Transparent lampshade

Abstract

A transparent lampshade for a luminaire, comprising a closed, translucent hollow body (1) whose wall (2) is provided with a recess (3) projecting into the interior of the hollow body (1), forming an externally accessible receiving space for one or more electrical light sources (4), wherein this receiving space is covered externally by a cover (5) which is fixed to the hollow body (1) and simultaneously serves as an interface for the electrical connection of the light sources (4) and for the mechanical attachment of the lampshade to the luminaire. In order to manufacture such a lampshade cost-effectively and stably with a largely free design, the invention proposes that the hollow body (1) and its recess (3) be designed as a one-piece casting made of thermoplastic material using a rotational molding process.

Description

[0001] The invention relates to a transparent lampshade for a luminaire, comprising a closed, translucent hollow body, the wall of which is provided with a recess projecting into the interior of the hollow body, forming an externally accessible receiving space for one or more electric light sources, wherein this receiving space is covered externally by a cover that is fixed to the hollow body and simultaneously serves as an interface for the electrical connection of the light sources and for the mechanical fastening of the lampshade to the luminaire. The invention further relates to a method for manufacturing such a lampshade.

[0002] A lampshade with the characteristics described above is known, for example, from US Patent 8,348,482 B1. Such closed lampshades have a fundamental advantage over lampshades with an open light-emitting surface: neither water, dirt, nor insects can penetrate the interior of the hollow body and thus reach the outer light-emitting surface of the lampshade. For this reason, lampshades with these properties are particularly suitable for outdoor lighting or for lighting in challenging indoor environments, such as bathrooms, gymnasiums, or factory floors.

[0003] In the aforementioned, previously known, closed lampshade, the hollow body is made of glass and is produced in a first process step as a hollow sphere using a glass-blowing process typical for glass. Subsequently, in a second process step, the indentation is created in the wall of this hollow sphere using additional molten glass, also in a correspondingly modified blowing process. This manufacturing process using glass-blowing is clearly extremely labor-intensive and cumbersome, and moreover allows for very little freedom in shape design.

[0004] Finally, a glass lamp body is highly susceptible to breakage and therefore sensitive to stresses from wind and weather, impacts, vandalism, etc. For example, glass covers for lighting fixtures must not be used in swimming pools.

[0005] It is therefore the object of the invention to further develop the lampshade of the type mentioned above in such a way that it can better withstand the stresses discussed above, is considerably more cost-effective to manufacture and is largely free in its design.

[0006] To solve this problem, the invention proposes, starting from the lampshade of the type mentioned above, that the hollow body and its molding are designed as a one-piece casting made of thermoplastic material.

[0007] The design of the hollow body and its molding as a single-piece casting made of thermoplastic material makes it possible, for the first time, to produce the hollow body in a rotational molding process in a particularly simple and cost-effective manner, with a largely free design. Furthermore, thermoplastic material is largely break-resistant and therefore particularly well-suited to the operating conditions of such lampshades.

[0008] A particularly advantageous embodiment of the invention provides that nuts and / or bolts for a screw connection between the cover and the hollow body are cast into the edge region of the mold. When manufactured using rotational molding, the bolts and / or nuts can be embedded in the wall of the hollow body in the same operation.

[0009] Furthermore, at least one pressure equalization opening is arranged in the wall of the mold, which can be closed by a pressure equalization element. Such a pressure equalization opening, which can be closed by a pressure equalization element, makes it possible to adjust the pressure prevailing in the hollow body of the lampshade to the prevailing pressure. Such pressure equalization may become necessary, for example, if the interior of the hollow body of the lampshade heats up excessively, for example, due to certain weather conditions or the installed electrical power.

[0010] A first embodiment of the lampshade according to the invention provides that the hollow body is spherical and the recess projecting into the interior of the hollow body is cylindrical. In this case, the cylindrical recess advantageously extends to the region of the center of the spherical hollow body. Furthermore, in this embodiment, a support plate serving to cover the recess is advantageously provided with a cable gland for securing and routing electrical connecting cables. All the aforementioned features of this first embodiment of the lampshade according to the invention make the lampshade according to the invention particularly suitable for use as hanging or standing luminous sphere lamps.

[0011] A second embodiment of the lampshade according to the invention provides that the hollow body has the shape of a circular disc with a flat top and a convex bottom, wherein the recess projecting into the interior of this disc is arranged in the flat top of this circular disc. Furthermore, in this disc-shaped lampshade, a support plate serving to cover the recess is provided with a ceiling junction box on its upper surface. This second embodiment of the lampshade according to the invention is particularly suitable for ceiling lights.

[0012] Finally, a third embodiment of the lampshade according to the invention provides that the hollow body has the shape of a hollow ring, wherein the indentation projecting into the interior of this ring is arranged on the upper side of this ring and has the form of a circular groove covered by an annular cover. This third embodiment of the lampshade according to the invention is particularly suitable for mounting on flat surfaces, for example, on the ceiling or a wall. However, it is also suitable, for example, for floor lamps with a corresponding design. Further embodiments of the hollow body with a wide variety of shapes are also possible.

[0013] The invention relates to a method for manufacturing the transparent lampshade described above from thermoplastic material, characterized in that the hollow body and its molding are produced using rotational molding. While rotational molding is known in the art, it has not yet been used for this specific application. Its advantages include the ability to produce castings with highly complex geometries in a single operation and to melt metal inserts into the plastic, thereby creating a particularly strong bond with the component. In the present case, the melted-in parts of the screw connection significantly reduce the need for time-consuming assembly work.

