GB2138552A - Fabrication of lampshades and the like - Google Patents

Abstract

A method is disclosed of making lampshades in which frame members 10, 12, 14 of plastics rod are supported in juxtaposition in a jig to form a frame in which each of a plurality of areas is bounded by plastics rods of the frame members, and each said area is covered, on the inside of the frame, by a correspondingly contoured fabric panel 16, the fabric panel 16 extending over the bounding plastics rods. Strips of plastics material 26 are placed on the inner sides of the panels in the regions of the frame members and the panels are united with the frame members and adjoining frame members with each other, by ultrasonic welding of the plastics strips with the frame members through the interstices of the fabric. <IMAGE>

Description

SPECIFICATION Fabrication of lampshades and the like This invention relates to the fabrication of Iampshades and the like articles.

Lampshades are conventionally fabricated by constructing firstly a framework of wire, cane or the like to which panels of an appropriate covering material, such as translucent cloth, are thereafter secured, for example by stitching, stapling or the like. This conventional mode of manufacture does, of course, require considerable labour so that the resulting Iampshades are somewhat expensive.

It is an object of the present invention, in one aspect, to provide an improved method of manufacturing Iampshades and analagous articles which is relatively inexpensive as compared with known methods.

According to this aspect of the invention there is provided a method of fabricating a lampshade or other article including a framework, supporting fabric, the method comprising providing a framework comprising at least one frame member consisting of or coated with thermoplastics material, providing at least one piece of a fabric, supporting the fabric in a desired position in relation to the frame member, and securing the fabric to the frame member by a fixing step utilizing the action of heat on the plastics of said framework member.

According to another aspect of the invention there is provided an article including a framework comprising at least one frame member consisting of or coated with thermoplastics material, and at least one piece of fabric, secured to said frame member by the action of heat.

Although the invention has been conceived in relation to the manufacture of lampshades, it will be apparent that the invention is applicable to the manufacture of other articles having a similar or analogous structure.

An embodiment of the invention is described below, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a perspective view of a lampshade embodying the invention, FIGURE 2 is a plan view from above of the lampshade, FIGURE 3 is a fragmentary perspective view, from the interior, of part of the lampshade, and FIGURE 4 is fragmentary sectional view showing the construction of the lampshade.

Referring to the drawings, a lampshade having the approximate form of an inverted bowl has a lower, relatively wide scalloped rim 10 and an upper, generally circular rim 12 of relatively small diameter. The lampshade has a framework with a lower peripheral portion defining the rim 12 and arcuate struts 14 extending in respective planes passing through the common axis of the upper and lower rims 10, 12, and thus radially as viewed in Figure 2. Each of the spaces between adjoining arcuate struts 14 is occupied by a respective fabric panel 16 contoured to correspond with the respective space, the edges of the panels 1 6 being secured to the framework as described below.

In the arrangement shown, the framework comprises three lengths of round-section thermoplastics rod each bent to form two loops as shown in Figure 2, which define adjacent panel spaces in the shade. Thus, each such length of rod constitutes a respective frame member which comprises an intermediate portion 20 which defines a respective part of the upper rim 12, a respective strut portion 22 extending from each end of portion 20, the strut portions 22 extending at 1200 to each other as viewed in Figure 2, each strut portion 22 extending to a respective rim portion 21 forming a respective part of the lower rim 10, the two rim portions 21 of the frame member, in the region where they adjoin one another, being connected with respective end portions 19 which terminate in the free ends 18 of the length of plastic rod, which free ends meet the portion 20 midway along the latter.

Thus, each such length of plastics rod provides, by the two adjoining, parallel end portions 19 thereof, a respective strut 14, whilst the struts 14 not so provided are each produced by a corresponding portion 22 of one such frame member and an adjoining, parallel portion 22 of the adjoining frame member. The plastics rod may be heat-formed to the desired shape. In a variant, plastics-covered thick metal wire or rod may be used in place of plastics rod.

