GB2337582A

GB2337582A - Fire incorporating a flame effect generator

Info

Publication number: GB2337582A
Application number: GB9911423A
Authority: GB
Inventors: Robert Mcpherson
Original assignee: Gazco Ltd
Current assignee: Gazco Ltd
Priority date: 1998-05-18
Filing date: 1999-05-18
Publication date: 1999-11-24
Also published as: GB9911423D0; GB9810572D0

Abstract

The generator comprises a rotatably driven drum 14 carrying a mottled or marbled pattern with plain windows or apertures. The drum contains a lamp which casts an image through a ribbon array 12 onto a heavily translucent screen 11. The ribbons 12 are moved by a fan 16 so that they are visible as moving shadows against a rising smoky background with intermittent clear areas produced by the plain windows in the drum.

Description

2337582 1 FLAME EFFECT GENERATOR

TECHNICAL FIELD OF THE INVENTION

This invention relates to flame effect generators which simulate the flames produced during the combustion of solid fuels such as coals or logs.

Whilst the primary use of the generator is in conjunction with a noncombustion heat source such as in an electric fire, the generator may also be used purely for display purposes, independently of any heat source.

BACKGROUND

Primarily, flame effect generators must provide an aesthetically pleasing result. The effect should be relaxing and soothing to the eye. Although highly desirable, the flame effect need not necessarily look realistic. In practice too, a balance must be struck between aesthetic considerations on the one hand and increased cost and complexity on the other, although to some extent a more aesthetically pleasing result will support a higher selling price.

One known form of flame effect generator utilises a light source inside a 2 moving drum containing flame-shaped apertures. The light source projects moving images of the apertures through a fixed mask onto the front surface of an opaque viewing screen.

In recent years considerable attention has been paid to the development of flame effects produced by an array of flexible coloured ribbons which are caused to flutter at random between a light source and a translucent viewing screen. Whilst the screen diffuses light passing through the screen, producing a blurred or hazy image, the ribbons are still visible through the screen so that they appear as dancing flames against a substantially uniform background glow.

The present invention seeks to provide a new and inventive form of flame effect generator.

SUMMARY OF THE INVENTION

The present invention proposes a flame effect generator comprising: - a rotatably driven drum carrying a mottled or marble-like pattern; - a translucent viewing screen; - a light source located inside the drum to project light through the pattern on the moving drum and onto the screen to create a moving smoke- like image; - a plurality of ribbons positioned between the drum and the screen to cast shadows onto the screen within said smoke-like image; and - means for causing movement of said ribbons.

3 By combining a moving smoke-like image with shadows cast by the moving ribbons a more aesthetically pleasing and realistic image is produced without a prohibitive increase in cost.

The viewing screen can be disposed above and rearwardly of a synthetic fuel bed so that the flames appear to emerge from the fuel bed.

The means for causing movement of the ribbons preferably operates to create a movement of air over the ribbons.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings:

Figure 1 is a general view of an electric fire incorporating a flame effect generator in accordance with the invention; Figure 2 is a general vertical section through the fire taken in a front- rear direction; Figure 3 is an elevatonal view of the ribbon array prior to mounting in the fire; Figure 4 is a general view of the ribbon array in use in the fire; 4 Figure 5 is a general view of the projector drum assembly with the drum shown in outline only; Figure 6 is an elevational view of a sheet from which the projector drum of Fig. 5 is constructed; Figures 7 and 8 show general views of the drum in the course of assembly; Figure 9 is a detail of the translucent viewing screen of the fire; and Figure 10 is a cross section through the bottom mounting of the ribbon array.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring firstly to Fig. 1, the fire incorporates a sheet metal housing 71 defining a front opening 72 at the bottom of which is mounted a translucent moulding, e.g. resin reinforced with glass fibres, forming a simulated fuel bed 21. A translucent light-diffusing viewing screen 11 extends upwardly behind the fuel bed 21 at the back of the opening 72. One or more air intake grills 13 are formed in the housing 71 below the fuel bed 21.

