Luminaire comprising a lens or cover arranged on a housing

Abstract

The invention relates to a luminaire (100) comprising a housing (60) having a receiving opening (31) for accommodating at least part of a lens (40) or cover (70, 80). A circumferential seal in the form of an O-ring (5) is arranged on the outer periphery of the lens (40) or cover (70, 80), which seal rolls from a first peripheral groove (51) or constriction over an over-center point (55) into a second peripheral groove (52) or constriction when the lens (40) or cover (70, 80) is inserted into a receiving region (30) of the housing (60).

Description

Luminaire comprising a lens or cover arranged on a housing [1] The present invention relates to a luminaire which has at least one lens or cover which is arranged on a housing of the luminaire or on a housing part of the luminaire. In particular, the invention relates to an emergency luminaire which has a lamp and an emergency lighting lens which is provided for directing the light emitted by the lamp into a specific region in order to illuminate an escape route. A particularly preferred application example of the invention is a so-called escape route sign luminaire, which additionally also has an escape route illumination function. [2] Reliable illumination of escape routes plays a central role in safety concepts for buildings, since such illumination is a prerequisite for ensuring safe evacuation in an emergency. Clear illumination makes orientation easier and allows people to quickly and safely find the shortest route to the exits, even in the event of power outages or smoke. For this reason, a corresponding emergency exit illumination is often combined with a graphic representation of the direction of an escape route, which is why such escape route illumination is used in particular in so-called escape route sign luminaires. [3] Illumination pointing in a specific direction is here usually achieved with the aid of correspondingly designed lenses that purposely deflect the light from an associated lamp into a specific direction. The emergency lighting lens is positioned on or in the wall of a corresponding luminaire housing and aligned in such a way that the emission of the light generated by the lamp arranged in the luminaire housing is directed in the desired direction. Since the emergency lighting lens must be aligned in a specific direction depending on the field of application and mounting situation, it is often provided to design this such that it can be rotated in a desired direction while still attached to the housing. [4] A luminaire with such an emergency lighting lens is known from the prior art, which luminaire is accommodated with its light coupling region in a reception opening in a luminaire housing, a lamp then being positioned inside the housing, which lamp is associated with the emergency lighting lens. In this case, the emergency lighting lens is held in place on the luminaire housing in a latching manner by means of latching elements, a flange-like section of the lens being in contact with the luminaire housing from the outside. An annular sealing element is often provided between the luminaire housing and the flange-like section of the emergency lighting lens, the housing being pressed towards the sealing element due to the latching mounting of the emergency lighting lens on the housing, so that a simple seal exists between the luminaire housing and the emergency lighting lens. In particular, in this way spray water perpendicularly striking the outside of the luminaire and thus the emergency lighting lens can be prevented from penetrating the luminaire housing. [5] This known implementation therefore makes it possible, to a certain extent, to protect the emergency luminaire from the penetration of spray water. However, it has been found that the solution known from the prior art only inadequately protects the luminaire from a water jet striking at an angle or horizontally, since in this case the contact pressure of the emergency lighting lens and the sealing element is not sufficiently high to prevent water from penetrating. This is relevant in particular with regard to a desired better IP rating of the luminaire, as a higher IP rating corresponds to a better sealed luminaire, and said luminaire can therefore be used in a more versatile and flexible manner. [6] The present invention is therefore based on the object of specifying a novel solution that makes it possible to arrange a lens in the housing wall of a luminaire in a reliable and sealed manner. Particularly preferably, an emergency luminaire is intended to be better protected against the penetration of moisture, while still ensuring the aforementioned adjustability of the emergency lighting lens in order to reliably illuminate escape routes regardless of the specific mounting situation of the luminaire. [7] The object is achieved according to the present invention by a luminaire that has the features of claim 1. Advantageous developments of the invention are the subject-matter of the dependent claims. [8] According to the present invention, it is provided that an O-ring is used to seal the luminaire housing with respect to the lens, the sealing situation provided for this purpose being designed such that when the lens is inserted or pressed into a corresponding receptacle of the housing or housing element, the O-ring rolls over an over-center point on the outer periphery of the lens body and then secures the lens in the receptacle in a clamped manner, to prevent it from falling out. In this case, to insert the lens the O-ring must therefore first be placed in a starting position in front of the over-center point on the lens, the lens then rolling into the desired mounting position, during the insertion of the lens into the housing or housing element, due to the design of said lens. The lens then remains in the housing solely due to the frictional force of the squeezed O-ring. However, the lens can still be rotated with a certain amount of force so that - if desired - the light output can be directed in a desired direction, e.g. for escape route illumination. [9] Furthermore, it still remains possible to replace the lens, the O-ring again rolling past the over-center point and returning to its starting position, upon removal of the lens from the housing or housing element. 

[10] Moreover, the concept according to the invention is not limited to the detachable arrangement of lenses on a luminaire housing but can be used in a variety of ways. Thus, according to the solution according to the invention, for example a cover element can also be arranged detachably on a luminaire housing, which cover element allows access if necessary to components arranged inside the housing. The present invention can thus also be used, for example, to provide a cover that can close the housing in a sealing manner, the removal of which allows access to a maintenance or configuration element arranged inside the housing, for example a fuse, a battery or a switch for setting parameters. 