In manufacture of the lampshade, the frame members are supported in the desired relationship with respect to one another by a suitable jig (not shown) so that the inner sides of the frame members, i.e. the sides which lie on the concave side of the lampshade as a whole, are exposed, and the fabric pieces 1 6 are placed in position.

Each of the fabric pieces 1 6 preferably comprises a facing layer of a woven fabric, for decorative purposes, and a backing layer of translucent or transparent thermoplastics sheeting for stiffening purposes and to afford the thermoplastics material for welding as described below. Each panel 16 is shaped to correspond with any of the identical spaces defined between adjoining struts 14 but the panels 1 6 are somewhat larger than such spaces so that each panel, when appropriately positioned, overlaps slightly the respective members 19, 20, 21 and 22 bounding the respective panel space. Until secured by welding as described below, each panel 16 may be held automatically in place, for example by suction by providing orifices connected with a vacuum source in appropriate parts of the jig.The marginal portions of the fabric pieces 16 overlapping the members 1 9, 22, are then secured to these members, preferably as follows. When the frame members and the fabric pieces 16 are located in the appropriate positions in the jig, strips of a selected plastics material are placed, on the exposed inner surface of the shade, along the lines of the respective pairs of adjoining members 19, 22, so that each such strip overlaps the respective fabric pieces 1 6 which adjoin at the respective strut 14 and the respective members 19, 22 which form the respective strut 1 4. In Figures 3 and 4, such a strip of plastics material is indicated at 26.The adjoining members 1 9 or 22 of each strut 14 and the respective adjoining edge portions of the respective adjoining panels 1 6 are united by the action of heat, so that the adjoining members 1 9 or 22 of each strut are welded together and to the plastics backing of the fabric pieces and the plastics strip 26, with the plastics material of the weld permeating the interstices of the fabric so that the fabric is thereby secured to the frame members. The welding, which is preferably effected ultrasonically, is effected in such a manner as to melt the strip 26 in the appropriate areas and to fuse this strip with the members 1 9, 22 and secure the adjoining edge portions of the fabric.If the fabric is itself of thermoplastics yarn, this may itself be welded to the plastics of the strip 26 and the frame members during the welding step or may merely be permeated by the plastics of the strip 26 and/or the frame members. Preferably a supply of the plastic strip 26 will be incorporated in an appropriate welding tool, so that the strip 26 can be applied and simultaneously welded to the edges of the fabric pieces 1 6 and the members 1 9 or 22 in one continuous stroke of the welding tool.

The material of the strip 26 is preferably selected so as to heat to the desired extent under the ultrasonic energy utilised and to have a melting point which is appropriate in relation to that of the plastics backing of the fabric pieces and the plastics rod forming the frame members. The welding is preferably affected in such a way that not only are the fabric pieces 1 6 secured to the members 19, 22 of the respective frame space which they occupy, but a welded connection is provided between adjoining members 22, 19.

During the welding step, the portions of the panels 1 6 overlapping the frame portions 20 and 21 may be secured thereto in the same manner as that in which the panels are secured to the struts 14, but it has been found that where the fabric pieces comprise woven fabric backed by plastics sheeting, as described, the resulting stiffness of the panels is sufficient to keep these in place against the respective portions 20, 21 without welding to the portions 20, 21. It is preferable, however, for the welding effected to be effective to weld the free ends 1 8 of each frame member to the adjoining portion 20 of that frame member.

In a variant of the method, the plastics backing of the fabric pieces 1 6 may be omitted, the fabric pieces simply being secured by the fusing of the plastics material of the strip 26 with that of the frame members through the interstices of the fabric.

In a further variant, the plastics strip 26 may be omitted and the fabric pieces, with their plastics backing, made somewhat wider so that adjoining fabric pieces overlap one another over the region of the respective strut 14, the welding step then serving to fuse the plastics backings of the overlapping fabric pieces with one another and with the respective strut so as to secure the members 19, 22 together and secure the fabric pieces to the members 19, 22.

