GB2087542A

GB2087542A - Open fireplaces

Info

Publication number: GB2087542A
Application number: GB8128521A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-11-18
Filing date: 1981-09-21
Publication date: 1982-05-26
Also published as: GB2087542B

Abstract

A fireplace accessory comprises a resilient reflective metal sheet (17) held in place by its own resilience against the side walls (15) of the fireplace and angled rearwardly and downwardly from the front wall (13), which it contacts or approaches closely. A restricted flue access (20) is permitted behind the sheet. Slidably and pivotally mounted ears may be provided at the top portion (19) of the sheet to conform with a variety of fireplace surrounds, the position of the ears being frictionally retained in use. The accessory improves combustion efficiency, reduced heat loss via the flue, and reflects radiant heat into the room space to be heated. <IMAGE>

Description

SPECIFICATION Accessory for a fireplace Description of Invention This invention relates to an accessory for a domestic fuel burning fireplace.

There are problems involved in burning some types of fuel for example damp or poor grade goal but more particularly smokeless fuel. When burning poor grade or smokeless fuel, there may be difficulty in reaching and maintaining a suitable combustion temperature in a conventional domestic fireplace.

In the following description, the fireplace should be taken as being of a conventional type having a front opening above which there is a front wall, the combustion zone also being surrounded by back and side walls.

It has been proposed to provide a metal shield to blank off the upper part of the front opening, the shield being slotted into brackets at opposite ends of a carrier bar inserted in the front opening and having screw-threaded adjusters to enable it to be extended to wedge the bar in the opening.

This arrangement has certain disadvantages. In particular, the successful fitting of the carrier bar is difficult because there is a danger of overextending the bar and damaging the fire brick surround, or of extending it insufficiently, in which case the carrier bar may be insecure. In time, because of repeated heating and cooling cycles causing expansion and contraction, the carrier bar can work loose and this may damage the fire brick surround or cause the shield to fall down with unpredictable results.

The carrier bar also tends to be expensive since the ends must be provided with pads mounted on universal joints in order to fit different types of fireplace. The effect of heat and dirt from the fire on the screw-threaded adjusters is likely to prevent the carrier bar from being readily removable for chimney cleaning for example.

It is an object of the present invention to provide a new or improved fireplace accessory adapted to be fitted to a conventional domestic fuel-burning fireplace which is capable of ensuring more effective combustion of fuel, and improved heat output to a room space to be heated.

According to the invention there is provided, for fitment to a domestic fuel-burning fireplace, an accessory comprising a sheet of resilient, noncombustible material having a top edge and a pair of side edges and adapted to be inserted into the fireplace at an angle inclined to the vertical so that the top edge is disposed closely adjacent or in contact with the front wall of the fireplace, and the side edges abut respective side walls of the fireplace and extend downwardly and rearwardly from the front wall, the sheet being spaced from the back wall to afford a restricted cross-section opening to the flue at a horizontal level below that of the front wall and being retained in position by its own resilience.

Said horizontal level may be between one third and three quarters of the depth of the fireplace below the front wall.

The sheet is preferably made of metal.

The sheet may have a reflective, or preferably a polished front surface to reflect radiant heat and light through the front opening of the fireplace, into a room space.

The sheet may have one or more selectively openable hinged or slidable flaps covering ports to adjust the cross-sectional area of the opening to the flue and/or modify the air flow through said opening to the flue.

The sheet may be curved, in use, and preferably may present a concave curvature as viewed through the fireplace opening.

The curvature, in use, may be solely as considered in a horizontal cross-section.

Alternatively, the sheet may additionally be concave, in use, as considered in a vertical crosssection adjacent the top portion thereof.

The side edges of the sheet may be tapered inwardly and downwardly.

The top portion of the sheet may be provided with a pair of ears extending laterally beyond the respective side edges, the ears being capable of limited movement relative to the sheet and being frictionally retained in position.

Where the top portion of the sheet is concave in a vertical cross-section, the ears may be resilient and may each be curved, having a different curvature from that of said top portion, such that the ears are under resilient compression when secured to the sheet for limited movement so as to generate said frictional restraint.

Each each may have a slot, receiving fastener means by which it is secured to the sheet to permit said limited movement.

The invention will now be described in more detail by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a front elevational view of a fireplace fitted with the accessory embodying the invention; FIGURE 2 is a vertical sectional view on the line 2-2 of Figure 1; FIGURE 3 is a rear scrap view of a part of the top edge portion of the accessory; FIGURE 4 is a section on the lines 4-4 of Figure 3.

Referring to the diagrammatic drawings, the fireplace illustrated includes a conventional grate 10 supporting solid fuel, diagrammatically shown at 11 and an opening 12 defined beneath the lower edge of a front wall 13. The fireplace also has a back wall 14, and a pair of side walls, one of which is shown at 1 5. A flue 1 6 has its lower end defined by the front wall 13, back wall 14 and side walls 15.

An accessory in the form of a sheet 1 7 of resilient non-combustible material such as metal is placed within the fireplace opening so as to abut, or closely approach, the rear face of the front wall 13 and it also abuts the side walls 1 5 at each side of the fireplace opening. The sheet 1 7 extends inwardly towards its lower end so that its lower edge 1 8 approaches the back wall 14 of the fireplace, whereas its upper edge 1 9 abuts, or is closely adjacent, say within 20mm of, the front wall 13. A restricted space 20 exists between the sheet 1 7 and the back wall 14, and opens into the larger cross-section flue 1 6 above.

This means that, in addition to primary combustion air which is drawn through the grate 21 in the usual way, some of the air entering the fireplace (which would normally be swept up the flue) is deflected downwardly by the sheet 1 7 and onto the fuel. It is believed that this induces more efficient burning of the fuel, particularly at the upper surface, resulting in reduced carbon monoxide formation and increasing the surface brightness of the fire. It may be possible to reduce primary air intake through the grate where surface combustion takes place in this way.