Referring to the sectional view of Fig. 2, it will be seen that air drawn in through the grifl/s 13 passes upwardly within the housing behind the screen 11 to be heated by a fan heater 57 mounted at the top of the housing before exiting through a forwardly-directed outlet grill 23 above the opening 72. Cool air flow within the housing is indicated by the clear arrows 58 whereas warmed air is indicated by the shaded arrows 59.

The fuel bed 21 is illuminated from below in known manner by a filament lamp 35 mounted in a lamp compartment 39 within the housing 71. Overheating is prevented by passage of air through the lamp compartment via vent grills 36 and 38. At least one spinner 37 may be rotatably mounted above the lamp 35 in known manner so that warm air rising from the lamp causes the spinner to rotate and produce a moving shadow on the underside of the fuel bed 21. Motorised spinners could also be used.

Within the housing 71 a fan 16 is mounted in a bottom compartment 26, rearwardly of the lamp compartment 39, to draw air through the housing. Above the fan 16 there is a horizontal grill 15 which extends from the bottom of the screen 11 to separate the bottom compartment 26 from a rear compartment 25 located behind the screen 11. A rotatably driven projector drum 14 is mounted in compartment 25 above the grill 15, and an array of vertically extending flexible ribbons 12 is mounted between the drum 14 and the screen 11 extending between top and bottom mountings 28 and 29 respectively.

Referring now to Fig.s 3 and 4, it can be seen that the ribbons 12 are formed from a sheet of flexible coloured material (e.g. orange) containing a series of parallel vertical slits 32 with larger i rreg u larly-sh aped cutouts 33. The slits and cutouts may conveniently be formed using a hot tool so that the cut edges are sealed to prevent fraying. The sheet is held non-taut between the mountings 28 and 29 so that a proportion of the air flow created by the fan 6 16 passes vertically along the ribbons causing them to flutter randomly. The mountings 28 and 29 can be adjusted to set the horizontal position of the ribbons so as to vary the spacing between the ribbons and the screen, giving a certain amount of control over the sharpness of the shadow produced by the ribbons. Close spacing will produce sharper shadows whereas larger spacing will produce a more diffuse shadow.

Referring back to Fig. 2, fixed or adjustable deflector vanes 31 may be mounted within the compartments 25 andlor 26 to control the amount of air flowing over the ribbons 12. A user can control the frequency and magnitude of the fluttering movement by adjusting the fan 16 to operate at different speeds. The fan speed could be varied continuously by means of a variable resistor or it could be varied in steps using a rotary switch and an array of fixed resistors. The mountings 28 and 29 can also be adjusted vertically to change the tension in the ribbons and provide further control over the amount of fluttering movement.

As can be seen in Fig.s 5 and 2, the projector drum 14 contains an elongate fluorescent or filament-type strip light 19 extending axially along the length of the drum. A drum end cap or internal-fitting hub 44 at one end of the drum allows the drum to be rotated by an electric motor 42 via a reduction gearbox 43 and drive spindle (not shown). The opposite end of the drum is supported on circumferentially spaced rollers 18, which allows easy removal of the drum for lamp replacement and reduces vertical loading on the drive spindle. The drum could be entirely supported by such pairs of rollers if desired, with the rotational drive being via a frictional engagement between the drum and one or more of the rollers.

7 Referring to Fig. 6, the drum 14 is formed from a flat sheet 24 of a stiff but resiliently deformable transparent or translucent plastics material which is screen printed with a random or pseudo-random marblelike pattern comprising continuously inter-liked areas of dark or preferably black inkwith the individual intervening spaces left substantially clear. A mottled or flecked pattern of small discreet and random ly-d istri buted opaque areas would produce a similar effect. The sheet 24 is perforated with flameshaped apertures 22 forming clear windows in the marble pattern. Although apertures are preferred since they allow air flow through the drum (as indicated by the arrows in Fig. 2) thereby reducing heating of the drum by the lamp 19, the windows could also be formed by non-printed areas of the sheet if desired. One margin of the sheet is formed with a row of slots 73 and the opposite margin is formed with corresponding bull-nosed tabs 74 which form an interference press-fit in the slots 73. The sheet 24 is thus formed into the drum 14 by rolling the sheet into a tube and inserting the tabs 74 through the slots 73 as shown in Fig.s 7 and 8. Although this method of construction is quick to assemble and inexpensive the overlapping edges of the sheet could be secured by other means such as adhesive tape.

