HK1081328B - Piezoelectric ignition mechanism - Google Patents

Description

Piezoelectric ignition mechanism

Technical Field

The present invention relates generally to ignition mechanisms and devices incorporating ignition mechanisms, such as lighters (or igniters), including pocket lighters and extension-wand-type lighters, both disposable and non-disposable lighters. More particularly, the present invention relates to piezoelectric ignition mechanisms and piezoelectric lighters, including in particular ignition mechanisms and lighters that provide increased resistance to operation.

Background

Disposable gas lighters are available in many forms. Typically, one common component of disposable lighters is a fuel release lever, which is used to generate a stream of fuel. The fuel release lever is typically operated in conjunction with a spark generating mechanism to ignite the fuel flow shortly after it begins. For example, one type of lighter requires the user to rotate a toothed spark wheel against a flint in order to generate a spark, while simultaneously releasing gas and producing a flame by depressing, or immediately thereafter, depressing, a fuel release lever.

Other ignition devices 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 generate an electric spark. A spark is generated at the fuel outlet or nozzle, igniting the gaseous fuel. Under the user's forced downward pressure, the fuel release lever typically initiates fuel flow and subsequently the ignition process. One example of such a Piezoelectric ignition Mechanism is disclosed in U.S. patent No.5262697 entitled "Piezoelectric Mechanism For Gas Lighter" (piezo electric Mechanism For Gas Lighter).

Some measures have been introduced to make lighter actuation difficult. One typical method employed is in conjunction with a latch member that prevents downward depression of the fuel release lever. In U.S. patent nos. 5435719; 5584682 and 5636979, examples of such mechanisms are given. Another example of a piezoelectric lighter that provides greater resistance to operation is disclosed in U.S. patent No. 5854530. The' 530 patent describes a piezoelectric ignition mechanism having a telescoping assembly with inner and outer pieces separated by a return spring. The return spring biases the inner and outer pieces apart and the user must press the inner and outer pieces downward toward each other in order to activate the ignition mechanism. The device of the' 530 patent also includes a resistance spring that provides additional resistance to movement of the inner and outer members toward each other in order to provide greater resistance to operation.

However, there remains a need for an ignition device that provides greater resistance to operation and also improves user friendliness and minimizes the number of parts required.

Disclosure of Invention

The present invention relates to a piezoelectric ignition mechanism that provides greater resistance to operation, and lighters, including pocket and extension-wand type lighters, incorporating the ignition mechanism. In one embodiment, a piezoelectric ignition mechanism includes first and second body members, a piezoelectric element, a plexor member, and an engagement portion coupled to the body members. When the body member is in the first position, the plexor member is releasably retained a distance from the piezoelectric element and is released to drive it into impact with the piezoelectric element upon movement of the body member toward the second position. The engagement portion may be configured and dimensioned to provide resistance to movement of the body members toward the second position.

According to one embodiment, one of the body members may define a retaining surface for releasably retaining the plexor member at a distance from the piezoelectric element, and the engagement portions may resist release of the plexor member from the retaining surface. For example, the plexor member may form at least one lug portion, and the engagement surface may resist release of the lug portion from the retaining surface.

Additionally or alternatively, one of the body members may define a ramp configured and dimensioned to contact the lug portion and release the lug portion from the retaining surface upon movement of the first and second body members toward the second position, and the engagement portion may be disposed on the ramp.

The piezoelectric ignition mechanism of the present invention may be used, for example, to generate a spark in a lighter, such as a pocket lighter or utility lighter, having a nozzle disposed at one end of an extended rod. However, other applications and implementations of the piezoelectric ignition mechanism are within the scope of the present invention.

