GB2350885A

GB2350885A - Flame effect generator

Info

Publication number: GB2350885A
Application number: GB9913520A
Authority: GB
Inventors: Philip Paul Wilson; Stuart Hodgkinson
Original assignee: BAXI HEATING Ltd
Current assignee: BAXI HEATING Ltd
Priority date: 1999-06-11
Filing date: 1999-06-11
Publication date: 2000-12-13
Also published as: GB9913520D0; IE20000470A1

Abstract

A flame effect generator for a flame effect fire comprises a light source 2 and a rotatable cylinder 1 having apertures therein, the light source 2 being positioned outside the cylinder 1 so light passes through the apertures and onto to a screen 3. The apertures are shaped to create a flame effect on the screen 3. A second larger cylinder 12 of transparent material may be located eccentrically around the first cylinder 1 and rotate at a different speed. The inner cylinder 1 may drive the outer cylinder 12 by engaging an indexing portion 13 on the inner cylinder 1 with teeth on the inner rim 19 of the outer cylinder 12. A coloured, movable plate 18 may also be used to vary the colours of the flame effects. The plate 18 may be moved from a first to a second position by engagement of a projection 19 on the outer rim of the second cylinder 12 with a projection 20 on the plate 18. When engagement of the projections 19 and 20 ceases the plate 18 is biassed to return to the first position.

Description

1 2350885 FLAME EFFECT GENERATOR The present invention relates to a flame

effect generator for use in a fire in which a flame effect is projected on to a screen to give the illusion of a solid fuel fire.

A flame effect illumination that simulates real flames, either provided on its own or with an electric or gas heater, is pleasing to view, and this type of illumination is well known. However, known flame effect generators suffer from disadvantages in that there is no real "dancing" effect or variation in the flames as would be present with real flames, and the flame pattern repeat is in most cases immediately obvious and unconvincing. Further, the range of colours of the flame effects available is also limited.

A vertically moving flame effect is the most realistic, and this has been easiest to obtain with the use of horizontally rotating reflectors or apertured plates, which reflect or project light onto a vertical or nearvertical screen.

British patent application GB-A-2321700 describes the use of a horizontally rotating drum having a cylinder that is printed with a coloured flame effect image and has an internal lamp. The lamp illuminates the drum, and light is projected upwards through a separate perforated mask provided with flame shaped apertures onto a screen. As the perforated mask is stationary, the flame effects are generally of the same shape, and the projected image is not realistic.

British patent specification 414280 describes the use of a horizontally rotating drum having apertures cut into its surface, again having an internal lamp. Light is projected through the apertures in the drum and through a separate perforated mask onto a screen. The pattern repeat is also easily noticed with this prior art system, and the effect is not realistic due to the stationary mask.

British patent specification 450941 also describes the use of a horizontally rotating drum, in this case using reflective mirrors positioned on the drum to reflect light from a light source external to the drum onto a vertical screen. As this does not produce flarne-shaped reflections, a mask is used to impose a flame shape to the reflections before they hit the screen. Again, the flame effect is not realistic, as there is no movement of the flame shapes, only a flickering of the light within them.

It has proved difficult to impart the necessary degree of randomness to the size, shape, colour and degree of movement of the flame effects at the same time, 2 whilst retaining a flame-like shape to the light projections that is required if the viewer is not to immediately notice that the flames are not real.

It is an object of the present invention to obviate or mitigate some or all of the problems outlined above.

According to the present invention there is provided a flame effect generator for a flame effect fire comprising a light source and a rotatable cylinder having apertures provided therein, wherein the light source is positioned outside the cylinder and is arranged such that light therefrom passes through the cylinder apertures onto a screen.

By placing the light source outside the cylinder, such that it projects through the cylinder, the light passes through two sets of moving apertures. This therefore projects realistic flame effects onto a projection screen.

The cylinder need not have a circular cross-section, for example, it may have a flattened cross section, which would enable the use of a larger surface area on which to provide apertures, thus giving a longer time between the pattern repeat.

Preferably, the cylinder is rotatable about a horizontal axis. The light source is preferably placed underneath the cylinder so that light passes upwards through the cylinder onto the screen. Alternatively, the light source may be placed so that light is reflected towards the screen by a reflective surface. The cylinder is preferably rotatable such that the nearest part of the cylinder to the screen moves in an upward direction. The projection of the light upwards onto the screen thus has the advantage that the flames appear to move upwards with the rotation of the cylinder, in a similar manner to the upward movement of real flames from a fuel source.

The cylinder is preferably driven by a variable speed motor, which is preferably a stepper motor. The variation of the speed of rotation of the cylinder introduces more variation into the flame pattern, thus making the pattern repeat of the apertures on the cylinder harder to detect.

