Prior Art A flat torch is known which comprises a substrate carrying a flat battery and flat on/off switch, a pair of miniature incandescent lamps wired to the battery and switch and positioned outside the substrate, and a thick paper cover folded over the substrate and the lamps on both sides thereof, the cover incorporating at the fold a cut-out closed by a light transparent or translucent insert through which light from the lamps is transmitted in use.

A primary aim of the present invention is to provide an improved construction of flat torch and a method of making the same.

The Invention According to one aspect of the invention. there is provided a flat torch comprising a rigid chassis in the form of a flat frame. one or more outer panels of sheet material secured to opposite sides of the frame. at least one light emitter recessed into the body of the chassis for directing light outwardly thereof, and a flat battery and flat on/off switch accommodated within the free space inside the chassis between the panels.

According to another aspect of the invention. there is provided a method of making a flat torch according to which one or more light emitters are secured within a recess or recesses in the body of a rigid chassis in the form of a flat frame, a flat battery and a flat on/off switch are wired to the one or more light emitters wherebv in use the light emitter or emitters when switched on direct (s) light outwardlv of the chassis, the flat battery and flat switch are positioned within the free space inside the chassis, and one or more outer panels of sheet material are secured to the chassis.

It will be apparent that the term"flat"as generally used herein is not intended to indicate that the integers so described are two dimensional, but that the integers are substantially flattened such that their depth is enerally small compared to their length or breadth. Flat electrical cells or batteries are well known to those skilled in the art and do not require turther definition.

The or each light emitter is preferably constituted by a white LED. Suitable LEDs include those obtainable from Nichia (type NSPW 300AS) or from Siemens (Germany). LEDs are fairly delicate and easily damaged compared to incandescent bulbs. The presence of the rigid chassis, within which the LEDs may be recessed, serves to protect the light emitters against physical damage.

The chassis is preferably made of lightweight metal (such as aluminium) or a rigid plastics material (preferred examples are moulded thermoplastic materials such as ABS [acrylonitrile-butadiene-styrenel or HIPS [high impact-resistant polystyrene]) and may conveniently be substantially rectangular in shape, with the LED (s) or other light emitter (s) in a recess preferably at or near the centre of one end of the chassis. For this purpose, the chassis may be smoothly tapered in thickness to a thicker end, at least over the central region, at which the lamps are located. The minimum thickness of the chassis, however, is preferably such that the flat battery and flat switch do not disturb the smooth flow of the outer panels which enclose them so that, assuming the panels are opaque, the battery and switch are concealed from view. The position of the switch may be indicated by a suitable marking on the panel on one or both sides of the torch. In addition, in preferred embodiments, no lens is visible from front or rear elevations, so that the torch may be constructed so as to represent a conventional credit card or other promotional card item (e. g. loyalty card, debit card, playing card and the like) and is preferably of corresponding dimensions.

The outer panel (s) of the torch may be formed from a single, continuous sheet of material formed or moulded around the chassis. Such an arrangement is particularly suitable where the panels comprise a particulariv flexible material. Alternatively a pluralitv of separate sheets may he secured to the chassis. This arrangement is particularly suitable where the panels are too rigid to be bent around the edges of the chassis without imposing undesirable stresses.

The outer panels are preferably sufficiently rigid to provide a degree of strength, whilst preferablv being sufficiently flexible to allow operation of an on/off switch positioned between the panels, and to follow any curves in the shape of the chassis. Suitable materials for the panels include plastics (e. g. semi-rigid thermoplastic sheet), thick paper, cardboard or metallic sheet material. Preferably waterproof materials are selected.

Various kinds of batteries may be used, including button cells, Polaroid and Gould (US type 3B500 or 6B500 flat lithium) or Panasonic (Lithium, CR2430) flat cells. The switch is preferably a pressure operated on/off button switch, with operation enabled by the flexibility of the outer panels.

In manufacture of the flat torch, which is primarily intended to be a throw-away item after battery consumption, the outer panels, depending on the material of which they are made, may be secured by adhesive or bonded, as by plastics welding, to the chassis.

The flat torch may conveniently be made of credit card size (i. e. substantially planar rectangle. with sides of about 85mm by about 54mm), and preferably be made waterproof and crushproof (i. e. resistant to crushing when subjected to forces which may be created by an average human hand). In a preferred embodiment the torch is about 5mm thick at one end region (at which the light emitters, battery and switch are located), tapering to a thickness of about 1-5mm at the opposed end region. It possible to add a magnetic stripe or Smartcard chip to the construction.

