GB2243439A - Coal effect gas fires - Google Patents

Abstract

A coal effect gas fire has a bed of irregularly shaped, moulded, imitation coal pieces. The bed is an assembly of sub-units 3a to 3f arranged in a predetermined manner on support means. Each sub-unit includes a plurality of simultaneously both moulded and interconnected imitation coal pieces. The coal pieces are connected by wires 9. <IMAGE>

Description

IMPROVEMENTS IN COAL EFFECT GAS FIRES This invention relates to coal effect gas fires.

The idea of attempting to imitate a real coal fire is well known.

Fires having false coal and a gas burning flame are common in domestic fire places.

In a known coal effect gas fire separate ceramic imitation coal pieces are piled up over a flame in a similar manner to real coal. The coals are mounted on a support structure over the flame to give the impression of a large bed of coal. The support structure is commonly a structure of steps on which the coals are located, the steps escalating from the front to the rear of the fire. A gas burning flame below the supporting steps is drawn up into the coals by the presence of a chimney above the fire.

The disadvantages encountered with existing systems include the difficulty of achieving a realistic flame propagation amongst the coals and hiding the supporting structure from view. The individual coal pieces have to be arranged in a certain manner to achieve a realistic fire. Unless an expert is employed to construct the fire inconsistent results are generally achieved by a trial and error method of arranging the coals, and a great deal of time and effort is expended. The repeatability of constructing a good fire is obviously not very high when undertaken by an untrained individual. Individual coals can easily fall out of the fire bed. Flame propagation is important not only amongst the coals but across the breadth of the fire; a tall flame is required at the rear of the coal bed and a small flame at the front of the bed.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantages.

In accordance with the present invention there is provided a coal effect gas fire comprising a bed of irregularly shaped, moulded, imitation coal pieces characterised in that the bed is an assembly of sub-units arranged in a predetermined manner on support means, each sub-unit including a plurality of simultaneously moulded and interconnected imitation coal pieces.

Preferably the imitation coal pieces of each sub-unit are interconnected by wire links.

Preferably the support means comprises a plurality of transverse bars and the sub-units comprise rows of imitation coal pieces supported on said bars.

Preferably, the bars are supported on feet with steps such that adjacent bars are at progressively higher levels from the front to the back of the fire.

Preferably, one or more surfaces of the bars are corrugated or of irregular surface.

Preferably the sub-units define locating pins designed to locate with the support means in order to facilitate the arrangement of the sub-units in said predetermined manner.

Preferably a gas emitting pipe is positioned below the support means, the pipe defining a plurality of holes along its length to emit the gas.

Preferably, the gas emitting pipe defines a loop passing around the periphery of the support means.

A specific embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which Fig. 1 is a front view of a coal effect gas fire embodying the invention; Fig. 2 shows plan views of six individual coal rows incorporated in the embodiment of Fig. 1; Fig. 3 is a perspective view of a fire supporting structure of the embodiment of Fig. 1; Fig. 4 is a perspective view of the fire supporting structure of Fig. 3 with elongate bars mounted thereon; Fig. 5 shows a gas burner pipe and piezoelectric ignition assembly, and Fig. 6 is a side view of the coal effect gas fire of Fig. 1.

Referring to Fig. 1 in which a fire 1 is shown assembled in a fireplace 2, six rows of coals 3a to 3f extend upwards and backwards from the front of the fire. The front row of coals 3a rests on box 4 which houses a gas burner 5 (see Fig. 5). Below box 4, at the front of fire 1, a facade 6 defines a slot 7 which is defined to accept a key (see Fig. 5) which actuates a piezoelectric ignition unit (see Fig. 5).

Fig. 2 shows the six individual rows of moulded ceramic coals 3a (front row) to 3f (back row). Each coal 8 in a particular row is linked to its neighbouring coal 8 or coals by a wire link 9 which is-mbedded in the coal piece 8 during the moulding process of the ceramic. The link 9 is carefully positioned such that it is hidden from view when the rows of coals 3a to 3f are assembled on the fire. In addition the links 9 hold the individual coal pieces 8 at a predetermined spacing designed to give a realistic flame propagation amongst the coals 8, to provide for easy assembly of the coal rows 3a to 3f on to the fire, and to hide the support members described below.

Fig. 3 shows the base of the fire 1 with the coals 8 removed. Box 4 supports a layer 10 which is manufactured from shot blast granulated slag steel which can withstand the high temperatures involved and acts as a heat-reflector as will be described below. The cover 10 supports a set of three identical ceramic steps 11 which extend from a point clear of the front of the box and extend upwards to the rear of the box. One step 11 is positioned in a central position, and the other two steps 11 are positioned at either side at the edge of the box 4. Each step 11 defines an archway 12 between itself and the cover 10. The archway 12 is designed to allow the flame to propagate underneath the coals 8.The front portion of each step 11 defines a triangular cross-section "nose" portion 13 designed to locate the front coal row 3a such that it is held away from the supports to define an air gap and thus improve flame propagation. Each step 11 defines three levels 14 on which elongate bars 15 are located as shown in Fig. 4. Each bar 15 extends transversely across the steps being supported in three positions along its length by each step level 14. The bar 15 at the rear of the fire 1 is supported at its rear face by pins 16 extending upwardly from the rear of each step. Each bar 15 is substantially of square cross-section and each of its four faces defines a corrugated or serrated surface.