The apertures may be flaine-shaped or may include elongate slots, at least part of each slot being aligned with the direction of rotation of the cylinder. At least part of at least one aperture is preferably aligned on a diagonal to the direction of rotation of the cylinder. The diagonally aligned part of the slot may be part of a substantially v- or u-shaped section of the at least one elongate aperture. A diagonal, v- or ushaped aperture will cause the flame effect to appear to move horizontally across the screen.

3 A second cylinder is preferably provided, with the two cylinders being located such that light passes through both cylinders to the screen. The second cylinder is preferably formed of a transparent material having differently coloured areas. The colourations may be elongate stripes, for example of reds, oranges, yellows and/or blues. The two cylinders are preferably located one within the other, and preferably are rotatable about parallel, spaced apart axes. The cylinders may be separately powered to rotate at different speeds or one cylinder may be powered to rotate at a first speed, the other cylinder being advanced in a step-wise manner as the result of engagement by an indexing member rotating with the one cylinder.

The provision of a coloured cylinder rotating at a different speed around the first cylinder means that the pattern repeat of the flame effects is more variable than with one cylinder on its own and is therefore harder to detect.

A transparent coloured member such as a screen or plate may also be provided to impart a colouration to the flame effects. This may take the form of a plate positioned between the light source and the screen, such as between the light source and the apertured cylinder, or between the apertured cylinder and the screen, or the member may be positioned between the apertured cylinder and imitation fuel, such as is normally provided in front of flame effect generators. The member may be flat or curved.

The transparent member may be moveable, and the movement of the member may be caused at least in part by rotation of the apertured cylinder. The member may be moveable between a first position and a second position, and may be biased into the first position and moveable into the second position by means of rotation of the apertured cylinder or the second cylinder. The movement of the transparent member may be achieved by an indexing member provided on a rotating cylinder engaging with a projection provided on the member.

Movement of the transparent member between two positions during rotation of the apertured cylinder, and second cylinder if provided, means that different colours may be given to the flame effects, making the pattern repeat of the flame effects much less noticeable.

Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is front view showing a flame effect generator and screen in accordance with the present invention; 4 Figure 2 is a front view showing an apertured cylinder for use in the flame effect generator of Figure 1; Figure 3 is a side view showing a fire incorporating the flame effect generator of Figure 1; Figure 4 is an end view of an alternative embodiment of flame generator in accordance with the present invention; and Figure 5 is a view of a second cylinder for use in the flame generator of figure 3.

Referring to figures I to 3 of the drawings, there is illustrated a flame effect generator comprising an apertured cylinder I and a lamp 2, the flame effect generator being placed below and slightly in front of a screen 3, on which brick effects 4 have been printed. Other background effects to simulate other fire surround materials may of course be printed on the screen 3 instead of a brick effect. The apertured cylinder is typically formed of metal, although could be formed of a different material, and is horizontally rotatable about its axis by means of a motor 5 and an actuator (not shown) such as a roller positioned underneath one end of the cylinder. A frame 6 holds apertured cylinder I in place above lamp 2.

The apertures formed in the cylinder I have a variety of shapes, but are generally elongate and extend around the circumference of the cylinder. The apertures may include diagonal sections, U-shaped sections or Vshaped sections. Flame shaped apertures may be provided in addition to or instead of elongated apertures, but the elongated apertures provide the longest lasting illumination to the screen and hence give a better impression of a flame.

The lamp 2 is positioned underneath the apertured cylinder I and is provided in a reflective tray 7 to ensure that as much light as possible passes through the cylinder. A transparent plate 8 of glass or similar material that is coloured or has colourations provided thereon may be placed in brackets 9 between the lamp 2 and the apertured cylinder I so that the light passing into the apertured cylinder I is coloured. Alternatively, the transparent plate may be placed above the apertured cylinder 1, at the position identified by arrow A.

The screen 3 is angled to the vertical so that it projects forwards at its top to ensure that light projected by the flame effect generator is visible on the screen.

In use, the flame effect generator is placed in an electric or gas fire, with the cylinder I and lamp 2 being placed out of sight of a viewer, for "ample behind heating elements 10. In a flame effect fire, an imitation of fossil fuel such as coal is also often provided above the heating elements. This may take the form of suitably shaped pieces of coloured glass or other display, generally designated 11 in Figure 3. The screen 3 is visible to the viewer, and is situated above the flame effect generator, which is placed in a heat resistant easing 12. A transparent aperture (not shown) may be provided in casing 12, to allow some light from lamp 2 and cylinder 1 to pass into the imitation fuel 11 to provide illumination thereto. When the fire is turned on, a variable speed motor (not shown) drives the actuator to rotate the cylinder in a forwards direction whilst power is supplied to the lamp 2. The heating elements 10 may also powered (or if the heating is provided by a gas burner, may be ignited), although the flame effect may be generated to give a pleasing effect without heating.

