Patent Publication Number: US-2003232297-A1

Title: Child-resistant disposable lighter

Description:
[0001] This application claims the benefit of U.S. Provisional Application No. 60/387,561, filed Jun. 12, 2002. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The present invention pertains to a disposable lighter that includes a safety feature which makes it difficult for a child to operate the lighter.  
       BACKGROUND OF THE INVENTION  
       [0003] A disposable gas lighter generally includes a fuel tank, a flint, a gas release and a spark wheel. Rotation of the spark wheel when in contact with the flint creates a spark which ignites gas released via the gas release, such that a flame is created. Because this flame is easy to create, a potentially hazardous situation exists when the lighter is in the hands of children. In an effort to prevent hazardous situations from arising when a lighter is in the hands of a child, various safety features have been incorporated into lighters. However, many of these safety features are either complex or do not sufficiently prevent a child from using the lighter to create a flame.  
       [0004] Accordingly, there remains a need to provide a safety feature for a lighter, which is simple in its construction yet adequate to make it difficult for a child to operate the lighter.  
       SUMMARY OF THE INVENTION  
       [0005] The primary object of the present invention is to provide a disposable lighter that includes a safety feature which is simple in construction yet adequate to prevent a child from operating the lighter to create a flame.  
       [0006] In accordance with a first aspect of the present invention there is provided a lighter that includes a frame, a first turn wheel rotatably supported by the frame, a second turn wheel rotatably supported by the frame, a spark wheel constructed and arranged to be rotated by the first turn wheel but not by the second turn wheel, and a flint constructed and arranged to be contacted by the spark wheel during rotation of the spark wheel.  
       [0007] Because the second turn wheel does not serve to rotate the spark wheel regardless of pressure applied to the second turn wheel , or in other words, is freewheeling relative to the spark wheel, when a user&#39;s thumb is placed on both of the turn wheels to rotate these wheels, the second turn wheel will serve no purpose in rotating the spark wheel. Accordingly, with the lighter of the present invention a force which is generally twice as much as that associated with a conventional lighter, which utilizes two turn wheels to rotate a spark wheel, is required to rotate the spark wheel. This is a safety feature of the lighter of the instant invention.  
       [0008] In accordance with a second aspect of the invention, the second turn wheel is slightly larger in diameter than that of the first turn wheel, which makes it more difficult for a child to apply sufficient force to the first turn wheel so as to rotate the spark wheel.  
       [0009] In accordance with a third aspect of the invention, the first turn wheel has a smooth circumferential surface, as opposed to a knurled or other gripping surface, such that additional force is required to rotate the spark wheel. The second turn wheel can have a smooth or textured circumferential surface.  
       [0010] In accordance with a fourth aspect of the invention, the diameter of the turn wheels are chosen such that the spark wheel cannot be contacted and rotated directly by a user.  
       [0011] In accordance with a fifth aspect of the invention, the turn wheels are provided with annular portions which extend over the spark wheel such that the spark wheel cannot be contacted and rotated directly by a user.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0012]FIG. 1 is an exploded view showing a preferred embodiment of a lighter of the invention.  
     [0013]FIG. 2 is a cross-sectional view showing the lighter in an assembled condition.  
     [0014]FIG. 3 is an enlarged and exploded view of turn wheels and a flint wheel of the lighter. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0015] As seen in FIG. 1, a lighter comprises a fuel tank  2 , a frame  1 , a coil spring  3 , a flint  4 , a gas release  6 , a spark wheel  7 , a flame—guard  5 , and turn wheels  9  and  10 .  
     [0016] In operation, a user turns the turn wheels  9  and  10  with his thumb such that the spark wheel  7  rotates. The flint  4  is pressed into abutting engagement with the spark wheel  7  by the coil spring  3 , and friction between the spark wheel  7  and the flint  4  creates a spark during rotation of the spark wheel. Simultaneously, when the thumb leaves the turn wheels  9  and  10  it depresses the gas release  6  so as to release gas. Released gas in combination with the spark creates a flame that lasts as long as the user depresses the gas release  6 .  
     [0017] A specific construction and assembly of the turn wheels  9  and  10  and spark wheel  7  makes rotation of the spark wheel difficult for a child, yet easy for an adult.  
     [0018] As seen in FIG. 2, the turn wheels  9  and  10  are situated on either side of spark wheel  7 . The turn wheel  10  has two projections  101  and  102 . The projection  101  is smooth and rests inside the frame  1  and allows the turn wheel  10  to rotate freely with respect to the frame  1 . The projection  102  can be geared or left smooth, and is received within an interior of the spark wheel  7 . When the projection  102  and an interior of the spark wheel  7  are both geared, this projection and the interior of the spark wheel are meshed so as to rotate together. The second projection  102  can also be adhesively adhered or welded to the interior of the spark wheel  7 . Accordingly, the turn wheel  10  transmits torque to the spark wheel  7  such that this turn wheel serves to rotate the spark wheel.  