[11] According to the present invention, a luminaire is proposed which comprises:a) a housing or housing element which has a receiving opening for accommodating at least part of a lens or a cover;b) a lens or cover that can be attached to the receiving opening;wherein the receiving opening of the housing or housing element forms a hollow cylindrical receiving region in which, in the mounted state of the lens or cover, a rotationally symmetrical bearing region of the lens or cover is rotatably positioned,wherein a circumferential seal in the form of an O-ring is arranged on the outer periphery of the bearing region of the lens or cover, which seal acts between the housing or housing element and the lens or cover,wherein the bearing region of the lens or cover has a first peripheral groove or constriction for receiving the O-ring in a starting position and also, axially offset thereto, a second peripheral groove or constriction for receiving the O-ring in a mounting position,wherein the first and second peripheral groove or constriction are separated from each other by an elevation defining an over-center point, and wherein the O-ring, when the lens or cover is being inserted into the receiving region, rolls from the first peripheral groove or constriction over the over-center point into the second peripheral groove or constriction. 

[12] The advantage of the solution according to the invention is that a sealed arrangement of the lens or cover in the luminaire housing can be achieved in a very simple way, so that in this region the housing is sufficiently well protected against the penetration of dust and / or moisture and thus the requirements for a so-called higher type of protection are met. Due to the special design of the lens or cover, it is possible to produce both the lens and the luminaire housing or the luminaire housing part holding the lens or cover very easily and reliably by an injection-molding process, thus reducing outlay and production costs. 

[13] It is preferably provided that the elevation forms a ramp leading from the first peripheral groove or constriction to the over-center point, which facilitates the rolling of the O-ring during the insertion of the lens or cover into the housing or housing element. Since, as already mentioned above, it should also be possible to remove the lens or cover at a later time, and in this case the O-ring should return to its starting position, it is furthermore particularly preferably provided that the elevation additionally also forms a further ramp leading from the second peripheral groove or constriction to the over-center point, this further ramp, however, preferably being designed to be steeper than the first ramp leading from the first peripheral groove or constriction to the over-center point. The rolling from the starting position to the mounting position should therefore be easier, while removing the lens or cover from the housing or housing element should be possible only with increased effort. 

[14] In order to assist the rolling of the O-ring according to the invention during the mounting of the lens or cover or the removal of the lens or cover, it can preferably be provided that the receiving region of the housing or housing element has an inwardly projecting small projection or rib on a peripheral wall of the receiving opening, which correspondingly assists the rolling along the bearing region of the lens or cover between the two grooves. 

[15] As already mentioned, the seal acting between the lens or cover and the housing is solely responsible for the reliable retention of the lens or cover in the housing or housing part. It also exerts a certain frictional force, which prevents the lens or cover from being rotated without application of considerable force. 

[16] Ideally, this frictional force is so great that simply gripping and twisting the lens or cover is not possible, but instead the use of a suitable tool is required. Accordingly, it may be provided that one or more indentations are formed on a region of the lens or cover projecting outwards beyond the housing element, which indentations allow the lens or cover, inserted into the housing element, to be rotated and / or the lens or cover to be removed only with the aid of a suitable tool, wherein these indentations are preferably slot-shaped. Using appropriate screwdrivers, the lens or cover can therefore then be rotated and / or removed from the housing, ensuring that it remains permanently in the desired position and orientation. In this case, the projecting region of the lens or cover may have a collar, at least some of the indentations preferably being formed on the outer periphery of the collar. 

[17] The concept according to the invention is applicable to all types of luminaires in which one or more lenses are to be reliably sealed in the wall of the housing or a housing part of the luminaire. In this case, the luminaire is particularly preferably a so-called emergency luminaire, which is used for escape route illumination and in which the lens(es) is / are used to emit light in the direction of an escape route to be illuminated. In particular, the lens(es) can be designed in such a way that the light is emitted asymmetrically in a specific direction of radiation. 

[18] As already mentioned, the illumination of an escape route is furthermore often also combined with a graphic representation of the direction of the escape route. According to a further particularly preferred embodiment of the present invention, the emergency luminaire is therefore an escape route sign luminaire which, in addition to the lamp for escape route illumination, also has further lamps with which an escape route symbol is illuminated and displayed This may in particular be an escape route sign luminaire based on the known fiber optic technology. That is to say that the luminaire preferably has a light guide element which forms a plate-shaped light guide into which the light from the additional lamps is coupled, a pictogram element being arranged on at least one flat side of the light guide, and the light guide being designed to distribute the coupled-in light and emit it distributed over the flat side, in order to illuminate the pictogram element. In this case, the emergency lighting lens provided for illuminating the escape route is preferably arranged on a holder for the light guide and laterally next thereto. 

