EP1013987B1 - Lamp - Google Patents

Abstract

The lighting unit (1) includes a socket (3) with an external thread (6) for the bulb (2) (in particular, an energy saving bulb) and an adapter ring (5) which is screwed onto the thread (6). It further includes a changeable hood (4) which is constituted as a color filter, and can be joined to the adapter ring by means of a combined bayonet and snap joint.

Description

The invention relates to a lamp according to the preamble of claim 1 and a cover device for a lamp according to the preamble of claim 11. Luminaires are already known which usually additionally comprise, in addition to an artificial light source in the form of an incandescent or energy-saving lamp as a fixing component, a lampholder into which the lamp - such as a lamp. B. from the DE-PS 38 438 or from the U.S. Patent 2,177,188 known for an incandescent lamp - can be used by means of a bayonet catch or into which the lamp can be screwed. In lighting technology, ceiling lights ( DE-PS 38 438 ) and wall lights ( U.S. Patent 2,117,188 ) as well as floor lamps ( U.S. Patent 3,166,254 ) with lampshades in a variety of designs, which surround the luminaire completely or partially depending on the embodiment.

The screen, which according to the U.S. Patent 1,735,180 directly or according to the U.S. Patent 2,117,188 held on an adapter ring on the lamp socket bayonet-like and according to the DE-PS 38 438 In addition, it can be secured against unintentional release by means of screws, serves as a reflector or to produce diffused light and can also be embodied in different shapes and different materials to impart a decorative appearance to the entire lighting device. In this case, spherical, cylindrical or pyramidal luminescent screens are often used in such lights, which at least partially cover the lamp and possibly provided further fastening means. A lighting device in which in the assembled state, only the preferably spherical lampshade visible and the lamp itself is invisible, is from the international patent application WO 98/00671 known.

In such a luminaire or lighting device, there is often the desire, on the one hand, to achieve the most uniform possible light distribution, so that no shadow areas and no irregular brightness areas occur along the entire lampshade surface. On the other hand, a light in a particular color is often desired. In order to provide luminaires that produce a colored light, it is basically possible to provide lamps with differently colored lamp bodies or a correspondingly colored lampshade. The effort for the production and the provision of a variety of different shades is particularly significant if individual color needs to be met. Also, a change between different individual colors is disadvantageously associated with a change of the lamp or lampshade.

In addition, in a lighting device, the light distribution depends essentially on the lamp and on the shape and the material of the surrounding lampshade. An uneven distribution of light is given in particular when using an energy-saving lamp, since the voluminous lamp base containing the electronics required for igniting the energy-saving lamp represents a comparatively weakly illuminated shadow area. A subsequent change or improvement of the light distribution can not be achieved even with an incandescent or fluorescent lamp practically or only with considerable effort.

From the generic US-A 1,338,194 already a light of the type mentioned above is known, which carries a spherical hood. The spherical hood of the prior art lamp encloses in its hood inside a light bulb or similar bulbs, which illuminant is preferably detachably screwed into an internal thread on a lamp socket of the prior art lamp. The lamp socket of the prior art lamp is at its end facing away from the light source with an external thread in such a way that the previously known lamp can be screwed to the external thread in a conventional lamp socket. In this case, the spherical cap compared to the located inside the hood bulbs on a much larger outer circumference to make the prior art light for aesthetic reasons in comparison to the much smaller light bulbs appear considerably more powerful and brighter.

The invention has for its object to provide a lamp and cover of the type mentioned above, in particular with an energy-saving lamp, with a uniform light distribution is achieved, and also in a simple manner as a color light usable or usable.

This object is achieved according to the invention by the features of claim 1 and of claim 11. For this purpose, an adapter ring which can be screwed onto the external thread of the lampholder and a cylindrical hood which can be placed over it and which surrounds the lamp are provided as interchangeable color filters which can be used as lattice. and / or color filter is used. The hood has at the opening edge of a cooperating with the adapter ring, positive connection point in the form of a bayonet connection, which is secured by a snap connection against unintentional loosening. The compound acts like a Federrastgesperres and expediently has both a centering and a stop.

