Patent application title: COOKING DEVICE USING SOLAR ENERGY
Jean-Marc Terraz (Chatenoy, FR)
IPC8 Class: AF24J202FI
Class name: Stoves and furnaces solar heat collector energy concentrator with support for material heated
Publication date: 2013-10-03
Patent application number: 20130255669
Cooking device using solar energy and comprising a parabolic mirror
characterised in that the mirror (1) has a large cut-out (3) extending up
to the apex of the mirror which is fixed to the lower end of an angled
arm (6) articulated in its upper part to the end of an upright (4),
arranged substantially vertically, with means being provided to allow
said mirror to pivot.
1. Cooking device using solar power and comprising a parabolic mirror
with a focal point, the mirror (1) having a cut-out (3) and being fixed
to an arm (6) that is articulated onto an upright (4), the upright (4)
defining with the focal point a plane known as the reference plane (P),
characterised in that the arrangement is such that the mirror can pivot
in relation to an axis (B) forming an angle (a) with the reference plane
(P) which is in particular lower than 90.degree..
2. Device according to claim 1, characterised in that the angle (A) is less than 30.degree..
3. Device according to claim 1, characterised in that the angle (A) is substantially zero.
4. Device according to claim 1, characterised in that the arm (6) is fixed to the mirror substantially at the level of the apex of the mirror.
5. Device according to claim 1, characterised in that the upright (4) is substantially vertical.
6. Device according to claim 1, characterised in that the arm (6) is angled in such a way as to have at least one section (22) extending substantially along the focal axis (A) of the mirror.
7. Device according to claim 6, characterised in that the angled arm (6) also comprises a section that is substantially parallel to the upright (4).
8. Device according to claim 1, characterised in that the mirror (1) is formed by the assembly of elementary parabolic surfaces (1a) each delimited by the intersection of two planes passing through the axis of the theoretical mirror or focal axis (A) of the mirror.
9. Device according to claim 1, characterised in that the cut-out (3) is formed by assembling a smaller number of elementary surfaces (1a) than is necessary to form a complete parabola.
10. Device according to claim 8, characterised in that the elementary surfaces are assembled and supported by arms (12) joined to the lower part of the arm (6) which traverses the mirror with a recess (7) being provided for this.
11. Device according to claim 1, characterised in that the upright (4) has in its upper part and according to its axis, a finger (15) on which a bushing can slide axially and be locked to a support (2) for holding the cooking vessel.
 The present invention relates to a cooking device using solar energy. This type of device is formed in particular by a parabolic mirror which concentrates light rays into the focal area which comprises a support for holding the food to be cooked.
 Devices of this kind are still less than perfect and have numerous disadvantages some of which are described below.
 To be effective the parabolic mirror needs to have a diameter of in the order of 1.2 to 1.6 metres. Because of this access to the support for holding the food is very difficult.
 Known devices all have a problem with controlling the orientation of the mirror relative to the light rays or positioning the holder containing the food.
DISCLOSURE OF THE INVENTION
 The device according to the invention which overcomes these disadvantages is as defined in the claims.
 The parabolic mirror is formed by assembling elementary parabolic surfaces, each delimited by the intersection of two planes passing through the axis of the theoretical mirror. In the following each element will be referred to as a "petal".
 On the basis of the technique defined above the cut-out can be formed by assembling a smaller number of petals than is necessary to form a complete parabola.
 According to one embodiment the cut-out mirror is fixed to the lower part of an angled arm, the upper part of which is articulated onto the upper part of an upright in two parts, the upper part being able to pivot on the lower one which forms the support member of the assembly. In this case the lower part can be sunk into the ground or supported by a weighted base such as those used to hold parasols.
 The petals are assembled by means of arms joined to the lower part of the angled arm.
BRIEF DESCRIPTION OF THE DRAWINGS
 The invention is explained in more detail in the following description with reference to the attached drawings, given by way of example only, in which
 FIG. 1 is a perspective view of the device of the invention;
 FIG. 2 is a view, similar to FIG. 1, showing the possibility of orienting the parabolic mirror;
 FIG. 3 shows a parabolic element in perspective;
 FIG. 4 shows an example of a support arm for the petals in elevation;
 FIG. 5 shows in elevation and on a larger scale the upper part of the upright in two parts;
 FIG. 6 is a view from above of FIG. 5;
 FIG. 7 shows the lower part of the angled arm;
 FIG. 8 is a view from above of FIG. 7
 FIGS. 9A and 9B shows another embodiment of the device of the invention, respectively in an extended state and a folded non extended state.
PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION
 With regard to the drawings it can be seen that the device is composed of a parabolic mirror 1 comprising in its focal area a support 2 for holding a cooking vessel.
