BACKGROUND

The invention relates to a fireplace system comprising a housing with side walls that bound a receiving space and with a top surface that is perpendicular to the side walls and is fitted with a positioning opening at the top, and a gas-burning section with a gas-fire and a gas inlet pipe, which gas-burning section can be moved up and down between a retracted position, in which the gas-burner section is placed under the positioning opening inside the housing, and an operating position, in which the gas-burning section lies in or near the positioning opening.

A combined wood-and-gas burning fireplace is known from EP 0,477,456. This patent application discloses a gas- burning fireplace in which the gas-fire can be placed in a bottom retracted position inside the housing with the aid of a lever. The user can place a wood-bearing platform above the gas-fire, so that logs of wood can be burned on the wood-bearing platform, and the gas-burner lying below it is shielded from the fire and the ash by the wood-bearing platform.

This known fireplace suffers from the disadvantage that the gas-fire can be fouled by soot and dirt particles that are liberated when wood is burned and which can drop into the housing when the wood-burning platform is being moved.

Another disadvantage is that, when the wood- burning platform is being moved in order to clean it, soot, dust and ash can be easily released into the surroundings. As the combustion residues lie above the flat wood-burning platform, they can easily drop off or waft off from the wood-burning platform, so that the gas-burning section and/or the surroundings of the wood-and-gas burning fireplace get dirty, as do also the user's hands.

In addition, the temperature above the gas-fire can rise to high values during the stoking of the log fire, which may be detrimental to the flexible gas pipe connected to the gas-fire.

Furthermore, the gas does not burn here as well as it should, because there can only be a secondary air inlet to the gas-burning section.

In one of the embodiments of the known fireplace, the gas-burning section is operated with the aid of a hinged arrangement of the wood-burning platform, which is connected to the gas-fire by means of a lever. As a result, cleaning the wood-burning platform is laborious, because it has to be removed from the gas-burning section. If this platform is not cleaned properly, the operation of the gas-burning section can make the user's hands dirty when moving the wood-burning platform into its vertical position with the aid of the hinged arrangement.

In addition, the temperature above the gas-fire can rise to high values during the stoking of the log fire, which may be detrimental to the flexible gas pipe connected to the gas-fire.

The gas-fire of the fireplace system is always provided with a pilot flame for lighting the gas in the gas- fire. The pilot flame is also a safety feature, which prevents the formation of an explosive air-gas mixture in the fireplace, due to gas flowing out of the fireplace, for example when the pilot light has been blown out. Gas-fires are fitted with a gas regulating unit, attached to the gas mains in the room or premises in question. Leading from the gas regulating unit, there is a burner gas pipe to the gas- fire, and there is a pilot-light gas pipe to the pilot light. When the pilot light is "out", a sensor in the pilot- light unit (generally a bimetal switch) turns off the inlet of gas to the gas-fire and to the pilot light in the gas regulating unit.

The gas-fire can be supplied with gas through a bending, flexible burner gas pipe, so that the gas-fire can be easily moved from its retracted position into the operating position, and vice versa. However, the gas pipe for the burner is preferably made of bending material, such as a heat-resistant material. A bending but stiff or rigid material is for example a metal that can be bent into the required shape, but which is not suitable for moving and deformation by the user every time the gas-burning section is moved. A supple, flexible material is therefore needed for this purpose. The gas pipe for the pilot light is preferably made of a bending, flexible material, which can be easily bent when the gas-burner section is being moved.

The known fireplace has the disadvantage that the bending pilot light gas pipe can spring a leak, for example when it is old or damaged, so that gas can flow into the fireplace without the pilot light going out. This pipe must therefore be regularly checked, which is part of the maintenance work. However, it has been found that the user often forgets or neglects to replace this flexible pipe, which can lead to dangerous situations.

It is an object of the present invention to provide a fireplace system with a gas-burning section and a wood-burning platform of the type described above, but which can be easily changed from the wood-burning mode to the gas- burning mode, and the gas-burning section can be easily switched between an operating position and a retracted position .