[0014] Three embodiments of the invention are explained in more detail below with reference to the accompanying drawings. They show: Fig. 1: Perspective view of a spherical lampshade according to the invention, cut in half lengthwise; Fig. 2: A perspective view of a disc-shaped lampshade according to the invention, cut open in the middle; Fig. 3: a perspective view of a ring-shaped lampshade according to the invention, cut open in the middle; Fig. 4: Enlarges a cross-section through a section of the Fig. 4 ring-shaped lampshades shown.

[0015] The in Fig. The spherical lampshade shown in Figure 1 has a spherical hollow body 1 made of a translucent thermoplastic material. The wall of this hollow body is integrally formed with a stepped cylindrical indentation 3 that projects approximately to the center of the spherical hollow body 1. Electrical light sources 4, for example in the form of a circuit board equipped with LEDs, are arranged in the interior of this indentation 3, which is accessible from the outside. These light sources 4 are supported by a mounting plate 5, which covers the outwardly open side of the indentation 3 and simultaneously serves as an interface for the electrical connection of the light sources 4 and for attaching the lampshade to a luminaire (not shown).

[0016] A screw connection 6 is provided for attaching this support plate 5 to the hollow body 1. This screw connection is located in the edge region of the molded-in recess 3 and includes nuts cast into the wall of the hollow body 1, as well as screws that clamp the support plate 5 against the outside of the hollow body 1. For improved sealing of the interior of the molded-in recess 3, a sealing ring 7 is also arranged between the support plate 5 and the outside of the hollow body 1. Furthermore, the support plate 5 is provided centrally with a cable gland 8 for securing and routing electrical connection cables.

[0017] Finally, a pressure equalization opening 9 is arranged in the wall of the molded cavity 3 of the hollow sphere, which can be closed by a pressure equalization element. This pressure equalization opening 9 with the pressure equalization element located therein serves to equalize the pressure that develops in the interior of the hollow body 1 with the external pressure of the environment.

[0018] The exemplary embodiment according to Fig. 2 corresponds in its technical function and components largely to the embodiment shown in the Fig. 1, with the difference that here the hollow body designated by reference numeral 11, or its wall 12, has the form of a circular disk with a flat top and a convex bottom, wherein the indentation 13 projecting into the interior of this disk is here associated with the flat top of this circular disk. Analogous to the embodiment according to Fig. 1 also shows the embodiment according to Fig. The following two characteristics are present: electric light bulbs 14 a carrier plate 15 a screw connection 16 a sealing ring 17 and a pressure equalization opening 19 with a pressure equalization element.

[0019] In contrast to the exemplary embodiment according to Fig. 1 is in the embodiment according to Fig. 2 the carrier plate 15 is not fitted with a cable gland, but with a ceiling connection box 18.

[0020] The embodiment according to the Fig. 3 and Fig.In its technical function, embodiment 4 largely corresponds to the previously described embodiments, with the difference that here the hollow body designated by reference numeral 21, or rather its wall 22, has the form of a hollow ring, wherein the recess 23 projecting into the interior of this ring has the form of a circular channel. This channel 23 also serves here as a receiving space for ring-shaped electrical light sources 24, which are supported by an annular carrier plate 25 covering the channel 23. Here, too, a sealing ring 27 is arranged between the edge regions of the channel 23 and the carrier plate. Finally, here, too, a pressure equalization opening 29 with a pressure equalization element is arranged in the wall of the channel forming the recess. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 8 348 482

[0002]

Claims

[1] Transparent lampshade for a luminaire, comprising a closed, translucent hollow body (1, 11, 21) whose wall (2, 12, 22) is provided with a recess (3, 13, 23) projecting into the interior of the hollow body (1, 11, 21), forming an externally accessible receiving space for one or more electric light sources (4, 14, 24), wherein this receiving space is covered externally by a cover (5, 15, 25) which is fixed to the hollow body (1, 11, 21) and simultaneously serves as an interface for the electrical connection of the light sources (4, 14, 24) and for the mechanical attachment of the lampshade to the luminaire, characterized by , that the hollow body (1, 11, 21) and its molding (3, 13, 23) are designed as a one-piece casting made of thermoplastic material. [2] Lampshade according to claim 1, characterized by, that nuts and / or bolts for a screw connection (6, 16, 26) of the cover are cast into the edge area of ​​the molding (3, 13, 23). [3] Lampshade according to claim 1 or 2, characterized by , in the wall of the molding (3, 13, 23) at least one pressure equalization opening 9, 19, 29) is arranged, which can be closed by a pressure equalization element. [4] Lampshade according to one of claims 1, 2 or 3, characterized by , that the hollow body (1) is spherical and the indentation (3) projecting into the interior of the hollow body is cylindrical. [5] Lampshade according to claim 4, characterized by , that the cylindrical indentation (3) protrudes towards them up to the area of ​​the middle of the spherical hollow body (1). [6] Lampshade according to one of claims 1-5, characterized by, that a carrier plate (5) serving to cover the molding (3) is provided with a cable gland (9) for securing and routing electrical connection lines. [7] Lampshade according to any of the preceding claims, characterized by , that the hollow body (11) has the shape of a circular disk with a flat top and a convex bottom, wherein the indentation (13) projecting into the interior of this disk is arranged in the flat top of this circular disk. [8] Lampshade according to claim 7, characterized by , that a carrier plate (15) serving to cover the molding (13) is provided on its upper side with a ceiling connection box (19). [9] Lampshade according to any of the preceding claims, characterized by, that the hollow body (21) has the form of a hollow ring, wherein the indentation (23) projecting into the interior of this ring is arranged on the top of this ring and has the form of a circular channel, which is provided with an annular support plate (25) serving as a cover. [10] Method for manufacturing a lampshade according to any one of claims 1 to 9, characterized by , that the hollow body (1, 11, 21) and its molding (3, 13, 23) are manufactured using the rotational casting process.

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