 According to the invention the mirror 1 comprises a cut-out 3 extending up to the apex of said mirror. In this way the user has easy access to the cooking support 2 during cooking and is almost as close to the vessel as when using a cooker.
 The mirror is supported by an upright 4, in two parts 4a and 4b, part 4a forming a sleeve mounted on part 4b, the lower part of which is sunk into the ground or is supported by a weighted base of the type use to hold parasols. In this way part 4a can pivot freely.
 At the upper end of part 4a a cap piece 5 is provided, between the sides of which the upper part of an angled arm 6 is articulated. The mirror 1 is fixed to the lower part of the aforementioned arm which traverses the latter through a recess 7 provided for this at the level of the apex of said mirror.
 As shown in FIG. 1, when the upper part of the arm 6 extends parallel to the axis of the upright 4, the peak of the mirror is situated outside said axis.
 It follows from the description above that the control of the mirror, in relation to the rays of sun, is performed in two ways.
 The first way consists of pivoting the sleeve 4a, and the second way consists of pivoting the arm 6 (according to arrow F, see FIG. 5).
 In both cases means are provided for locking the movable elements after adjustment. It is possible to use a compass device 8 to maintain the inclination of the arm 6 and a pressure screw 9 to lock the sleeve 4a onto part 4b of the upright 4.
 The upper part of part 4b is introduced partially into the lower section of part 4a. Part 4b has a shoulder 10 against which the lower end of part 4a bears.
 The parabolic mirror 1 is formed by the assembly of elementary parabolic surfaces 1a or petals (see FIG. 3), each delimited by the intersection of two planes passing through the axis of the theoretical mirror.
 Each petal has an edging 11, making it possible to reinforce and ensure the connection of the petals with one another.
 According to one feature of the invention the cut-out 3 is obtained by omitting one or more petals.
 The assembly and support of the petals is provided by arms 12 (see FIG. 4).
 According to one embodiment, the lower part of the arm 6 has tabs 13 for securing the arms 12. If the angle formed by the generating planes of the petals is 60°, there will be a total of six tabs that are offset by an angle of 60°.
 Two petals are connected to each arm (except at the cut-out), the assembly being secured by screws and nuts (not shown), hence the provision of holes 14, the latter are not shown on the edging 11.
 Each arm can comprise an angled bracket 12a on its lower edge for reinforcement.
 Part 4a of the upright comprises, according to its axis, a finger 15 on which a bushing (not shown) can be fitted supported by the support 2. This arrangement makes it possible to adjust the position of the support in relation to the focal point of the mirror.
 The arm 6 comprises, in its folded back position shown in FIG. 1, an upper straight section 20 (here vertical) parallel to the upright 4, a first upper bend, an intermediate straight section 21 inclined in relation to the upper section, a second bend and a lower straight section 22 extending along the focal axis (virtual line passing through the apex of the mirror and the focal point).
 In particular, and as shown in the figures, the arm 6 is angled such that the arm 6, at the level where it passes through the apex of the mirror, is situated in the folded back position shown in FIG. 1 in which the upper part of the arm 6 is substantially parallel to the upright 4, comprises a lower part which extends along the focal axis A of the mirror (i.e. the virtual line passing through the apex of the mirror and the focal point).
 For the parabolic mirror the reference plane P is defined passing on the one hand through the axis (vertical to the figures) of the upright 4 and on the other hand through the focal point of the parabola.
 According to the invention, the arrangement is such that the mirror can pivot in relation to an axis of rotation B which forms an angle a that is definitely less (in absolute value) than 90° with the reference plane, which corresponds to the movement represented by arrow F in FIG. 5, which is in the plane perpendicular to this axis of rotation.
 Preferably, angle a is less than 60°, more preferably less than 30°, even more preferably less than 25°. In particular, it may be equal to 0. For example the angle a is equal to 21°.
 The user of the device who positions himself for cooking in the area of the cut-out by staying substantially perpendicular to the plane of reference (and therefore facing the rest of the mirror) is in a lateral position relative to the sun (the sun being in the focal axis A) and not opposite it. To follow the sun the user pivots the mirror in relation to axis of rotation B (that is according to arrow F). This pivoting action following the sun (so that the latter remains in the focal axis or substantially in the focal axis A) does not reduce the useful surface (exposed to the sun) and the pivoting does not hinder access to the support (arranged substantially in the focal point) for cooking. The use of the device is therefore particularly simple and effective.
 The device shown in FIGS. 9A and 9B is identical to the one shown in the other figures, with the exception of the fact that the upright 4 can be folded on itself for passing from an extended state of use to a non extended state of non use, in which the concavity of the parabolic mirror is turned towards the ground. To allow this folding/unfolding, an hinge 30 may be provided. Other analogous means providing the same function can also be provided.
Patent applications in class Energy concentrator with support for material heated
Patent applications in all subclasses Energy concentrator with support for material heated