It is an object of the present invention to provide a fireplace system in which the fouling of the gas- burner and/or the surroundings with soot and dirt is prevented.

It is an object of the present invention to provide a fireplace system in which the wood-burning platform can be both easily placed into its operating position and easily removed from it, without fouling the gas-fire and/or the surroundings with soot particles, dust or ash.

The fireplace system according to the invention should also have a low heat transfer to the gas pipe under the wood- burning platform when the latter is in use.

It is an object of the present invention to provide a wear-resistant movable gas pipe that does not easily spring a leak and is made of a material that resists ruptures and high temperatures, which gas pipe is suitable for use with the mobile gas-burning section, and with which primary air can also be introduced into the gas stream.

It is an object of the present invention to provide a fireplace system with a gas-burning section and a wood-burning platform of the type described above, but which can be easily changed from the wood-burning position to the gas-burning position.

It is an object of the present invention to provide a fireplace system in which the fouling of the gas- burner and/or the surroundings with soot and dirt is prevented.

It is an object of the present invention to provide a fireplace system in which the wood-burning platform can be easily placed into its operating position and it can also be easily removed from it without fouling the gas-fire and/or the surroundings with soot particles, dust or ash.

It is an object of the present invention to provide a fireplace system with a gas-burning section that can be moved between an operating position and a retracted position . It is an object of the present invention to provide a fireplace system with a bending pilot-light gas pipe, in the case of which, if the flexible gas pipe for the pilot light springs a leak or otherwise becomes defective, it does not lead to a hazardous situation, such as the formation of an explosive air-gas mixture, because the pipe can be easily bent with the gas-burner section when the latter is being moved.

It is an object of the present invention to provide a fireplace system in which the gas pipe for the pilot light can be easily replaced without removing or inactivating its safety arrangement against undesirable gas leaks .

It is an object of the present invention to provide a fireplace system in which the wood-burning platform can be easily placed into its operating position over the gas-fire that has been put in its retracted position, and in which wood and other solid fuels can be burned safely, that is, without any danger of an undesirable gas leak.

SUMMARY OF THE INVENTION According to a first aspect the invention provides a fireplace system comprising a housing with side walls that bound a receiving space and a top surface lying perpendicularly to the side walls, wherein the a top surface has a positioning opening at the top, a gas-burning section with a gas-fire and a gas inlet pipe, which gas-burning section can be moved up and down between a retracted position, in which the gas-burning section is located under the positioning opening inside the housing, and an operating position, in which the gas-burning section is situated in or near the positioning opening, wherein the gas inlet pipe is a telescopic pipe or tube that comprises at least two pipe sections, which can be moved or displaced over or into each other .

The use of a telescopic gas pipe means that one can dispense with a flexible gas pipe. Flexible gas pipes rupture and eventually start to leak, due to the movements of the material and to the high temperatures. This can create dangerous situations if these pipes are not replaced regularly, and they are generally not favoured by the relevant inspectorates. However, heat-resistant gas pipes must be insulated and therefore have a certain stiffness, which means a high risk of ruptures and fractures occurring.

In embodiment the first pipe section is fixed near the bottom of the housing, and the second pipe section is connected to the gas-fire section, wherein both pipe sections extending essentially in the vertical direction. In this way, the second, higher pipe section slides into or around the first, lower fixed pipe section when the gas-burner section is moved into its retracted position .

The first pipe section can be fitted with a nozzle orifice at its top end, near the second pipe section, wherein the nozzle orifice is at least partly inserted into the second pipe section, wherein the nozzle orifice comprises a nozzle tube and a wider cover, wherein the cover comprises a base that is connected to the top end of the first pipe section. This nozzle orifice ensures the correct position of the first pipe section inside the second pipe section, while the nozzle tube ensures a directional flow of the gas, which helps to prevent gas leaks from the telescopic pipe.

In an embodiment thereof extends in the operating position of the gas-burning section only the lowest part of the second pipe section still above the lowest part of the base of the nozzle orifice.