The hood serves as a scatter filter or additionally as a color filter, in which case only the hood is colored in the desired color, while the lampshade itself is colorless. The hood is preferably made of polycarbonate as a special thermoplastic polymer. It has been recognized that the use of amorphous polycarbonate for the hood has the significant advantage of being functionally transparent and colorless on the one hand, and of being able to be colored in virtually any shade, on the other hand. Moreover, the hood made of polycarbonate by injection molding, extrusion or hot forming has high strength and rigidity as well as hardness, and at the same time has good electrical insulating properties. It is also particularly resistant to weather and radiation. Also, by printing or materializing a surface finish to achieve the desired scattering properties in a simple manner possible. In the production as a color filter, the dye is mixed into the liquid during production (polycarbonate), the dye, wherein a worm gear ensures uniform mixing. In tests, colorings in more than 250 different shades could be successfully carried out and corresponding hoods produced as color filters.

The connection between the screwed onto the lamp holder adapter ring and the hood is a combination of a positive, releasable bayonet connection as a special Renkverbindung and a snap connection. The hood is in engagement or Eindrehstellung with the adapter ring suitably guided to a stop and against unintentional loosening in both directions, ie in the screwing and in the direction of unlocking, secured. Thus, the hood can be released by rotation against the insertion direction after overcoming the Schnappgesperres and lifted from the lamp holder, while overrunning in the screwing prevented by the stop.

The luminaire is expediently used in conjunction with an energy-saving lamp. Therefore, the hood is cylindrical in an advantageous embodiment and has an open foot end opposite rounded head end. The radius of the rounding at the free or head end of the hood can be optimized with regard to the desired uniform light scattering. Since, in particular, in the case of an energy-saving lamp, the light scattering is also known to depend on the distance between the luminous element of the lamp and the hood wall, in an advantageous embodiment the hood surrounds the lamp over the substantial part of its length with a constant, minimized, preferably minimized distance.

In a further expedient embodiment, a number of circumferentially distributed and radially outwardly directed holding elements are provided on the adapter ring facing the opening edge of the hood. These are inserted in the connection with the adapter in this arranged hook elements as a result of the screwing. For this purpose, as a static determination of the connection, three holding elements and three corresponding hook elements are expediently provided, which are arranged distributed uniformly on the circumference of the hood or on the circumference of the adapter ring.

Each hook element of the adpater ring is expediently formed from a longitudinal web projecting axially beyond its bearing or contact surface for the hood and from a radially inwardly directed transverse web which is integrally formed on the latter. While in contrast to the usual snap connection, the switching element is formed by the integrally formed on the opening edge of the hood and thus spring-back holding element, the mating surface of the snap connection is realized on the longitudinal web. This points to its Inside a radially inwardly directed mold element in the form of a point or line-shaped bead which extends in the axial or longitudinal direction of the lamp. The switching element in the form of the holding element on the hood has a radially inwardly directed receiving groove corresponding to the bead or a fillet.

The adapter ring is formed in an expedient embodiment by a cylindrical shaft with a corresponding with the external thread of the lamp socket internal thread. In this case, an annular carrier plate is formed with central passage opening to the shaft. The radius of the passage opening is selected such that the adapter ring abuts when screwing onto the lamp holder at the edge of the screw-in opening for the lamp. Conveniently, the diameter of the passage opening is equal to the inner diameter of the lamp holder, so that the lamp can be passed unhindered through the through hole with screwed-on adapter ring and screwed into the internal thread of the lamp holder.

The adapter ring is preferably made of plastic. He also has a number of through holes in the area of its support or footprint for the hood. This ensures that the heat from the interior of the hood can flow through the through holes during operation of the lamp.

The hood thus forms, in conjunction with the adapter ring, a cover device for a luminaire consisting of a lamp cap with external thread and a lamp. The usable as a stray filter hood is as a color filter with simple handles against a different color, but at least in terms of the bayonet lobes similarly designed cap interchangeable, while the adapter ring is to provide only once with its corresponding bayonet approach.

The advantages achieved by the invention are, in particular, that by providing a collar-shaped screw or adapter ring which can be screwed onto a conventional lamp socket for an incandescent or energy-saving lamp, and a lamp which can be placed on it and which is connected to the adapter ring in the manner of a combined snap-action. and Renkverbindung by rotational movement latchable hood on the other hand, virtually any lamp can also be retrofitted with a scatter and color filter in a particularly simple manner. Due to the small, preferably adapted to the shape of an energy-saving lamp dimensions of the hood can be retrofitted virtually any lamp with further use their lampshade with such a color filter. If the hood is white or very light colored, this can also be used as a pure scatter filter.

