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(11) | EP 1 486 731 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Hand held lighter with safety device |
| (57) The present invention provides a hand held lighter 1 comprising a fuel container
3, a fuel valve 4 for allowing fuel to be fed to an ignition point 12, and a piezoelectric
ignition means 5 for igniting fuel fed to the ignition point. The fuel valve 4 and
the ignition means 5 are operable by an operating body 6, 7 which is movable from
a rest position in a first direction. A safety button 8 is provided which is movable
at right angles to the first direction from a first, safety position in which the
safety button blocks movement of the operating body, and a second, operating position
in which the safety button allows movement of the operating body 7. In use, a user
must move the safety button 8 from the first position to the second position to operate
the operating body 7. When the operating body 7 is returned to its rest position,
the safety button 8 is automatically returned to its first position. A second embodiment is disclosed in which a piezoelectric ignition mean 27 is provided for creating a spark at an ignition point 25 supplied with fuel by a fuel valve assembly 24, the fuel valve assembly 24 and the piezoelectric ignition means 27 being jointly operated by an operating body 29. The safety body 34 is provided, lying over the operating body 29. A safety body 34 has to be moved to the left, in the direction of arrow X to disengage an abutment 36 from the stop part 38 of the hand held lighter before the lighter can be used. The resilience of the safety body 34 returns it to its safety position after the lighter has been used. |
[0001] The present invention relates to a hand held lighter of the type which is operated by a piezoelectric ignition means. Hand held lighters having piezoelectric ignition means are well known in the art and typically comprise a fuel container, a fuel valve for allowing fuel to be fed to an ignition point, a piezoelectric ignition means and means for operating the piezoelectric ignition means and the fuel valve, typically simultaneously.
[0002] The piezoelectric ignition means typically comprises a mechanism including a striker for delivering a blow to a piezoelectric crystal to generate an electric charge which is used to create a spark to ignite the fuel. Such systems are very well known in the art.
[0003] It has been desired for a number of years to provide a safety feature with such hand held lighters to prevent accidental operation or operation by children.
[0004] It is known in the art to provide an ON/OFF switch which is switched by the user between an ON position which allows operation of the lighter and an OFF position which prevents operation of the lighter. However, this system is found to be inconvenient as the user must remember to switch it on when using the lighter. Further, if the user forgets to switch the switch off, it remains possible to operate the lighter accidentally. The lighter is accordingly not safe, particularly where there is a danger that children can play with it.
[0005] The present inventor has set out to provide a hand held lighter with a safety feature which prevents accidental use of the lighter or operation of the lighter by children, which is easy to use by adults and secure.
[0006] The present inventor has realised that it is desirable to provide a hand held lighter which has a safety "OFF" configuration in which it cannot be used and an operating "ON" configuration, in which it can be used, with a safety device which automatically returns the lighter to the OFF condition immediately after use.
[0007] Accordingly, the present invention provides a hand held lighter comprising a fuel container, a fuel valve for allowing fuel to be fed to an ignition point, a piezoelectric ignition means, for igniting fuel fed to the ignition point, wherein the fuel valve, the piezoelectric ignition means or both of them are operable by an operating body which is movable in a first direction from a rest position, a safety body being provided movable in a second direction which lies at an angle to the first direction from a first, safety operating position in which the safety body blocks movement of the operating body, and a second, operating position in which the safety body allows movement of the operating body, whereby, in use, a user must move the safety body from the first position to the second position to operate the operating body, and whereby when the operating body is returned to its rest position, the safety body is returned to its first position.
[0008] By providing a safety body which is returned to its first, safety or non-operating position when the operating body is returned by a user to its rest position, the safety body automatically reapplies itself after use of the hand held lighter.
[0010] The fuel container, fuel valve, piezoelectric ignition means and operating body may be of any suitable design. Each may be of a design which is known in the art. For example, the hand held lighter may be of the type which has a main body which is holdable in the hand of the user and an ignition point at the end of a longitudinally extending tube so that the user can light an object which is at a distance from the user's hand. The main body may comprise a "trigger" formation with the operating body inside a trigger guard to further prevent accidental operation. In an alternative embodiment, the hand held lighter is in the form of a cigarette lighter, being relatively small and operable with one hand. In this case, the ignition point is located relatively close to the fuel container and valve, being preferably contained within a shield which prevents air draughts blowing the flame out.
