Device for attaching a lighting unit under a ceiling

Abstract

Device (1) for fastening a lighting unit (2) under a ceiling (3), comprising a housing (4) with a fastening device (5) for fastening the housing (4) under the ceiling (3), wherein a drum (6) is rotatably received in the housing (4), wherein the axis of rotation of the drum (6) is aligned parallel to the longitudinal axis of the housing (4), wherein the drum (6) receives a plurality of cables (7), wherein the cables (7) are guided via deflection units (8) arranged in the housing (4) and through openings made in the housing (4).

Description

The invention relates to a device for fastening a lighting unit under a ceiling, comprising a housing with a fastening device for fastening the housing under a ceiling, wherein a drum is accommodated in the housing, wherein the axis of rotation of the drum is oriented parallel to the longitudinal axis of the housing.For fastening lighting units under a ceiling, there are frequently used baldachines which make it possible to fasten a lighting unit under the ceiling and to electrically contact the lighting unit with the electrical building installation in a concealed manner. The lighting units are usually connected to the canopy via a cable, wherein the cable first serves to remove the mechanical load of the lighting unit into the canopy. Depending on the configuration of the cable, this cable can also carry electrical current to the lighting unit.EP 3 217 061 B1 discloses a cable holder in which a spindle is rotatably mounted in the housing, the spindle receiving the cable to which the lighting unit is fastened. By rotating the spindle, the cable length can still be varied even after assembly.The invention is based on the object of providing a device for fastening a lighting unit under a ceiling, which device makes it possible to accommodate a plurality of cables adjustable in length.This object is achieved with the features of claim 1. Advantageous embodiments are referred to in the dependent claims.The device according to the invention for fastening a lighting unit under a ceiling comprises a housing with a fastening device for fastening the housing under the ceiling, wherein a drum is rotatably accommodated in the housing, wherein the axis of rotation of the drum is oriented parallel to the longitudinal axis of the housing, wherein the drum accommodates a plurality of ropes, wherein the ropes are guided through openings made in the housing via deflection units arranged in the housing.The device according to the invention accordingly enables the accommodation of a plurality of ropes, wherein all ropes are length-adjustable. Because the ropes are arranged on a single drum, the length adjustment of the ropes takes place uniformly and synchronously. As a result, larger and also complex-shaped lighting units, which require fixing via a plurality of cables, can be mounted under a ceiling in a height-adjustable manner.The drum is preferably of annular configuration. In this embodiment, the drum does not have any elements rotating in the axis of rotation, such as hubs, shafts or pins. This results in additional installation space in the volume enclosed by the drum, in which additional elements of the device, for example transformers or drives, can be arranged.The deflecting units can be assigned radially on the outside of the drum, wherein the ropes are guided in the tangential direction from the drum to the deflecting units and wherein the ropes are deflected in the deflecting units in such a way that the ropes run through the opening parallel to the longitudinal axis of the housing. In this embodiment, the ropes are first removed from the drum in the tangential direction and fed to the deflecting units. In the deflection unit, the cables are preferably deflected by an amount of 90 degrees, so that they extend to the longitudinal axis. The deflecting of the ropes can take place via rollers arranged in the deflecting units.The drum may be configured to accommodate four ropes. In further embodiments, three or five cables are assigned to the drum. The drum is configured to accommodate at least two ropes. Depending on the number of ropes, preferably 2, 3, 4 or 5 deflecting units are provided, which are preferably arranged uniformly distributed over the circumference of the drum and fixed to the housing.The drum can be of modular construction and have a plurality of segments, it being possible for one segment to be provided for each cable. This makes it possible to adapt the drum to the required number of ropes by simple means.The drum can be mounted via holders which bear radially on the outside against the drum. The holders can be substantially cylindrical and fixed on one end face to the housing. The holders can be fixed to the housing in a radially adjustable manner, so that the distance between holder and drum can be adjusted during assembly.The holders can be designed in the shape of mushroom heads, wherein the thickening forming the mushroom head is assigned to the free end of the holder. As a result, the drum can be fixed to the holders in a form-fitting manner.The drum is guided only radially on the outside by the holders, wherein the mounting of the drum by the holders is particularly space-saving and at the same time mechanically stable.The drum may have grooves running in the circumferential direction, wherein the cables are assigned to the grooves. Preferably, one groove is provided for