EP1467142A1 - Luminaire recessed in the ground comprising a temperature reduction system - Google Patents

Abstract

The light has a reservation pot (3) including vertical blades (13) passing through interior of a circular space (11) filled with air. A lighting body (4) has exterior vertical blades (14) that pass through interior of the space and are inserted between the blades (13). The blades (13, 14) are distributed all around the periphery of the light to form a temperature reduction system at a level of a closing sheet (5). The circular space is defined between the reservation pot and a lateral wall (9) of the light body.

Description

The present invention relates, in general, to the field technical lighting fixtures and, more specifically, luminaires recessed on the ground, especially on sidewalks, squares, halls, etc ... in order to lighting in public or private places, especially in an outdoor environment but also inside buildings. More particularly, this invention relates to a recessed floor light with temperature reduction system.

Most recessed floor lights are currently composed of a cylindrical or prismatic barrel or tank with a square base, and a booking pot. The reservation pot, sealed in the ground, allows a easy maintenance of the luminaire, since it can be removed for a possible maintenance, for example to replace a socket or jar.

The interior of a ground-recessed light is the seat of a significant heating, due to the heat given off by the lamp, in usually a metal halide lamp, and the fact that the luminaire is closed to its upper part by a very thick glass plate, flush with the ground.

In the case of a luminaire placed in a reservation pot, the temperature inside the luminaire is even higher, and can be 40 ° C higher than the temperature observed for a recessed luminaire directly into the ground. This difference in temperature is mainly due to the insulating air mattress, trapped between the tank of the luminaire itself said, and the tank constituting the reserve pot. As a result, the temperature, measured in the middle of the luminaire's closing glass, on the outside of it, can become excessively high, especially higher than the maximum recommended temperature of 75 ° C, resulting in risk of burns for people who come directly into contact with this window. The risk of reaching, in the center of the closing window, excessive temperatures far above 75 ° C, especially when the device is equipped with a powerful lamp, for example a 150 watts, metal iodide, associated with a reflector returning to this glass a very narrow or very concentrated light beam, for example with a opening angle of the order of 10 °.

Some improvements, aimed at reducing the temperature of such recessed lights, can be made by reducing the thickness of the air mattress trapped between the two tanks, or else by choosing, for the manufacture of these tanks, materials other than stainless steel usually used, in order to increase heat dissipation as well as possible, but the results thus obtained remain very limited.

According to another proposal, indicated in the requests for French patents 2,711,222 and 2,755,212, the interior volume of luminaires built-in floor is ventilated through a communication with the outside, the heat being evacuated through holes provided in the part upper of these luminaires, therefore at ground level. One such solution is inappropriate, especially in outdoor applications, due to inevitable entry of rainwater, humidity and various dirt to inside the fixtures, through the ventilation holes. In addition, these holes are likely to be quickly clogged with dirt or debris, especially there also when used in an outdoor environment, which then makes the ineffective ventilation.

The present invention aims to avoid all of the drawbacks previously exposed, by providing a recessed floor light and provided a particularly effective temperature reduction system, particular suitable for a luminaire placed in a reservation pot, and does not requiring no communication opening between the interior volume of the fixture and exterior, therefore waterproof and moisture proof.

To this end, the invention relates to a recessed floor light, of type consisting of a reserve pot intended to be sealed in the ground, and a luminaire body removably placed inside the pot reservation, the luminaire body containing a lamp and a reflector, a intermediate space filled with air being provided between the reserve pot and the luminaire body, and the assembly being closed at its upper part by a glass, this recessed floor light being essentially characterized by the fact the reservation jar has fins on its side wall substantially vertical protruding inside the filled intermediate space air, while the luminaire body has, on its lateral surface, substantially vertical outer fins also protruding inside of the air-filled intermediate space, the outer fins of the luminaire interposed between the interior fins of the reserve pot, and these fins being distributed over the entire periphery of the luminaire, so as to constitute a temperature reduction system, in particular at the level of the closing window.