Drawings

In order to facilitate an understanding of the nature, construction and operation of the invention, a preferred feature thereof will be described in the following discussion, wherein like reference numerals represent like parts throughout the several views of the embodiments, and wherein:

FIG. 1 is a front elevational view of a first embodiment of the 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;

FIG. 3 is a front elevational view of a portion (shown in phantom) of the end piece and first body piece of the ignition mechanism of FIG. 1;

FIG. 4 is a front view of a plexor member (or plexormerber) of the firing mechanism of FIG. 1;

FIG. 5 is a side view of the plexor member of FIG. 4;

FIG. 6 is a perspective view of a second body member of the ignition mechanism of FIG. 1;

FIG. 6A is a detail view of the retaining surface and engaging portion of the second body member of FIG. 6;

FIG. 7 is a side view of the first body member of the ignition mechanism of FIG. 1;

FIG. 7A is a side view of a wall portion of an alternate embodiment of the first body member of FIG. 7;

FIG. 8 is a side elevational view of an alternative embodiment of the first body member of FIG. 1 with an engagement portion formed on the lower ramp surface;

FIG. 9 is a front view of the ignition mechanism of FIG. 1 in a partially compressed position;

FIG. 10 is a partial cross-sectional view of FIG. 9;

FIG. 11 is a front elevational view of the ignition mechanism of FIG. 1 in a second or released position;

FIG. 12 is a partial cross-sectional view of FIG. 11;

fig. 13 is a front partial cross-sectional view of the piezoelectric ignition mechanism of fig. 1 incorporated into a lighter assembly, showing the ignition mechanism in a first position;

FIG. 14 is a forward partially exploded view of the second embodiment of the piezoelectric ignition mechanism; and

fig. 14A is a side view of a wall portion of an alternative embodiment of the first body member of the ignition mechanism of fig. 14.

Detailed Description

Referring to the drawings, wherein like reference numerals are used to refer to like components, 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 present invention, FIG. 1 shows one embodiment of a piezoelectric ignition mechanism 10 in accordance with the present invention. The ignition mechanism 10 includes first and second members 12, 14, respectively, that are configured and dimensioned to move, or preferably slide, relative to each other along a 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. However, those skilled in the art will know and appreciate that any number of geometric configurations may be used to effect movement between first and second members 12, 14. Those skilled in the art will also know and appreciate that first and second members 12, 14 are not limited to movement along longitudinal axis 18, but may move relative to each other along any axis. In addition, the first and second members 12, 14 may rotate or pivot relative to one another, e.g., about the longitudinal axis 18.

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

A piezoelectric element 24 and an optional impact pad 26 may be associated with the first and second members 12, 14. For example, as shown in FIG. 2, an anvil member 22 may be mounted to one end of second member 14 and retain piezoelectric element 24 and impact pad 26 within second member 14. Anvil member 22 is preferably attached to second member 14 by cooperating projections and recesses, but may alternatively or additionally be attached by other attachment means such as screws, cooperating threads, pins, welding or adhesive. Alternatively, anvil member 22 and second member 14 may be formed (e.g., by insert molding) as a single piece around piezoelectric element 24 and optional impact pad 26. Preferably, the impact pad 26 is disposed adjacent the piezoelectric element 24 and transfers impact energy from the impact pad 26 directly to the piezoelectric element 24. Thus, anvil member 22, piezoelectric element 24, and impact pad 26 are all part of a circuit and cooperate to generate a spark when a plexor member 28 is struck against impact pad 26 with sufficient force, as will be discussed in greater detail below. Those skilled in the art will know and appreciate that impact pad 26 is optional and that plexor member 28 may alternatively be used to directly slap piezoelectric element 24.

As shown in fig. 2 and 3, an end piece 32 may be provided at one end of first member 12 and may have hooks 54 provided on opposite sides thereof that engage openings 58 (shown in fig. 1) in first member 12 to retain end piece 32 on first member 12. Other fastening means known in the art such as gluing, welding, screwing, pinning for retaining the end member 32 to the first member 12, or the end member 32 may be integral with the first member 12. As shown in FIG. 3, the end piece 32 may be provided with a boss 48 and/or a protrusion 46 to retain one end of the impact spring 30, as will be discussed in more detail below.