The customary fitting for engagement with an elelctric light bulb holder is not shown in the drawings, but may be designed for ready attachment to the upper rim 12; by way of example such fitting may comprise resilient formations for engagement with the upper rim 12 so that it can be simply snapped into place after the lampshade has been assembled by welding as described. Alternatively such fitting may be designed to be placed in the appropriate position in the jig before the welding steps and have appropriate formations which are secured to the remainder of the structure by the welding steps described.

The method of lampshade fabrication described has the great advantage, over prior methods, that it is not necessary first to construct a complete frame and then to fasten the fabric panels, but rather a single welding step serves to secure together the frame members and the fabric pieces to form a rigid, substantially completed lampshade.

Furthermore, the method of lampshade fabrication described provides a rigid light-weight lampshade of pleasing appearance, analogous to that of a traditional lampshade, but lends itself to automated niass production techniques, whereby such a shade may be produced economically.

Various modifications are, of course, possible within the scope of the appended claims. Thus, for example, the welding may be effected other than ultrasonically, for example, dielectrically, or using heated tools, hot air, or the like.

The plastics framework, being exposed on the outside of the lampshade, also acts as a decorative trim for the fabric panels, so that an additional trim, such as is necessary in lampshades having an internal frame, to conceal the junctions between adjoining panels, is unncessary.

Claims (17)

1. A method of fabricating a lampshade or other article including a framework, supporting fabric, the method comprising providing a framework comprising at least one frame member consisting of or coated with thermoplastics material, providing at least one piece of a fabric, supporting the fabric in a desired position in relation to the framework member, and securing the fabric to the framework member by a fixing step utilizing the action of heat on the plastics of said framework member.

2. A method according to claim 1 wherein said framework comprises a plurality of discrete frame members consisting of or coated with thermoplastics material and wherein a plurality of such fabric pieces are secured to the framework by said fixing step which interconnects the framework members and the fabric pieces with one another to produce an integral, selfsupporting structure.

3. A method according to claim 1 or claim 2 wherein said fixing step utilizes the action of heat produced ultrasonically.

4. A method according to claim 2 wherein said frame members and said fabric pieces are supported in a jig prior to and during said fixing step.

5. A method according to any of claims 1 to 4 wherein the or each said fabric piece comprises a porous fabric with a plasics backing, and wherein, during said fixing step, said plastic backing is welded to the respective said frame member through said fabric.

6. A method according to any of claims 1 to 4 wherein prior to or during said fixing step a piece of thermoplastics material is placed on the side of the or each said fabric piece remote from the respective frame member, and during said fixing step, said piece of thermoplastics material is welded to the respective said frame member through said fabric.

7. A method according to claim 5 or claim 6 when dependant on claim 2 wherein during said welding, adjacent said frame members are welded together.

8. An article including a framework comprising at least one frame member consisting of or coated with thermoplastics material, and at least one piece of fabric, secured to said frame member by the action of heat.

9. An article according to claim 8 wherein said framework comprises a plurality of separately formed frame members consisting of or coated with thermoplastics material, and wherein a plurality of such fabric pieces are secured to the framework by welding which interconnects the framework members and the fabric pieces with one another to produce an integral, selfsupporting structure.

10. An article according to claim 9 wherein each said frame member comprises a length of material of generally uniform section bent to form one or more loops.

1 An article according to claim 10 in the form of a lampshade.

12. A lampshade in accordance with claim 11 wherein said frame members are exposed to view on the outside of the lampshade and said fabric pieces are welded to the inner sides of said frame members.

13. A lampshade incorporating a framework of plastics rod or tube and panels of sheet material adhered or otherwise connected together.

14. A lampshade according to claim 10 wherein said framework is exposed to view on the outside of the lampshade and forms a decorative trim for said panels.

1 5. A method of fabricating a lampshade, substantially as hereinbefore described with reference to the accompanying drawings.

1 6. A lampshade substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

17. Any novel feature or combination of features described herein.