[19] In this case, the light guide element in question can additionally also form part of the housing or a cover for the housing of the luminaire, the light guide element preferably forming the housing element on which the emergency lighting lens is arranged. This results in a very simple design for the escape route sign luminaire, in which, despite everything, the graphic representation of an escape route is efficiently combined with illumination of the escape route, and in addition, a reliable sealing of the luminaire housing is achieved. In particular, it is ensured that the luminaire also meets the requirements for a higher protection class (IP class) in this way. 

[20] Naturally, the luminaire according to the invention can also have a plurality lenses with associated lamps. In the case of an escape route sign luminaire like the one mentioned above with a light guide, the use of a plurality of emergency lighting lenses is particularly useful, since regardless of the respective mounting situation, at least one of the available emergency lighting lenses can be used for efficient illumination of an escape route. 

[21] According to another development, it can further be provided that the luminaire has a sensor element arranged in the housing, which element is positioned in the region of the receiving opening. This sensor element can in particular be a camera sensor or a PIR sensor, the lens fastened in the manner according to the invention then serving as optics for the sensor element. Furthermore, it may be provided that a maintenance or configuration element, for example a fuse, a battery, a switch for setting parameters, or a memory (e.g. in the form of a memory card), is arranged in the housing, the maintenance or configuration element being accessible via the receiving opening that is closed by the cover, in order to, for example, carry out maintenance work, read out data, or perform an update. Finally, the element protected by the cover according to the invention could also be a communication module, for example an NFC antenna or a Bluetooth module, which should also be accessible if necessary. 

[22] The invention is explained in more detail in the following using the accompanying drawings. In the drawings:Fig. 1 shows a particularly preferred application example of the present invention in the form of an escape route sign luminaire, which is designed according to the present invention and in which emergency lighting lenses for escape route illumination are therefore arranged on a luminaire housing according to the solution according to the invention;Fig. 2 is a view of the underside of the escape route sign luminaire from Fig. 1;Fig. 3 is the view of a light guide element which serves as the holder for the emergency lighting lens according to the invention;Fig. 4 is an enlarged view of the light guide element with corresponding receptacles for two emergency lighting lenses;Fig. 5 is a view of the light guide element from above;Figs. 6 and 7 are perspective views of a lens according to the invention, the O-ring being in the mounting position.Fig. 8 is a sectional view of the emergency lighting lens attached to the light guide element before its mounting;Figs. 9a and 10a are side views of the emergency lighting lens, the O-ring being in its starting position and mounting position, respectively;Figs. 9b and 10b are sectional views of the emergency lighting lens attached to or inserted into the light guide element;Figs. 9c and 10c are each enlarged representations of sub-regions of Figs. 9b and 10b;Fig. 11 shows a further embodiment of a luminaire according to the invention, in which access to an underlying functional part can be obtained by means of a detachably fastened cover;Figs. 12 to 14 show a further exemplary embodiment in which production-related openings of a luminaire housing are closed in a detachable and sealed manner with the aid of corresponding covers. 

[23] Figs. 1 and 2 are two views of an escape route sign luminaire generally designated with reference sign 100 according to the invention, i.e. an escape route sign luminaire in which the direction of an escape route is indicated by means of an illuminated pictogram, and at the same time the escape route is also illuminated in a targeted manner by additional lamps. It should be noted, however, that the concept according to the invention for the optimized mounting of at least one lens can also be used with other types of luminaire. In principle, the solution according to the invention can always be used when lenses are to be arranged in a sealed manner on the housing wall of a luminaire, ideally arranged in a rotatable manner. The solution according to the invention can thus also be used, for example, in floor-standing, ceiling-mounted, suspended or recessed luminaires that are not necessarily used for illuminating escape routes, even though the invention is explained below in particular with reference to the illustrated escape route sign luminaire. As will be explained again further below, a cover can also be detachably fastened to a luminaire housing in a similar way, via which access can to components located inside the luminaire can then be obtained. 

[24] In the illustrated embodiment, the direction of the escape route is indicated in an illuminated manner by means of a pictogram element 90, which is arranged on a flat side of a plate-shaped light guide which will be described in more detail below. Light is coupled into this light guide from one narrow side, the light then being distributed in a known manner as evenly as possible over the entire surface via multiple reflections and then emitted via the flat side on which pictogram element 90 is located. The pictogram element 90 is usually formed by a film or a thin plate-like part, which is arranged on the outside of a so-called light guide element 10 and fastened there in a suitable manner. However, this aspect plays a rather subordinate role for the present invention, and the realization of the pictogram and its arrangement on the light guide element 10 could be carried out in different ways. Printing directly on the light guide would also be conceivable in principle. 

[25] In the present case, the light coupled into the light guide element 10 originates from elongate luminaires, which can be formed, for example, by a linear arrangement of LEDs that are arranged inside the housing 60 of the luminaire 100. In this case, the positioning of the LEDs is such that the light is coupled into the light guide element 10 as efficiently as possible, i.e. completely, and then emitted via its flat side. For this purpose, the light guide element 10 can have corresponding outcoupling structures in the region of the pictogram 90, which structures no longer totally reflect incident light rays but rather deflect them in such a way that they can leave the light guide element 10. In this case, the positioning of these outcoupling structures depends on whether corresponding pictograms 90 are arranged on one or on both sides of the light guide element 10. 

