Patent Description:
In order to light candles, a utility lighter is directed downwards, contrary to a light for lighting a cigarette for instance, in which the flame is directed upwards. So, to ignite a candle (or other such for example a barbecue grill) while keeping the fingers and especially the thumb of the user away from the flame, the utility lighter must have its flame away from the activation button. Therefore, it is already known, e.g. from <CIT>, to use utility lighters provided with an extended wand at the end of which the flame emanates. In particular, <CIT> and <CIT> disclose a flame producing assembly according to the preamble of claim <NUM>.

The present invention is directed to a flame producing assembly according to claim <NUM>. The dependent claims depict further developments of the present invention.

In various embodiments of the invention, one and/or the other of the following features may be incorporated in the flame producing assembly of the invention, alone or in mutual combination:.

Other characteristics and advantages of the invention will readily appear from the following description of one embodiment, provided as non-limitative examples, in reference to the accompanying drawings.

<FIG> illustrate a utility lighter <NUM> according to the present invention. The utility lighter <NUM> comprises a pocket lighter <NUM> and a sub-unit assembly <NUM>. The pocket lighter <NUM> comprises a body <NUM>, a pusher <NUM> and a cover <NUM>. The pocket lighter <NUM> extends along a longitudinal axis X. The length L1 of the pocket lighter <NUM> along the longitudinal axis X is comprised between <NUM> and <NUM>. More precisely, the length L1 of the pocket lighter <NUM> is approximately <NUM>. The width L2 of the pocket lighter <NUM> is measurable along a transversal axis Y, which is perpendicular to the longitudinal axis X. The width L2 can be comprised between <NUM>,<NUM> and <NUM>. For example, the width L2 can be approximately <NUM>,<NUM>.

As depicted in <FIG> and <FIG>, the pocket lighter <NUM> further comprises a piezoelectric ignition device <NUM>. The pocket lighter <NUM> is also provided with a pusher <NUM>. The piezoelectric ignition device <NUM> is connected to the pusher <NUM>. The connection between the pusher <NUM> and the piezoelectric ignition device <NUM> is such that the pusher <NUM> and a portion of the piezoelectric ignition device <NUM> which is the closest to the pusher <NUM> are firmly attached together. Consequently, when a user pushes the pusher <NUM> inward the pocket lighter <NUM>, the piezoelectric ignition device <NUM> is compressed to produce an elevated potential difference between its two poles <NUM>- and <NUM>+. A first pole <NUM> is connected to a jet <NUM> and a second pole <NUM> is connected to an electrode spring <NUM>. The electrode spring <NUM> is connected at a first end to the pusher <NUM>. The second end of the electrode spring <NUM> is connected to the sub-unit assembly <NUM>. The jet <NUM> comprises an upper end <NUM> and a lower end <NUM>, regarding the longitudinal axis X. In addition, the jet <NUM> is movable along the longitudinal axis X. The piezoelectric ignition device <NUM> provides a potential difference between the first pole <NUM>, located at the level of the upper end <NUM> of the jet <NUM> and the second pole <NUM>, located at the second end of the electrode spring <NUM>, which is in contact with the sub-unit assembly <NUM>. The first pole <NUM> and the second pole <NUM> are electrically insulated from one another by an insulated member <NUM>. The pocket lighter <NUM> also comprises a reservoir <NUM> of gaseous fuel. A valve <NUM> is located between the reservoir <NUM> and the jet <NUM>. The reservoir <NUM> is in fluid communication with the valve <NUM>. The jet <NUM> is movable along the longitudinal axis X inside the valve <NUM> between an open position and a closed position to selectively release gaseous fuel. Besides, the pocket lighter <NUM> comprises a biased pivotal arm <NUM>. The biased pivotal arm <NUM> is located between the piezoelectric ignition device <NUM> and the jet <NUM>. In addition, the biased pivotal arm <NUM> is made of an electrical conductive material. Thus, the biased pivotal arm <NUM> conducts the electrical potential from the piezoelectric ignition device <NUM> to the first pole <NUM>. For example, the material of the biased pivotal arm <NUM> is made of electrical conductive material. For example, the biased pivotal arm is made of metal or carbon filled resin. As the pusher <NUM> compresses the piezoelectric ignition device <NUM>, the pusher <NUM> also acts on the biased pivotal arm <NUM> which is operatively connected to the jet <NUM> in order to open the outlet of the valve <NUM> to selectively release gaseous fuel. An arm spring <NUM> is placed underneath the biased pivotal arm <NUM>. The arm spring <NUM> allows maintaining the jet <NUM> in the closed position. Moreover, the pocket lighter <NUM> comprises a cover <NUM>. The cover <NUM> is usually provided for limiting the access of the ignition of the pocket lighter. In the present embodiment, the cover <NUM> comprises several abutments <NUM>. The abutments <NUM> cooperates with parts of the sub-unit assembly <NUM> in order to snap-fit the sub-unit assembly <NUM> and the pocket lighter <NUM> together. In addition, a cylindrical seal <NUM> is placed above the jet <NUM>. The cylindrical seal <NUM> provides the gaseous seal between the upper end <NUM> of the jet <NUM> when lifted by the pivotal arm <NUM> and the lower portion of the sub-unit assembly <NUM>, the top of the jet <NUM> being in electrical contact with the lower end <NUM> of the helical spring <NUM>.