The sheet 1 7 may be of relective resilient sheet metal such as aluminium, steel or copper. It is flexed into a bow-shaped condition as shown in the drawings and held in place against the side walls 1 5 and front wall 13 by its own resilience.

The relective surface, which may be highly polished, hammered or brushed to give a pleasant visual effect, tends to reflect radiant heat and light inwardly into the room space through the opening 12.

Although the sheet 17 may be curved in a convex sense as seen from the front of the fireplace, it is preferred that it is curved so as to be concave, as considered in a horizontal crosssection, as viewed from the front of the fireplace.

The top portion 1 9 of the sheet is, however, also preferably curved concavely in the vertical crosssection, since this enables the sheet to approach more nearly the rear of the fireplace and more effectively restrict the flue. It also has the effect of reflecting heat outwardly and downwardly into the room space.

A pair of ears 22 may be provided as illustrated in Figures 3 and 4 of the drawings, to improve the sealing between the sheet and the fireplace. The ears are secured on opposite sides of the top portion 1 9 of the sheet 1 7. For good appearance, they are secured to the rear surface of the sheet but they could be secured to the front if desired.

Each ear 22 is curved as shown in Figure 4, with a curvature which differs from that of the top portion 1 9 of the sheet. The ear 22 is secured to the sheet under resilient compression, for example by means of the arrangement shown in Figures 3 and 4. A rivet 23 is passed through a clearance hole in the sheet 1 7 and through a slot 24 in the ear. A further head 25 is formed on the end of the rivet to trap the ear under resilient compression.

It will be seen that the ear can move to a limited extent relative to the sheet 1 7 because of the presence of the slot 24. It can also rotate relative to the sheet 1 7. However, any movement of the ear is resisted by a frictional resistance generated between the ear and the sheet, and due to the resilient compression of the ear.

In fitting the accessory to the fireplace, the ears are extended fully outwardly and the accessory is then presented to the fireplace in the correct position, the ears being forced inwardly, according to the shape and size of the upper part of the fireplace opening, until they are received within the opening.

It will be appreciated that the accessory can readily be removed from the fireplace simply by flexing the sheet inwardly so as to release it from the side walls of the fireplace opening. However, in normal use, it will remain in position held by the resilience of the metal, irrespective of expansion and contraction due to heating and cooling.

It would be possible to provide hinged or slidable flaps covering ports (not shown) in the top portion of the sheet 1 7 which could be opened selectively to reduce the strength of the draught through the restricted space 20, thereby reducing the rate of combustion of the fuel.

This may enable the same grate to be used for different types of fuel or alternatively would enable the combustion to be started by drawing the maximum possible draught through the grate.

When the fire was well established, the draught could be reduced using the flaps.

In addition to use with solid fuel burning fireplaces, the accessory can be used with gas fired solid fuel effect fires, in which inert imitation fuel blocks, for example silica, are placed in a grate and heated to red heat by gas flames directed through them. The amount of draught required is less than for burning solid fuel, particularly smokeless fuel and it is therefore envisaged that the lowermost part of the sheet could be provided in the form of a pair of overlapping sheets, which could be extended or contracted in depth, to enable the appropriate amount of draught to be provided for. This could be alternative or additional to the flaps referred to above. Various other modifications are possible within the scope of the invention.

Claims

1. For fitment to a domestic fuel burning fireplace, an accessory comprising a sheet of resilient, non-combustible material having a top edge and a pair of side edges and adapted to be inserted into the fireplace at an angle inclined to the vertical so that the top edge is disposed closely adjacent or in contact with the front wall of the fireplace, and the side edges abut respective side walls of the fireplace and extend downwardly and rearwardly from the front wall, the sheet being spaced from the back wall to afford a restricted cross-section opening to the flue at a horizontal level below that of the front wall and being retained in position by its own resilience.

2. A fireplace accessory according to Claim 1 wherein said horizontal level is between one third and three quarters of the depth of the fireplace below the front wall.

3. A fireplace accessory according to Claim 1 or Claim 2 wherein the sheet is made of metal.

4. A fireplace accessory according to any preceding claim wherein the sheet has a reflective front surface to reflect radiant heat and light through the front opening of the fireplace, into a room space.

5. A fireplace accessory according to Claim 4 wherein the reflective surface is highly polished.

6. A fireplace accessory according to any preceding claim wherein the sheet has one or more selectively openable hinged or slidable flaps covering ports to adjust the cross-sectional area of the opening to the flue and/or modify the air flow through said opening to the flue.

7. A fireplace accessory according to any preceding claim wherein the sheet is curved, in use.

8. A fireplace accessory according to Claim 7 wherein the sheet presents a concave curvature as viewed through the fireplace opening.

9. A fireplace accessory according to Claim 8 wherein the curvature is concave solely as considered in a horizontal cross-section.

10. A fireplace accessory according to Claim 8 wherein the sheet is concave as considered in a horizontal cross-section and additionally the top portion of the sheet is concave as considered in a vertical cross-section.

11. A fireplace accessory according to any preceding claim wherein the top portion of the sheet is provided with a pair of ears extending laterally beyond the respective side edges, the ears being capable of limited movement relative to the sheet and being frictionally retained in position.

12. A fireplace accessory according to Claim 10 and Claim 11 wherein the ears are resilient and are each curved, having a different curvature from that of said top portion, such that the ears are under resilient compression when secured to the sheet for limited movement so as to generate said frictional restraint.

1 3. A fireplace accessory according to Claim 12 wherein each ear has a slot which received fastener means by which it is secured to the sheet to permit said limited movement.

1 4. A fireplace accessory substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

15. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.