Patent Publication Number: US-5833448-A

Title: Child resistant lighter

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a lighter employing an ignition system which presents increased difficulty of operation by unintended users and, more particularly, a piezoelectric lighter with such system. 
     2. Discussion of the Related Art 
     Disposable gas lighters are available in a variety of forms. One common element of disposable lighters, though, is an actuator pad or lever used to initiate the flow of fuel. An actuator pad is operated in conjunction with a spark producing mechanism so that the flow of fuel is ignited soon after it commences. For example, lighters employing conventional spark wheels require a user to rotate a toothed spark wheel against a flint in order to generate a spark. The user then depresses the actuator pad, releasing gas and producing a flame. 
     Another means of ignition for disposable lighters employs a piezoelectric mechanism. In this type of ignition mechanism, a piezoelectric element, such as a crystal, is struck by a hammer in order to produce an electric spark. The spark is conducted to the opening of the fuel valve to ignite the gaseous fuel. The actuator pad, upon forced depression by a user, commences both the flow of the fuel and the ignition process. An example of such a piezoelectric ignition mechanism is disclosed in U.S. Pat. No. 5,262,697, entitled &#34;Piezoelectric Mechanism for Gas Lighters.&#34; 
     As with spark wheel ignition mechanisms, measures have been introduced to prevent activation of piezoelectric mechanisms by unintended users such as children 5 years old and younger. One typical method employed is to incorporate a latch member under the actuator pad that inhibits depression of the actuator pad. Examples of such mechanisms are shown in U.S. Pat. Nos. 5,435,719, 5,584,682, and 5,636,979. 
     There remains, however, a need in the art for mechanisms which increase the difficulty of operation by unintended users and at the same time are user-friendly for the intended user. 
     SUMMARY OF THE INVENTION 
     It is thus an object of this invention to provide a lighter that is easily operated by an adult, but which is resistant to operation by young children. 
     This and other objectives are met by a lighter according to the present invention, with an elongated body defining a fuel reservoir and including a valve for dispensing such fuel. The lighter further includes an actuator that, upon depression, activates the ignition system, which requires the release of fuel from the reservoir and activation of a piezoelectric mechanism which makes a spark. Depression of the actuator is normally barred, however, by a blocking mechanism. Displacement of the blocking mechanism in the specified manner allows the actuator to be depressed. The blocking mechanism, which is integral to the actuator, is displaced through pressure by a user. Upon removal of the displacing force the blocking mechanism returns to its initial blocked position, once again preventing the actuator from being depressed sufficiently to activate the ignition system. 
     The blocking mechanism of the current invention requires tilted displacement in both the horizontal and vertical directions in order to permit ignition. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, features, and advantages of the invention will become more readily apparent from the following detailed description which should be read in conjunction with the accompanying drawings, in which like elements are labeled similarly, and in which: 
     FIG. 1 is a partial perspective view of one embodiment of a lighter according to the present invention in its idle configuration; 
     FIG. 2 is a partial cross-sectional view of the lighter depicted in FIG. 1; 
     FIG. 3 is a partial cross-sectional view of the lighter depicted in FIG. 1 in a locked position; 
     FIG. 4 is a partial cross-sectional view of the lighter depicted in FIG. 1, in which the actuator is displaced prior to activation of the ignition system; and 
     FIG. 5 is a partial cross-sectional view of the lighter depicted in FIG. 1 in an ignition position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a partial view of a first illustrative embodiment of the present invention is provided, in which lighter 10 is comprised of body portion 12, depressible valve actuator 14, and wind guard 16. 
     Referring now to FIG. 2, further details of the ignition system and safety feature of lighter 10 are depicted. An upper portion of piezoelectric ignition mechanism 20 is connected to actuator 14, as is blocking ridge 22. Spark conductor 24 is electrically connected to ignition mechanism 20 in a known manner. A lower portion of ignition mechanism 20 is received in a cooperating recess in body 12. Projection 26 is connected to an appropriate section of body portion 12, preferably at an upper central area of the housing. Coil spring 38 is positioned between the upper and lower portions of ignition mechanism 20. 
     Leaf spring 28 is positioned between rear wall 30 and actuator 14 so as to exert an inward biasing force upon actuator 14 to resist outward movement of the actuator toward rear wall 30 of body 12. Coil spring 38 serves to resist the compression of ignition mechanism 20. Coil spring 38 also applies an upward bias against, thereby resisting the depression of, actuator 14. 
     The upper and lower portions of ignition mechanism 20 are compressibly joined. When at rest, the upper and lower portions of ignition mechanism 20 are separated by a gap, denoted by X in FIG. 2. In piezoelectric lighters such as the present invention, depression of actuator 14 compresses ignition mechanism 20, thereby causing a hammer (not shown) within ignition mechanism 20 to strike a piezoelectric element (not shown), also within ignition mechanism 20. Depression of actuator 14 also opens the fuel valve, thus releasing fuel from reservoir 34 through nozzle 32. Striking the piezoelectric element, or crystal, produces an electrical impulse that is conducted across spark conductor 24 to ignition cavity 36. An electrical arc is generated across the gap from spark conductor 24 to metal nozzle 32, thus igniting the escaping fuel. The basic operation of disposable piezoelectric lighters is well known. 
     In FIG. 2, actuator 14 is shown in its normal or at-rest position. From its normal position, depression of actuator 14 will cause blocking ridge 22 to engage projection 26, thus allowing only minimal, if any, compression of ignition mechanism 20. Referring now to FIG. 3, actuator 14 is depressed as far as blocking ridge 22 and projection 26 will allow. The upper and lower portions of ignition mechanism 20 remain separated by distance X&#39; and cannot be compressed sufficiently to activate the ignition system, thus preventing the production of a flame. 
     In order for intended users to operate lighter 10, actuator 14 must first be displaced outwardly or rearwardly from nozzle 32, away from its normal position. Alternatively, the actuator may be moved away from the nozzle in a sideways motion. When moved to this &#34;ready&#34; position, demonstrated in FIG. 4, the biasing force of leaf spring 28 has been overcome by an outward force applied by the user. It can also be seen that outward displacement of actuator 14 causes ignition mechanism 20, spark conductor 24, and blocking ridge 22 to be proportionally displaced. To aid the user in displacing actuator 14 from the normal position to the ready position, in the present embodiment of the invention the rear surface of actuator 14 may be shaped to increase friction between actuator 14 and the user. Illustratively, this may be accomplished by forming actuator 14 to include one or more ridges 40. 
     In the ready position, blocking ridge 22 is clear of projection 26. Thus, as shown in FIG. 5, actuator 14 can be depressed by the user in order to cause the activation of the ignition system, at which time the gap between the upper and lower portions of ignition mechanism 20, denoted by X&#34; in FIG. 5, is at a minimum. The upward bias exerted by coil spring 38 forces actuator 14 upward when the downward pressure applied by the user is removed. The combined inward and upward biases imparted by leaf spring 28 and coil spring 38, respectively, ensure that lighter 10 returns to the normal (locked) position after use. 
     The description this embodiment is intended to be illustrative, not limitative. Thus, it will be apparent to those skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below. For example, spring 38 is illustrated as a coil spring, but any other suitable biasing element may be employed, such as a separate leaf spring or integrally molded plastic spring. Leaf spring 28 may also be replaced by other flexible biasing means, as described above. 
     The ignition system described herein is not limited to use in a lighter. The ignition system can also be incorporated in other devices that require an enhanced child resistant mechanism, such as piezoelectric ignitions for gas grills, etc.