As depicted in <FIG>, the sub-unit assembly <NUM> comprises a rigid support <NUM>, a helical spring <NUM> and an extended wand <NUM>. The extended wand <NUM> extends along the longitudinal axis X. The length L3 of the sub-unit assembly <NUM> along the longitudinal axis X and extending outside the pocket lighter <NUM> is comprised between <NUM>,<NUM> and <NUM>. More precisely, the length L3 of the sub-unit assembly <NUM> is approximately <NUM>,<NUM>. When the sub-unit assembly <NUM> is mounted on the pocket lighter <NUM>, the extended wand has a free end 42E. The free end 42E extends away from the pocket lighter <NUM>. <FIG> shows the rigid support <NUM> without the others elements of the sub-unit assembly <NUM>. The rigid support <NUM> comprises a plastic material, and thus does not have electrical conductive properties.

As it can be seen in <FIG>, <FIG> and <FIG>, the rigid support <NUM> is mounted inside the extended wand <NUM>. When the sub-unit assembly <NUM> is mounted on the pocket lighter <NUM>, the rigid support <NUM> has a free end 44E, extending away from the pocket lighter <NUM>. The free end 44E of the rigid support <NUM> is located on the same side of the free end 42E of the extended wand <NUM> along the longitudinal axis X. An inner space <NUM> is kept free between the free end 44E of the rigid support <NUM> and the free end 42E of the extended wand <NUM>. As depicted in <FIG>, the inner space <NUM> is located inside the extended wand <NUM>, but outside the rigid support <NUM>.

A protrusion <NUM> is provided on the external surface of the rigid support <NUM>. This protrusion <NUM> cooperates with a recess <NUM> of the extended wand <NUM>. The cooperation of these two elements helds the rigid support <NUM> in position inside the extended wand <NUM>. The rigid support <NUM> is further provided with a first notch <NUM> and a second notch <NUM>. The first notch <NUM> and the second notch <NUM> allow to assemble the sub-unit assembly <NUM> to the pocket lighter <NUM>. Thus, the connection of the sub-unit assembly <NUM> to the pocket lighter <NUM> is possible by corresponding abutment <NUM>. The first notch <NUM>, the second notch <NUM> and the abutments <NUM> are snap-fitted together. When snap-fitted, this connection is not removable. The rigid support <NUM> comprises also a longitudinal inner opening <NUM>. The longitudinal inner opening <NUM> extends along the longitudinal axis X and allows the helical spring <NUM> to pass inside. Thus the helical spring <NUM> traverses from side to side the rigid support <NUM> through the longitudinal inner opening <NUM>. The helical spring <NUM> is guided and maintained inside the extended wand <NUM> by the rigid support <NUM>.

A shown in <FIG>, the helical spring <NUM> has a length L4, taken along the longitudinal axis X, comprised between <NUM> and <NUM>. More preferably, the length L4 of the helical spring <NUM> is of <NUM>. The outer diameter D46 of the helical spring <NUM> is comprised between <NUM>,<NUM> and <NUM>. For example, the outer diameter D46 is of <NUM>.