The screen 11 may be colour-tinted (e.g. orange) or it may be colourless. As shown in Fig. 9, the screen comprises a relatively rigid transparent or translucent carrier sheet 78, e.g. of polycarbonate or acrylic, with a thin light-diffusing textured film 79 applied to its front face. The film has a grainy or textured rear surface which is disposed against the sheet 78 and a smooth but non-reflective outer front surface. The screen is therefore nonreflective but heavily diffuses light passing therethrough.

8 When the drum 14 and its internal lamp 19 are operational the ribbons 12 are only visible as shadows which they cast on the screen against an upwardly moving smoky background. The fan 16 causes dynamic fluttering movements of the ribbons. The windows 22 in the drum 14 create additional upwardly moving clear areas in the smoky background so that the overall effect is reminiscent of randomly moving flames against a background of smoke which appear to rise from the fuel bed 21. Airflow emerging from the windows in the drum creates interference with the air flowing over the ribbons to enhance the randomness of the fluttering movements.

The form of top and bottom mounting 28, 29 shown in Fig. 10 can be used to provide a simple combined adjustment for the ribbon array 12. Each mounting comprises a flat bottom bar 80 to which the ribbon array is secured. The bar is mounted between inturned lugs 81 which pivotally support the bar off-centre at 82. Thus, by moving the bar about the pivot 82 in the direction of the arrow the bar can be moved vertically to adjust the tension in the ribbons whilst at the same time moving the ribbons towards orawayfrom the screen 11. In addition, the bottom bar forms an adjustable deflector for air rising up the front of the compartment 25 providing a certain amount of control over the air flow over the ribbons.

Dynamic movement of the ribbons may be produced by other means such as a vibrator or a separate dedicated fan. The illuminated drum can be rotated without the fan so that the ribbons remain largely stationery whilst still producing a relaxing ethereal rising smoke effect. Clearly, the flame effect generator could employ multiple ribbon arrays andlor drums with more than one fan to produce movement of the ribbons. The screen 11 may be flat or curved, and may be inclined rearwardly towards the top to give a 1 1 9 better viewing angle.

A fan heater or electrical heating element could be mounted at the base of the fire within the bottom compartment 26 instead of using a top heater 57.

Claims

It will be appreciated that the features disclosed herein may be present

in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any inventive combination of the features disclosed herein.

CLAIMS A flame effect generator comprising: a rotatably driven drum carrying a mottled or marble-like pattern; a translucent viewing screen; a light source located inside the drum to project light through the pattern on the moving drum and onto the screen to create a moving smoke- like image; - a plurality of ribbons positioned between the drum and the screen to cast shadows onto the screen within said smoke-like image; and - means for causing movement of said ribbons.
2. A flame effect generator according to Claim 1, in which the translucent viewing screen diffuses light passing therethrough such that the ribbons are not visible through the screen other than as shadows which they cast on the screen.
3. A flame effect generator according to Claim 1 or 2, in which the distance between the ribbons and the screen is adjustable.
4. A flame effect generator according to any preceding claim, in which the means for causing movement of the ribbons acts by creating an air flow over the ribbons.
5. A flame effect generator according to Claim 4, in which the means for causing movement of the ribbons is adjustable to control the rate 11 of air flow over the ribbons.
6. A flame effect generator according to any preceding claim, including an air deflector in the air flow to the ribbons.
7. A flame effect generator according to Claim 6, in which the deflector is adjustable to control the direction of air flow over the ribbons.
8. A flame effect generator according to any preceding claim, in which the viewing screen comprises a transparent or translucent sheet with a non-reflective light-diffusing front layer.
9. A flame effect generator according to any preceding claim, in which the drum is formed from a flat sheet which is rolled into a tube.
10. A flame effect generator according to any preceding claim, which incorporates a heat source.
11. A flame effect generator substantially as described with reference to the drawings.