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(11) | EP 0 052 443 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Solar lighter |
| (57) O A solar lighter (10) has a body (16) defining a recess (17) between opposed walls
(16.1) thereof, and a lens (12) pivotal into and out of the recess (17) respectively
into inoperative and operative conditions. A holder (18), is pivotally mounted on
the body (16) via a stem (20). In the operative condition, the holder (18) is spaced
from the lens (12) a distance corresponding to the focal distance of the lens (12).
In use, material to be ignited is frictionally engaged in the holder (18) and solar
rays (38) are focussed onto the material to ignite it. |
[0002] In accordance with the invention, there is provided a solar lighter for igniting a combustible material, the lighter comprising
a lens for refracting solar rays to a focal point or zone;
a holder for holding the material to be ignited and being arranged with respect to the lens such that the material, in use, is held in the vicinity of the focal point or zone; and
a lighter body supporting the holder and defining a recess to accommodate the lens, the lens being movably mounted on the lighter body such that it is movable to an operative position clear of the recess, and to an inoperative position inside the recess.
[0003] The holder may be movably mounted on the lighter body to be movable between an operative position and an inoperative position, the holder and the lens being spaced from each other when in their respective operative positions, the spacing corresponding to the focal distance of the lens.
[0004] The lighter body may be constructed to have a box-like shape when the lens is in its inoperative position, the recess being defined between two opposed walls of the box. The lens may be pivotally mounted on the lighter body to be pivotal into and out of the recess. Thus, the lens will be protected against accidental damage when not in use.
[0005] Conveniently, the lens may be biassed by biassing means to one of its operative or inoperative positions.
[0006] The holder may have frictional engagement means adapted frictionally to grip the combustible material to be ignited. The holder may further have adjustment means to permit gripping combustible materials of differing sizes or shapes. Thus, the holder may comprise a shoulder and a slide between which the combustible material is gripped, the slide being slidable relative to the shoulder to provide the adjustability.
[0008] The invention is now described by way of example with reference to the accompanying diagrammatic drawings.
[0009] In the drawings,
Figure 1 shows a side elevation of a solar lighter according to the invention, in an operative condition;
Figure 2 shows an end-on view of the lighter of Figure 1;
Figure 3 shows a view similar to Figure 1, but with the lighter in an inoperative condition;
Figure 4 shows a sectional three-dimensional view of an aspheric Fresnel lens suitable for use with the lighter of Figure 1;
Figure 5 shows, in plan view, a holder of the lighter of Figure 1;
Figure 6 shows a side elevation of the holder of Figure 5;
Figure 7 shows, in side elevation, an aspheric lens of another embodiment of a solar lighter in accordance with the invention; and
Figure 8 shows, in section, a modified Fresnel-type lens.
[0010] With reference to Figures 1, 2 and 3 of the drawings, reference numeral 10 generally designates a solar lighter according to the invention. The lighter 10 comprises, broadly, a lens 12 mounted on a stem 14, a body in the form of a support structure 16, and a holder 18 mounted on a stem 20. In Figures 1 and 2, the lens 12, stem 14 and support structure 16 are shown turned as a unit, relative to the holder 18 and stem 20, through 90°, as will emerge in more detail hereunder.
[0011] The support structure 16 is of hollow, rectangular box-like construction and comprises a pair of opposed elongate, rectangular side walls 16.1, a floor 16.2 interconnecting the side walls 16.1 at one end thereof, and a rear wall 16.3 interconnecting the side walls 16.1 along one side thereof. The walls 16.1 are normal to the wall 16.3, and said walls are normal to said floor. In Figure 3, the support structure 16 is shown with one wall 16.1 removed for clarity.
[0013] The stem 14 is pivotally mounted on an axis 22 defined by a pin extending between the walls 16.1 and normal thereto, located adjacent the wall 16.3 and at the end of the structure 16 remote from the floor 16.2. The stem 14 is resiliently biassed by a stressed coil spring (not shown) coiled around the pin forming the axis 22, one end of the spring engaging the inside of the wall 16.3 and the other end engaging said stem 14. The bias is in the direction of arrow 24, as shown in Figure 3. The lens 12 is pivotal out of the recess 17 to its operative position, as shown in Figures 1 and 2, and into the recess 17 to its inoperative position, as shown in Figure 3.
[0014] The stem 20 is an L-shaped metal bar of flattened rectangular cross-section, and is pivotally connected via the the base of the L to the floor 16.2 about an axis 26 which is normal to said floor. The holder 18 is in turn pivotally connected to the axis defined by a pin 28 which is normal to the axis 26. The holder 18 has a passage 30 for receiving the end of a material to be ignited, eg a cigarette.