each cable, so that one cable can be wound or unwound in each groove. This ensures that the cables have the same longitudinal adjustment uniformly and always as a function of the reel rotation.The groove is preferably designed in such a way that it can accommodate at least two layers of a cable. Accordingly, the groove depth of a groove preferably corresponds in each case to at least twice the diameter of a cable. In connection with a comparatively large diameter of the drum, large length changes of the cables can thereby be achieved. Furthermore, the arrangement of the cables in cable layers radially one above the other is particularly space-saving, in particular compared to an arrangement next to one another.The holders can abut the drum in such a way that the cables are fixed in the groove. This can ensure that the cables are guided in the drum in a captive manner and do not accidentally slide out of the groove.The drum can have an internal toothing which is operatively connected to a drive. The drum can be set in rotation via the drive. For this purpose, the drive can comprise an electric motor and a transmission. The gear can be designed as a worm gear.In addition, a further gear can be attached to the internal toothing, which by means of a suitable reduction reduces the maximum amount of movement of the drum from several possible revolutions to the fraction of one revolution. Furthermore, it is conceivable to assign an end position detection to a gear wheel. This can be effected, for example, by mechanically lockable cams which will actuate a limit switch. In this embodiment, an operator can independently and without tools define the mechanical end positions of the device with regard to the length adjustability of the cables within given limits.The cables can be supplied with electric current. In this embodiment, the cables serve not only for mechanical load transfer, but also for supplying the lighting unit with electric current.The cables can be connected to a voltage source via electrical conductors, wherein the electrical conductors are guided in a spiral shape from the drum to the longitudinal axis of the housing. The electrical conductors can be formed by the cables themselves. It is likewise conceivable for the electrical conductors to comprise power cables. In this embodiment, the contacting of the electrical conductors can take place in the central region of the housing. There, the connection to the building installation can be made. By the spiral-shaped guidance of the electrical conductors, the connection between ropes and building installation can be effected while avoiding sliding contacts. Depending on the position of the drum or the angle of rotation, the spiral opens or closes, in which the electrical conductors are guided in the direction of the central region of the housing.The housing can be configured in two parts. In particular, it is conceivable to provide a maintenance flap which can be operated independently of the other housing part within the pitch circle defined by the openings for the cables. The maintenance flap can be magnetically fastened to the other housing part, so that it can be removed and reassembled simply and without tools.The housing or the housing parts can be connected to the fastening device via housing holders. The connection between the housing holder and the housing is particularly user-friendly by means of magnetic contacts. A particularly good positionability results if centering pieces are provided, by means of which the distance between the housing, housing parts and housing holders can be adjusted particularly accurately.Some embodiments of the device according to the invention are explained in more detail below with reference to the figures. The figures show, in each case schematically: FIG. 1 shows an apparatus with a lighting unit attached under a ceiling; FIG. 2 shows the device according to FIG. 1 with the housing partially open; FIG. 3 shows the device according to FIG. 1 with the housing opened; FIG. 4 shows the device according to FIG. 1 with the housing opened in a side view; FIG. 5 shows the device according to FIG. 1 with the housing opened in a plan view with the drive covered; FIG. 6 shows the device according to FIG. 1 with the housing opened in a plan view with the drive housing opened; FIG. 7 shows the device according to FIG. 1 with the housing opened in a three-dimensional view; FIG. 8 shows in detail a deflection unit and holder; FIG. 9 shows the drive in detail; FIG. 10 shows in detail the end position control of the drive.FIG. 1 shows an apparatus 1 for fastening a lighting unit 2 under a ceiling 3 having a housing 4 made of metallic material, in which a fastening device 5 for fastening the housing 4 under the ceiling 3 is arranged. By means of the fastening device 5, the housing 4 can be fastened under the ceiling 3 by means of a screw connection. For this purpose, corresponding perforations are made in the fastening device 5.The housing 4 is formed in multiple parts and comprises an outer, L-shaped housing part 17 in section and a maintenance flap 18 which is arranged centrally on the device 1. The maintenance flap 18 is held on the device 1 via a magnetic connection.Openings 9 are made in the housing 4, through which four cables 7 are guided from the inside to the outside. The openings 9 are located between the housing part 17 and the service flap 18.FIG. 2 shows the device 1 according to FIG. 1 with the service