Actually, as shown in <FIG>, when the sub-unit assembly <NUM> is assembled on the pocket lighter <NUM>, the rigid support <NUM> protrudes outside the pocket lighter <NUM> and along the longitudinal axis X at a length L5. The length L5 is thus measured between the free end 44E of the rigid support <NUM> and a contact line <NUM> between the sub-unit assembly <NUM> and the cover <NUM>. The length L5 can be comprised between <NUM> and <NUM>. For instance, the length L5 is of <NUM>,<NUM>. In addition, still when the sub-unit assembly <NUM> is assembled on the pocket lighter <NUM>, the helical spring <NUM> protrudes to a length L6 outside the pocket lighter <NUM> and along the longitudinal axis X. The length L6 is thus measured between a free end 46E of the helical spring <NUM> and the free end 44E of the rigid support <NUM>. The length L6 can be comprised between <NUM> and <NUM>. For instance, the length L6 is of <NUM>. Therefore, we can understand that the free end 46E of the helical spring <NUM> is located inside the extended wand <NUM>, but outside the free end 44E of the rigid support <NUM>.

Besides, when assembled together, the helical spring <NUM>, the rigid support <NUM> and the extended wand <NUM> extend concentrically around the longitudinal axis X, outside the pocket lighter <NUM>. The arrangement being such that the helical spring <NUM> is the closest element from the longitudinal axis X, the extended wand <NUM> being the furthest element from the longitudinal axis X, and the rigid support <NUM> being located concentrically between the extended wand <NUM> and the helical spring <NUM>. Therefore, as depicted in <FIG>, the outer diameter D46 of the helical spring <NUM> is smaller than the outer diameter D42 of the extended wand <NUM>, and the outer diameter D44 of the rigid support <NUM> is comprised between the outer diameter D42 of the extended wand <NUM> and the outer diameter D46 of the helical spring <NUM>. For example:.

Coming back to <FIG>, the helical spring <NUM> comprises three portions along its length: a first end portion <NUM>, a middle portion <NUM> and a second end portion <NUM>. The first end portion <NUM> is provided to cooperate with the jet <NUM>. The middle portion <NUM> is provided to be received in the longitudinal inner opening <NUM> of the rigid support <NUM>. The top portion <NUM> is provided to protrude in the inner space <NUM> of the length L6 when the long helical spring <NUM> is assembled in the sub-unit assembly <NUM>. In such a configuration, the helical spring <NUM> has a free end 46E which corresponds to the end of the top portion <NUM>. Thus, as shown for example in <FIG>, the free end 46E of the helical spring <NUM> is located on the same side of the free ends 42E and 44E of the extended wand <NUM> and the rigid support <NUM>. In addition, the free end 46E of the helical spring <NUM> is located inside the extended wand <NUM>, but outside the free end 44E of the rigid support <NUM>.

The pitch of the three portions <NUM>, <NUM>, <NUM> of the helical spring <NUM> is comprised between <NUM>,<NUM> and <NUM>,<NUM>. The pitch of the middle portion <NUM> can be comprised between <NUM>,<NUM> and <NUM>,<NUM>. For example, the pitch of the middle portion <NUM> is <NUM>,<NUM>. The pitch of the first end portion <NUM> is comprised between <NUM>,<NUM> and <NUM>,<NUM>. The pitch of the second end portion <NUM> is comprised between <NUM>,<NUM> and <NUM>,<NUM>. Regarding the entire helical spring <NUM>, the pitch of the middle portion <NUM> is always smaller than the pitch of the first end portion <NUM> and the pitch of the second end portion <NUM>. Actually, the coils of the middle portion <NUM> are dead coils. In other words, the coils of the middle portion <NUM> are jointive whereas coils of the first end portion <NUM> and the second end portion <NUM> are not jointive. Such dimensioning has the following interesting features. In the area of the first end portion <NUM>, the pitch is dimensioned such that the first end portion <NUM> easily contacts the upper end <NUM> of the jet <NUM>. Indeed, the coils of the first end portion <NUM> are not jointive. The helical spring <NUM> can therefore be compressed in the first end portion <NUM>. Thus, the helical spring <NUM> contacts the upper end <NUM> of the jet <NUM> in being in compression, which guarantees a suitable contact between these two members. In the area of the second end portion <NUM>, the pitch is dimensioned in order to suitably diffuse the gas in the air and thus in order to create an easily flammable mixture of air and gas in the inner space <NUM>. In others words, the second end portion <NUM> of the helical spring <NUM> is the gas diffuser of the utility lighter. Consequently, the helical spring <NUM> according the invention fulfills the function of diffuser for the utility lighter <NUM>. In the area of the middle portion <NUM>, the coils of the helical spring <NUM> delimit an inner duct <NUM>. The inner duct <NUM> extends concentrically along the longitudinal axis X. The pitch of the helical spring <NUM> in the area of the middle portion <NUM> is so small that the gas cannot easily go through the coils. The gas is thus confined inside the helical spring <NUM> and thus inside the inner duct <NUM>. Therefore, the helical spring <NUM> according to the invention fulfills a function of gas duct for the utility lighter <NUM>. In addition, the coils being jointive in the middle portion <NUM>, they create a rigid portion which facilitates the insertion of the helical spring <NUM> in the rigid support <NUM> during the assembly.