Still referring to FIG. 2, a plexor member 28 (shown partially in phantom) is associated with first and second members 12, 14, and preferably plexor member 28 is disposed within second member 14. Plexor member 28 is movable longitudinally along longitudinal axis 18 within a hollow passage 35 of second member 14. An impact spring 30 is associated with first and second members 12 and plexor member 28 and biases plexor member 28 in the direction of impact pad 26 and piezoelectric element 24. As shown in FIG. 2, spring 30 is preferably seated on one end of boss 48 of end member 32, and plexor member 28 is attached to the other end of impact spring 30.

Referring to FIGS. 4 and 5, plexor member 28 may be generally cylindrical with a blunt end and may have two lug portions 34 on opposite sides thereof. Lug portion 34 may be formed integrally with plexor member 28 or alternatively may be formed separately from plexor member 28 and attached to plexor member 28. According to an alternative embodiment, lug portion 34 is formed by a cylindrical rod having ends that extend outwardly through a bore formed through plexor member 28. Plexor member 28 is not limited to the shape shown and may have any overall shape that permits it to move within first and second members 12, 14.

As shown in fig. 6, a track 36 may be associated with one of the body members. Rails 36 are sized and configured to receive lug portions 34 and guide the movement of plexor member 28 along longitudinal axis 18. Retaining surface 38 may also be associated with one of the body members. In the illustrated embodiment, a retaining surface is formed on second member 14 and is sized and configured to retain ledge portion 34 and substantially prevent plexor member 28 from moving toward piezoelectric element 24. In the illustrative embodiment shown in fig. 6, the tracks 36 are elongate grooves formed in the side walls of the second member 14 and the retaining surfaces 38 are formed by indentations located adjacent to the elongate grooves, however, other configurations are possible. For example, the retaining surface 38 may alternatively be formed by a shelf or ledge formed by increasing the width of the track 36.

As shown in fig. 7, an upper ramp 42 and a lower ramp 44 may be formed on one of the body members. Alternatively, first side surface 41 and second side surface 43 may be formed on one of the body members. In the illustrative embodiment shown, upper and lower ramp surfaces 42, 44 and first and second side surfaces 41, 43 are formed in each side of first member 12. Lug portion 34 is configured and dimensioned to project beyond track 36 and/or retaining surface 38 and contact upper and lower ramp surfaces 42, 44, and optionally first and second side surfaces 41, 43. As shown in the embodiment of fig. 7, upper and lower ramp surfaces 42, 44 and first and second side surfaces 41, 43 may be formed by the edges of an aperture extending completely through the side walls of first member 12. These surfaces may alternatively be formed by grooves or indentations formed in the side walls of first member 12, as shown in fig. 7A. Further, those skilled in the art will know and appreciate that any number of configurations may be implemented in order to provide the upper and lower inclined surfaces 42, 44 and the first and second side surfaces 41, 43.

Referring back to fig. 6, the retention surface 38 may be configured and dimensioned to prevent the lug portion 34 from being released from the retention surface 38 and into the track 36. As shown in fig. 6 and 6A, the retaining surface 38 may be provided with an engaging portion 39 that is bent to conform to the shape of the lug 34 or to partially surround the lug 34 and, as a result, act on the lug 34 to retain it on the retaining surface 38. Those skilled in the art will know and appreciate that the engagement portion 39 is not limited to the shapes shown and described, and may have any number of shapes suitable to resist release of the lug portion 34 from the retaining surface 38. For example, the engagement portion 39 may alternatively be ramp shaped, notched, or toothed, or any other shape known to those skilled in the art to inhibit release of the lug portion 34 from the retaining surface 38. The engagement portion 39 may be resilient, or it may be rigid. Additionally or alternatively, the engagement portion 39 may include a saw tooth shaped member 39A formed on the retention surface 38 or adjacent the retention surface 38, or a resilient latch or a bump formed on the retention surface 38 or adjacent the retention surface 38 to further resist release of the lug portion 34. Those skilled in the art will also appreciate that the engagement portion 39 and/or member 39A is not limited to the positions shown and described, but may be provided on the lower ramp 44 as shown in fig. 8. In fact, engagement portion 39 and/or member 39A may be disposed anywhere on ignition mechanism 10 (or any portion of an assembly in which ignition mechanism 10 is incorporated) where engagement portion 39 and/or member 39A provides a resistance that resists release of lug portion 34 from retaining surface 38.

