of the driven body so as to enable the driving wheel to loosely rotate around the driven body without being depressed, and a receiving cavity which is indented on an outer side of the driving wheel and has a diameter larger than that of the central driving hole, wherein a plurality of axial driving grooves are evenly spaced and indented around a periphery of the driving hole, thereby when a depressing force is applied downwardly to the two driving wheels, the driving grooves thereof are pressed to engage with the driven spurs of the two driven bodies, so that when the driving wheels are depressed and turned, the two driven bodies are driven to strike the spark wheel against the flint; and 
     two positioning discs, which are disposed in the receiving cavities of the two driving wheels and supported by the two driven bodies of the two wheel axles respectively, each having a center hole adapted for fittedly engaging with an outer portion of the respective driven body, whereby the two driving wheels are guided to rotate between two sides of the spark wheel and the two positioning discs respectively so as to prevent lateral movement of the driving wheels during rotation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a safety lighter according to a first preferred embodiment of the present invention. 
     FIG. 2 is a sectional end view of the safety lighter according to the above first preferred embodiment of the present invention. 
     FIG. 3 is a partial side view of a driving wheel of the safety lighter according to the above first preferred embodiment of the present invention, illustrating the relationship between the driving wheel and the respective driven body. 
     FIG. 4 is an exploded perspective view of a safety lighter according to a second preferred embodiment of the present invention. 
     FIG. 5 is s sectional end view of the safety lighter according to the above second embodiment of the present invention. 
     FIG. 6 is a partial side view of the driving wheel of the safety lighter according to the above second preferred embodiment of the present invention, illustrating the relationship between the driving wheel and the respective driven body. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 through 3 of the drawings, a safety lighter according to a preferred embodiment of the present invention is illustrated, wherein the safety lighter comprises a supporting frame  20  and an ignition means  40 . The supporting frame  20  is disposed on a gas reservoir  11  having a valve  12  which is actuated by a gas lever  30  pivotally mounted on the supporting frame  20  for releasing gas therefrom. The supporting frame  20  is protruded from a frame cover  21  which is sealedly secured onto the gas reservoir  11  filled with liquid petroleum gas such as butane therein. 
     The supporting frame  20  comprises a pair of supporting walls  22 ,  23  protruded on opposite sides of the gas lever  30 . The gas lever  30  is pivotally mounted between the two supporting walls  22 ,  23  by means of two pivots  31 ,  32  protruded from two opposite sides of the gas lever  30 . The gas lever  30  has a front end  33  extending frontward to engage with a nozzle  121  of the gas valve  12  and a depressible rear end  34  extending rearwards of the frame cover  21  for enabling the depressing of the depressible rear end  34  for lifting up the gas nozzle  121  to open the gas valve  12 . 
     The ignition means  40  comprises a flint  41  supported by a resilient element  42  and a spark wheel  43  which is rotatably mounted on the supporting frame  20 . The spark wheel  43  has an outer circular striking surface  431  contacting with the flint  41 . 
     The flint  41  and the resilient element  42  are received in a flint housing  24  which is underneath the spark wheel  43  and provided on the frame cover  21  between the two supporting walls  22 ,  23 . An upper portion of the flint  41  must be retained exposing outside the flint housing  24  and urging against the striking surface  431  of the spark wheel  43  by means of the resilient element  42  for generating sparks directed toward the gas valve  12  when the striking surface  431  is driven to turn against the flint  41 . 
     Each of the supporting walls  22 ,  23  has a circular supporting hole  221 ,  231  provided therein for mounting the spark wheel  43  between the two supporting walls  22 ,  23 . Each side of the spark wheel  43  has an axle hole  44 ,  45  which periphery has a plurality of evenly spaced engaging indentions  441 ,  451 . 
     The ignition means  40  further comprises two wheel axles  46 ,  47  and two driving wheels  48 ,  49 . Each of the driving wheels  48 ,  49  has an outer knurling surface  481 ,  491  adapted for better contact by a user. Each of the wheel axle  46 ,  47  has a round supporting axle  461 ,  471  for rotatably inserting into the respective circular supporting hole  221 ,  231  of the two supporting walls  22 ,  23 , a driving axle  462 ,  472  for inserting into the respective axle hole  44 ,  45  of the spark wheel  43 , wherein a periphery of the driving axle  462 ,  472  has a plurality of evenly spaced protrusions  462   a,    472   a  adapted for firmly engaging with the respective engaging indentions  441 ,  451  of the corresponding axle hole  44 ,  45  of the spark wheel  43 , and a round driven body  463 ,  473  integrally formed between the supporting axle  461 ,  471  and the driving axle  462 ,  472 , wherein the driven body  463 ,  473  has a diameter at least equal to a maximum size of the driving axle  462 ,  472  and larger than that of the supporting axle  461 ,  471 . Axial driven spurs  463   a,    473   a  are evenly spaced and protruded on an outer circular surface of the driven body  463 ,  473 . 
