Note: Descriptions are shown in the official language in which they were submitted.
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Stick lighter with safety device
Technical field
The present invention relates to a lighter, in
particular a so-called stick lighter (bar lighter),
having the features of the preamble of Claim 1.
Prior art
A stick lighter is understood as meaning a specific
configuration of a gas lighter which is particularly
suitable for igniting candles, gas flames in cookers,
chimneys, grills, etc. For this purpose, a stick
lighter has a housing with a longitudinally extending,
often rod-like front region. A tank for a fuel, usually
a liquefied lighter gas such as a propane/butane
mixture, and an actuating mechanism are arranged in the
rear region of the housing. A fuel line is led from the
tank to the front end of the housing, where an igniting
device, e.g. a piezoelectric igniter, is located. As
long as the actuating mechanism is not activated, the
mechanism interrupts the supply of fuel through the
fuel line. Upon actuation of the actuating mechanism,
fuel is led through the fuel line to the front end and
is ignited there by the igniting device. In this way, a
flame is produced at this end. A stick lighter is also
occasionally referred to as a utility lighter or
chimney lighter.
There is a need for stick lighters to be protected by a
safety mechanism against undesired or unauthorized use,
e.g. by a child at play. Various safety mechanisms have
been proposed, e.g. in US-A 5,697,775. The lighter here
has a locking element in addition to an actuating
element. The actuating element is designed in each case
in the manner of a trigger of a handgun, i.e. it is
actuated, by pulling with the index finger, in a
direction away from the front end of the lighter. The
safety mechanisms which are proposed for this purpose
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can only be used for lighters in which the actuating
element is actuated in the manner of a gun trigger.
They are of relatively complex construction and, in
some cases, require a considerable amount of space. In
addition, these mechanisms have the risk of the locking
element getting caught in a position in which it
permanently releases the actuating element, as a result
of which the safety mechanism would be rendered
permanently inoperative.
US 6,669,466 discloses a stick lighter of which the
safety mechanism comprises a button which is arranged
on a side of the housing which is located opposite an
actuating slide. A locking element is connected to the
button. The locking element has a main portion which
extends in the direction of the actuating slide and
from which a guide flange extends in the direction of
the rear end of the housing. When the button is located
in its starting position, the guide flange blocks the
actuating slide. When, in contrast, the button is
pushed, the guide flange releases the actuating slide.
Since the main portion and the guide flange are
relatively delicate, there is a risk, with this design,
of the locking element breaking, as a result of which
the safety mechanism would become inoperative.
Description of the invention
It is thus an object of the present invention to
provide a lighter which is reliably safeguarded on a
permanent basis against undesired actuation, which,
while having a highly stable safety mechanism, is
nevertheless compact and, in particular, can be
produced with a low overall height, and of which the
safety device is of simple construction.
This object is achieved by a lighter according to
Claim 1. Advantageous configurations are specified in
the dependent claims.
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A lighter according to the invention thus comprises:
- a housing with a proximal end and a distal end,
- an actuating device, which comprises an actuating
element which can be displaced relative to the housing,
counter to an actuating force, between a starting
position and an actuating position, wherein the
actuating device, in the starting position, prevents
fuel from being supplied to the distal end of the
housing and, in the actuating position, releases the
supply of fuel, and
- a safety device, in order to prevent accidental
displacement of the actuating element.
The safety device comprises a safety lever which is
connected to the actuating element and is pivotable
relative to the actuating element between a locking
position and a release position. The safety lever, in
the locking position, is in engagement with a locking
element which is stationary relative to the housing and
thus prevents the actuating element from moving from
the starting position into the actuating position.
Biasing (preloading) means are present, and these push
the safety lever, counter to a biasing force, into the
locking position. In order to allow actuation of the
lighter, a release device is provided, and this can be
moved between a rest position and an activated
position, wherein the release device, in the activated
position, pushes the safety lever, counter to the
biasing force of the biasing element, into the release
position.
By virtue of the safety lever being articulated on the
actuating element, locking of the actuating element is
achieved in a particularly straightforward manner. Both
the safety lever and the locking element may be
designed in a straightforward, and therefore very
robust, manner. There is no need for any delicate
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structure which can easily get caught or break. The
proposed design of the safety device, in addition,
requires only a small amount of space, in particular
only a low overall height.