[0011] The means for operating the piezoelectric ignition means may be of any suitable design, for example of the type which comprises a hammer for striking the piezoelectric trigger element. The operating body may operate the hammer via a lever or the hammer may be operated by the operating body directly.
[0012] In a particularly preferred embodiment, a single operating body operates both the means for operating the fuel valve and the means for operating the piezoelectric ignition means.
[0013] Suitably, the operating body is movable in a substantially longitudinal direction. Alternatively, it may be pivoted so that it moves in circumferential direction. In the latter case, the second direction, in which the safety body moves, should be at an angle to the direction of movement of the operating body at at least the first part of its motion and preferably at all parts of its motion. The angle between the first direction and second direction is suitably greater than at least 15° preferably greater than at least 30°, and most preferably greater than the 60°. Suitably, the second direction is substantially perpendicular to the first direction.
[0014] The safety body may prevent operation of the operating body in the first position by any suitable means. For example, it may comprise a part which extends into the path of motion of the operating body, when the safety body is in the first position.
[0015] Alternatively, the safety body may be permanently engaged with the operating body and movable with it and may comprise a part which abuts a stop formed on the lighter in the first position of the safety body.
[0016] In a first preferred embodiment, the safety body is incorporated within the operating body and movable with respect to it so that, in the first position, a part of the safety body projects from the operating body so that it engages with an abutment formed in the hand held lighter, whereby movement of the part of the safety body and hence movement of the operating body past the abutment are prevented in the first position. In this case, the safety body is movable in the first direction as well as the second direction.
[0017] In a second preferred embodiment, the safety body comprises a movable part which is engaged with the operating body and located above it so that the user can only operate the operating body through the safety body, a part of the safety body projecting so that it engages with an abutment formed in the hand held lighter, whereby movement of the safety body and the operating body past the abutment are prevented in the first position.
[0018] Suitably, the operating body is movable against the force of a resilient means, such as a leaf spring or coil spring, so that the operating body is returned to its rest position after the user releases the operating body.
[0019] The resilient means may be integral with the fuel valve or the piezoelectric ignition means, or both of them.
[0020] The resilient means may be separate from the safety body. In an alternative embodiment, the safety body itself comprises at least one resilient formation which urges the safety body into the first position. In a particularly preferred embodiment, the safety body comprises a first section for lying over the operating body so that the user can only operate the operating body through the safety body, the first part of the safety body extending in the second direction, the safety body comprising a second, resilient part which extends generally in the first direction and adjacent the operating body and engaged with mounting means whereby the resilient part of the safety body urges the safety body into the first position.
[0021] A third part of the safety body may project from the second part of the safety body, projecting generally in the second direction, for engagement with a stop member of the lighter for preventing operation of the safety body in the first position.
[0022] As noted above, the safety body may be positioned so that the operating body can only be operated through the safety body.
[0023] The safety body may be returned from the second position to the first position by any suitable means. For example, resilient means may be provided for biasing the safety body into the first position. In this way, if the user releases the safety body, the biasing means will tend to restore it to the first position. Preferably, means are provided so that, if the operating body is in its operating position, the safety body is not returned to its first position. This prevents the safety body locking the operating body in its operating position, which could be dangerous.
[0024] For example, in embodiments where the safety body is movable with the operating body, the safety body may be configured so that it can only engage the abutment or stop on the lighter when the operating body returns to its rest position.
[0025] In another embodiment, the operating body comprises an operating surface for engagement with a user's finger or thumb to operate the lighter, the safety body being mounted at a distance from the operating surface such that, for the normal size of adult digit, it will be possible to operate the safety body and the operating surface of the operating body, whereas it will be difficult for children to do so as their digits are smaller. For example, the distance between the operating surface and the safety body is preferably greater than 1 cm, preferably greater than 1.5cm and most preferably around 2cm.