As light from the lamp 2 passes upwards through the apertures in the cylinder 1 onto the screen 3, it creates flame effect patterns of light on the screen. Due to the relative placing of the screen 3, the imitation fuel 11 and the flame effect generator, the flames can be made to appear just behind and above the imitation fuel. The flame effects may be coloured due to light passing through the transparent plate 8, or may be coloured by a different means, for example by the use of a coloured bulb in lamp 2.

The rotation of the cylinder 1 causes the flame effects to appear to move due to the relative movement of the apertures on opposite sides of the cylinder. By rotating the cylinder in a forwards direction, the flame effects appear to rise on the screen in a similar manner to real flames. This is achieved by the forwards motion of a leading edge of an aperture in the cylinder as it passes the top of the rotation. The flames also appear to die down due to the backwards motion of a leading edge of an aperture in the cylinder as it passes the bottom of the rotation. The different shapes of the apertures across the cylinder create different effects at the same time across the screen as the cylinder is rotated. Some light may also be allowed to project onto the screen around the back of the cylinder, to provide a general "glow" to the projection.

ReferTing now to figures 4 and 5 of the drawings, an alternative embodiment of the invention is described.

A flame effect generator comprising an apertured cylinder 1 and light source 2 as described for figures 1 to 3 is provided and will not be further described. An indexing projection 13 is provided on one end of the apertured cylinder 1.

A second cylinder 14 is also provided around apertured cylinder 1, the diameter of the second cylinder being larger than that of apertured cylinder 1. The 6 axis of rotation of the second cylinder 14 is parallel to, and spaced apart from the axis of rotation of the apertured cylinder 1. Teeth 15 are provided around an end of the second cylinder 14, designed for co- operation with indexing projection 13 of apertured cylinder 1. Teeth 15 have different sizes and are at different positions around the circumference of the cylinder 14.

Cylinder 14 is formed of a transparent, heat-resistant material. Different colourations are provided in cylinder 14, to simulate the colours of flames. The colourations in the illustrated embodiment are in generally diagonal, elongate stripes 16 and triangular shapes 17, and include different hues of reds, oranges, yellows and/or blues.

A transparent plate 18 is optionally provided to the side of the apertured cylinder 1 and cylinder 14. Plate 18 may be flat or curved, and is provided with either a single colour or colourations to imitate flames. Two indexing projections 19 are provided on the outside of cylinder 14 to co-operate with a projection 20 provided on transparent plate 18. it will be appreciated that one or more projections 19 may be used, to co- operate with one or more plates 18. Plate 18 is spring-loaded to fall back into a lower position if it is not contacted by a projection 19.

In use, rotation of apertured cylinder 1 causes rotation of the second cylinder 14 by means of the indexing projection 13 co-operating with teeth 15. The different sizes of the two cylinders coupled with their different axes of rotation cause the cylinders to be rotated at different speeds. One full rotation of apertured cylinder 1 moves the second cylinder 14 by the circumferential distance between adjacent teeth 15. As teeth 15 are placed around the circumference of cylinder 14 with different spacings between them, the cylinder 14 is thus moved by different amounts, depending on which tooth the indexing projection 13 connects with. The exact sizes and spacing of teeth 15 are worked out having reference to the flame pattern that is desired in a particular fire.

Projections 19 abut projection 20 on the transparent plate 18 as cylinder 14 is rotated. This moves plate 18 upwardly until rotation of the cylinder 14 means that projections 19 and 20 no longer mesh, causing plate 18 to fall downwardly. A suitable sound dampening device is provided to prevent the noise of plate 18 hitting a stop to prevent further downward movement becoming apparent to a person near the fire. The light passing through plate 18 illuminates the imitation fuel 11 through an aperture provided in casing 12. The variation in timing of the movement of plate 18 7 causes the colour of the illumination of fuel 11 to be varied without the pattern repeat being immediately obvious. Another transparent plate (not shown) may be provided above the flame effect generator, to provide a further colouration of the flame effects, and this may also be moved due to rotation of indexing projections 19, to provide a variation in pattern repeats. A transparent plate provided above the flame effect generator will generally be horizontal, and will be spring biassed into one position so that it is moveable by indexing projection 19.

As light is projected from lamp 2 through the two cylinders, the flame effect patterns caused by rotation of the apertured. cylinder 1 are illuminated in different colours due to the rotation of the second cylinder 14 (and also movement of plate 18 if provided). The fact that the two cylinders are rotated by different amounts means that even once the apertured cylinder 1 has been fully rotated so that the flame pattern of the apertures is repeated, the colours of the flame pattern are not repeated at the same speed and so the pattern repeat is much more difficult for an observer to notice. The colours given to the flame effects by the second cylinder 14 interact with the colours provided by plate 18, especially if plate 18 is provided above the second cylinder 14, to create a greater array of colours.

