GB2043874A - Gas Fire - Google Patents

Abstract

A gas fire having a hearth, a heat reflector surrounding at least the rear of the hearth and at least one radiant burner plaque (14) mounted in the hearth. <IMAGE>

Description

SPECIFICATION Gas Fire The present invention relates to a gas fire and in particular a gas fire having burner plaques which simulate natural fires.

According to one aspect of the present invention there is provided a gas fire having a hearth, a heat reflector surrounding at least the rear of the hearth and at least one radiant burner plaque mounted in the hearth. Preferably the hearth is horizontal and the or each burner plaque is inclined to the horizontal so as to direct radiant heat directly outwards.

Preferably, the radiant burner plaques are of the type which simulate natural fires, such as coal or log fires.

The reflector conveniently extends along both sides of the hearth as well as along its rear. The gas fire may be a mobile gas heater which includes a housing for storing bottled gas or a heater mounted say on a wall.

Reference is now made to the accompanying drawings, in which: Figure 1 is a schematic side elevation, partly broken away, of a gas fire according to the present invention; Figure 2 is a schematic exploded perspective view of the front assembly of the gas fire shown in Figure 1; Figures 3 and 4 are respectively front and side views of the hearth and reflector assembly shown in Figure 1; Figure 5 is a broken away side view showing the hearth and reflector assembly in situ; Figures 6, 7 and 8 are respectively, plan, front and side views of the plaque support and burner assembly of the gas fire shown in Figure 1; Figure 9 is a schematic diagram illustrating supply of gas to the plaques and the lighting sequence thereof.

The gas fire illustrated in Figure 1, basically comprises a housing 10, in which is housed a bottle of liquified gas such as butane or propane, and a front assembly 12 which houses the plaque burners 14. The housing includes a base 1 Oa on which the bottle stands and to which castors 1 Ob are attached to enable the fire to be moved around. Access to the interior of the housing is achieved via a hinged rear door 9.

A wire guard 1 4a is provided to prevent direct contact of personnel with the burners. The plaque burners used are preferably of the type which simulate natural fires such as a simulated log or coal plaque.

Conveniently, the plaques used are the coal effect plaque burners as supplied by J. Tennant & Sons (Warrington) Limited under the name 'Tennaglo'.

The front assembly 12 includes two side members 14 and 1 5 (Figure 2) which have identical features (i.e. side member 14 is a mirror reflection of side member 1 5).

Each side member is a metal pressing housing an exterior surface covering of a decorative nature, such as a wood grain or paint finish. Each pressing is provided with a marginal flange portion 1 6 which extends about its periphery to give the side member rigidity.

An upper front panel 20, having a decorative outer surface, is secured between the side members 14 and 1 5. The front panel 20 is preferably a metal pressing having a peripherally extending flange 21. The portions of flange 21 extending along the side edges of the panel 20 are provided with apertures 22 which align with apertures 23 formed in flange extensions 24, which extend perpendicularly from flange 1 6. Pop rivets (not shown) are introduced through the aligned apertures to permanently connect the front panel to both side members 14 and 1 5.

An L-shaped strut 25 is fixedly secured, preferably by riveting the lower end of each side member. The strut 25 is provided with apertures 26 for securing the front assembly to the housing.

A tab 30 extends perpendicularly from each flange extension 24 and is provided with a series of apertures 31. Lower members 32 in the form of metal pressings of L-shape configurations extend in a side by side relationship between the side members to define a grill 34 beneath the front panel 20. Each member 32 is provided adjacent its ends with apertures 33 for alignment with the apertures in tabs 30. Pop rivet may be used to permanently attach the lower members 32 to the side members 14 and 1 5. Each lower member 32 is provided with a series of elongated apertures 35. Thus as shown by the arrow in Figure 5, hot air may escape through the grill 34 whether it approaches the grill from below or above.

Each side member is provided with a flange extension 37 which provided an abutment face 38 extending parallel to flange 1 6. Each extension 37 is provided with a stud 39 which co-operates with a resilient clip 40 formed in a lower front panel 41. The lower front panel 41 is also a metal pressing having a peripheral flange 42. By virtue of the studs 39 and co-operating resilient clips 40 the lower front panel 41 is releasably secured to the side members 14 and 1 5.

The hearth and reflector assembly 50 is assembled as shown in Figures 3 and 4 before it is secured in position between the side members 14 and 15.

The assembly 50 basically includes four components viz. A hearth member 51, a back reflector 52 and two side reflectors 53 and 54. All four components are formed from a metal having a suitable reflecting surface. The components are secured together, preferably by pop-riveting and they are designed for interconnection so that the curvatures of the reflectors are accurately reproduced using metal pressings.

