Technical field

The present disclosure relates to a lamp shade, comprising an inner face and an outer face. The outer face has an approximately overall convex shape and the inner face has a correspondingly approximately overall concave shape, such that a partly closed inner space may be formed between the lamp shade and a wall or the like, if attached thereto. The lamp shade is formed in a translucent plastic material, colored with a dye. The disclosure further relates to a method for producing a lamp shade.

Background

Such lamp shades may typically be attached to a wall in a children’s room to provide a softly colored lighting effect. A general problem associated with lamp shades of this kind is how to produce them in an efficient manner to provide a product at a low cost to the end user.

Summary

One object of the present disclosure is thus to provide a lamp shade that can be produced in an efficient manner. This object is achieved by a lamp shade as defined in claim 1. More particularly, in a lamp shade of the initially mentioned kind, there is provided at least one inner ridge of increased thickness, projecting from the inner face and extending over a part of the lamp shade inner face. When produced, typically by injection molding, such a ridge provides for a flow path for molten material which facilitates molten plastic material’s distribution over the entire tool space forming the lamp shade. This allows, at the lateral sides of the ridge, the lamp shade to be very thin, thereby providing a high light flow there through. At the same time, the risk is reduced of having some space in a tool unfilled by the plastic material, thereby leading to a faulty final product with a hole in the lamp shade face. Therefore, the provision of these ridges provides an increased production yield leading to an efficiently produced product. The ridges may also provide esthetically interesting patterns to the lamp shade surface, in particular when a light source is lit inside the lamp shade, and more light will be emitted via the portions located between the ridges than via the ridges themselves. A corresponding outer ridge may project from the outer face and extend, at least partly aligned with the inner ridge, over a part of the lamp shade outer face. This provides an even stronger flow pattern. However, in cross a section, the outer ridge may typically project a distance do from the surrounding surface of the outer face which is less than a factor 0.8, such as 0.6, of to the distance di the inner ridge projects from the surrounding surfaces of inner face. This means that the outer face will e.g. collect dust to a lesser extent.

The distance dj the inner ridge projects from the surrounding surfaces of the inner face may be in the range 0.1 -2.5 mm, preferably 0.3-2.0 mm, and most preferably 0.4-1.5 mm.

The distance do the outer ridge projects from the surrounding surfaces of said outer face may be in the range 0.1 -1.5 mm, preferably 0.2-1.0 mm, and most preferably 0.3-0.8 mm.

The outer face may even be smooth and have no outer ridges at the location of the inner ridge.

The thickness d _s of the lamp shade in areas surrounding said inner ridge may be in the range 0.2-1.0 mm, preferably 0.3-0.8 mm, and most preferably 0.3-0.6 mm.

A plurality of such inner ridges may be provided, and optionally at least some of the inner ridges may be interconnected. This provides efficient flow patterns over the surface as a whole.

The lamp shade may comprise, at its periphery, an edge portion configured to be directed towards a wall to which the lamp shade is intended to be attached. This enlarges the inner space created by the lamp shade and reduces light flow parallel to e.g. a wall surface.

The lamp shade is typically provided by injection molding in a material in the group including polypropylene, PP, polyamide, PA, polyethylene terephthalate, PET, recycled PET, acrylonitrile butadiene styrene, ABS, synthetic rubber, polyethylene, PE, polylactic acid, PLA, and polymethylmethacrylate, PMMA, for instance.

The inner face may comprise means for attaching the lamp shade to a wall or the like. The present disclosure further relates to a method for producing a lamp shade comprising an inner face and an outer face, wherein the outer face is has an approximately overall convex shape and the inner face has a correspondingly approximately overall concave shape, such that a partly closed inner space may be formed between the lamp shade and a wall or the like if attached thereto, wherein the lamp shade is formed at least partly in a translucent plastic material, colored with a dye. The method includes injection molding the lamp shade with at least one tool channel of increased thickness, extending over a part of the lamp shade surface, forming in the lamp shade at least one inner ridge of increased thickness, projecting from the inner face and extending over a part of the lamp shade inner face.

The method may be varied and altered in correspondence with the above-discussed lamp shade.

Brief description of the drawings

Fig 1 illustrates a front view of a lamp shade according to the present disclosure.

Fig 2 shows a cross section of the lamp shade in fig 1.

Fig 3 shows a perspective view of the lamp shade as seen from a wall and with fastening means partly removed.

Detailed description

The present disclosure relates to a lamp shade as illustrated with an example in the front view of fig 1. This lamp shade is typically intended for a wall-attached lamp for example in a children’s room and is typically made in one piece by injection-molding a plastic material. Typical materials used include polypropylene, PP, polyamide, PA, polyethylene terephthalate, PET, recycled PET, acrylonitrile butadiene styrene, ABS, synthetic rubber, polyethylene, PE, polylactic acid, PLA, and polymethylmethacrylate, PMMA, for instance. The lamp shade may be figurative, in the illustrated case a butterfly. The view of fig 1 shows the lamp as seen attached to a wall, showing the outer face 5 of the lamp shade. The lamp shade 1 may be made in a translucent plastic material which is colored with a dye, such that, when lit by an electric lamp inside the lamp shade, it may emit a toned light.