In a preferred embodiment of the invention, the pot reservation comprises, on its side wall, on the one hand the fins substantially aforementioned verticals protruding inside the filled intermediate space air, and on the other hand substantially vertical fins projecting towards outside.

Advantageously, the various aforementioned fins extend over substantially the entire height of the reserve pot, and of the body part of luminaire surrounded by the reservation pot.

The bottom of the luminaire body may include still others fins, for example arranged parallel to each other, making protruding under this background.

Thus, the idea underlying the present invention consists in putting take advantage of the intermediate space filled with air, located between the reservation pot and the body of the luminaire, by having fins in this intermediate space, made in the manner of ribs, which maximize the surface area distribution and heat exchange. These fins, arranged around the periphery of the luminaire, practically over its entire height, as well as at the level from the bottom of the appliance, will allow the heat to be removed to the outside released inside this appliance, as soon as the luminaire is switched on. In in particular, the "external" fins of the luminaire body, inserted between the "inner" ribs of the reserve pot, will transmit to them the heat from inside the luminaire body, and this heat can then be communicated to the environment via "outer" fins of the reservation jar.

This results in an effective and significant reduction in the temperature, especially at the closing window, on which the desired maximum temperature of 75 ° C can be effectively observed, even in the case of a recessed luminaire with a powerful lamp and beam concentrated, and this by a simple, economical and offering technical solution all convenience and security. In particular, the different fins are obtained directly from the foundry, during the manufacture of the reserve pot and of the luminaire tank itself, which for the rest are not modified. The nesting of the vertical fins, without direct contact, always allows extraction of the luminaire body for maintenance operations. Through elsewhere, the solution proposed by the invention does not involve any communication with the outside through holes or openings, which have the disadvantages previously exposed, so that the luminaire, object of this invention, is completely waterproof and moisture-proof, and thus responds to the standard protection index IPx7, ie "waterproof submersible temporarily ".

In addition, if the limit value of set temperature may be exceeded, the reduction system temperature of the recessed floor light, object of the invention, also includes a fan placed in the lower part of the luminaire body, and creating during operation, inside the luminaire body, a circulation air. The fan thus makes it possible to homogenize the temperatures, between the luminaire closing window and the region of the bottom of the luminaire body, until reaching an intermediate value. The action of this fan combines here advantageously with the effect of the fins, which carry out the heat exchange with the booking pot and from there with the outside, because thanks to this heat exchange the temperature in the lower part of the body luminaire is lowered, which has the consequence (also thanks to the circulation above) to further reduce the temperature in the center of the window closing. Finally, note that the improvement in temperature reduction is here obtained by a purely internal air circulation, so without creating undesirable openings for communication with the outside, and this at by means of a small fan, compact and of low power, placed in the lower part of the luminaire body where there is space necessary and also of the power supply necessary for the motor of this fan.

Figure 1 est une vue d'ensemble, en coupe verticale, d'un luminaire conforme à la présente invention ;

Figure 2 est une vue en coupe horizontale de ce luminaire, suivant II-II de figure 1 ;

Figure 3 en est une vue par dessous, suivant la flèche F de figure 1.

The invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of example, an embodiment of this luminaire recessed on the ground, with temperature reduction system:

Figure 1 is an overall view, in vertical section, of a luminaire according to the present invention;

Figure 2 is a horizontal sectional view of this light, according to II-II of Figure 1;

Figure 3 is a view from below, along arrow F of Figure 1.

The luminaire, shown in Figure 1, is intended to be embedded in the ground, very roughly represented by its surface 2. This luminaire generally consists of a sealed reservation pot 3 in the ground 2, and a luminaire body 4 removably placed at inside the reserve pot 3. In the example illustrated in the drawing, the pot of reservation 3 and the luminaire body 4 have shapes substantially cylindrical, coaxial. The whole is closed, at its upper part, by a thick closing glass 5, flush with the ground 2.

In a generally known manner, the interior of the luminaire body 4 forms a master bedroom, in which are placed a lamp 6 and a reflector 7, which make it possible to create a more or less open light beam or concentrated, directed upwards and thus achieving an illumination of the environment outside, through the closing window 5. The lamp 6 and the reflector 7 are mounted above a horizontal plate 8, placed inside the body luminaire 4, at a certain height above the base of this body 4.