[26] Not only the lamps are arranged within the housing 60, which extends along the longitudinal axis L defined by the LED lamps. In addition, the housing 60 also contains further electronic components for operating and supplying power to the lamps. In particular, this may be a suitably designed converter, which supplies the preferably used LEDs with a voltage suitable for their operation. Emergency power supplies in the form of batteries or accumulators can also be arranged within the cuboid housing 60, which is then fastened, for example, to a ceiling or another suitable carrier element. 

[27] The previously mentioned light guide element 10 is shown in isolation in Fig. 3. This is preferably a single-piece component which, in addition to the transmission and planar output of the light emitted by the LED lamps over a surface, also fulfills other functions. For this purpose, the light guide element 10 essentially consists of three regions or sections, namely a light coupling section 15, a light guide section 20, and a cover 25. All three sub-regions are preferably integrally joined to form a single component, which is produced in particular by an injection-molding process. In principle, it would be conceivable for the three sub-regions to consist of different materials, e.g. the cover 25, which will be explained in more detail below, consists of an opaque material. However, as a rule, the light guide element 10 according to the invention will consist entirely of the same material, preferably clear plastic, PMMA or PC being particularly suitable for this purpose. 

[28] The task of the light coupling section 15 is to absorb and transmit the light emitted by the LED lamps as completely as possible. In this case, the rib-shaped light coupling section 15 has a narrow end face 16 on its upper side, which is directed towards the LEDs and is positioned in such a way that their light can enter the light coupling section 15 with as little loss as possible. If necessary, the front surface 16 may also have additional structures such as lenses or the like that are matched to the LEDs, in order to thereby further improve the efficiency of the light coupling. 

[29] The light guide section 20 following the light coupling section 15, which is designed in a known manner as a classic planar light guide, is responsible for the actual light emission, i.e. the illumination of the pictogram 90. The light guide section 20 is thus designed in a plate-like shape, such that light is totally reflected internally several times and is thus transmitted and evenly distributed within the light guide section 20. The light can then be correspondingly emitted uniformly via the light outcoupling structures already mentioned above via one or via both flat sides 21 of the light guide section 20. 

[30] Finally, the third region of the light guide element 10, namely the cover 25, adjoins the transition region between light coupling section 15 and light guide section 20. In addition to the lighting-related tasks described above, the light guide element 10 simultaneously also forms part of the housing of the luminaire 100. Strictly speaking, the cover 25 of the light guide element 10 serves to close the open underside of the actual housing 60 of the luminaire 100. Adjacent to the light coupling section 15 and the light guide section 20, the cover 25 thus initially forms a cover region 26 oriented perpendicularly thereto, which region forms the underside of the housing when the light guide element 10 is mounted on the housing 60. The dimensions of this cover region 26 therefore correspond to the dimensions of the further housing 60, here too as tight as possible a connection between cover 25 and housing 60 being desired. For this purpose, a vertically extending web 28 is formed peripherally at the edge of the cover region 26, which web, when mounted on the housing 60, engages in a corresponding annular channel of the housing 60 (see, for example, Fig. 8). In this channel, in particular a seal can be positioned, into which the upper end of the web 28 dips, so that an extremely efficient connection is achieved in the transition region between housing 60 and cover 25, which connection prevents the ingress of dust, but especially also of moisture and spray water. In this case, corresponding latching or clamping elements may also be formed on the cover 25, which elements are used to fasten the light guide element 10 to the luminaire housing 60. 

[31] In addition, however, the cover 25 also serves as a holder for the emergency lighting lenses 40 used for the escape route illumination. These lenses are arranged laterally next to the centrally extending light guide section 20, in the horizontal cover region 26, and are designed in a known manner such that they emit light in a targeted manner in a specific direction, in order, for example, to illuminate an escape route running below or diagonally below the luminaire 100. For this purpose, inside the luminaire housing 60, in addition to the first lamps already mentioned for illuminating the pictogram 90, further lamps are additionally arranged, which are associated with the emergency lighting lenses 40 and can be activated selectively in order to illuminate an escape route with the help of an emergency lighting lens 40 associated therewith. 

[32] As can be seen in this case in particular from Fig. 2, the horizontal cover section 26 of the cover 25 has a total of three receptacles 30 for holding associated emergency lighting lenses 40, wherein in Fig. 2 the two upper receptacles 30 are equipped with emergency lighting lenses 40, the lower receptacle 30, the design of which will be described in more detail below, being shown without an associated lens 40. It should be noted that during the subsequent operation of the luminaire 100, all three receptacles 30 will be equipped with corresponding emergency lighting lenses 40; however, it is not necessarily required that all emergency lighting lenses 40 be used simultaneously for the actual illumination of the escape route. The illustrated arrangement of the three receptacles 30, in conjunction with the fact that the light guide element 10 can also be arranged rotated about 180° on the luminaire housing 60 and that the emergency lighting lenses 40 can be variably rotated, as explained in more detail below, covers all conceivable situations, so that, depending on the mounting situation of the luminaire 100 and the course of the escape route, also only some of the associated lamps can be used with appropriate alignment of the associated emergency lighting lens(es) 40. 