The color filter is interchangeable in a particularly simple manner against such a scatter filter or a color filter with a different hue. For this purpose, first the hood is released by rotational movement in the direction of rotation of the adapter ring and removed from the lamp. Subsequently, a differently colored hood is placed on the adapter ring and locked with this by rotary motion. By providing an adapter ring and a single or a number of hoods of different shades a suitably designed light can be used both as such and within an existing lighting device and thus universally.

FIG 1

in perspektivischer Explosionsdarstellung eine Leuchte mit einem Adapterring und einer Haube als Streu- und/oder Farbfilter,

FIG 2a-2c

den Adapterring aus FIG 1 in Draufsicht, im Schnitt entlang der Linie A-A bzw. im Ausschnitt Z der FIG 2a, und

FIG 3a-3c

die Haube aus FIG 1 in Seitenansicht, im Schnitt entlang der Linie B-B in FIG 3a bzw. im Ausschnitt Y aus FIG 3b.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

FIG. 1

in a perspective exploded view of a lamp with an adapter ring and a hood as a scatter and / or color filter,

FIGS. 2a-2c

the adapter ring of Figure 1 in plan view, in section along the line AA or in the detail Z of Figure 2a, and

FIGS. 3a-3c

the hood of FIG 1 in side view, in section along the line BB in FIG 3a or in the detail Y of FIG 3b.

Corresponding parts are provided in all figures with the same reference numerals.

The lamp 1 shown in exploded view in Figure 1 comprises a lamp 2 and a lamp holder 3 and a lamp 2 in the assembled state sheathing cylindrical hood 4 and an adapter ring 5. The lamp holder 3 has an external thread 6 and an internal thread 7. In the exemplary embodiment, the lamp 2 is an energy-saving lamp with two light-emitting or discharge tubes 8 bent in a U-shape. These are led into a housing 9 which contains the electronics necessary for igniting the energy-saving lamp. At the foot of the energy saving lamp 2 is provided with an external thread 10 lamp base 11, z. B. a screw E27 provided, with which the lamp 2 in the corresponding internal thread 7 of the lamp holder 3 can be screwed.

In the assembled state, the adapter ring 5 is screwed over its corresponding with the external thread 6 of the conventional lamp holder 3 internal thread 12 on this. After screwing the lamp 2 into the lamp holder 3, the hood 4 is slipped over the lamp 2 in the direction of attachment 17 and placed on a contact surface formed by the adapter ring 5 or footprint 13. At the opening edge 14 of the hood 4 on the one hand and in the area of the footprint 13 of the adapter ring 5 on the other hand corresponding connecting elements 15 and 16 are provided which form a junction in the form of a Renk- or bayonet connection. By rotational movement of the hood 4 in a clockwise direction in the insertion direction 18 is a non-positive and positive, releasable connection between the rotationally symmetrical design at the junction hood 4 and the likewise rotationally symmetrical shaped adapter ring 5 is made. In the bayonet connection 15,16, the hood 4 and the adapter ring 5 are axially joined together. In this joint or bayonet connection 15,16, the adapter ring 5 on the internal thread 12 and the hood 4 with respect to their insertion direction 18 the same direction of rotation, so that upon rotation of the hood 4 or the adapter ring 5 of this or the hood 5 is not solved , There the external thread 6 of the lamp cap 3 is usually a right-hand thread, also corresponds to the insertion direction 18 a clockwise rotation.

To protect against unintentional loosening of the connection 15,16 the hood 4 and the adapter ring 5 are hooked as a result of mutual rotation into each other and thus secured in a form-fitting manner. For this purpose, according to FIG. 2a, which shows the adapter ring 5 in plan view, this preferably has three hook elements 16, which are distributed uniformly over the contact surface 13 and thus distributed along its circumference. Such a hook element 16 is shown in FIG. 2b in a sectional view along the line A-A from FIG. 2a. In FIG. 2c, which shows a section Z from FIG. 2a on a larger scale, such a hook element 16 is shown in section.

As FIG. 2b shows, the or each hook element 16 is formed in the region of the contact surface 13 against an annular support plate 20, which forms the adapter ring 5 together with a cylindrical shaft 21 integrally connected thereto. The shaft 21 carries on its inner side the internal thread 12 of the adapter ring 5. The molded hook elements 16 are formed by a longitudinally of the lamp 1, d. H. formed opposite the Aufsetzrichtung 18 of the hood 4, extending and perpendicular from the footprint 13 outstanding axial longitudinal ridge 22 and an integrally formed on the free end of the transverse web 23, which is directed radially inward. On the inside of the longitudinal web 22 of the hook member 16 carries a radially inwardly directed bead 24, the semi-circular rounded shape of FIG 2c is comparatively clearly visible. The bead 24 forms the mating surface of a snap connection between the hood 4 and the adapter ring. 5