Fig 2 shows partially a cross section of the lamp shade in fig 1 , along the line A-A of fig 1. As shown, the lamp shade 1 has an inner face 3 and an outer face 5, where the latter has an approximately overall convex shape and the former a correspondingly approximately overall concave shape, such that the lamp shade bulges or arches outwardly. This forms a partly closed inner space 6 between the lamp shade 1 and a wall or the like, when the lamp shade is attached thereto, which provides room optionally for a lamp, driving electronics therefore, and an attachment device for attaching the lamp shade to the wall or the like.

The lamp shade comprises at least one inner ridge 7 of increased thickness, project ing from the inner face 3, as illustrated in the enlarged portion B of the cross section. The inner ridge 7 extends over at least a part of the lamp shade inner face 3, and facilitates, during production, the flow of molten plastic material over the entire sur face forming the lamp shade 1. This allows the lamp shade to be thinner in other areas, located at the sides of the ridges, with a maintained production yield. This provides for a greater light flow through the lamp shade at a given lamp power.

Further, the ridges provide some structural strength, and may as illustrated provide figurative patterns, in the illustrated case the butterfly’s wing veins. When the lamp is lit, the ridges give a darker pattern over the surface of the lamp shade.

As illustrated, the ridge 7 may have an approximately rectangular shape, although other shapes, such as a triangular shape or a half-circular shape would be equally possible.

Optionally, corresponding outer ridges 9 may project from the outer face 5 of the lamp shade 1. The outer ridges may extend at least partly aligned with corresponding inner ridge 7 over a part of the lamp shade outer face 5, as illustrated in the enlarged portion of fig 2.

Typically, such outer ridges 9, may be less protruding, projecting a distance do from the surrounding parts of the outer face 5 of the lamp shade which is less than a factor 0.8 of the distance di the inner ridge 7 projects from the inner face 3. In the illustrated case, di is about 0.85 mm while do is about 0.55 mm, and the surrounding part of the outer face 5 is about 0.4 mm thick. Having a less protruding outer ridge means that the lamp shade 1 will be less prone to collect dust. It is also possible to let the outer face 5 be smooth at the inner ridge 7. The pattern formed by the inner ridges 7 will still be visible when the lamp in the lamp shade 1 is lit. The distance dj the inner ridge projects from the surrounding surfaces of the inner face may be in the range 0.1 -2.5 mm, preferably 0.3-2.0 mm, and most preferably 0.4-1.5 mm.

The distance do the outer ridge projects from the surrounding surfaces of said outer face may be in the range 0.1 -1.5 mm, preferably 0.2-1.0 mm, and most preferably 0.3-0.8 mm.

The thickness d _s of the lamp shade in areas surrounding said inner ridge 7 may be in the range 0.2-1.0 mm, preferably 0.3-0.8 mm, and most preferably 0.3-0.6 mm.

Fig 3 shows a perspective view of the lamp shade as seen from a wall and with fastening means 15 partly removed. A shown, a plurality of inner ridges 7 may be provided over the inner face 3 of the lamp shade 1 , and as is evident from fig 1 corresponding outer ridges 9 may be provided as well. At least some of the inner ridges 7 may be interconnected at crossings 11 , further improving distribution of molten plastic material during production.

The lamp shade 1 may as showed in fig 2 and 3 include a peripheral edge portion 13 configured to be directed towards a wall to which the lamp shade 1 is intended to be attached. This gives a larger inner space created by the lamp and reduces or stops uncolored light flow parallel to e.g. a wall surface. The peripheral edge portion 13 also makes the lamp shade as a whole stiffer. In some cases, this edge portion may be wholly or partly directed more or less perpendicularly to the wall, although as shown in fig 2, a more obliquely directed edge portion 13 is as useful.

There may be provided a fastening device 15 at the inner face 3 if the lamp shade, for attaching the lamp shade 1 to a wall or the like. Such a fastening device may comprise a lamp fitting and the like and may comprise e.g. screw holes 17 to facilitate fastening on a wall. When the fastening device has been fastened, the lamp shade 1 may be attached thereto using snap locks 19.

The present disclosure also relates to a corresponding method for producing a lamp shade comprising an inner face and an outer face. The outer face has an approxi mately overall convex shape and the inner face has a correspondingly approximately overall concave shape, such that a partly closed inner space may be formed between the lamp shade and a wall or the like if attached thereto. The lamp shade is produced at least partly in a translucent plastic material, which is colored with a dye. In the method, injection molding of the lamp shade takes place with a tool having at least one tool channel of increased thickness, extending over a part of the lamp shade surface, forming in the lamp shade at least one inner ridge of increased thickness, projecting from the inner face and extending over a part of the lamp shade inner face. The present disclosure is not restricted to the above examples and may be varied and altered in different ways within the scope of the appended claims.