[0026] The present invention will further be described by way of example only with reference to the accompanying drawing in which:
Figure 1 is a schematic cross sectional view through a first embodiment of hand held lighter according to the present invention.
Figure 2 is a cross sectional view, at enlarged scale, of a part of the hand held lighter of figure 1.
Figure 3 is a cross sectional view at enlarged scale of a part of the hand held lighter of figure 1, with the safety body in the operating position.
Figure 4 is a cross sectional view at enlarged scale, of a part of the hand held lighter of figure 1, with the operating body in the operating position.
Figure 5 is a cross sectional view, taken in the same plane as figure 1, of the safety body.
Figure 6 is a cross sectional view of the safety body, takes at right angles to the plane of figure 5.
Figure 7 is a cross sectional view taken in the same plane as figure 1 of the operating body.
Figure 8 is a cross sectional view of the operating body, taken in the plane at right angles to the plane of figures 7 and 5, with the safety body, in the OFF position.
Figure 9 is a cross sectional view of a second embodiment of hand held lighter according to the present invention.
Figures 10 and 11 show the lighter of Figure 9 in different positions.
[0027] Figure 1 shows a hand held lighter 1 of the piezoelectric ignition type. It comprises a main body 2 housing the components, which include a fuel container 3 for containing liquid or liquified gaseous fuel, a valve for allowing fuel to be fed from the container 3 along a tube 11 to an ignition point 12. The valve is of the type known in the art and is shown in more detail in figure 2-4.
[0028] The lighter 1 further comprises a piezoelectric ignition device 5 which is of known type. The piezoelectric ignition device 5 and a fuel valve 4 are each operated by a lever 6. The lever 6 is itself operated by an operating body 7 in the form of trigger, in a manner in which is known in the art.
[0029] The safety device according to the invention is provided by a safety body in the form of a safety button 8. The safety button 8 is shown in its OFF position. The safety button is biased into the OFF position by a flat spring 9.
[0031] Figure 2 shows the central section of the hand held lighter of figure 1 in more detail. It can be seen that the fuel valve comprises a plug which is to be lifted away from a seat in order to allow fuel to be fed. The fuel valve is biased into a closed position by resilient means in the form of a coil spring. The fuel valve is operated by the right hand end of the lever 6, the lever 6 being pivoted about a pivot 13.
[0032] The operation of the lever 6, piezoelectric ignition device 5 and valve 4 are as known in the art.
[0033] The piezoelectric ignition device 5 is for generating an electrical charge for creating a spark. The spark is created at the ignition point 12, the electrical current being delivered to the ignition point along the tube 1 in a manner which is known in the art.
[0034] Figure 2 further shows that the trigger 7 comprises a flange 17 (seen in cross section cross hatched) which extends at right angles to the plane of the page. The flange 17 is slidably retained between two bearing surfaces 16 which are integrally formed with the body 2. In this way, if the safety button is in the correct position as will be explained further below, the operating body 7 can be moved downwards with the flange 17 sliding downwards between the bearing surfaces 16.
[0035] However, as can be seen figure 2, the safety button 8 is in a position in which a projection 14 of the safety button which extends at right angles to the plane of the page comes to rest against the edge 15 of the right hand bearing surface 16. As can be seen in figure 7 and figure 8, the safety button 8 is retained in a slot 18 in the trigger 7. The safety button 8 is prevented from movement in the downward direction in figure 2 by the engagement of the projection 14 with the edge 15 of the bearing surface 16. Because of the engagement of the safety button 8 in the slot 18, it prevents downward movement of the operating body 7. The safety button 8 and its projection 14 are biased into a position in which the projection 14 engages the edge 15 by the spring 9. This is the rest, OFF-operating position of the hand held lighter 1.
[0036] Figure 3 shows the same view as figure 2, in which the safety button 8 has been depressed by a user so that it is moved to the right of Figure 3. It can be seen that the projection 14 of the safety button is now clear of the edge 15 of the bearing surface 16. If the user now exerts a force on the trigger 7 in a downward direction, the movement of the trigger will not be prevented by the safety button. As a result, the trigger 7 moves downwards and the hand held lighter 1 will enter the configuration shown in figure 4. In figure 4, the trigger has moved downwards operating the lever 6 to open the fuel valve 4 and to operate the piezoelectric ignition system 5.