The adapter ring 5 has a central passage opening 25, which passes through the support plate 20 such that an inwardly directed abutment collar 26 is formed in the transition region between the cylindrical shaft 21 and the support plate 20. The inner diameter d _{1 of} the through hole 25 of the support plate 20 is therefore smaller than the outer diameter d _a and smaller than the inner diameter d _{i of} the shank 21 of the Adpaterrings 5. The diameter d ₁ the passage opening 25 is preferably equal to the inner diameter d ' _{i of} the lamp holder 3 at the screw-in opening 19 (FIG 1). On the other hand, the rotational movement of the adapter ring 4 is blocked due to the abutment of the support plate 20 at the screw 19 of the lamp holder 3 and thus prevents further rotation of the adapter ring 5 ,

The adapter ring 5 also has a number of through holes 27 which pass through its footprint 13. In FIG 2a, two at an angular distance of 120 ° to each other through holes 27 are shown. The through holes 27 are used for heat dissipation from the formed with attached hood 5 between this and the lamp 7 interior 28 (Figure 1).

FIGS. 3a to 3c show the hood 4 in a side view, in a section along the line BB from FIG. 2a or in the cutout Y from FIG. 2b with a holding element 15 on a larger scale. As can be seen in particular from FIGS. 3b and 3c, the holding elements 15 formed on the outside of the opening edge 14 of the hood 4 form the switching element for closure generation, while the flexible hood wall represents the spring and thus the energy store for generating the snap-in movement of the snap connection. As can be seen from FIG 3a, the holding elements 15 are aligned at the bottom with the opening edge 14 of the hood 4 and thus form when placed on the adapter ring 5 hood 4 with its support plate 20 a surface contact. The holding elements 15 are each provided with a rounded, preferably approximately 0.5 mm deep, radially inwardly directed recess 29. This corresponds in the combined bayonet and snap connection geometrically exactly with the integrally formed on each hook element 16 of the adapter ring 5 bead 24. The holding elements 15 of the hood 4 and the hook members 16 of the adapter ring 5 thus form in the snap connection a point or line contact, while in the bayonet connection a two-sided surface contact of the holding elements 15 with the hook elements 16 on the one hand and with the footprint 13 on the other hand is formed.

When screwing the retaining elements 15 into the corresponding hook elements 16 of the adapter ring 5, the longitudinal web 22 and the transverse web 23 of the respective hook element 16 cause centering and guiding of the retaining elements 15 of the hood 4 both in the direction of contact 18 of the rotationally symmetrical connection point and in the axial direction 17 the respective holding element 15 is guided along the corresponding bead 24, and the hood 4 is biased radially inwardly in the region of its opening edge 14. As soon as the respective recess 29 is aligned with the bead 24 as a result of the rotational movement, the opening edge 14 of the hood 4 springs back radially outwards in the corresponding rotational position, with the result that the bead 24 engages in the respective recess 29. As a result, a releasable, but secured against unintentional release snap connection is made.

In order to prevent over-rotation of the hood 5 in the screw-in direction 18, a stop 30 (FIGS. 1 and 2c) in the form of a radially inwardly directed stop web 31 formed on the longitudinal web 22 is provided on the or each hook element 16 of the adapter ring 5. The or each hook element 16 is closed by the stop web 31 on one longitudinal side.

ist.Like the hood 4, the adpater ring 5 is preferably made of plastic. The hood 4 is suitably made of polycarbonate, which is a thermoplastic polymer having the general structural formula

is.

The use of polycarbonate on the one hand manufacturing advantages and on the other hand allows in a simple and reliable way the fulfillment of the desired properties with respect to the hood 4, in particular a uniform light distribution of the lamp 1. Thus, in the use of Luminaire 1 in one of the international patent application WO 98/00671 known ball lamp advantageously achieved that no shadow areas and no uneven brightness ranges along the entire spherical surface of the transparent, dim or milky lampshade occur.

In addition, when polycarbonate is used as starting material for the production of the hood 5, a coloring of the hood in virtually any color can be done. Such a colored hood 4 then serves as a scatter filter and as a color filter.

Furthermore, polycarbonate is suitable as a starting product for the production of the hood 4, in particular because of its high strength and stiffness, which has a particularly advantageous effect, in particular with regard to the snap connection. Namely, in the snap connection, the hood 4 exerts the function of the spring or the energy accumulator for generating the snap movement of the holding elements 15.