     [0019] The turn wheel  10  and the spark wheel  7  can be attached by any one or combination of the above-described manners, or by any other manner well known in the art.  
     [0020] Like the turn wheel  10 , the turn wheel  9  includes two projections  8  and  15 . The projection  8  is smooth and rests inside the frame  1  and allows the turn wheel  9  to rotate freely with respect to the frame  1 . The projection  15  is received within an interior of the spark wheel  7 ; however; the projection  15  and the interior of the spark wheel within which this projection is received are constructed and arranged relative to one another such that the turn wheel  9  is allowed to rotate freely and independently of the spark wheel. Accordingly, the turn wheel  9  transmits no torque to the spark wheel  7  such that this turn wheel serves no purpose in rotation of the spark wheel.  
     [0021] Because the turn wheel  10  is arranged to rotate the spark wheel  7 , while the turn wheel  9  is arranged not to rotate the spark wheel  7 , an effective area of the turn wheels utilized to rotate the spark wheel is half that of a conventional lighter, which employs two turn wheels to rotate a spark wheel. Accordingly, because the effective area to rotate the spark wheel  7  is half that of a conventional lighter, a force required to rotate the spark wheel  7 , and thus create a flame, is about twice as much as that of a conventional lighter. This additional required force makes it more difficult for a child to use the lighter to create a flame.  
     [0022] The turn wheels  9  and  10  can also include additional safety features which make it even more difficult for a child to use the lighter to create a flame.  
     [0023] For example, the turn wheel  9  can have a larger diameter than that of the turn wheel  10 , whereby the larger turn wheel  9  is designed to initially make contact with a thumb pad of a user. Accordingly, when the thumb first comes into contact with the larger wheel  9 , provided is an obstacle to rotating the spark wheel  7 , whereby a person with little or weak fingers will not be able to turn the smaller wheel  10 . Specifically, the larger turn wheel  9  redirects pressure and torque away from the spark wheel  7 .  
     [0024] That is, when the turn wheels  9  and  10  are of different sizes, effective pressures applied to these turn wheels are different such that an even greater force-will be required to turn the spark wheel  7 . In this regard, because the larger turn wheel  9  intercepts the user&#39;s thumb first, the user must then apply additional pressure to establish contact between his thumb and the smaller turn wheel  10 . This additional pressure corresponds to an additional force required to rotate the spark wheel  7 , since the larger turn wheel  9  is rotatable independently of the spark wheel  7  and does not serve to rotate the spark wheel. Therefore, only one with strength greater than that of a child will be able to actuate the lighter. The difference in diameter between the turn wheel  10  and the turn wheel  9  can be slight.  
     [0025] As an additional safety feature, an outer circumferential surface of the turn wheel  10  can be smooth such that an even greater force is required to rotate this turn wheel, as compared with a turn wheel exhibiting a gripping surface such as a knurled surface, and thereby rotate the spark wheel  7 . Also, an outer circumferential surface of the turn wheel  9  can be either smooth or textured.  
     [0026] When the diameter of the turn wheel  9  is greater than the diameter of the turn wheel  10 , and the outer circumferential surface of the turn wheel  9  is textured while the outer circumferential surface of the first turn wheel  10  is smooth, the turn wheel  9  will redirect even greater pressure and torque away from the spark wheel  7  such that it is even more difficult to rotate the spark wheel. Similarly, when the outer circumferential surface of the turn wheel  9  is textured while the outer circumferential surface of the first turn wheel  10  is smooth, with the turn wheels  9  and  10  being of the same diameter, a greater force is required to rotate the spark wheel  7  than would be when required both turn wheels have the same diameter and same texture for their outer circumferential surfaces.  
     [0027] As a further safety feature, diameters of the turn wheels  9  and  10  can be chosen to be large enough so as to prevent a user&#39;s thumb from contacting and directly rotating the spark wheel  7 , regardless of the pressure applied by the thumb.  
     [0028] As a further additional safety feature, the turn wheels  9  and  10  can be respectively provided with annular portions  103  and  109  which extend over the spark wheel  7  such that a user&#39;s thumb will not be able to make contact with and directly rotate the spark wheel  7 . The annular portion  103  of turn wheel  10  can be provided with ridges on an interior surface thereof so as to engage with corresponding ridges on an exterior surface of the spark wheel  7 . Alternatively, the annular portion  103  can be welded or adhesively bonded to the spark wheel  7 .  
     [0029] The above-described safety features can be used separately or in combination with one another.  
     [0030] While preferred embodiments of this invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the appended claims.