Accordingly, each side reflector 53, 54 is provided with tabs 56 and 57 and are each provided with an accurately curved edge portion 58 extending between tabs 56 and 57. The back reflector 52 is provided with tabs 59 and 60. Tabs 56, 59 and 57, 60 are provided with apertures which align with one another to receive pop rivets 61 and 62.

The tabs 56 and 59 are initially attached to one another and then tabs 57 and 60 are connected together.

Tabs 57 and 60 are so positioned that when they are connected together, the side portions of the back reflector are caused to overlap and bear down onto the curved edge portion 58 of each side reflector. This ensures that the back reflector assumes a curvature as dictated by the curved edge portion 58 and is thereby consistently and accurately reproduced in mass production.

Each side reflector 53, 54 has a degree of curvature to define a concave reflecting surface.

This curvature is consistently and accurately reproduced by virtue of securing, for instance by pop rivets, the lowermost edge of each side reflector in abutment with curved edge portions 63 of the hearth member 51.

The hearth member 51 is a metal pressing and is provided with a central window 65 through which the radiant plaques project in use. The hearth member 51 is provided with a peripheral flange 66.

The flange 66 in the region of edge portions 63 is provided with apertures to receive rivets for securing the side members thereto. The portion of flange 66 extending along the rear edge 67 of the hearth member 51 is also provided with apertures for enabling the lowermost region of the back reflector to be riveted thereto.

The hearth and reflector assembly 50 is secured in position between the side members 14 and 1 5 by riveting tabs 68 formed on the back reflector to tabs 69 formed on the side members 14 and 1 5 and also by riveting flange extensions (not shown) extending inwardly from the portions of flange 66 extending along the sides 70,71 of the hearth member 51 to the portions 1 6a of flange 16.

The front assembly 12 may now be secured to the housing 10. This is achieved by hooking the upper part of the front assembly to the housing and by securing the strut 25 to the lower part of the housing.

The plaque support and burner assembly 80 illustrated in Figures 6, 7 and 8 is located beneath the hearth member 51 and positioned so that the burner plaques 14 project through the window 65.

The assembly 80 includes a platform 80a which is conveniently a metal pressing having upturned side flanges 82, 83 and an upturned rear flange 84.

The platform 80a is supported on a pair of support brackets 85, 86 which stand on the base 1 Oa and which are secured to wall 10c (Figure 1) of the housing 10. The strut 25 is secured to the front of brackets 85, 86 in order to secure the front assembly 12 to the housing 1 0.

Three burner plaques 1 4a, 1 4b, and 1 4c are mounted on ceramic boxes 93, 94 and 95 respectively. The boxes stand on the platform 80a with their front walls in abutment with a pair of retaining brackets 96 and 97.

The retaining brackets 96 and 97 are secured to the platform 80a, and are provided with a projecting lip 98 which co-operates with a groove 99 formed in the front wall of each box in order to prevent the boxes from lifting off the platform 80a.

The rear wall of each box is provided with an opening which communicates with a mixing tube located inside the box. A U-shaped bracket 100 is provided for cooperation with each box, the bracket being secured to the platform 80a by virtue of self tapping screws which pass through apertures punched in the platform 80a.

Both arms 101,102, of each bracket 100 are formed with apertures which are in axial alignment.

A gas jet 103 is located in the aperture of arm 102 and a locating tubular member 104 is located in the aperture of arm 101. Accordingly, the jet is automatically axially aligned with the tubular member 104. As shown in Figures 6 and 8, the tubular member 104 of each bracket 100 is introduced into the aperture formed in the rear wall of each box so that each jet is automatically aligned with the mixing tube formed in the box.

Preferably, each tubular member 104 is provided with radially projecting resilient lugs (not shown) in order to ensure that the tubular member is positively located in the aperture of a box. Since each bracket 100 is secured to the platform, the tubularmember serves to positively retain each box in position on the platform.

A gas valve 120 is secured to the platform 80a, and includes a valve spool 121 which is operated by a rotary handle (not shown) which on rotation alters gas flow to the plaques. Thus as schematically shown in Figure 9 the valve 120 is arranged to provide three different heat settings, viz. a low rate whereat restricted gas flow is permitted to the centre plaque 1 4b only; a medium rate whereat full gas flow is permitted to the centre plaque only; and a high rate whereat full gas flow is permitted to all plaques 1 4a, 1 4b and 14c.

In order to ensure cross ignition between the centre plaque and the outside plaques it is necessary to position the plaques together as closely as possible. In this respect, the position of the brackets 100 either side of the central bracket 100 is adjustable by the provision of elongate slots 1 00a in the U-brackets, thereby enabling the outside plaques to be positioned as close as possible to the central plaque.

The valve 120 also supplies gas to a pilot gas jet 125 which serves to cause ignition of the centre plaque.