Another, with regard to the scattering effect particularly advantageous structural design of the hood 4 on the one hand in a rounding or rounding 32 whose head end 33. This rounding 32 is shown in Figures 1 and 3a. The rounding radius R is determined empirically and is preferably 10 mm. Another relevant for the scattering property of the hood 4 parameters is the distance w, d. H. the clear width, between the hood 4 and the lamp 2 (FIG 1). The distance w is practically minimized by the distance w 'in the region of the housing 9 of the lamp 4 is dimensioned so small that on the one hand the hood 4 can be slipped over the lamp housing 9 with sufficient play. On the other hand, a heat dissipation from the inner space 28 along the annular space defined by the distance w 'between the hood 4 and the lamp housing 9 and via the through holes 27 is ensured.

Claims (11)

1. Lamp with a lamp socket (3) having an external thread (6), into which a bulb (2), particularly an energy saving bulb, can be screwed, with

   - an adapter ring (5) that can be screwed onto the external thread (6) of the lamp socket (3), said adapter ring (5) having an internal thread (12), and

   - a cover (4) surrounding the bulb (2) and constructed as an exchangeable colour filter, which can be connected by its opening edge to the adapter ring (5), characterised in that

   - the cover (4) can be placed with its opening edge onto the adapter ring (5),

   - the cover (4) can be connected to the adapter ring (5) by a combined bayonet and snap-fit connection (15, 16, 24, 29), and

   - the internal thread (12) of the adapter ring (5) has a direction of rotation which corresponds to the direction of screwing in (18) of the cover (4) in the clockwise direction during connection (15, 16) to the adapter ring (5).
2. Lamp according to claim 1, characterised in that the cover (4) is cylindrical and comprises a rounded head end (33) located opposite the opening edge (14), the cover (4) surrounding the lamp (2) over the majority of its length at a constant spacing (w, w') therefrom.
3. Lamp according to claim 1 or 2, characterised in that the cover (4) consists of polycarbonate.
4. Lamp according to one of claims 1 to 3, characterised in that the cover (4) is guided to a stop (30, 31) in the position of engagement with the adapter ring (5).
5. Lamp according to one of claims 1 to 4, characterised in that the cover (4) comprises on the opening edge (14) facing the adapter ring (5) a number of retaining elements (15) distributed around the circumference and directed radially outwards, which in making the connection to said adapter ring (5) are pushed in a rotary action into hook elements (16) provided on said adapter ring (5).
6. Lamp according to claim 5, characterised in that the hook element (16) of the adapter ring (5) is formed from a longitudinal web (22) protruding axially above the contact surface (13) thereof for the cover (4), and from a transverse web (23) formed thereon and directed radially inwards, said longitudinal web (22) comprising, on its inner surface that forms the mating surface for the snap-fit connection, a shaped element (24) which, in making the connection, engages in a radially inwardly directed receiving groove (29) of the retaining element (15) for the cover (4).
7. Lamp according to one of claims 1 to 6, characterised in that the adapter ring (5) has a cylindrical shaft (21) with an internal thread (12) corresponding to the external thread (6) of the lamp socket (3) and a circular carrier plate (20) formed thereon, with a central through-opening (25).
8. Lamp according to claim 7, characterised in that the diameter (d₁) of the through-opening (25) is smaller than the external diameter (d_a) of the lamp socket (3).
9. Lamp according to claim 7 or 8, characterised in that the diameter (d₁) of the through-opening (25) is smaller than or equal to the internal diameter (d_i) of the lamp socket (3).
10. Lamp according to one of claims 1 to 9, characterised in that the adapter ring (5) comprises at least one through-bore (27) which is offset radially outwards relative to the thiough-opening (25) thereof.
11. Covering device comprising an adapter ring (5) and a cover (4) for a lamp with a lamp socket (3) having an external thread (6), particularly for an energy saving bulb (4),

    - wherein the adapter ring (5) has an internal thread (12) with which it can be screwed onto a lamp socket (3), and

    - the cover (4) is constructed as an exchangeable colour filter and is cylindrical in shape, characterised in that

    - the cover (4) can be connected to the adapter ring (5) in the manner of a spring latching mechanism in the form of a combined bayonet and snap-fit connection (17, 16; 24, 29),

    - wherein a releasable frictional and interlocking connection is produced between the cover and the adapter ring by clockwise rotation of the cover (4) in the direction of screwing in.

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