[33] In principle, however, the cover 25 could also have four receptacles for emergency lighting lenses 40, or just two receptacles 30 positioned diagonally opposite each other. For the present invention this plays a rather subordinate role, since it is primarily concerned with the task of reliably fastening the lenses 40 to the associated receptacles 30 in such a way that they can be aligned in the desired manner and yet a permanently reliable seal between the emergency lighting lens 40 and the housing 60 or the cover 25 for the housing 60 can be achieved. This will be explained in more detail below with the aid of the other figures. 

[34] The basic shape of the lenses 40 is best seen in Figs. 6, 7, 9a and 10a. With regard to the components responsible for light emission, the emergency lighting lens 40 according to the invention is similar to emergency lighting lenses already known from the prior art. The emergency lighting lens 40 shown in the figures therefore initially has a lens body 41 which is approximately conical in shape and forms a recess 42 at its upper end. The lamp, which is preferably formed by a high-performance LED and is not shown in the figures, projects at least partially into this recess 42, so that the lateral surface and the bottom surface of the recess 42 represent light entry surfaces of the lens body 41. The surrounding outer wall of the cone-shaped body then serves to direct incident light rays downwards towards the region for light emission, by means of total internal reflection. In this sense, the lens body 41 therefore primarily serves as a collimator for the light typically emitted by the LED over a relatively wide angular range. 

[35] The light from the LED, directed towards the underside by this collimator, is then emitted via a Fresnel-like structure 45. In this case, this sawtooth-shaped structure 45 is provided with flanks in such a way that the light rays are again deflected correspondingly and then emitted laterally obliquely downwards in a preferred direction, as is schematically indicated by the arrow in Fig. 7. In this way, the light produced by the associated lamp can be emitted in a highly directed manner in a specific radiation direction A, in which an escape route runs, in order to illuminate it. 

[36] A collar 46 is formed peripherally around the Fresnel structure 45, which collar is designed with a reduced height in the region corresponding to the direction A of light emission, so that undisturbed light emission can take place here. The further region of this collar 46 forms a peripheral, approximately semi-cylindrical outer wall, which is provided with two opposing, slot-shaped indentations 48, which will be described in more detail below. In this case, the corresponding design of the collar 46 makes it easier to recognize the direction of the light emission, in order to be able to arrange the emergency lighting lens 40 in the desired orientation on the luminaire housing 60 or the cover 25. Furthermore, the collar 46 prevents unwanted emission of scattered light in other directions. 

[37] The bearing region 50 adjoins the upper side of the collar 46, which bearing region, in the state in which the emergency lighting lens 40 is mounted on the cover 25, engages in the receptacle 30 of the cover 25 and serves to bear an O-ring 5 acting as a seal. The outer contour of this bearing region 50 is completely rotationally symmetrical, which facilitates the production of the emergency lighting lens 40, which, for example, can take place as part of an injection-molding production process. The bearing region 50 forms two grooves 51 and 52 arranged one above the other in the axial direction of the lens 40; the design of the grooves can be seen in particular in the enlarged sectional views of Figs. 9c and 10c. 

[38] Both grooves or constrictions 51, 52 are separated from each other by a single sawtooth-like elevation 53, the tip of which defines an over-center point 55 which will be explained in more detail below. In this case, the design of the elevation 53 is such that a first ramp is formed starting from the upper peripheral groove 51 and a second ramp is formed starting from the lower groove 52, the slope of which is steeper than that of the first ramp. Below the lower groove 52, a flange-like peripheral projection 58 is also formed, which, as described in more detail below, serves as a stop element during insertion of the emergency lighting lens 40 into the receptacle 30 of the cover 25. 

[39] With regard to the receptacle 30 itself, it should be noted that this forms a corresponding circular receiving opening 31, which is enclosed by an annular peripheral wall 32. This peripheral wall 32 preferably extends into the interior of the luminaire, but could optionally also project beyond the horizontal region 26 of the cover 25, towards the underside. Furthermore, at the lower end of the peripheral wall 32, a slightly inwardly projecting projection or collar 35 is formed, which according to the procedure according to the invention supports the rolling of the O-ring, as described in more detail below, and prevents the lens 40 from slipping out with the O-ring 5. 

[40] Specifically, as indicated in Fig. 4, for mounting an emergency lighting lens 40 in the receptacle 30 of the cover 25, the lens 40, with the O-ring 5 located in the upper groove 51 and thus in the starting position, is placed against the opening 31 from the underside, and then pressed into said opening. This process is shown in detail in Figs. 9a to 9c and 10a to 10c, Figs. 9a to 9c showing the starting position of the seal, i.e. of the O-ring 5. Figs. 10a to 10c show the resulting arrangement when the emergency lighting lens 40 is arranged in the receptacle 30. 