The lighter according to the invention is preferably a
stick lighter, i.e. the housing is preferably of
elongate form or has at least one elongate front
(distal) region, the actuating element being located in
a region which is remote from the distal end of the
housing.
The actuating element is preferably designed as a slide
which is arranged on the top side of the housing. The
slide is preferably designed such that it can be
actuated by a thumb. The actuating element is
preferably actuated by displacement in the direction of
the distal end of the housing. In other words, the
actuating element is preferably closer to the distal
end of the housing in the actuating position than in
the starting position.
The release device preferably comprises a button which
is arranged on the bottom side of the housing. This
button can be pushed into the activated position, from
the rest position, in the direction of the top side of
the housing. The button preferably comprises an
activating portion which, at least in the activated
position, is in contact with the safety lever. It is
then preferably possible for the safety lever, in the
activated position of the button, to be moved slidingly
on the activating portion. The button is preferably
designed and arranged such that it can be actuated by a
finger, while the slide is actuated by the thumb.
The safety lever preferably has an elongate region
which, starting from the pivot axis, extends in the
direction of the distal end of the housing. Movement of
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the elongate region in the direction of the distal end
is blocked by the locking element when the safety lever
is located in the locking position. In other words, in
this position, the locking element is located between
the elongate region of the safety lever and the distal
end and, if an attempt is made to displace the
actuating element, the elongate region, with its end,
pushes against the locking element. It is thus possible
to dispense with the formation of hooks or other
features on the safety lever, and the safety lever can
easily be produced throughout, from the pivot axis to
its front end, with an approximately uniform material
thickness and thus with a high level of breaking
strength.
The biasing (preloading) means preferably comprise a
spring, in particular a helical spring or a (bent-over)
leaf spring, with a first and a second free end. The
first free end then pushes against the actuating
element and the second end pushes against the safety
lever, such that the spring pushes a region of the
safety lever away from the actuating element. If the
safety lever is articulated on the actuating element by
way of a pin, the spring is preferably passed around
the pin. In particular in the case of a helical spring,
the helix axis is preferably concentric with the pivot
axis.
A particularly simple construction of the safety device
is achieved if the lighter has a frame which is
arranged in the housing and in which the release device
(that is to say preferably the button) is guided
upwards, that is to say in the direction of the top
side of the housing. An upwardly projecting protrusion
on the frame then preferably forms the locking element.
The actuating element is then preferably also guided on
the frame. The actuating and safety devices can thus
easily be realized on a single frame. The frame
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preferably has a region of essentially U-shaped cross
section.
The lighter advantageously has further elements which
are usually present in a stick lighter, in particular
at least one of the following elements:
- a fuel tank, in particular for a liquid gas,
arranged in the vicinity of the proximal end of the
housing,
- a fuel nozzle arranged at the distal end of the
housing,
- a fuel line which is arranged in the housing and
is intended for supplying fuel from the fuel tank to
the nozzle,
- a valve device in order to interrupt or release
the supply of fuel to the nozzle, and
- an igniting device, preferably a piezoelectric
igniting device, for igniting fuel at the distal end of
the housing.
Both the valve device and the igniting device can
preferably be actuated by displacement of the actuating
element from the starting position into the actuating
position.
In order to increase child safety further, the lighter
preferably has resistance means which, upon
displacement of the actuating element from the starting
position into the actuating position, generate a force
which is at least 30 Newton, preferably at least
40 Newton, particularly preferably at least 45 Newton.
For this purpose, it is possible to provide a helical
spring which extends in the longitudinal direction of
the housing, is fitted to act between the actuating
element and the housing and thus generates an
additional resistance force. It is also possible,
however, for the force to be generated solely by the
igniting device (in particular piezoelectric igniter).
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Brief description of the drawings
An advantageous embodiment of the invention will be
described in more detail hereinbelow with reference to
the drawings, in which:
Figure 1 shows a schematic side view, partly in
longitudinal section, of a detail of an
actuating mechanism with a safety device in
the starting position;
Figure 2 shows a schematic lateral X-ray view of the
actuating mechanism of Figure 1;
Figure 3 shows a schematic side view, partly in
longitudinal section, of the actuating
mechanism of Figure 1 in the actuating
position;
Figure 4 shows a schematic X-ray view of part of the
actuating mechanism of Figure 1, as seen from
the rear;
Figure 5 shows a schematic plan view of a stick
lighter;
Figure 6 shows a schematic side view of a stick
lighter; and
Figure 7 shows a schematic lateral X-ray view of
selected parts of a stick lighter.