Actually, according to one embodiment of the present invention, the pitches of the first end portion <NUM> and the second end portion <NUM> are identical. Therefore, the helical spring is symmetrical with respect to a perpendicular axis S through its middle along its length L4. The pitch of the first end portion <NUM> is similar to the pitch of the second end portion <NUM> in order to insert the helical spring <NUM> in any longitudinal direction inside the longitudinal inner opening <NUM> during the assembly of the sub-unit assembly <NUM>. Any free end of the helical spring <NUM> can thus be inserted at first inside the longitudinal inner opening <NUM>. Consequently, this feature facilitates the assembly of the sub-unit assembly <NUM> by avoiding a step of differentiation between the first end portion <NUM> and the second end portion <NUM>. According to another embodiment of the present invention, the pitches of the first end portion <NUM> and the second end portion <NUM> are not identical. However, in such a configuration, the pitch of the middle portion <NUM> is still smaller than the pitch of the first end portion <NUM> and the pitch of the second end portion <NUM>.

As better shown in <FIG>, the sub-unit assembly comprises the extended wand <NUM>. The extended wand <NUM> has a general cylinder shape, which extends along the longitudinal axis X. The extended wand <NUM> comprises an aperture <NUM> at its upper end. The upper end of the extended wand <NUM> corresponds to its free end 42E when the sub-unit assembly <NUM> is assembled with the pocket lighter <NUM> to form the utility lighter <NUM>, as illustrated in <FIG> and <FIG>. The flame escapes from this aperture <NUM>. The extended wand <NUM> further comprises at its lower end <NUM>, opposite to the free end 42E, an extension <NUM>. This extension <NUM> has a general shape of a tongue, and has a free end 48E. The length L7 of the extension <NUM> along the longitudinal axis X is measured between the lower end <NUM> of the extended wand <NUM> and the free end 48E of the extension <NUM>. The length L7 of the extension <NUM> can be comprised between <NUM> and <NUM>. For instance, the length L7 is of <NUM>,<NUM>. During the actuating downwards of the pusher <NUM>, the extension <NUM> allows for contact of the extended wand <NUM> with the electrode spring <NUM>. The electrical potential created at the second pole <NUM> is therefore transmitted to the extended wand <NUM> through the extension <NUM>. In other words, the electrode spring <NUM> is connected to the sub-unit assembly <NUM> by means of the extension <NUM>. The extended wand <NUM> also comprises an antenna <NUM>. The antenna <NUM> protrudes forwards the inner space <NUM>. The antenna <NUM> has a general triangular shape when viewed from the face. The antenna <NUM> comprises a base <NUM> and a tip <NUM>. The distance D5 between the tip <NUM> and the free end of the helical spring <NUM> is favorable for the apparition of the electrical arc, which results of the potential difference created by the piezoelectric ignition device <NUM>. For example, as illustrated in <FIG>, the distance D5 between the tip <NUM> and the free end of the helical spring <NUM> is comprised between <NUM>,<NUM> and <NUM>. The electrical arc is thus created in an interelectrode space which is located in the inner space <NUM>. When the arc electric created between the tip end <NUM> of the antenna <NUM> and the free end of the helical spring <NUM> (i. the end of the top portion <NUM>) meets the mixture of gas and air, a flame is so created. As a result, the flame escape from the utility lighter <NUM> through the aperture <NUM>, located at the free end 42E of the extended wand <NUM>.

The sub-unit assembly <NUM> thus assembled is rigid. Especially, the sub-unit assembly <NUM> is rigid enough to not bent and to keep a straight and elongated shape during the assembly between the sub-unit assembly <NUM> and the pocket lighter <NUM>. The feature is made possible partly thanks to the rigid support <NUM> and the extended wand <NUM>.