flap 18 open. A drum 6, which is of annular design, is rotatably accommodated in the housing 4, the axis of rotation of the drum 6 being oriented parallel to the longitudinal axis 19 of the housing 4. The longitudinal axis 19 of the housing 4 extends perpendicular to the ceiling 3.The drum 6 accommodates a plurality of ropes 7, wherein the ropes 7 are guided through openings made in the housing 4 via deflection units 8 arranged in the housing 4. The diameter of the drum 6 is 30 cm in the present exemplary embodiment, so that approximately 90 cm of cable 7 can be deposited over the circumference of the drum 6. Several layers of cable 7 can be laid on the drum 6, in the present embodiment the drum 6 can accommodate two layers of cable 7. Accordingly, the cable length can be adjusted to 180 cm.The drum 6 is of annular design and does not have any elements in the region of the longitudinal axis. Hubs, shafts and the like are omitted. Accordingly, the volume enclosed by the drum 6 results in an available installation space for further components of the device.The deflection units 8 are assigned radially on the outside of the drum 6, wherein the ropes 7 are guided in the tangential direction from the drum 6 to the deflection units 8, and wherein the ropes 7 are deflected in the deflection units 8 in such a way that the ropes 7 run through the openings 9 parallel to the longitudinal axis of the housing 4. In the present embodiment, the drum 6 accommodates four ropes 7.FIG. 3 shows the device 1 according to FIG. 1 with the housing 4 removed. In this illustration, the fastening device 5 can be seen in particular, by means of which the device 1 can be mounted under a ceiling 3. The fastening device 5 is plate-shaped and at the same time forms the carrier on which the components of the apparatus 1 are fastened.FIG. 4 shows the device 1 according to FIG. 3 in a side view.FIG. 5 shows the device 1 according to FIG. 3 in a plan view. The drum 6 is provided with an internal toothing 11 which is operatively connected to a drive 12. In this illustration, the drive 12 is covered by a drive housing 20. The drive 12 is assigned an end position control 21 by means of which the maximum length adjustability of the cables 7 can be established within given limits. For this purpose, the end position control 21 has electrical switches which are actuated via cams which are arranged on the gear mechanism 14 of the drive 12.FIG. 6 shows the device according to FIG. 5, with the drive housing 20 removed. The internal toothing 11 of the drum 6 is operatively connected to the drive 12. The drive 12 comprises an electric motor 13 and a transmission 14, wherein the transmission 14 comprises a worm transmission.FIG. 7 shows in detail the drum 6 in the region of a deflection unit 8, the drum 6 having grooves 15 running in the circumferential direction, wherein the ropes 7 are assigned to the grooves 15. The grooves 15 are designed in such a way that they can accommodate two cable layers in each case. The drum 6 is of modular design and has individual segments 22, from which a groove wall and a groove base are respectively formed. Accordingly, the number of segments 22 corresponds to the number of grooves 15 provided in the drum 6, and the segments 22 are connected to one another by a screw connection. The segments 22 are again composed of pitch circle elements. This simplifies the production of the drum 6. The grooves 15 are designed to accommodate two layers of cable 7 in each case. The groove depth of the grooves 15 corresponds accordingly to twice the cable diameter. The cables 7 are each arranged lying one above the other in the groove 15.The cables 7 can be supplied with electric current, wherein the cables 7 are connected via electric conductors to a voltage source, wherein the electric conductors are guided spirally from the drum 6 in the direction of the longitudinal axis of the housing 4.The electrical conductors finally open in the central region of the housing 4 and can be connected there to the building installation. For the spiral guidance of the electrical conductors, a protective sheath 16 is provided, which runs spirally from the central region of the housing 4 in the direction of the drum 6. The spirally bent region of the protective sheath 16 opens and closes as a function of the angle of rotation of the drum 6, the electrical contacting of the cables 7 being effected by means of a direct and fixed electrical contacting, while avoiding sliding contacts.FIG. 8 shows in detail the drum 6 in the region of a holder 10. the drum 6 is mounted via holders 10, wherein the holders 10 bear radially on the outside against the drum 6.The holders 10 are cylindrical and mushroom-head-like and are fixed radially adjustably on the housing 4. The radial adjustability of the holders 10 takes place via an eccentric screw connection. Due to the radial adjustability, the holders 10 can be arranged on the drum 6 such that the cables 7 are fixed in the grooves 15. The holders 10 have a thickening 23 at the free end, which in the present embodiment is formed by a ball bearing, so that the drum 6 is rotatable with little resistance. Due to the thickening 23, the drum 6 is secured captive and positively between the holders 10.FIG. 9 shows in detail the drum 6 in the region of the drive 12; FIG. 10 shows in detail the drum 6 in the region of the end position control 21.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 3 217 061 B1