When the ignition mechanism 10 is in the first or rest position shown in fig. 1 and 2, the return spring 16 biases the first and second members 12, 14 apart. Likewise, impact spring 30 biases plexor member 28 upwardly such that lugs 34 contact upper ramp surfaces 42. Because upper ramp 42 is inclined, the interaction between lug portion 34 and upper ramp 42 causes lug portion 34, and thus plexor member 28, to rotate such that lug portion 34 rotates to the left and biases lug portion 34 against retaining surface 38. The ledge portion 34 thus holds the plexor member 28 a distance X' from the impact pad 26 and partially compresses the impact spring 30.

To operate the ignition mechanism 10, a user first compresses the first and second members 12, 14 toward each other a predetermined distance, overcoming the force of the return spring 16 and the impact spring 30, until the ledge portion 34 first contacts the lower ramp 44. At or near this position, as shown in fig. 9 and 10, the interaction between lug portion 34 and lower ramp 44 causes lug portion 34 to rotate away from retaining surface 38 and into track 36. The amount of force required to further compress the first and second members 12, 14 together is abruptly increased due to the interaction between the lug portions 34 and the engagement portions 39. More specifically, further compression of first and second members 12, 14 pushes lug portion 34 down along lower ramp 44, thereby rotating lug portion 34 away from retaining surface 38. However, the engagement portion 39 will prevent the lug portion 34 from rotating away from the retaining surface 38. Thus, to continue to compress the first and second members 12, 14 toward the second position, the user must increase the force sufficient to overcome the continuing resistance of the return spring 16 and impact spring 30, and to overcome the additional resistance created by the interaction between the lug portions 34 and the engagement portions 39.

Continued downward pressure of the first and second members 12, 14 further compresses the return spring 16 and impact spring 30 and also pushes the lug portion 34 down the ramp 44, subject to the necessary additional force applied by the user. Once first and second members 12, 14 are moved to the second position, as shown in FIGS. 11 and 12, lower ramp 44 rotates plexor member 28 and lug portions 34 such that lug portions 34 are released from retaining surfaces 38. In this position, compressed impact spring 30 drives plexor member 28 toward impact pad 26 and strikes impact pad 26, thereby transferring the energy stored in impact spring 30 to piezoelectric element 24 and, as a result, causing piezoelectric element 24 to generate an electrical potential.

After plexor member 28 has struck impact pad 26 and pressure is removed from first and second members 12, 14, return spring 16 expands to separate first and second members 12, 14 from one another. Once lug portions 34 contact upper ramp 42, continued separation of first and second members 12, 14 under the action of return spring 16 causes lug portions 34 to move along upper ramp 42 until lug portions 34 once again rest on retaining surface 38. Once first and second members 12, 14 are sufficiently separated and lug portions 34 are positioned on retaining surfaces 38, ignition mechanism 10 is in the first or rest position discussed above and is ready for the next operation.

Engagement portion 39, as well as return spring 16 and/or impact spring 30, may be selectively configured to provide a desired increase in resistance to compression of first and second members 12, 14 to the second position. For example, return spring 16 and/or impact spring 30 may be configured (e.g., by changing their spring constants) to provide a first amount of resistance to movement of first and second members 12, 14 to the predetermined position shown in fig. 9 and 10, and engagement portion 39 may be configured (e.g., by changing their shape or material properties) to provide a second, greater amount of resistance to movement of first and second members 12, 14 to the second or release position shown in fig. 11 and 12.

Ignition mechanism 10 may be used to create a spark in a lighter. For example, the ignition mechanism may be included in the circuitry of a pocket lighter, such as the pocket lighter disclosed in U.S. patent No.5854530, the contents of which are expressly incorporated herein by reference. As shown in fig. 13, ignition mechanism 10 may be disposed within lighter body 60 and connected in an electrical circuit comprising first and second electrodes 62, 64. Thus, actuation of the ignition mechanism 10 generates an electrical potential that conducts through the circuit and creates a potential difference between the first and second electrodes 62, 64 sufficient to discharge a spark between the two electrodes. Ignition mechanism 10 may also be associated with a button 66 that operates a valve to release fuel from a nozzle 68. Thus, button 66 is depressed downwardly and simultaneously causes ignition mechanism 10 to operate to produce a spark and release fuel from the nozzle and ultimately produce a flame.