The luminaire body 4 is delimited by a tank, itself formed of a side wall 9 and a bottom 10.

When the lamp 6, which is in particular an iodide lamp metal, is illuminated, and in particular if the light beam returned by the reflector 7 is narrow or concentrated, there is heating of the window closing 5, the temperature T1 at the center of this window 5 thus being able to rise up to excessively high values, if no special provision is not taken. This rise in temperature is due in particular to the presence an insulating "air mattress" in the annular space 11 delimited between the jar reservation 3 and the side wall 9 of the luminaire body 4.

The recessed floor light, here described, is provided with a system which aims to reduce the temperature T1 at the center of the closing window 5, by homogenization of temperatures and evacuation of heat.

For this purpose, the reservation pot 3 comprises, on the one hand, fins vertical 12 outside, formed around its entire circumference, and practically over its entire height, at regular angular intervals, following radial directions (see in particular Figure 2).

The reserve pot 3 also has fins vertical 13 interior, also formed over its entire circumference, and practically over its entire height, at regular angular intervals, in radial directions. When the luminaire body 4 is in place, the inner fins 13 of the reservation pot 3 take place in space annular 11 filled with air, delimited between the reserve pot 3 and the wall side 9 of the luminaire body 4.

As regards the luminaire body 4, its side wall 9 has 14 external vertical fins, formed over its entire circumference in radial directions, over a height that corresponds at least that of its part surrounded by the reserve pot 3. The fins 14 of the luminaire body 4 are the same number as the fins inside 13 of the reservation pot 3, and they are separated by the same angular intervals.

Thus, when the luminaire body 4 is in place, these fins 14 are inserted between the inner fins 13 of the reserve pot 3, in the annular space 11 filled with air delimited between the reservation pot 3 and the side wall 9 of the luminaire body 4.

Under the bottom 10 of the luminaire body 4 are formed other fins 15, arranged parallel to each other in planes vertical, as shown more particularly in Figure 3.

In the example illustrated in the drawing, the reduction system of temperature also includes a small fan 16, placed in the part lower part of the luminaire body 4, more particularly in a chamber 17 located under the plate 8 which serves as a support for the reflector 7. A passage 18 of air outlet is provided in plate 8, above the location of the fan 16. Another air inlet passage 19 is provided in the same plate 8, opposite the air outlet passage 18.

The plate 8 also supports a deflector 20, which extends in oblique, upwards, above the air outlet passage 18, between this passage 18 and the reflector 7.

Finally, the recessed floor light includes means power supplies, not shown, which provide power necessary on the one hand for the lamp 6, and on the other hand for the fan 16.

The operation of the temperature reduction system of this recessed floor light is as follows:

At the level of the annular space 11, delimited between the pot of reservation 3 and the luminaire body 4, the outer fins 14 of the body of luminaire 4 and the inner fins 13 of the reserve pot 3 allow the transfer of heat, generated inside this luminaire body 4, to the reserve pot 3. The outer fins 12 of this reserve pot 3 provide heat dissipation to the ground 2, in which they are drowned.

In addition, the operation of the fan 16 creates, inside the luminaire body 4, a closed circuit air circulation, indicated by arrows in figure 1. The air is drawn towards chamber 17 from the lower part of the luminaire body 4 by the air inlet passage 19, and it is discharged by the fan 16 through the air outlet passage 18. Thanks to the deflector 20, the discharged air is necessarily directed towards the upper part of the body of luminaire 4, where it heats up in contact with the closing glass 5, before return to the lower part to be sucked back through the passage inlet 19. Thus, the fan 16 and the internal air circulation created by it ensure temperature uniformity in the luminaire body 4, in particular between the temperature T1 at the center of the closing window 5, on the one hand, and the temperature T2 in the lower part of the luminaire body 4, on the other hand. This temperature T2, lower than the temperature T1, is itself lowered by the heat dissipation achieved by means of the fins 12, 13 and 14, as described above.