[41] Thus, before the emergency lighting lens 40 is pressed in, the O-ring 5 is located in the upper groove 51. In this case, it projects slightly beyond the lateral periphery of the upper end region of the emergency lighting lens 40, as can be seen in Fig. 9c, and accordingly, when the emergency lighting lens 40 is being placed, the cover 25, it comes to rest against the aforementioned projection 35. 

[42] If the emergency lighting lens 40 is now pressed in, in the direction of the arrow (see Figs. 9b and 9c), i.e. into the receptacle 30, the O-ring 5 rolls slightly along the first ramp 51 of the elevation 53 but already enters the receiving region 30 of the opening 31. Since the O-ring 5 consists of a flexible material, it will compress slightly and can therefore overcome the over-center point 55 as the emergency lighting lens 40 is further pressed into the opening 31, so that the ring rolls into the lower groove 52. In this case, the lens 40 is pressed into the receiving opening 31 until the lower flange-like projection 58 comes into contact with the lower edge of the projection 35, resulting in the arrangement of the O-ring 5 on the outer periphery of the emergency lighting lens 40, as shown in Fig. 8 or in Figs. 10b and 10c. 

[43] Here, the abutment of the projection 58 at the lower edge of the receptacle 30 prevents the lens 40 from being pressed further into the receptacle 30. At the same time, the O-ring 5 abuts the upper side of the projection or collar 35, as can be seen in Fig. 10c, which ensures that the flange-like projection 58 is pressed against the underside of the cover 25. This results in an exact positioning of the lens 40 relative to the associated LED, thus ensuring efficient coupling of the corresponding light. 

[44] Furthermore, the size and flexibility of the O-ring 5 is such that it cannot easily overcome the steeper lower ramp of the elevation 53 and thus the over-center point 55, in particular not due to the dead weight of the lens 40. In this situation, the emergency lighting lens 40 is reliably and precisely positioned in the receptacle 30 of the cover 25, at the same time extremely reliable sealing of the receptacle opening 31 being provided, which prevents the penetration of dust and / or moisture or spray water. 

[45] Since both the outer contour of the emergency lighting lens 40 and the peripheral wall 32 of the receptacle 30 are rotationally symmetrical, the emergency lighting lens 40 can obviously be inserted into the receptacle 30 in any arbitrary rotational position. This means that, depending on the mounting situation of the luminaire 100 and the course of an escape route to be illuminated, the emergency lighting lens 40 can be oriented in a suitable way in order to emit light in the direction of the escape route and to illuminate it. 

[46] Furthermore, the discussed rotationally symmetrical design of the various components also offers the advantage that production can be carried out relatively easily in the context of an injection-molding process, since there are no recesses or similar structures that would make demolding after injection-molding more difficult. In this case, the flexibility of the O-ring is intended not only to ensure the desired sealing of the receiving opening 31 of the cover 25, but rather also to ensure that the mounted emergency lighting lens 40 remains permanently in the desired position and orientation. That is to say the friction caused by the O-ring 5 is such that a certain amount of force is required to rotate the emergency lighting lens 40. In particular, simple twisting by grasping the collar 46 should not be possible. Instead, the previously mentioned slot-like indentations 48 provided on the outer periphery, and a further indentation 49 provided in the region of the Fresnel structure 45 (see, for example, Fig. 5 or Figs. 7 / 8), are responsible for this. These indentations 48 and 49 can thus be provided for inserting the end region of a suitable tool, e.g. a screwdriver, and then, with the help of this tool, twisting the emergency lighting lens 40 or levering it out of the receptacle 30 of the cover 25. This represents an additional safety measure that prevents the already fully assembled emergency lighting lens 40 from being unintentionally or easily rotated out of the desired orientation at a later time. 

[47] Ultimately, the solution according to the invention allows lenses - e.g. for targeted illumination of an escape route - to be easily mounted in a sealed manner on a corresponding housing of a luminaire or a part of a luminaire housing, and aligned as desired. The sealing that can be achieved here represents a significant improvement compared to previously known solutions, such that there is reliable protection against external influences even in this region of the housing. 

[48] Moreover, the concept according to the invention can be used in an extremely versatile manner, and is not limited to the rotatable arrangement of lenses for variable escape route illumination. 

[49] In a comparable manner, lenses could be arranged on a luminaire housing that do not serve to influence the light emitted by the lamp, but rather the purpose of which is to form optics for a sensor arranged inside the luminaire housing. For example, it would be conceivable for a sensor, such as a camera sensor or a PIR sensor, to be provided inside the luminaire housing, for detecting the presence of people, this sensor then being located in the region of the receiving opening. The lens, which is detachably fastened to the receiving opening in a sealed manner, in the way described above, can in this case represent optics for the sensor, with the help of which the region monitored by the sensor is defined. In this case too, the preferably provided rotatable arrangement would be useful in order, for example in the case of a motion sensor or PIR sensor, to selectively define the region that is captured or monitored by the sensor, by appropriately aligning the lens forming the optics. Of course, the lens could, however, also be designed to be rotationally symmetrical, in order to completely capture a region located below the luminaire, i.e. across its entire periphery. 