It should be appreciated that, although the illustrated embodiment has a coloured cylinder larger than and rotating around the apertured cylinder, the coloured cylinder could be placed inside the apertured cylinder for a similar effect. The second cylinder could instead be placed between the apertured cylinder and the screen. The second cylinder may be driven separately from the apertured cylinder. Many different arrangements of apertures and colourations on the cylinders may also be used for different flame effects.

Coloured transparent plates may also be provided at various positions around the flame effect generator, and may be moveable to provide many different variations in the colours given to the flame effects. Alternatively, or in addition, a third cylinder may be indexed for rotation with the second cylinder, the third cylinder having colourations provided thereon.

Claims

1. A flame effect generator for a fire comprising a light source and a rotatable cylinder having apertures provided therein, wherein the light source is positioned outside the cylinder and is arranged such that light therefrom passes through the cylinder apertures onto a screen.

2. A flame effect generator according to claim 1, wherein the cylinder is rotatable about a horizontal axis.

3. A flame effect generator according to claim I or 2, wherein the light source is placed underneath the cylinder so that in use light passes upwards through the cylinder onto the screen.

4. A flame effect generator according to claim 1, 2 or 3, wherein the light source is placed so that in use light is reflected towards the screen by a reflective surface.

5. A flame effect generator according to any preceding claim, wherein the cylinder is rotatable in use such that the nearest part of the cylinder to the back-projection screen moves in an upward direction.

6. A flame effect generator according to any preceding claim, wherein the cylinder is driven by a variable speed motor.

7. A flame effect generator according to claim 6, wherein the variable speed motor is a stepper motor.

8. A flame effect generator according to any preceding claim, wherein the apertures provided in the cylinder are flame-shaped.

9. A flame effect generator according to any of claims I to 7, wherein the apertures provided in the cylinder include elongate slots, at least part of each slot being aligned with the direction of rotation of the cylinder.

10. A flame effect generator according to claim 9, wherein at least part of at least one aperture is aligned on a diagonal to the direction of rotation of the cylinder.

11. A flame effect generator according to claim 10, wherein the diagonally aligned part of the slot is part of a substantially v- or u-shaped section of the at least one elongate aperture.

12. A flame effect generator according to any preceding claim, wherein a second rotatable cylinder is provided, the two cylinders being located such that light passes through both cylinders to the screen.

9

13. A flame effect generator according to claim 12, wherein the second cylinder is formed of transparent material having differently coloured areas.

14. A flame effect generator according to claim 13, wherein the coloured areas are elongate stripes.

15. A flame effect generator according to claim 12, 13 or 14, wherein the two cylinders are located one within the other.

16. A flame effect generator according to claim 15, wherein the two cylinders are rotatable about parallel spaced apart axes.

17. A flame effect generator according to any of claims 12 to 16, wherein the cylinders are separately powered to rotate at different speeds.

18. A flame effect generator according to any of claims 12 to 16, wherein one cylinder is powered to rotate at a first speed, and the other cylinder is advanced in a step-wise manner as the result of engagement by an indexing member rotating with the one cylinder.

19. A flame effect generator according to any preceding claim, wherein a transparent coloured member is provided to impart a colouration to the flame effects.

20. A flame effect generator according to claim 19, wherein the transparent member is provided between the light source and the screen.

21. A flame effect generator according to claim 19 or 20, wherein the transparent member is moveable, the movement of the member being caused at least in part by rotation of the apertured cylinder.

22. A flame effect generator according to any of claims 19 to 21, wherein the transparent member is moveable between a first position and a second position.

23. A flame effect generator according to claim 22, wherein the transparent member is biased into the first position and is moveable into the second position by means of rotation of the apertured cylinder.

24. A flame effect generator according to claim 23, wherein the movement of the transparent member is achieved by an indexing member provided on the second cylinder engaging with a projection provided on the member.

25. A flame effect generator according to claim 22 when dependant on any of claims 12 to 18, wherein the transparent member is biased into the first position and is moveable into the second position by means of rotation of the second cylinder.

26. A flame effect generator according to claim 25, wherein the movement of the transparent member is achieved by an indexing member provided on the second cylinder engaging with a projection provided on the member.

27. A flame effect generator substantially as hereinbefore described with reference to figures 1 to 3 of the accompanying drawings.

28. A flame effect generator substantially as hereinbefore described with reference to figures 4 and 5 of the accompanying drawings.

29. A fire comprising a flame effect generator according to any preceding claim, a screen onto which the flame effects are projected and a heating element.