In order to effect ignition of the pilot gas jet a piezoelectric electrode 126 is provided. A temperature sensor 1 27 is also provided which in use is enveloped in the flame of the pilot gas jet.

The temperature sensor 127 is connected to the valve 120 and serves to actuate the valve to cut off flow of gas to all of the plaques in the event of it sensing the absence of a flame at the pilot jet.

The sensor 127 also serves as the earth electrode for the piezoelectric electrode 1 26. The relative positions of the electrode 1 26, sensor 127 and pilot jet 125 are critical in order to ensure ignition of the pilot jet and subsequent ignition of the central plaque. In order to remove the necessity of adjusting the relative positions of the sensor, electrode and pilot jet during assembly a bracket 130 is provided which is secured to the platform 80a in a predetermined position and which is provided with apertured lugs 1 32 to 136 which are accurately positioned during forming of the bracket 1 30. Accordingly, when the pilot jet, sensor and electrode are located in position on their associated lugs they are automatically located at the desired relative positions.

The distance between the pilot jet and the central plaque is unaffected by manufacturing tolerances of the plaque and box since the front wall of the box bears against brackets 96 and 97 so that tolerances in the plaques and box are accommodated at the rear of the plaque and box.

As seen in Figures 1 and 8 the plaques are inclined to the horizontal so that a large proportion of heat generated by the plaques is directly radiated outwards.

The angle of inclination may vary as desired; an angle of about 50 has proved satisfactory.

The remaining radiated heat is reflected by the reflectors outward. It will be appreciated that since the bottom of the front assembly is open, air is drawn upwards into the enclosed space between the dividing wall 1 0c and the front panels 20, 41 and reflectors.

The air is heated and exhausts through the grill 34 and therefore ensures that the reflectors, front panels 20, 41 and wall 1 0c remain relatively cool.

In order not to prevent sufficient flow of air past the back reflector it is important that the distance B between the back reflector and wall 1 Oc be adequate. Also the distance A, of the rear of the plaques from the back reflector should be great enough so as not to cause excessive heating of the back reflector. In this respect a distance A of about 1 5-20 mm and a distance B of about 25 mm for plaques giving an output of 3 kilowatts have proved acceptable.

It will be appreciated, that the front assembly 12 need not necessarily be attached to a mobile housing 10 but may be attached to a housing adapted for attachment to a fixed surface, such as a wall.

Claims (14)

Claims

1. A gas fire having a hearth, a heat reflector surrounding at least the rear of the hearth and at least one radiant burner plaque mounted in the hearth.

2. A gas fire according to claim 1 wherein the or each burner plaque is inclined to the horizontal so as to direct a portion of the generated radiant heat directly outwards away from the reflector.

3. A gas fire according to claim 1 or 2 wherein the reflector also extends along both sides of the hearth.

4. A gas fire according to claim 3 wherein the reflector includes two side portions each having a side wall including a lower portion and a curved upper portion, the lower portion being attached to a central portion of the reflector so that the side portion projects outwardly from the central portion, the central portion having marginal edge portions which abut the curved portion of the side wall of each side portion in order to assume the same degree of curvature as the curved portions.

5. A gas fire according to claim 4 wherein the lower portion of each side portion and the central portion of the reflector are integrally joined.

6. A gas fire according to claim 4 wherein the lower portion of each side portion and the central portion of the reflector are provided with tabs which are secured together.

7. A gas fire according to any preceding claim wherein the hearth comprises a metal pressing having a window formed therein through which the or each burner plaque projects.

8. A gas fire according to any preceding claim wherein the or each burner plaque is mounted on a burner box which in turn is releasably mounted on a platform.

9. A gas fire according to claim 8 wherein a retaining bracket is provided which is releasably secured to the platform, the bracket including a lip which is co-operable with a groove formed in a front wall of each box to retain the box on said platform.

10. A gas fire according to claim 9 wherein the rear wall of each box is provided with an aperture which communicates with a mixing tube located inside the box, a bracket releasably secured-to the platform being provided for each box which carries a gas jet and location means, the location means when located in said aperture serving to axially align the gas jet with said mixing tube and serving to retain the box on said platform.

11. A gas fire according to any of claims 8, 9 or 10 wherein the burner box is a ceramic box.

12. A gas fire according to any preceding claim wherein the hearth, reflector and burner plaques are mounted in a housing which is mounted on wheels so as to define a mobile heater.

13. A gas fire according to any of claims 1 to 11 wherein the hearth, reflector and burner plaques are mounted in a housing adapted for securance to a wall.

14. A gas fire according to any preceding claim wherein the burner plaques simulate a natural fire such as a coal or log fire.

1 5. A gas fire substantially as described with reference to and as illustrated in any of the accompanying drawings.