[50] Another application example of the concept according to the invention is that, with the help of the solution described above, a cover, in particular even an opaque cover, is detachably fastened to the luminaire housing, in order to close the receiving opening in a sealed manner but to allow the possibility of opening the housing in this region if necessary. A maintenance or configuration element, or generally a functional part, can then be arranged inside the housing, in the region of the receiving opening, which element or part can be accessed by removing the cover. This would then make it possible to easily access, for example, a fuse or battery arranged inside the luminaire. Access to switches or other elements that can be used to set and / or save the operating parameters of the luminaire (e.g. a memory card or similar) would also be possible in this way, for example in order to then carry out maintenance, read out data, or perform an update. The positioning of a communication module, i.e. for example an NFC antenna or a Bluetooth module, in the region of the cover according to the invention, would also be conceivable. 

[51] This further application possibility is first shown in Fig. 11, comparable elements having been provided with the same reference signs here. The housing 60 of the luminaire 100 shown here, which in turn is designed as an escape route sign luminaire, also has a receiving region 30 which, analogously to the embodiment shown in Figs. 1 - 10, has a receiving opening 31 with a peripheral wall region 32. 

[52] In this case, this receiving opening 30 is closed by a cover 70, which in turn has a circumferential seal in the form of an O-ring 5 on its periphery, in particular the bearing region 50 of the cover 70 being identical to the bearing region 50 of the lenses 40 described above. That is to say, in this case too, the contour of the bearing region 50 of the cover 70 is chosen such that when the cover 70 is inserted into the receiving opening 31 of the luminaire housing 60, the O-ring 50 rolls off and, in accordance with the process shown in Figs. 9 and 10, a sealed fastening of the cover 70 on the housing 60 is achieved. 

[53] However, the cover 70 now does not serve to emit light but rather is intended to allow access to a functional part 75 arranged underneath it, i.e. inside the housing 60. As already mentioned, it could be, for example, a fuse or a battery, but may also be another component that is used, for example, to set an operating parameter of the luminaire 100. With the aid of the cover which is detachably fastened to the housing 60, access to this functional part 75 can be easily obtained if necessary, the housing 60 being closed reliably and in a sealed manner, with the aid of the cover 70, during the period in which no access is required. In order to facilitate the removal of the cover 70 when necessary, an opening or notch can be provided, analogously to the lenses 40 described above in the previous embodiment, which facilitates the insertion of a tool to lever the cover 70 out of the position fastened to the housing 60. In this case, the cover can consist of any material, in particular also an opaque material. 

[54] A third exemplary embodiment is shown in Figs. 12 - 14, in which the luminaire 100 does not have a light guide element but rather a vertically oriented, box-shaped housing 65, which in turn could be used, for example, to illuminate pictograms to display information, i.e. for example to show the direction of an escape route. In this case, corresponding lamps – not shown in detail in the figures – are then arranged inside the housing 65, these lamps then preferably being designed in such a way that light is emitted over a large area and uniformly across the side walls of the housing 65, in order, for example, to backlight pictograms arranged here. 

[55] In the exemplary embodiment shown, it is provided for three openings 67 to be formed on the underside of the housing 65, which openings may be necessary for manufacturing reasons or, if required, are intended to allow access to an underlying functional part (not shown in further detail). Again, suitable covers 80 are used for this purpose, which are intended to be fastened to the luminaire housing 65 in a sealed manner by means of an annular seal in the form of an O-ring 5. The components used for this purpose are again identical in design. That is to say each housing opening 67 in turn has a corresponding receptacle 30, which is designed analogously to the two previous exemplary embodiments in Figs. 1 - 11, the cover 80 having the rotationally shaped bearing region 50 in this case too, which is used for the bearing of the O-rings 5 according to the invention. 

[56] What is new here is that the circular receptacle 30 extends from a square housing opening 67, as can be seen in Fig. 12. In an analogous manner, the cover 80 now has a correspondingly shaped, square cover plate 82, from which the bearing region 50 then extends. This makes it possible to close the square opening 67 with precise contours, as can be seen in the further Figs. 12 and 13. However, the interaction between the receptacle 30, the bearing region 50 and the O-ring 5 is identical to the interaction in the previously discussed exemplary embodiments. In this case, as can be seen in Figs. 12 and 14, it can of course also be provided that the housing openings 67 and associated covers 80 are of different sizes.

