Lamp

Abstract

A lamp, in particular for the use in potentially explosive areas, has at least one illuminant, one cooling device for the illuminant and one lamp enclosure with a light emission opening, whereby at least the illuminant and the cooling device are arranged in the lamp enclosure. To improve a heat transmission from the illuminant, in particular from the cooling device to the lamp enclosure, in a simple and safe way without the additional use of a heat-conducting paste or the like, whereby respective manufacturing tolerances that can negatively influence a good thermal contact shall no longer be considered, the cooling device for heat transmission to the lamp enclosure has a longitudinally variable cooling element or is formed as such.

Claims

1. A lamp, in particular for use in potentially explosive areas, with at least one illuminant, a cooling device for the illuminant and a lamp enclosure with a light emission opening; the lamp enclosure in which at least the illuminant and the cooling device are arranged, characterized in that the cooling device for heat transmission to the lamp enclosure has a cooling element having a length that is longitudinally variable independent of an arrangement of the at least one illuminant, and characterized in that the cooling element extends between a cooling body of the cooling device on which the at least one illuminant is disposed and an enclosure part.

2. The lamp according to claim 1, characterized in that the cooling element is formed as a cooling spring.

3. The lamp according to claim 1, characterized in that the cooling element is formed as a telescopically extendable cooling element.

4. The lamp according to claim 1, characterized in that the cooling element comprises a plurality of cooling elements arranged on different sides of the cooling body between said cooling body and the enclosure part.

5. The lamp according to claim 1, characterized in that the cooling element is retrofittable.

6. The lamp according to claim 1, characterized in that the cooling body is longitudinally variable.

7. The lamp according to claim 1, characterized in that the cooling body has two meshing cooling body parts that can be displaced in relation to each other while a heat transmission contact is maintained.

8. The lamp according to claim 7, characterized in that the two meshing cooling body parts are spring-loaded in a direction of separation of the cooling body parts.

9. The lamp according to claim 7, characterized in that the two meshing cooling body parts have a retention device to limit a length variation in a direction of separation to ensure a meshing between the meshing cooling parts.

10. The lamp according to claim 1, characterized in that the cooling element has cooling surfaces on its ends to fit closely with the associated enclosure part and/or with the cooling body.

11. The lamp according to claim 10, characterized in that a heat transmission medium is arranged between the cooling surfaces and/or the cooling element and the enclosure part and/or cooling body.

12. The lamp according to claim 10, characterized in that the cooling surfaces are replaceable.

13. The lamp according to claim 1, characterized in that the illuminant has a single LED or a plurality of LEDs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, advantageous embodiments of the invention will be explained in greater detail by means of the Figures included in the drawing.

(2) The Figures show:

(3) FIG. 1 a schematic display of a lamp with a cooling device according to the invention and

(4) FIG. 2 a section along the line II-II from FIG. 1 for a further embodiment of the invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

(5) FIG. 1 shows a side view in form of a cross-section through a lamp 1 according to the invention. This lamp comprises a lamp enclosure 4 in which at least a number of illuminants 2 and an associated cooling device 3 are arranged. Further electric or electronic devices and also reflection devices are not displayed in FIG. 1 for reasons of simplification.

(6) The cooling device 3 comprises for example a cooling body 7 in form of a cuboid or the like on which, however, also cooling fins can be arranged. Three illuminants 2 in form of LEDs (light-emitting diodes) are displayed on a light emission opening 5 of the top side of the cooling body 7 that faces the lamp enclosure 4. It is clear that also more of such LEDs 2 can be arranged. In addition, there has to be no appropriate space between the illuminants but they can for example be arranged in form of a LED light band or stripe directly on top of the cooling body.

(7) According to the invention, an additional cooling element in form of a cooling element 6 with a variable length is arranged besides the cooling body 7 as part of the cooling device 3. For example, such a cooling element 6 with a variable length is arranged in the form of a cooling spring 10 in a one-sided position in relation to the cooling body 7. This cooling spring extends between one end side of the cooling body 7 and an enclosure part 8 in form of an enclosure wall 9. The cooling spring 10 presses with both of its ends on one side against the enclosure wall and on the other side against the cooling body 7. To increase the contact surface, the cooling spring can have cooling surfaces 15 and/or 16 on its ends. These cooling surfaces are connected to the cooling spring 10 and fit flatly with the enclosure wall 9 and/or the cooling body 7.