Ignition mechanism 10 may alternatively be included in the circuitry of a utility lighter of the stretch-stick type, such as the utility lighter disclosed in U.S. patent No.6086360, the contents of which are also expressly incorporated herein by reference. One skilled in the art will know and appreciate that the ignition mechanism 10 may be adapted to generate a spark in any type of lighter or other device, such as a stove or an outdoor barbecue grill.

Fig. 14 shows an alternative embodiment of a piezoelectric ignition mechanism at 100. The structure and operation of the ignition mechanism 100 is substantially similar to the embodiments described above, and only the differences will be described below. As shown, plexor member 128 and impact spring 130 are associated with second member 114, and piezoelectric element 124 is associated with first member 112. Upper and lower inclined surfaces 142, 144 and optionally first and second side surfaces 141, 143 are formed on second member 114. Formed on first member 112 are track 136, retaining surface 138 and optional engagement portion 139. As shown in fig. 14, track 136 and retaining surface 138 may be formed by an aperture extending completely through the wall of first member 112. As shown in fig. 14A, the track 136 and/or the retaining surface 138 may alternatively be formed by a groove or indentation formed in a sidewall of the first member 112. However, one skilled in the art will know and appreciate that any number of structures may be employed in order to provide 136 and the retaining surface 138.

While preferred embodiments and features of the ignition mechanism and lighters using the ignition mechanism have been disclosed herein, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art. It is intended that the claims not be limited to these preferred embodiments or features.

Claims (33)

1. A piezoelectric ignition mechanism comprising:

first and second body members movable relative to one another between a first position and a second position;

a piezoelectric element coupled to one of the body members;

a plexor member associated with one of the body members, the plexor member defining a lug portion; and

an engagement portion associated with one of the body members;

wherein in the first position the plexor member is releasably retained a distance from the piezoelectric element and is released and actuated to impact the piezoelectric element upon movement of the first and second body members toward the second position, and the engagement portions are configured and dimensioned to receive the lug portions of the plexor member and provide additional resistance to release of the plexor member from the received position upon movement of the first and second body members toward the second position.

2. The piezoelectric ignition mechanism of claim 1, wherein one of the body members defines a retaining surface for releasably retaining the plexor member at a distance from the piezoelectric element, and the engagement portions resist release of the plexor member from the retaining surface.

3. The piezoelectric ignition mechanism of claim 2, wherein the engagement portion is disposed on the retaining surface.

4. The piezoelectric ignition mechanism of claim 2, wherein:

the plexor member is rotatable relative to the first and second body members;

rotation of the plexor member relative to the first and second body members causes the lug portions to be released from the retaining surfaces; and is

The engagement portion is configured and dimensioned to prevent the lug portion from being released from the retention surface.

5. The piezoelectric ignition mechanism of claim 4, wherein the engagement portion includes a curved surface that at least partially surrounds the lug portion.

6. The piezoelectric ignition mechanism of claim 4, wherein the engagement portion comprises a saw-tooth shaped portion.

7. The piezoelectric ignition mechanism of claim 4, wherein the engagement portion is resilient.

8. The piezoelectric ignition mechanism of claim 2, wherein:

one of the body members forming a ramp;

the ramp being configured and dimensioned to contact the lug portion and release the lug portion from the retaining surface upon movement of the first and second body members toward the second position; and is

The engagement portion is located on the inclined surface.

9. The piezoelectric ignition mechanism of claim 8, wherein:

the plexor member is rotatable relative to the first and second body members;

rotation of the plexor member relative to the first and second body members causes the lug portions to be released from the retaining surfaces; and is

The engagement portion is configured and dimensioned to prevent the lug portion from being released from the retention surface.

10. The piezoelectric ignition mechanism of claim 9, wherein the engagement portion includes a curved surface that at least partially surrounds the lug portion.