Claims

1. 1. Luminaire (1), comprising:a housing (60) or housing element (25), which has a receiving opening (31) for accommodating at least part of a lens (40) or cover (70, 80);a lens (40) or cover (70, 80) that can be attached to the receiving opening (31);the receiving opening (31) of the housing (60) or housing element (25) forming a hollow cylindrical receiving region (30) in which, in the mounted state of the lens (40) or cover (70, 80), a rotationally symmetrical bearing region (50) of the lens (40) or cover (70, 80) is rotatably positioned, anda circumferential seal in the form of an O-ring (5) being arranged on the outer periphery of the bearing region (50) of the lens (40) or cover (70, 80), which seal acts between the housing (60) or housing element (25), and the lens (40) or cover (70, 80),characterized in thatthe bearing region (50) of the lens (40) or cover (70, 80) has a first peripheral groove (51) or constriction for receiving the O-ring (5) in a starting position, and, axially offset from this, a second peripheral groove (52) or constriction for receiving the O-ring (5) in a mounting position,the first and second peripheral groove (51, 52) or constriction being separated from each other by an elevation (53) defining an over-center point (55), and the O-ring (5) rolling from the first peripheral groove (51) or constriction over the over-center point (55) into the second peripheral groove (52) or constriction when the lens (40) or cover (70, 80) is being inserted into a receiving region (30). 

2. 2. Luminaire according to claim 1,characterized in thatthe elevation (53) forms a ramp leading from the first peripheral groove (51) or constriction to the over-center point (55). 

3. 3. Luminaire according to claim 2,characterized in thatthe elevation (53) additionally forms a further ramp leading from the second peripheral groove (52) or constriction to the over-center point (55),this further ramp preferably being designed to be steeper than the ramp leading from the first peripheral groove (51) or constriction to the over-center point (55). 

4. 4. Luminaire according to claim 3,characterized in thatthe elevation (53) is approximately sawtooth-shaped. 

5. 5. Luminaire according to any of the preceding claims,characterized in thatthe receiving region (30) of the housing (609) or housing element (25) has an inwardly projecting projection (35) or collar on a peripheral wall (32) of the receiving opening (31), which projection or collar assists the rolling of the O-ring (5) along the bearing region (50) of the lens (40) or cover (70, 80). 

6. 6. Luminaire according to any of the preceding claims,characterized in thatone or more indentations (48, 49) are formed on a region of the lens (40) or cover (70, 80) projecting outwards beyond the housing (60) or housing element (25), which indentations allow the lens (40) or cover (70, 80), inserted into the housing (60) or housing element (25), to be rotated, and / or the lens (40) or cover (70, 80) to be removed with the aid of a tool,the indentations (48, 49) preferably being slot-shaped. 

7. 7. Luminaire according to claim 6,characterized in thatthe projecting region of the lens (40) or cover (70, 80) has a collar (46), at least some of the indentations (48, 49) preferably being formed on the outer periphery of the collar (46). 

8. 8. Luminaire according to any of the preceding claims,characterized in thatthe luminaire (1) further comprises a lamp arranged in the housing, and the lens (40) is provided for emitting the light produced by the lamp;the luminaire (1) preferably has a plurality of lenses (4) with associated lamps. 

9. 9. Luminaire according to claim 8,characterized in thatthe lens or lenses (40) are designed to emit the light, emitted by the associated lamps, asymmetrically in a direction of radiation (A). 

10. 10. Luminaire according to claim 9,characterized in thatit is an emergency luminaire, the lens or lenses (40) being emergency lighting lenses designed to emit light to illuminate an escape route. 

11. 11. Emergency light according to claim 10,characterized in thatit is an escape route sign luminaire which, in addition to the lamp(s) for the escape route illumination, has further lamps with whose light an escape route symbol is illuminated and displayed. 

12. 12. Escape route sign luminaire according to claim 11,characterized in thatthis has a light guide element (10) which forms a plate-shaped light guide (20) into which the light from the additional lamps is coupled,wherein a pictogram element (90) is arranged on at least one flat side (21) of the light guide (20), and the light guide (20) is designed to distribute the coupled light and emit it distributed over the flat side (21) in order to illuminate the pictogram element (90). 

13. 13. Escape route sign luminaire according to claim 12,characterized in thatthe emergency lighting lens(es) (40) is / are arranged on a holder for the light guide (20), laterally next to the side of the light guide. 

14. 14. Escape route sign luminaire according to claim 12 or 13,characterized in thatthe light guide element (10) also forms part of the housing (60) or a cover (25) for the housing (60) of the luminaire (100), preferably the light guide element (10) forming the housing element on which the emergency lighting lens(es) (40) is / are arranged. 

15. 15. Luminaire according to any of the preceding claims,characterized in thatthe luminaire (1) further comprises a sensor element arranged in the housing, which is positioned in the region of the receiving opening (31). 

16. 16. Luminaire according to claim 15,characterized in thatthe sensor element is a camera sensor or a PIR sensor, and the lens (40) serves as optics for the sensor element. 

17. 17. Luminaire according to any of the preceding claims,characterized in thatthe luminaire (1) further comprises a maintenance or configuration element (75) arranged in the housing, for example a fuse, a battery, a switch for setting parameters, or a memory element, wherein the maintenance or configuration element is accessible via the receiving opening (31) that is closed by the cover (70, 80). 

18. 18.Luminaire according to any of the preceding claims,characterized in thatthe luminaire (1) further comprises a communication module arranged in the housing, e.g. an NFC antenna or a Bluetooth module, wherein the communication module is accessible via the receiving opening (31) that is closed by the cover (70, 80). 

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