Detailed description of preferred embodimQnts
Figures 1 to 4 show one embodiment of an actuating
device which interacts according to the invention with
a safety device. Located to the right of the detail in
Figures 1 to 3 is a gas tank (not illustrated in
Figures 1 to 3) with a valve, and to the lef t of this
detail are a gas outlet (not illustrated either), in
the form of a nozzle, and a piezoelectric igniter. The
actuating mechanism serves for actuating the
piezoelectric igniter and for releasing the valve on
the gas tank. This is explained in more detail below in
conjunction with Figure 7. Figures 1 and 2 illustrate
the mechanism in its starting position, in which it
closes the valve, and Figure 3 illustrates the
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mechanism in the actuating position, in which it
releases the valve.
An actuating slide 2 is guided on the top side of a
frame 1. The actuating slide 2 is guided, by way of a
guide component 22, on a side wall 10 of the frame 1
and can be displaced to the left (in the actuating
direction 92) from the starting position into the
actuating position. This displacement takes place
counter to the force of a helical spring 26, of which
one end is connected to the slide 2 and the other end
is connected to the frame 1. In order to prevent
accidental actuation, a safety lever 4 is articulated,
via a pin 43, on the actuating slide 2, beneath the
guide component 22, on downwardly extending protrusions
and can be pivoted about the pin 43. The safety lever 4
has a front portion 41 which extends obliquely
downwards to the left. In the starting position, the
end of this portion 41 is located opposite a nose 15 on
the frame 1. The nose 15 thus blocks displacement of
the safety lever 4 to the left and ther_2rore prevents
the actuating slide 2 from being displaced into the
actuating position.
In order nevertb_Giess to allow displacement of the
actuating sl ide 2, a" safety button 3 is fitted on the
bottom Gi.de of the frame 1. This safety button has a
pr-essure-exerting surface 31, a main portion 32 and a
cylindrical activating portion 33 which extends
upwards, in the direction of the safety lever, and is
bevelled in a rearward direction at the top end. By
virtue of the pressure-exerting surface 31 of the
safety button 3 being pushed in the upward direction,
this button is pushed into a recess on the frame 1. The
activating portion 33 thus pushes the front portion 41
of the safety lever 4 upwards beyond the height of the
nose: 15 (this is the unlocking direction 91). In this
position, the actuating slide 2 can then be displaced
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to the Yeft (in the actuating direction 91) into the
actuating position, as is illustrated in figure 3.
As soon as the actuating slide 2 has reached the
actuating position, it is possible to let go of the
safety button 3 since, in this position, the front
portion 41 of the lever 4 is guided on the nose 15.
In order to ensure that the safety lever 4 reliably
prevents actuation of the slide 2 as long as the button
3 is not pushed, a helical spring 44 is passed around
the pin 43, the free ends of this spring pushing the
slide 2 and the front portion 41 of the lever 4 apart
from one another. This is illustrated in Figure 2.
Figure 2 represents a so-called X-ray view, i.e. a view
in which the boundary lines of all the relevant
components are illustrated irrespective of whether they
are visible in an actual model. Clearly visible is the
spring 44, which is otherwise located, without being
visible, between the slide 2 and lever 4. The front
portion 41 of the lever 4 is thus pushed downwards by
the spring force.
The safety lever 4 also has a rear portion 42, which is
of angled design and, starting from the pin 43, extends
first of all to the right (counter to the actuating
direction 92) and then upwards (in a direction towards
the slide 2). This rear portion 42 serves as a boundary
for the pivoting region of the lever 4. If the front
portion 41 moves downwards, away from the slide 2, then
the rear portion 42 moves in the direction of the
slide. When reaching a predetermined pivoting angle,
the rear portion 42 abuts against the slide 2 (or, in
an alternative configuration, against the frame 1) and
thus prevents the lever 4 from pivoting further. As a
result of its shape and its position of articulation,
the lever 4 can thus be pivoted only over a
predetermined, well-defined and relatively small angle
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range. In this way, on the one hand, straightforward
assembly of the mechanism is ensured and, on the other
hand, the lever 4 is prevented from getting caught on
the bottom region of the frame 1, which would render
the entire mechanism unusable.