The side of box 4 supports two brackets 17 welded thereto and projecting outwards from the box body. These are designed to enable correct positioning of the fire 1 in fireplace 2 as is shown in Fig. 6.

Fig. 5 shows the internal contents of box 4 (shown dotted). The box 4 is supported on four adjustable legs 18. Gas is supplied, via pipe 19 underneath the box, to piezoelectric ignition system 20 which is well known in the art. Ignition system 20 is positioned below the box 4 and is hidden behind facade 6 (see Figs. 1, 3 and 4). The front end of the ignition system supports a barrel 21 which defines slot 7. Slot 7 as described earlier protrudes from facade 6 and receives a key 22 which may be turned to actuate the ignition. Key 22 defines a diamond crosssection stem designed to allow easy manual location of key 22 into slot 7 without it being necessary for the operator to align his eye at the level of the slot. The key 22 is used to rotate barrel 21 to activate the ignition.The barrel is designed such that the rotational force required prevents manual actuation to the 'on' or ignition position but allows manual actuation to the 'off' position. Thus the system acts as a child proof ignition system but allows a fire already on to be turned off in the event of a lost key 22.

The electrical supply to the ignition system 20 is provided at unit 28 fixed to the outside of box 4.

The gas passes through pipe 23 which passes into box 4. The pipe extends around the inside periphery of the box 4 at approximately its mid-height point to define the gas burner 5. Gas is emitted along the length of the burner 5 through holes 24 in the pipe. The holes 24 face the box wall throughout. Along the length of the burner 5 the holes 24 become closer spaced to account for the drop in pressure as more gas escapes. In addition, for realism a taller flame is required at the rear of the fire to reach the coals 8 at the topmost level of step 11 and a small flame is required at the front of the fire. The gas emitted from holes 24 hits the side walls of box 4 in such a manner to provide even dispersion of the flame as it emerges up and over the cover 10.The contents of the box 4 below the burner 5 are embedded in vermiculite (not shown) to prevent air mixing with the gas within the box. Thus the gas exits from the burner 5 in the unlit condition, ignites around the edge of the cover 10, where it meets the surrounding air, and the flame is drawn across the cover 10 under the arches 12 in steps 11.

Fig. 6 shows the assembled fire 1 in position in the fireplace 2 below the chimney outlet 25. Brackets 17 ensure the fire 1 is positioned away from the walls of the fireplace 2 to allow air to flow in the appropriate manner and give realistic flame propagation. The gas as described ignites around the edge of the cover 10 and is drawn across the cover 10 by a chimney 'pull' effect. Arches 12 help in this effect.

The flame is drawn up into the coals 8. The positions of the coal rows 3a to 3f are fixed by legs 26 forming part of the links 9. These pass down into the box 4 (as in the case of coal row 3a), between the bar 15 and step 11 (as in the case of coal row 3b), or behind a coal row positioned underneath (as in the case of top coal row 3f). The coal rows 3a to 3f are thus fixed in position to define gaps 27 between themselves and the supporting steps 11 and bars 15. The gaps 27 are carefully designed to help to propagate the flame realistically amongst the coals 8. In addition the corrugated surface of the bars 15 beneath the coals 8 define further passageways and gaps for flame directing and separating in a realistic manner.

Claims (9)

1. A coal effect gas fire comprising a bed of irregularly shaped, moulded, imitation coal pieces characterised in that the bed is an assembly of sub-units arranged in a predetermined manner on support means, each sub-unit including a plurality of simultaneously moulded and interconnected imitation coal pieces.

2. A coal effect gas fire according to claim 1 wherein the imitation coal pieces of each sub-unit are interconnected by wire links.

3. A coal effect gas fire according to claim 1 or 2 wherein the support means comprises a plurality of transverse bars and the subunits comprise rows of imitation coal pieces supported on said bars.

4. A coal effect gas fire according to claim 3 wherein the bars are supported on feet with steps such that adjacent bars are at progressively higher levels from the front to the back of the fire.

5. A coal effect gas fire according to claim 3 or 4 wherein one or mcre surfaces of the bars are corrugated or of irregular surface.

6. A coal effect gas fire according to any preceding claim wherein the sub-units define locating pins designed to locate with the support means in order to facilitate the arrangement of the sub-units in said predetermined manner.

7. A coal effect gas fire according to any preceding claim wherein a gas emitting pipe is positioned below the support means, the pipe defining a plurality of holes along its length to emit tne gaps.

8. A coal effect gas fire according to claim 7 wherein the gas emitting pipe defines a loop passing around the periphery of the support means.

9. A coal effect gas fire substantially as hereinbefore described with reference to the accompanying drawings