According to still another aspect of the invention therefore, there is provided a flat torch of substantially the same dimensions as a credit card and incorporating an element comprising machine-readable encoded data (typically in the form of a magnetic stripe or, more preferably, a smartcard chip).

The llat torch incorporating the magnetic stripe or Smartcard chip may preferably be constructed and made as hitherto described, giving the torch the appropriate rigidity to be machine readable in the manner of a credit card. Where a magnetic stripe is provided on the torch, it may be preferred to offset the region of maximum thickness of the torch away from the mid-point. so that the magnetic stripe can be read by passing the torch through a conventional"swipe"card reader.

Description of Drawings The invention is further described with reference to the accompanying drawings, in which:- Figure 1 is a pictorial view of a flat torch in accordance with the invention ; Figures 2a, 2b and 2c show the torch in top view, side view and edge view, respectively; Figures 3a, 3b and 3c show the body of the torch in top view, interior side view and interior edge view; Figures 4a and 4b are views showing the interior parts of the torch; Figure 5a diagrammatically shows the parts of the torch to be assembled during manufacture and Figure 5b shows the torch after assembly; Figures 6a to 6d show four possible constructions of finished torch, each in top view and side views; and Figures 7a, 7h and 7c show an alternative embodiment of a torch in accordance with the invention in top view, side view and edge view respectively.

All Figures are drawn to the same scale, except perspective views in Figures 5a. b and pictorial representation in Figure 1.

Description of Embodiments The flat torch 10. when in operation, is pictorially shown in Figure 1. Two LEDs are referenced 12 and an on/off switch, operated by pressure applied between opposite side faces of the torch. is referenced 14.

The exterior form of the torch 10 is shown in Figures 2a, 2b and 2c, which are drawn to scale (life-size). The torch smoothly tapers or grades in thickness to a thicker central region 10A at one end where the LEDs 12 are located.

Figures 3a, 3b and 3c, (which are drawn to scale, life-size) show the interior body or chassis of the flat torch. This comprises a rigid rectangular frame 16, for example moulded of rigid plastics material such as polyethylene or PVC. At one end the thicker region 16A of the chassis 16 has recesses for accommodating the LEDs 12, within which the LEDs 12 are protected from physical damage.

Figures 4a and 4b (drawn to scale, life-size) show the interior of the torch 10, and in particular the operative parts thereof. The LEDs 12 are secured in the recesses by seals 18, and are wired to a simple PCB/switch assembly 20. Power is provided by a battery 22. which is conveniently a flat lithium battery.

Figure 5a illustrates the method of manufacture of the torch. The flat frame or chassis 16 has the LEDs 12 sealed into the recesses 16B in the region 16A and then wired to the PCB'switch assembly 20 and battery 22, which are then loosely positioned in the free space inside the chassis. The two outer panels 24 are then adhesively secured around the periphery of the chassis 16, on opposite sides thereof respectively, in order to complete assembly of the torch. Figure 5b shows the assembled torch.

Figures 6a to 6d (drawn to scale. life-size) show some possible constructions of finished torch. In the construction of Figure 6a, the torch has a Smartcard chip 26 incorporated. while in the construction of Figure 6h, the torch carries a magnetic stripe 28.

Figure 6c shows a construction having outer panels 30 of burnished or polished metal, while Figure 6d shows a construction having outer panels 32 of printed or textured plastics material. Plastics outer panels may be welded to the chassis instead of being adhesively secured thereto.

Figures 7a-7c (drawn to scale, life-size) show an alternative embodiment of a torch in accordance with the invention. The thicker region 10A of the torch is offset from the centre, so facilitating passage of the card (with a magnetic stripe 28) through a"swipe" card reading device.

The above-described flat torch, primarily but not essentially intended as an item to be thrown awav after exhaustion of the battery, has a number of advantages over the known flat torch.

The torch in accordance with the invention can be made waterproof and crushproof, of simplified manufacture resulting in a strong and elegant construction. The switch position is not visible through the outer panels, as the relatively flexible outer panels flow smoothly in conformity with the shape of the chassis. The use of white LEDs instead of incandescent lamps gives improved energy efficiency, and the LEDs are protected from damage by incorporation into the chassis body. Finally, the flat torch can be made of a convenient. lightweight credit card size and may, as above described, incorporate a Smartcard chip or bear a machine readable magnetic stripe.