[0037] As a result, fuel is fed to the ignition point and the spark is generated to ignite the fuel.
[0038] If the user now releases pressure from the trigger 7, the force of the coil spring within the valve 4 automatically returns the trigger 7 in an upward direction, through the action of the lever 6. The trigger slides upwards so that it is in the position shown in figures 3. If the user now removes their finger from the safety button 8, spring 9 will force the safety button back into the OFF position shown in figure 2.
[0039] In this way, as soon as the user has finished with the lighter and released the trigger and the safety button 8, the hand held lighter is automatically returned to the configuration shown in figure 2.
[0040] This provides a safety feature, as it is highly unlikely that both safety button 8 and figure 7 will be operated by accident. Further, if the operating surface 19 of the trigger is positioned a suitable distance away from the safety button 8, suitably around 2 cm, it will be difficult for children to simultaneously operate the safety button and the trigger 7, making the apparatus difficult for children to operate.
[0041] Figure 5 shows a cross sectional view of the safety button 8 in its central plane, in the same plane as figure 1. Figure 6 shows the safety button in a plane at right angles to the plane shown in figure 5. It can be seen that there are a pair of projections 14 on the side of the safety button 8.
[0042] Figure 7 shows the trigger 7 with the square shaped slot 18 in which the safety 8 is slidably received.
[0043] Figure 8 shows the trigger 7, including, in cross-hatching, the flange 17, mounted between the bearing surfaces 16. The safety button 8 can be seen with its projections in position. The surface 15 lies beneath the projections 14 and is not visible in figure 8.
[0044] Figure 9 is a cross sectional view of a second embodiment of hand held lighter according to the present invention.
A hand held lighter 20 comprises a fuel container 21 for containing liquid or liquified gaseous fuel, a wick 22 for feeding fuel to a valve assembly 23. The valve assembly 23 is not explained in detail. It is of the type normal in the art. It comprises a plug 24 which is lifted against the force of a spring in order to release fuel. When the plug 24 lifts, fuel is fed to an ignition point in the form of a nozzle 25. The nozzle 25 is contained within a shield 26 for preventing draughts from blowing out a flame formed at the nozzle 25.
[0045] Piezoelectric means 27 are provided. The Piezoelectric means 27 is for providing an electrical charge for making a spark. A conductor 28 can be seen leading to the nozzle 25 for forming a spark therewith for igniting fuel fed to the nozzle 25. The piezoelectric ignition means is operated by an operating body comprising a structure 29 which is movable in the vertical direction (direction Y as shown in the drawing) for operating the piezoelectric ignition means. The operating body 29 also operates a lever 30 which operates the valve plug 24.
[0046] The piezoelectric ignition means is contained within a part of the body of lighter 31 at the back. Also contained in the structure, between the piezoelectric ignition means and the wall 31 of the lighter is a safety body 32. The safety body 32 comprises a first part 34 which lies over the operating body 29 so that in use an operator can only operate the operating body through the safety body 34. The safety body further comprises a longitudinally extending part 35 which extends between the piezoelectric ignition means 27 and the wall 31 of the lighter. The part 35 is constructed of a resiliently deformable material constructed in a bowed shape which is compressed between the wall 31 and the piezoelectric ignition means 27 in such a way that the first part 34 is biased to the right, in the direction opposite to the direction X shown in figure 9. The safety body 32 further comprises a third part 36 in the form of short projection. This short projection 26 extends into a slot 37 formed in the wall 31 of the lighter body in such a way that that the projection 36 comes to rest in contact with an abutment edge 38 formed on the body 31 of the lighter. It can be seen that if pressure is applied to the safety body 34 in the direction Y, the safety body cannot move in the direction Y because of the interaction of the projection 36 with the abutment 38.
[0047] In use, a user applies a force using their thumb or finger 39 to the safety body in the direction X. By doing this, the first part 34 of the safety body 32 is moved to the left in the direction of the arrow X against the resiliency of the safety body. As a result, the projection 36 is drawn out of engagement with the abutment edge 38.
