Piezoelectric ignition mechanism

#The present invention relates generally to ignition mechanisms and devices containing ignition mechanisms, such as, for example, lighters, including pocket and extended-wand type lighters, disposable and non-disposable lighters. More specifically, the present invention relates to piezoelectric ignition mechanisms and piezoelectric lighters, including particularly such ignition mechanisms and lighters that present increased resistance to operation.

#Disposable gas lighters are available in a variety of forms. Typically, one common element of disposable lighters is a fuel release lever that is used to initiate a flow of fuel. The fuel release lever is typically operated in conjunction with a spark producing mechanism so that the flow of fuel is ignited soon after it commences. For example, one type of lighter requires a user to rotate a toothed spark wheel against a flint in order to generate a spark, simultaneously with, or immediately followed by, depressing the fuel release lever to release a gas and produce a flame.

#Other means of ignition for disposable lighters employ a piezoelectric mechanism. In this type of ignition mechanism, a piezoelectric material, such as a piezoelectric crystal, is struck by a hammer in order to produce an electric spark. The spark is created at the fuel outlet or nozzle to ignite the gaseous fuel. The fuel release lever, upon forced depression by a user, typically commences both the flow of the fuel and then the ignition process. An example of such a piezoelectric ignition mechanism is disclosed in U.S. Pat. No. 5,262,697, entitled “Piezoelectric Mechanism For Gas Lighters.”

#To facilitate an understanding of the characteristics, structure and operation of the invention, preferred features of the invention are described in the accompanying discussion, wherein similar reference characters denote similar elements throughout the several views or embodiments, and wherein:

#FIG. 1 is a front view of a first embodiment of a piezoelectric ignition mechanism of the present invention in a first, or rest, position;

#FIG. 2 is a partial cross-sectional view of the ignition mechanism of FIG. 1;

#Referring to the drawings, wherein like reference numbers are used to designate like parts, and wherein preferred features and embodiments of an ignition mechanism are shown for illustrative purposes only and are not intended to limit the scope of the invention, FIG. 1 shows an embodiment of a piezoelectric ignition mechanism 10 according to the present invention. Ignition mechanism 10 includes first and second members 12, 14, respectively, which are configured and dimensioned to move, or preferably slide, with respect to one another along longitudinal axis 18. As shown in FIG. 1, first and second members 12, 14 may be formed similar to concentric hollow tubes with second member 14 being received in first member 12, or vice versa. One skilled in the art will know and appreciate, however, that any number of geometric configurations may be used to provide for movement between first and second members 12, 14. One skilled in the art will further know and appreciate that first and second members 12, 14 are not to be limited to movement along longitudinal axis 18, and may move with respect to one another along any axis. In addition, first and second members 12, 14 may rotate or pivot with respect to one another, e.g., about longitudinal axis 18.

#A return spring 16, or any other type of resilient member known in the art, may be positioned between first member 12 and second member 14 to bias the first and second members 12, 14 apart. As shown in the figures, return spring 16 may be disposed over a portion of second member 14, however other configurations of return spring 16 are contemplated and the present invention is not limited to the configuration shown. The first and second members 12, 14 may be constructed with a stop, lip or other means to prevent the two parts from separating under the force of return spring 16. Alternatively or additionally, an external force may be applied to the members by, for example, a lighter body or housing, to maintain the first and second members 12, 14 together.

#A piezoelectric element 24, and an optional impact pad 26, may be associated with first and second members 12, 14. For example, as shown in FIG. 2, an anvil member 22 may be attached to an end of second member 14 and maintain both piezoelectric element 24 and impact pad 26 inside second member 14. Anvil member 22 is preferably attached to second member 14 with cooperating tabs and grooves, but may alternatively or additionally be attached by other means of attachment, such as screws, cooperating threads, pins, welding or bonding. Alternatively, anvil member 22 and second member 14 may be formed as a single piece around piezoelectric element 24 and optional impact pad 26 (e.g., by insert molding). Impact pad 26 is preferably located adjacent piezoelectric element 24 and transfers impact energy from impact pad 26 directly to piezoelectric element 24. Thus, anvil member 22, piezoelectric element 24, and impact pad 26 are all part of an electrical circuit and cooperate to produce a spark when impact pad 26 is struck by a plexor member 28 with sufficient force, as will be discussed in more detail below. One of ordinary skill in the art will know and appreciate that impact pad 26 is optional and that plexor member 28 may alternatively strike piezoelectric element 24 directly.