11. The piezoelectric ignition mechanism of claim 9, wherein the engagement portion comprises a saw-tooth shaped portion.

12. The piezoelectric ignition mechanism of claim 9, wherein the engagement portion is resilient.

13. The piezoelectric ignition mechanism of claim 8, wherein one of the body members further defines a track adjacent the retaining surface and the lug slides in the track when the plexor member is driven toward the piezoelectric element with the lug portion released from the retaining surface.

14. The piezoelectric ignition mechanism of claim 1, further comprising a spring for biasing the plexor member toward the piezoelectric element.

15. The piezoelectric ignition mechanism of claim 1, for generating a spark in a lighter.

16. The piezoelectric ignition mechanism of claim 1, for generating a spark in a utility lighter having an extended stem and a gas outlet disposed at one end of the extended stem.

17. A piezoelectric ignition mechanism, comprising:

first and second body members movable relative to one another between a first position and a second position, wherein one of the body members forms a track and a retaining surface adjacent the track, the retaining surface having an engagement portion;

a piezoelectric element disposed on one of the body members; and

a plexor member resiliently biased toward the piezoelectric element, the plexor member having at least one lug portion;

wherein when the body members are in the first position, the lug portions are retained by the retaining surface and the plexor member is resiliently biased toward the piezoelectric element, and when the first and second body members are moved a predetermined distance toward the second position, the engagement portions are configured and dimensioned to releasably engage the at least one lug portion to provide resistance to release of the lug portion from the engagement portions.

18. The piezoelectric ignition mechanism of claim 17, wherein the lug portion cooperates with the engagement portion to resist movement of the body member toward the second position.

19. The piezoelectric ignition mechanism of claim 17, wherein the engagement portion includes a curved surface that at least partially surrounds the lug portion.

20. The piezoelectric ignition mechanism of claim 17, wherein the engagement portion comprises a saw-tooth shaped portion.

21. The piezoelectric ignition mechanism of claim 17, wherein the engagement portion is resilient.

22. The piezoelectric ignition mechanism of claim 17, further comprising a spring for biasing the plexor member toward the piezoelectric element.

23. The piezoelectric ignition mechanism of claim 17, for generating a spark in a lighter.

24. The use of a piezoelectric ignition mechanism according to claim 17 for generating a spark in a utility lighter having an extended stem and a gas outlet disposed at one end of the extended stem.

25. A piezoelectric ignition mechanism comprising:

first and second body members movable relative to one another between a first position and a second position, wherein one body member forms a track and a retaining surface adjacent the track and the other body member forms an engagement portion;

a piezoelectric element disposed on one of the body members; and

a plexor member resiliently biased toward the piezoelectric element, the plexor member having at least one lug portion;

wherein when the body members are in the first position, the lug portions are retained by the retaining surface and the plexor member is resiliently biased toward the piezoelectric element, and when the first and second body members are moved a predetermined distance toward the second position, the engagement portions are configured and dimensioned to releasably engage the at least one lug portion to provide resistance to release of the lug portion from the engagement portions.

26. The piezoelectric ignition mechanism of claim 25, wherein the lug portion cooperates with the engagement portion to resist movement of the body member toward the second position.

27. The piezoelectric ignition mechanism of claim 25, wherein the other body member defines a ramp for releasing the lug portion from the retaining surface, and the engagement portion is disposed on the ramp.

28. The piezoelectric ignition mechanism of claim 25, wherein the engagement portion includes a curved surface that at least partially surrounds the lug portion.

29. The piezoelectric ignition mechanism of claim 25, wherein the engagement portion comprises a saw-tooth shaped portion.

30. The piezoelectric ignition mechanism of claim 25, wherein the engagement portion is resilient.

31. The piezoelectric ignition mechanism of claim 25, further comprising a spring for biasing the plexor member toward the piezoelectric element.

32. The piezoelectric ignition mechanism of claim 25, for generating a spark in a lighter.

33. The piezoelectric ignition mechanism of claim 25, for generating a spark in a utility lighter having an extended stem and a gas outlet disposed at one end of the extended stem.