[0048] The user can then apply pressure with their thumb or finger 39 in the direction of arrow Y. This causes the safety body 32 to move downwards. As a result, the piezoelectric ignition means 27 is operated to generate a spark and the lever 30 is used to actuate the valve plug 24 so that the fuel is fed to the ignition point 25 and ignited by the spark generated by the piezoelectric ignition means 27.
[0049] If the user now releases their thumb or finger from the second part of the safety body, the safety body and the piezoelectric ignition means will be returned to the position shown in figure 10 by resilient means incorporated in the valve assembly 23 and in the piezoelectric ignition means 27. Then, due to the resiliency of the safety body 32, the first part 34 of the safety body is moved to the right so that projection 36 engages against the abutment stop 38, returning the lighter to the condition shown in figure 9.
[0050] In this way, once the lighter has been operated, it is automatically returned to the position shown in figure 9. This contributes to the safety of the design. It can only be operated using the correct sequence of events which will be difficult to achieve accidentally and which are not easy for a young child to perform. Once the lighter has been used, it is automatically returned to its safe position without requiring any positive action from the user.
[0051] The present invention has been described above purely by way of example and modifications can be made within the sprit of the invention, which extends to equivalents of the features described. The invention also consist in any individual features described or implicit herein or shown or implicit in the drawings or any combination of any such features or any generalisation of any such features or combination.
1. A hand held lighter comprising a fuel container, a fuel valve for allowing fuel to
be fed to an ignition point, and piezoelectric ignition means for igniting fuel fed
to the ignition point, wherein the fuel valve, the piezoelectric ignition means or
both of them are operable by an operating body which is movable from a rest position
in a first direction, a safety body being provided movable in a second direction which
lies at an angle to the first direction from a first, safety, position in which the
safety body blocks movement of the operating body and a second, operating, position
in which the safety body allows movement of the operating body, whereby, in use, the
user must move the safety body from the first position to the second position to operate
the operating body and whereby, when the operating body is returned to its rest position,
the safety body is returned to its first position.
2. A hand held lighter according to claim 1, wherein a single operating body operates
both the fuel valve and the piezoelectric ignition means.
3. A hand held lighter according to claim 1 or 2, wherein the angle between the first
direction and the second direction is greater than at least 15°, preferably greater
than at least 30° and most preferably greater than 60°.
4. A hand held lighter according to any preceding claim, when the safety body is permanently
engaged with the operating body and comprises a part which abuts a stop formed on
the lighter in the first position of the safety body.
5. A hand held lighter according to any preceding claim, wherein the operating body is
movable against the force of a resilient means so that the operating body is returned
to its rest position after the user releases the operating body.
6. A hand held lighter according to any preceding claim, wherein the operating body is
returned to its first position by resilient means.
7. A hand held lighter according to any preceding claim wherein the operating body comprises
an operating surface for engagement with a user's finger or thumb to operate the lighter,
the safety body being mounted at a distance from the operating surface
8. A hand held lighter according to claim 7, wherein the distance between the operating
surface and the safety body is greater than 1 cm, preferably greater than 1.5 cm and
most preferably around 2cm.
9. A hand held lighter according to claim 1, wherein the safety body comprises a movable
part which is engaged with the operating body and located above it so that the user
can only operate the operating body through the safety body, a part of the safety
body projecting so that it engages with an abutment formed in the hand held lighter,
whereby movement of the safety body and the operating body past the abutment are prevented
in the first position.
10. A hand held lighter according to claim 1, wherein the safety body comprises at least
one resilient formation for urging the safety body into the first position.
11. The hand held lighter according to claim 10, wherein the safety body comprises a first
section for lying over the operating body so that the user can only operate the operating
body through the safety body, the first part of the safety body extending generally
in the second direction, the safety body comprising a second, resilient part which
extends generally in the first direction adjacent the operating body and engaged with
mounting means, whereby the resilient part of the safety body urges the safety body
into the first position.
12. A hand held lighter according to claim 11, wherein the safety body comprises a third
part projecting from the second part of the safety body, projecting generally in the
second direction, for engagement with an abutment member of the lighter, for preventing
operation of the safety body in the first position.