[0003]

Claims

Device (1) for fastening a lighting unit (2) under a ceiling (3), comprising a housing (4) with a fastening device (5) for fastening the housing (4) under the ceiling (3), wherein a drum (6) is rotatably accommodated in the housing (4), wherein the axis of rotation of the drum (6) is oriented parallel to the longitudinal axis of the housing (4), wherein the drum (6) accommodates a plurality of ropes (7), wherein the ropes (7) are guided via deflection units (8) arranged in the housing (4) and through openings (9) introduced into the housing (4).Device according to claim 1, characterised in that the drum (6) is of annular configuration.Device according to claim 1 or 2, characterised in that the deflection units (8) are assigned radially outside to the drum (6), wherein the ropes (7) are guided in the tangential direction from the drum (6) to the deflection units (8), and wherein the ropes (7) are deflected in the deflection units (8) in such a way that the ropes (7) extend through the opening (9) parallel to the longitudinal axis of the housing (4).Device according to one of Claims 1 to 3, characterized in that the drum (6) accommodates more than two cables (7).Device according to one of Claims 1 to 4, characterized in that the drum (6) is mounted via holders (10) which bear radially on the outside against the drum (6).Device according to one of Claims 1 to 5, characterized in that the holders (10) are fixed on the housing (4) in a radially adjustable manner.Device according to one of Claims 1 to 6, characterized in that the drum (6) has grooves (15) running in the circumferential direction, the ropes (7) being assigned to the grooves (15).Device according to claim 7, characterised in that the holders (10) bear against the drum (6) in such a way that the cables (7) are fixed in the grooves (15).Device according to one of Claims 1 to 8, characterized in that the drum (6) has an internal toothing (11), which is operatively connected to a drive (12).Device according to Claim 9, characterized in that the drive (12) comprises an electric motor (13) and a transmission (14).Device according to one of Claims 1 to 10, characterized in that the cables (7) can be supplied with electric current.Device according to one of Claims 1 to 11, characterized in that the cables (7) are connected to a voltage source via electrical conductors, the electrical conductors being guided in a spiral manner by the drum (6) in the direction of the longitudinal axis of the housing (4).

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