The frame 1 comprises a horizontal base 12 and two
vertical side walls 10 in a U-shaped arrangement. The
base 12 contains a recess, in which the button 3 is
guided vertically. This recess is formed by a front
vertical crosspiece 13, a front horizontal crosspiece
14, a rear horizontal crosspiece 17 and a rear vertical
crosspiece 16. The recess contains, in addition, an
opening which is open in the upward direction and
through which the activating portion 33 of the button 3
is guided.
Figure 4 shows a view of part of the mechanism, as seen
from the rear. Only half of the frame 1, the right-hand
half, is illustrated here. However, the frame 1 is
continued symmetrically on the left-hand side. Once
again, an X-ray view has been selected in order to show
the spring 44. This view shows a horizontal flange 11
on the frame 1, which serves for fixing the frame in
the housing (not illustrated). In order to improve
clarity, the spring 26 has been omitted from Figure 4.
Figures 5 and 6 illustrate a stick lighter as a whole.
The stick lighter comprises an elongate housing 5,
which is divided up into a main body 51 and a front
part 52 which extends out of the main body. The main
body 51 has a flattened, essentially elliptical cross
section. The snout-like front part 52 has a similar
cross-sectional shape, albeit with smaller lateral
dimensions. A part of the actuating slide 2 passed to
the outside, namely a thumb rest 21, is arranged in a
displaceable manner on the top side 54 of the main body
51. This thumb rest is connected to the guide component
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22 through a slot-like opening (not visible) in the top
side 54 of the main body 51. On the bottom side 55 of
the main body 51, the pressure-exerting surface 31 of
the safety button 3 is guided outwards through a round
opening. Located at the front (distal) end 58 of the
housing 5, in the region of slot-like openings 59, are
a piezoelectric igniter (not visible) and a gas-outlet
nozzle. A regulating wheel 53 for regulating the gas
supply is located at the rear (proximal) end 57 of the
housing 5. In the region of the transition from the
main body 51 to the front part 52, the main body is
tapered slightly in order for it to be possible for a
protective sleeve to be pushed on.
Figure 7 shows an X-ray view of a selection of the
elements arranged in the housing 5, in order to
illustrate how they interact. The actuating slide 2 and
the safety lever 4, which is articulated thereon, are
illustrated in the centre. Located in the direction of
the proximal end are a gas tank 7 with a tank housing
71, and a closure valve 72 which is arranged at the
front (distal) end of the gas tank. The closure valve
has a valve head 73 which is prestressed in the
direction of the proximal end by a spring and on which
an angled valve lever 74 is fitted. The latter is
supported on an edge of the valve such that movement of
the free end of the valve lever 74 downwards, in the
direction of the underside of the housing, results in
the valve head 73 being pulled forwards,, in the
direction of the distal end of the housing. The valve
is opened as a result. The flow of liquid gas which
escapes through the valve can be adjusted by the
regulating wheel 53 which can be seen in Figures 5 and
6.
A piezoelectric igniter 6 with a front end 61 and a
pressure-exerting element 62 is located in the region
of the distal end. Pushing in the pressure-exerting
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element 62 in the direction of the front end 61 makes
it possible to generate an ignition spark at the front
end 61. For this purpose, it is necessary to overcome
an ignition force which, in the case of conventional
piezoelectric igniters, is usually in the region of
approximately 5-25 Newton. A gas line (not illustrated)
is led from the valve 72 to the front end 61 of the
piezoelectric igniter 6 and terminates there in a
nozzle (not illustrated either).
A front extension component 24 which.extends in the
direction of the distal end of the housing, is fitted
on the actuating slide 2. The extension component 24
has a nose 25 which butts against the pressure-exerting
element 62 of the piezoelectric igniter 6. A
protuberance 23 for actuating the valve 72 is located
at the rear end of the actuating slide 2. This
protuberance butts against the valve lever 74.
In order to actuate the stick lighter, as has been
described above in conjunction with Figures 1 to 4,
first of all the safety button 3 is pushed in. The
actuating slide 2 is released as a result. Displacement
of the actuating slide 2 in the actuating direction (in
the direction of the distal end) then causes two things
to happen. On the one hand, the protuberance 23 pushes
the free end of the lever 74 in the direction of the
underside of the housing, as a result of which the
valve 72 is opened and gas flows through the gas line
to the distal end, where it passes out of the nozzle.
On the other hand, the nose 25 pushes the pressure-
exerting element 62, counter to the ignition force, in
the direction of the front end of the piezoelectric
igniter. This results in an ignition spark, by means of
which the gas flowing out through the nozzle is ignited
to form a flame. The flame will continue burning until
the user lets go of the actuating slide 2 again. The
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actuating slide 2 then returns automatically into the
starting position.