     The two driving wheels  48 ,  49  are supported by the two driven bodies  463 ,  473  of the two wheel axles  46 ,  47  respectively. Each of the driving wheels  48 ,  49  has a central driving hole  482 ,  492  having a diameter larger than that of the driven body  463 ,  473  and a plurality of axial driving grooves  483 ,  493  evenly spaced and indented around a periphery thereof, so as to enable the driving wheel  48 ,  49  to loosely rotate around the driven body  463 ,  473  when the driving wheels  48 ,  49  has not been depressed. Each of the driving wheels  48 ,  49  has a diameter larger than that of the central driving hole  482 ,  492  and has a circular receiving cavity  484 ,  494  coaxially indented in an outer side of the driving wheel  48 ,  49 . Thereby, when a depressing force applied downwardly to the two driving wheels  48 ,  49  presses the driving grooves  483 ,  493  to engage with the driven spurs  463   a,    473   a  of the two driven bodies  463 ,  473 , so that when the driving wheels  48 ,  49  are depressed and turned, the two driven bodies  463 ,  473  are driven to strike the spark wheel  43  against the flint  41 . 
     The ignition means  40  further comprises two positioning discs  401 ,  402  which are disposed in the receiving cavities  484 ,  494  of the two driving wheels  48 ,  49  and supported by the two driven bodies  463 ,  473 , wherein each positioning disc  401 ,  402  has a center hole  401   a ,  402   a  adapted for fittedly engaging with an outer portion of the respective driven body  463 ,  473 . In order words, the two positioning discs  401 ,  402  are supported by the two driven bodies  463 ,  473  of the two wheel axles  46 ,  47  by inserting the driven bodies  463 ,  473  into the center holes  401   a ,  402   a  respectively. Whereby, the two driving wheels  48 ,  49  are guided to rotate between two sides of the spark wheel  43  and the two positioning discs  401 ,  402  respectively so as to prevent lateral movement of the driving wheels  48 ,  49  during the rotation with respect to the wheel axles  46 ,  47 . 
     Accordingly, each driving wheel  48 ,  49  has a U-shaped cross section and comprises a circular wheel member  486 ,  496  and a driving ring  487 ,  497  integrally and perpendicularly extended from a circular edge of the wheel member  486 ,  496 , wherein the central driving hole  482 ,  492  is provided at the center of the wheel member  486 ,  496  and the receiving cavity  484 ,  494  is defined on the outer side of the wheel member  486 ,  496  and within the driving ring  487 ,  497 . 
     A diameter of each receiving cavity  484 ,  494  is gradually decreasing from an outer portion of the driving wheel  48 ,  49  to an inner portion thereof so as to define a slanted inner circumferential wall  485 ,  495  of the receiving cavity  484 ,  494  of the driving wheel  48 ,  49 . In other words, the driving ring  487 ,  497  has a thickness gradually decreasing from its outer portion to an inner portion thereof, so that the contacting area of the outer knurling surface  481 ,  491  of each of the driving rings  487 ,  497  of the two driving wheels  48 ,  49  is maximized, as large as the previous U.S. Pat. No. 5,913,674 while providing the receiving cavity  484 ,  494 . 
     A diameter of each of the positioning discs  401 ,  402  is smaller than that of the respective receiving cavity  484 ,  494  so as to ensure the driving wheels  48 ,  49  rotating in a free rotation manner. Thus, a width of the driven body  463 ,  473  should be larger than that of the positioning disc  401 ,  402 , such that the positioning disc  401 ,  402  is securely mounted on the respective driven body  463 ,  473  of the wheel axle  46 ,  47 . 
     Since each driving wheel  48 ,  49  is securely sandwiched between the wheel axle  46 ,  47  and the positioning disc  401 ,  402 , the driving wheels  48 ,  49  are locked up on the driven bodies  463 ,  473  in position respectively so as to prevent any lateral movement of the driving wheels  48 ,  49  with respect to the wheel axles  46 ,  47 . However, each driving wheel  48 ,  49  is adapted for turning on the respective driven body  463 ,  473  in a free rotating manner so as to prevent any unwanted ignition of the safety lighter. 
     According to the first preferred embodiment of the present invention, as shown in FIGS. 1 to  3 , each of the axle holes  44 ,  45  of the spark wheel  43  has totally four engaging indentions  441 ,  451  perpendicularly and outwardly extended so as to form a cross shaped cross section. Moreover, the two axle holes  44 ,  45  can be inwardly extended to form a through hole. Relatively, each of the two driving axles  462 ,  472  has totally four protrusions  462   a,    472   a  perpendicularly and outwardly extended to form a cross shaped cross section, wherein the two cross shaped driving axles  462 ,  472  are arranged to fittedly insert into the two cross shaped axle holes  44 ,  45  of the spark wheel  43  respectively until the two driving bodies  463 ,  473  are pressed against the two sides of the spark wheel  43 . Therefore, when either one of the two driving axles  462 ,  472  rotates, the spark wheel  43  can be exactly driven to rotate without slipping. The two driving axles  462 ,  472  may be made in tapered form, so as to facilitate the manufacturer to plug the slightly smaller ends thereof into the two axle holes  44 ,  45  of the spark wheel  43  respectively. 