When the sub-unit assembly <NUM> and the pocket lighter are connected together, the ignition of a flame is as follow. A user pushes downwards the pusher <NUM>. The piezoelectric ignition device <NUM> is thus actuated and creates a first electric potential on the electrode spring <NUM> and a second electric potential on the biased pivotal arm <NUM>. The extension <NUM> contacting the electrode spring <NUM>, the first electric potential is then transmitted to the extension <NUM>. Because of the electrical conductive properties of the extended wand <NUM>, the first electric potential is conducted along the extended wand, and especially until the tip <NUM> of the antenna <NUM>. When the pusher <NUM> is pushed downwards, the biased pivotal arm <NUM> contacts the piezoelectric ignition device <NUM>. The second electric potential is thus transmitted to the biased pivotal arm <NUM>. Then, the second electric potential is transmitted to the jet <NUM>. The second electric potential is therefore transmitted to the helical spring <NUM> through the upper end <NUM> of the jet <NUM>. The helical spring <NUM> of the present invention fulfills therefore a function of electrical conductor. The first electric potential and the second electric potential create therefore a potential difference which is favorable to the creation of an electrical arc in the interelectrode space. However, despite the electrical properties of the extended wand <NUM>, there is no risk of electric shock for a user, since the first pole <NUM> is surrounded by the body <NUM> of the pocket lighter <NUM>. The body <NUM> being made of a non-electrical conductive material, the user cannot therefore touch the first pole <NUM>. In the meantime, when the pusher <NUM> is pushed downwards, it actuates the biased pivotal arm <NUM> which raises the jet <NUM>. The jet <NUM> releases the valve <NUM>. As a result the gas is released from the reservoir <NUM> and through the jet <NUM> and the helical spring <NUM> until the second end portion <NUM> of the helical spring <NUM>. The mixture of gas and air thus created in the inner space <NUM> then catches fire should it meets the electrical arc.

<FIG>, <FIG>, <FIG> and <FIG> illustrate a second embodiment of a utility lighter <NUM> according to the invention. In this second embodiment, the rigid support <NUM> and the cover <NUM> are formed in a sole molded piece <NUM>. This molded piece <NUM>, shown in <FIG>, is molded in an electrically insulating thermoplastic resin. The sub-unit assembly <NUM>, according to this second embodiment, thus comprises also the cover <NUM>. Such a molded piece <NUM> has the advantage of reducing the number of pieces required, since the cover <NUM> and the rigid support <NUM> are the same piece. In addition, there is no more need for abutments <NUM> and second notch <NUM>, since the rigid support <NUM> and the cover <NUM> are already assembled together. Furthermore, such an embodiment improves the insulation of the electrical circuit by avoiding short-circuit through the cover <NUM>. Indeed, the cover <NUM>, usually metallic, could create a failure in the ignition. When the cover is made of an electrically insulating thermoplastic resin, there is no more risk of any short-circuit. Besides, this feature protects the user of a possible electrical discharge in his fingers.

The molded piece <NUM> comprises two protrusions <NUM>, which allows it to be snap-fitted to the body <NUM> of the pocket lighter <NUM>. When snap-fitted, this connection between the molded piece <NUM> and the body <NUM> is not removable. <FIG> illustrates only one protrusion <NUM>, the other protrusion <NUM> being hidden by the cover.

Claim 1:
A flame producing assembly comprising a pocket lighter (<NUM>) and a sub-unit assembly (<NUM>) comprising an extended wand (<NUM>), a rigid support (<NUM>), a helical spring (<NUM>), the pocket lighter (<NUM>) being connected directly to the sub-unit assembly (<NUM>), the pocket lighter (<NUM>) comprising a piezoelectric ignition device (<NUM>),
the rigid support (<NUM>) being located inside the extended wand (<NUM>),
the rigid support (<NUM>) having a longitudinal inner opening (<NUM>),
the extended wand (<NUM>) being electrically coupled to the piezoelectric ignition device (<NUM>), and
wherein the helical spring (<NUM>) extends along the longitudinal inner opening (<NUM>) and has a first end portion (<NUM>) a middle portion (<NUM>) and a second end portion (<NUM>),
characterized in that at least a portion of the helical spring (<NUM>) being located in the longitudinal inner opening (<NUM>) has a pitch smaller than the pitch of the second end portion (<NUM>).