The force which is necessary in order to actuate the
slide 2 is preferably selected to be such that children
under 36 months cannot usually apply.this force. In
particular, the actuating force is preferably greater
than 30, or better greater than 40, Newton. This force
can be adjusted by an appropriate selection of the
spring 26 and piezoelectric igniter 6. If a suitable
piezoelectric igniter is used, it is also possible to
dispense with the spring 26. In this case, the
piezoelectric igniter 6 should also generate, following
actuation, a restoring force which is sufficient for
the slide 2 to return automatically into its starting
position.
At least the front part 52 of the housing preferably
consists of metal, e.g. stainless steel, brass or
aluminium, in order to ensure sufficient heat
resistance. It is also possible, however, to use a
thermostable plastic.
While the invention has been described with reference
to a preferred exemplary embodiment, it is not
restricted to this embodiment, and numerous variations
are possible.
For example, the mechanism proposed can be used not
just for stick lighters in which a slide is actuated in
the direction of the distal end, but also for such
lighters in which an actuating element is actuated in
the direction of the proximal end, e.g. in the manner
of the trigger of a gun. In this case, the mechanism
can be installed in reverse direction.
In the embodiment explained above, the front portion 41
acts as the "operative" portion of the safety lever 4,
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i.e. this portion performs the locking function in
relation to an immovable locking element. However, it
is also possible instead, or in addition, for the rear
portion 42 to be the "operative" portion and, for this
purpose, to engage, e.g. by way of its end, in a recess
on the frame or housing or behind a downwardly
projecting protrusion on the frame or housing.
While the form of safety lever 4 proposed above results
in a particularly straightforward design and high level
of stability of the mechanism as a whole, the lever 4
may also be designed in a variety of other ways. It is
thus possible for the operative portion of the lever
(in the above embodiment the front portion 41) to
extend for example, rather than in the direction of the
distal end, in the direction of the proximal end.
Instead of being pushed, the lever then operates by
being pulled. In this case, the lever 4 may have
provided on it, for example, a protrusion which
interacts in the manner of.a hook with a protrusion in
the manner of the nose 15, which cannot be moved
relative to the housing. In order to prestress the
safety lever 4, it is also possible to use a type of
spring other than a helical spring, e.g. a bent-over
leaf spring. This need not necessarily be guided around
the pin 43. Instead of use being made of a pin-type
hinge, the lever 4 may also be fitted in a pivotable
manner on the slide 2 by means of a film hinge or in
some other known manner. It is also possible for the
lever 4 to be formed integrally with the slide 2, in
which case a flexible, preferably elastic, region is
located between the slide 2 and the lever 4. If this
region is elastic, it is possible to dispense with an
additional spring, and the prestressing means are
formed by the elastic region itself.
Instead of a button 3, the release device may also
comprise a lever or some other type of device which
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ensures that the safety lever 4 can be pushed into the
release position.
The slide 2 and the button 3 need not necessarily be
guided on a frame. Instead, other fastening and guide
means may be provided in the housing.
Of course, a different shape of housing to that
illustrated above may be selected. Numerous variations
are possible here, in particular for a housing shape
which is cylindrical throughout, or for a housing with
a rectangular or square cross section, etc.
List of designations
1 Frame
10 Side wall
11 Lateral flange
12 Frame base
13 Front vertical crosspiece
14 Front horizontal crosspiece
15 Nose
16 Rear vertical crosspiece
17 Rear horizontal crosspiece
18 Accommodating depression
2 Actuating slide
21 Thumb rest
22 Guide component
23 Valve-actuating protuberance
24 Front extension component
25 Nose
26 Spring
3 Safety button
31 Pressure-exerting surface
32 Main portion
33 Activating portion
34 Finger rest
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4 Safety lever
41 Front portion
42 Rear portion
43 Pin
44 Helical spring
5 Housing
51 Main body
52 Front part
53 Regulating wheel
54 Top side
55 Underside / Bottom side
56 Side wall
57 Proximal end
58 Distal end
59 Opening
6 Piezoelectric igniter
61 Front end
62 Pressure-exerting element
7 Gas tank
71 Tank housing
72 Valve
73 Valve head
74 Actuating lever
91 Unlocking direction
92 Actuating direction