     As shown in FIG. 2, the more deeper of the driving axle  462 ,  472  to be inserted into the respective axle hole  44 ,  45 , the engagement of the driving axle  462 ,  472  with the spark wheel  43  will be tighter. Furthermore, the spark wheel  43  is rigidly supported between the two wheel axles  46 ,  47  according to the present invention, so as to rotatably mount between the two supporting walls  22 ,  23 . In other words, the spark wheel  43  is permanently located at a central position between the supporting walls  22 ,  23  and aligned on top of the flint  41 . The two wheel axles  46 ,  47  substantially limit and hold the spark wheel  43  in a central position that absolutely prevents the spark wheel  43  from moving aside. Therefore, the best striking on the flint  41  can be always achieved. 
     According to the first preferred embodiment, the driven spurs  463   a,    473   a  on the driven bodies  463 ,  473  are in wave form, which are adapted to fittedly engage with the driving grooves  483 ,  493  of the driving hole  482 ,  492  of the two driving wheels  48 ,  49  respectively when the two driving wheels  48 ,  49  are downwardly depressed. Therefore, to depress and strike on the two driving wheels  48 ,  49  at the same time can drive the two wheel axles  46 ,  47  to turn. Then, the two wheel axles  46 ,  47  drive the spark wheel  43  to rotate and strike against the flint  41  to generate sparks. 
     Referring to FIGS. 4 to  6 , a second preferred embodiment of the present invention is illustrated, which is similar to the above first embodiment, except that an alternative mode of the ignition means  40  is disclosed. The ignition means  40  also comprises two wheel axles  46 ′,  47 ′ and two driving wheels  48 ′,  49 ′. Similarly, each of the wheel axles  46 ′,  47 ′ has a round supporting axle  461 ′,  471 ′ for rotatably inserting into the respective circular supporting hole  221 ,  231  of the respective supporting wall  22 ,  23 , a driving axle  462 ′,  472 ′, and a driven body  463 ′,  473 ′, wherein the driving axle  462 ′,  472 ′ and the driven body  463 ′,  473 ′ have the same diameter and the protrusions  462   a ′,  472   a ′ on the driving axle  462 ′  472 ′ and the driven spurs  463   a ′,  437   a ′ on the driven body  463 ′,  473 ′ are longitudinal semi-circular protruding ribs evenly spaced and extended from the driving axle  462 ′,  472 ′ to the driven body  463 ′,  473 ′. An isolating rim  464 ′,  474 ′ can be formed between the driving axle  462 ′,  472 ′ and the driven body  463 ′,  473 ′, so that the driving axle  462 ′,  472 ′ can be precisely inserted into the respective axle hole  44 ′,  45 ′ of the spark wheel  43 ′ until the isolating rim  464 ′,  474 ′ is pressed against the corresponding side of the spark wheel  43 ′. 
     Relatively, the engaging indentions  441 ′,  451 ′ on the axle holes  44 ′,  45 ′ of the spark wheel  43 ′ and the driving grooves  483 ′,  493 ′ on the driving holes  482 ′,  492 ′ of the driving wheels  48 ′,  49 ′ are also arranged in semi-circular shaped for engaging with the semi-circular protruding ribs as mentioned above. The second preferred embodiment works and operates similar to the above first preferred embodiment. Moreover, like the above first embodiment, each of the two driving wheels  48 ′,  49 ′ of the second embodiment also provides a central driving hole  482 ′,  492 ′ having a diameter larger than that of the driven body  463 ′,  473 ′ so as to enable the driving wheel  48 ′,  49 ′ to loosely rotate around the driven body  463 ′,  473 ′ without being depressed, and a circular receiving cavity  484 ′,  494 ′ which is indented in an outer side of the driving wheel  48 ′,  49 ′ and has a diameter larger than that of the central driving hole  482 ′,  492 ′, wherein a plurality of axial driving grooves  483 ′,  493 ′ are evenly spaced and indented around a periphery of the driving hole  482 ′,  492 ′, thereby when a depressing force is applied downwardly to the two driving wheels  48 ′,  49 ′, the driving grooves  483 ′,  493 ′ thereof are pressed to engage with the driven spurs  463   a ′,  473 ′ of the two driven bodies  463 ′,  473 ′, so that when the driving wheels  48 ′,  49 ′ are depressed and turned, the two driven bodies  463 ′,  473 ′ are driven to strike the spark wheel  43 ′ against the flint  41 ′. 
     The ignition means  40  further comprises two positioning discs  401 ′,  402 ′, which are disposed in the receiving cavities  484 ′,  494 ′ of the two driving wheels  48 ′,  49 ′ and supported by the two driven bodies  463 ′,  473 ′ respectively, each having a center hole  401   a ′,  402   a ′ adapted for fittedly engaging with an outer portion of the respective driven body  463 ′,  473 ′, whereby the two driving wheels  48 ′,  49 ′ are guided to rotate between two sides of the spark wheel  43 ′ and the two positioning discs  401 ′,  402 ′ respectively so as to prevent lateral movement of the driving wheels  48 ′,  49 ′ during rotation with respect to the wheel axles  46 ′,  47 ′.