[0015] The holder 18 is pivotal between an upright, operative position as shown in Figures 1 and 2, and a folded, inoperative position as shown in Figure 3.
[0016] When the lighter is in its inoperative condition as shown in Figure 3, the base of the L of the stem 20 extends flat along the outside of the floor 16.2 of the structure 16. The width of said base is substantially the same as the width of the outside of said floor, so that the base covers the floor. The upright of the L then extends along and encloses the open front of the structure 16, opposite the rear wall 16.3, said upright having a width equal to the spacing between the outer sides of the walls 16.1. The pin 28 is then located adjacent the corners of the walls 16.1 remote from the floor 16.2 and rear wall 16.3, and is parallel to the axis 22, the holder extending along the edges of the walls 16.1 remote from the floor 16.2 and closing off the open upper end of the structure 16.
[0017] To bring the lighter 10 into its operative condition, the holder 18 is first pivoted to its operative position against a stop acting between said holder and the stem 20, so that it forms an upward extension of the stem. The structure 16 (as a whole with the lens 12 and stem 14) is then pivoted through 90° in an anti-clockwise direction when seen from above, relative to the stem 20, to assume the position shown in Figures 1 and 2. The structure 16 is held in this position relative to the stem 20 by a spring-biassed detent ball 32 in the floor 16.2, which engages with a corresponding recess 34 in the base of the stem 20.
[0018] During pivoting of the structure 16 relative to the stem 20 (which is made possible by the particular off- centre location of the axis 26 which prevents pivoting in the opposite direction), the spring bias of the stem 14 acts to pivot the stem and the lens 12 in the direction of the arrow 24 (Figure 3) about the axis 22 to its operative positions until the stem 14 projects out of the open top of the structure 16 and abuts the wall 16.3. In this position, the lens is located concentrically with the passage 30.
[0019] In another embodiment, a detent arrangement may be provided to operate between the structure 16 and the stem 20 to allow relative movement therebetween in one direction only.
[0020] If desired, a catch may be provided to retain the lens 12 inside the recess 17 until the catch is released.
[0021] A cigarette is then inserted into the passage 30 from the end of the passage 30 remote from the lens 12 and is frictionally gripped by means of frictional engagement means which is described hereinafter. The end of the cigarette to be ignited is adjusted to be flush with the end 36 of the passage adjacent the lens. The lighter 10 as a whole is then oriented by hand so that solar rays 38 are as parallel as possible to the polar axis 40 of the lens 12 and passage 30. In this position, the lens focusses the rays 38 into a focal point or zone at the end of the cigarette to ignite the cigarette which can then be removed and smoked.
[0022] To close the lighter, ie to bring it into its inoperative condition, the above steps are in substance reversed. First, the stem 14 and lens 12 are pivoted by hand, opposite to arrow 24, about axis 22 against the bias of the spring until they are inside the recess 17. The detent ball between the floor 16.2 and base of the stem 20 is disengaged and, while the lens 12 and stem 14 are held inside the recess 17, the structure 16 is pivoted through 90° (clockwise when seen from above) about the axis 26, until the edges of the walls 16.1 abut the surface of the upright of the stem 20 which faces towards the axis 26. The holder 18 is then pivoted downwardly and inwardly about the pin 28 relative to the stem 20, until the holder lies along the top of, and encloses, the structure 16.
[0023] In this regard, it will be appreciated that the inner surface of the holder 18 has a projection 42 which locks and fits between the upper edges of the walls 16.1 to prevent accidental pivoting about the axis 26 when the lighter is inoperative. This projection 42 also defines the inner end 36 of the passage 30 to facilitate exact placement at the focal point of a cigarette end to be ignited, when the lighter is in its operative condition.
[0024] In Figure 4, reference numeral 44 shows an aspheric Fresnel lens which can be used as the lens 12 of Figure 1. The Fresnel lens 44 has a short focal length and a serrated profile made up of a plurality of concentric rings 46, arranged to focus incident solar rays 38, parallel to its polar axis 40, (refer to Figure 1), to a point or zone. The reduced thickness of this type of lens, compared to conventional lenses, permits a reduced spacing between the walls 16.1 while retaining a suitably short focal length, thus permitting overall size reduction of the lighter 10.
[0025] With reference to Figures 5 and 6, the holder 18 is shown in more detail. The holder 18 comprises frictional engagement means comprising a shoulder 50 provided on a holder body 52, and a slide 54 slidably mounted on the holder body. The slide 54 is slidable towards and away from the shoulder 50 to reduce and increase the spacing between the end 56 of the slide adjacent the shoulder, and the shoulder, thereby to permit material of differing sizes and shapes to be gripped. Thus cigarettes and cigars of different sizes and other material of different sizes can be accommodated within the holder.