The combination of the means described above, namely the various fins 12, 13, 14, 15 and the fan 16, allows to reduce in all cases the temperature T1 in the center of the closing window 5 up to a level acceptable, i.e. less than 75 ° C.

• en modifiant le nombre, la forme et la dimension des ailettes, qui sont à déterminer dans chaque cas, en fonction de la construction générale de l'appareil d'éclairage et de la quantité de chaleur à évacuer ; en particulier, la hauteur et l'épaisseur de ces ailettes peuvent varier, de même que le détail de leur forme (parallélisme des faces ou dépouilles) qui est dicté par des nécessités de moulage ;
• en appliquant le même système de réduction de température à des luminaires encastrés au sol de toutes configurations, en particulier de section horizontale autre que circulaire, et avec tout genre d'aménagement intérieur, en particulier en ce qui concerne le montage, fixe ou orientable, de la lampe et du réflecteur qui lui est associé.

One would not depart from the scope of the invention, as defined in the appended claims:

• by changing the number, shape and size of the fins, which are to be determined in each case, depending on the general construction of the lighting apparatus and the amount of heat to be removed; in particular, the height and thickness of these fins can vary, as can the detail of their shape (parallelism of the faces or undercuts) which is dictated by molding requirements;
• by applying the same temperature reduction system to recessed floor lights of all configurations, in particular of horizontal section other than circular, and with any kind of interior arrangement, in particular with regard to mounting, fixed or adjustable, of the lamp and the reflector associated therewith.

Claims (7)

Recessed ground luminaire, of the kind comprising a reserve pot (3) intended to be sealed in the ground (2), and a luminaire body (4) removably placed inside the reservation pot (3), the luminaire body (4) containing a lamp (6) and a reflector (7), an intermediate space (11) filled with air being formed between the reserve pot (3) and the luminaire body ( 4), and the assembly being closed at its upper part by a closing window (5), characterized in that the reserve pot (3) comprises, on its side wall, substantially vertical fins (13) projecting beyond the interior of the intermediate space (11) filled with air, while the luminaire body (4) comprises, on its lateral surface (9), substantially vertical external fins (14) also projecting inside the intermediate space (11) filled with air, the external fins (14) of the luminaire body (4) being inserted between the interior fins (13) of the reserve pot (3), and these fins (13, 14) being distributed over the entire periphery of the luminaire, so as to constitute a temperature reduction system, in particular at the level of the closing window ( 5). Recessed floor luminaire with temperature reduction system according to claim 1, characterized in that the reserve pot (3) has, on its side wall, on the one hand the above-mentioned substantially vertical fins (13) projecting inside of the intermediate space (11) filled with air, and on the other hand substantially vertical fins (12) projecting outward. Recessed floor luminaire with temperature reduction system according to claim 1 or 2, characterized in that the various aforementioned fins (12, 13, 14) extend over substantially the entire height of the reserve pot (3), and the part of the luminaire body (4) surrounded by the reserve pot (3). Recessed floor luminaire with temperature reduction system according to any one of Claims 1 to 3, characterized in that the bottom (10) of the luminaire body (4) has other fins (15), for example arranged in parallel to each other, projecting under this bottom (10). Recessed floor luminaire with temperature reduction system according to any one of Claims 1 to 4, characterized in that the temperature reduction system also comprises a fan (16) placed in the lower part of the luminaire body (4) , and creating during operation, inside the luminaire body (4), an air circulation. Recessed floor luminaire with temperature reduction system according to claim 5, characterized in that the fan (16) is placed under a plate (8) serving to support the reflector (7) of the luminaire, an outlet passage (18) of air being formed in the plate (8), above the location of the fan (16), and an air inlet passage (19) being formed in the plate (8), opposite of the air outlet passage (18). Recessed floor luminaire with temperature reduction system according to claim 6, characterized in that the plate (8) supports a deflector (20) which extends obliquely upwards above the passage (18) of air outlet, between this passage (18) and the reflector (7).

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