(8) The cooling surfaces 15, 16 can be formed in a replaceable and/or flexible way. Due to the flexibility, a better adaptation to possibly curved surfaces of the enclosure wall 9 and/or of the cooling body 7 takes place. Also, there is the possibility that respective cooling surfaces 15, 16 have structures that are complementary to structures of the enclosure wall 9 and/or of the cooling body 7.

(9) A further embodiment of a cooling element 6 with a variable length in form of a telescopically extendable cooling element 11 is arranged on the other side of the cooling body 7. It comprises for example two pipe elements that are plugged into each other and that can be slid apart from and into each other in a longitudinally variable way. The displayed form of the telescopically extendable cooling element 11 is only an exemplary one, whereby pipe-shaped, rail-shaped or other telescopically extendable elements can be used. Also in this telescopically extendable cooling element 11 it will be advantageous if the respective telescope elements are spring-loaded in the extension direction.

(10) The cooling body 7 lies on an support surface 18 and maintains a heat transmission contact with this surface. Through the telescopically extendable cooling elements 6, a further heat transmission contact to the respective points of the lamp enclosure 4 and in particular to the enclosure wall 9 as a respective enclosure part 8 is created.

(11) FIG. 2 shows a section along the line II-II from FIG. 1 for a further embodiment of the invention. In this embodiment, the cooling body 7 is formed directly as a cooling element 6 with a variable length. This means that the cooling body 7 consists of at least two cooling body parts 12 and/or 13 that can be slid into and out of each other in relation to each other. The respective cooling body 7 is arranged on the support surface 18, but can also create a further contact to an enclosure wall 9 as an enclosure part 8 through extension of the cooling body part 12 and/or 13. In FIG. 2, the two cooling body parts 12, 13 are still shown as compressed and not making use of their length variability and in addition in contact with the enclosure wall 9. Spring elements 17 that support the extension of the cooling body parts 12, 13 in the direction of separation 14 can be arranged between the two cooling body parts 12, 13. This means that if an extension of the cooling body part 12 out of cooling body part 13 is allowed, it will move through the spring elements 17 up to fitting closely with the enclosure wall 9 due to the spring load. Therefore, a further thermal contact to the lamp enclosure 4 is created, which at least compensateswhere requiredan impairment of a thermal contact between the cooling body 7 and the enclosure surface 18 due to manufacturing tolerances or the like.

(12) Other ways of interaction of the cooling body parts 12 and 13 are conceivable. In the displayed embodiment, both cooling body parts 12, 13 mesh in a comb-like way.

(13) A retention mechanism, which prevents for example a too wide separation of the cooling body part 12 from the cooling body part 13 in the direction of separation 14 so that a specific meshing process of the two cooling body parts 12 and 13 is always ensured, is not shown in FIG. 2. Such a retention mechanism can for example be a latching mechanism, a mechanical end stop or the like.

(14) Between the parts that can be moved in relation to each other, for example of the telescopically extendable cooling element 11 and/or cooling body parts 12 and 13, a respective heat-conducting medium can be applied for better coupling and heat transmission.

(15) According to the invention, a simple possibility arises to compensate respective manufacturing tolerances during manufacturing of the lamp and the cooling device that might have a negative influence on a heat transmission between these parts. For this purpose, the cooling device has a cooling element with a variable length that usually creates a further contact between a cooling element of the cooling device and a respective enclosure part of the lamp enclosure. Therefore, the overall heat transmission from the heat source, i.e. the illuminant(s) to the lamp enclosure, is improved, whereby the latter can emit heat to the environment accordingly.

(16) Through the use of the cooling element with a variable length, no additional active cooling of the illuminants, for example in form of a ventilator or the like, is required anymore for many embodiments of a lamp.