[0026] If desired, the slide 54 may be biassed, e.g. by means of a spring, towards the shoulder to facilitate frictional engagement of the material to be ignited.
[0027] Conveniently, the shoulder 50 and the end 56 of the slide 54 have part-circular shapes when seen in plan view, corresponding to the diameter of a cigarette.
[0028] The slide 54 has a slot 58 co-operating with a pin 60 mounted in the holder body 52 to guide the slide 54.
[0029] With reference to Figure 7, a conventional aspheric-type (ie not a Fresnel-type) lens is indicated by reference numeral 12.1. This type of lens will generally be thicker than a Fresnel-type having the same focal distance.
[0030] With reference to Figure 8, by way of development, the Fresnel-type lens 44 of Figure 4 is shown to be covered with a transparent cover 62 of transparent synthetic plastics material. The cover 62 protects the lens 44 against accidental damage and facilitates cleaning, as dirt cannot collect between the serrations 46.
[0031] The cost of a lens depends from the accuracy at which it is made. Relatively inexpensive lenses may have variations in their focal lengths. By way of development, to enable a relatively inexpensive lens to be used, the spacing between the lens 12 and the end 36 of the passage 30 when the lighter 10 is in its operative condition, may be adjustable, to make provision for lenses having different focal lengths. This may be effected by having the base of the stem 20 adjustable.
[0032] Furthermore, the base of the stem 20 may be extensible to provide for lenses having long focal lengths. The base may conveniently be telescopically extensible.
[0033] Advantages of the lighter are that it uses no fuel and causes no pollution. It is small, light, inexpensive and easy to use and has no parts which require regular or frequent replacement, such as flints or the like. For daytime use in parts of the world having abundant sunshine it is expected to work indefinitely at no expense, as only gross physical and accidental damage can harm it, if it is used with reasonable care and the lens is not exposed to scratching. Its simple parts can be made robust so that, in normal use, it can last a lifetime with reasonable care. A further advantage is that it can easily be cleaned and can be used immediately after immersion in water as it can be dried virtually instantaneously with a cloth.
1. A solar lighter (10) for igniting a combustible material, the lighter (10) comprising
a lens (12,44) for refracting solar rays (38) to a focal point or zone;
a holder (18) for holding the material to be ignited and being arranged with respect to the lens (12,44) such that the material, in use, is held in the vicinity of the focal point or zone; and
a lighter body (16) supporting the holder (18), characterized in that the body (16) defines a recess (17) to accommodate the lens (12,44), the lens (12,44) being movably mounted on the lighter body (16) such that it is movable to an operative position clear of the recess (17), and to an inoperative position inside the recess (17).
2. A solar lighter (10) as claimed in Claim 1, characterized in that the holder (18)
is movably mounted on the lighter body (16) and is movable between an operative position
and an inoperative position, the holder (18) and the lens (12,44) being spaced from
each other when in their respective operative positions, the spacing corresponding
to the focal distance of the lens (12,44).
3. A solar lighter (10) as claimed in Claim 1 or Claim 2, characterized in that the
lighter body (16) is constructed to have a box-like shape when the lens (12,44) is
in its inoperative position, the recess (17) being defined between two opposed walls
(16.1) of the box.
4. A solar lighter as claimed in any one of the preceding claims, characterized in
that the lens (12,44) is pivotally mounted on the lighter body (16) to be pivotal
into and out of the recess (17).
5. A solar lighter as claimed in any one of the preceding claims, characterized in
that the lens (12,44) is biassed by biassing means to one of its operative or or inoperative
positions.
6. A solar lighter (10) as claimed in any one of the preceding claims, characterized
in that the holder (18) has frictional engagement means (50,56) adapted frictionally
to grip the combustible material to be ignited.
7. A solar lighter (10) as claimed in Claim 6, characterized in that the frictional
engagement means (50,56) is adjustable to permit gripping combustible materials of
differing sizes or shapes.
8. A solar lighter (10) as claimed in Claim 7, characterized in that the frictional
engagement means (50,56) comprises a shoulder (50) and a slide (56) between which
the combustible material is gripped, the slide (56) being slidable relative to the
shoulder (50) to provide the adjustability.
9. A solar lighter (10) as claimed in any one of the preceding claims, characterized
in that the lens (12,44) is an aspheric lens (12,44).
10. A solar lighter (10) as claimed in Claim 9, and in which the lens (12,44) is a
Fresnel-type lens (44).