In an embodiment the second pipe section and the base of the nozzle orifice together define an annular space having in transverse cross-section an area of 5-12 percent of the inner area of the second pipe section, wherein the cross section of the annular space is substantially constant along the overlap between the second pipe section and the cylindrical base of the nozzle orifice.

This annular space ensures that primary air can be aspirated in and mixed with the gas stream from the nozzle tube, in such a limited extent that the gas burns in the gas-fire with the typical full red and dark orange flames like a wood fire.

This effect is further enhanced when the nozzle tube has in transverse cross section an inner area of 15-25% of the inner area of the second pipe section. This nozzle tube has a relatively large cross sectional area of the passage of the nozzle tube with respect to the area of the second tube section.

In an alternative advantageous embodiment the outer wall of the first pipe section and the inner wall of the second pipe section enclose a free space, so that air can be aspirated in through this free space when the gas- fire is in use. The first pipe section and the second pipe section are preferably not in contact with each other, so they bound a continuous free space between them.

The first pipe section and the second pipe section can have a circular cross-section, so that the free space between them is essentially an annular gap in cross-section .

In this way, primary air can be aspirated and introduced into the gas stream, so the gas burns in the best possible way. At the same time, the telescopic gas pipe obtained is very easy to manufacture, apart from being safe and resistant to high temperatures.

Furthermore, the nozzle tube is a tubular section with a reduced cross-section in one of the embodiments, as a result of which the gas stream flowing to the gas-fire through the reduced cross-section of the nozzle tube leaves the outlet orifice faster, so it aspirates air through the free space formed between the pipe sections. In particular, the nozzle tube is formed as a circumferential wall extending into the second pipe section, so the gas is injected into the second pipe section during use.

The narrowing of the gas pipe accelerates the gas flow and creates a sub-atmospheric pressure, so that air can be aspirated in from outside the pipe. This also largely reduces the risk of gas leaks.

In an embodiment a wood-burning platform is arranged for placement in or near the positioning opening when the gas-burning section is in its retracted position.

The wood-burning platform preferably comprises a grating and a removable ash collecting section that is connected to the grating, wherein the wood-burning platform can be removed by the user and placed in or near the positioning opening.

Since the wood-burning platform is integral with the grating and the ash-collecting section, the ash, soot and wood particles are collected in the ash-pan when wood is being burned on the grating. If after burning logs, the fireplace is to be put into its gas-burning position again, the user will remove the wood-burning platform from the positioning opening and put this unit in a place that is the most suitable for keeping the ash-pan and cleaning the grating. Fouling the surroundings is prevented here, since soot and ash are enclosed in the ash-collecting section. At the same time, collecting soot and ash in the ash-collecting section under the grating ensures that these particles of dirt cannot enter the gas-fire, which guarantees the safe operation of the latter. After the cleaning operation, the wood-burning platform is replaced into its parking position inside the housing.

In an embodiment a second wood-burning platform is provided in the receiving opening between the first wood-burning platform and the base for the gas-burner under the grating, Since an extra space is created for the ash-collecting section, an insulating effect is obtained that improves with the degree of filling of the ash- collecting section. This protects the gas pipe below from high temperatures, reached when wood is being burned.

In an embodiment the wood-burning platform is in the parking position inside the housing, being placed along the front side-wall of the housing. There is preferably also a receiving opening next to the positioning opening, wherein the receiving opening is incorporated to accommodate and/or store the wood-burning platform and is preferably fitted with a covering element. This arrangement makes the wood-burning platform both easily accessible for the user and invisible when the gas- fire is in use, which improves the aesthetic appearance of the fireplace.

In an embodiment the grating and the ash- collecting section are provided with grippable points to make it easy to handle the wood-burning platform and to be able to remove it from the housing in the horizontal position without having to touch it with the hands. As a result, a gripping device that is fitted with corresponding gripping elements can be used to raise the grating and the ash-collecting section.

In an advantageous embodiment, the gas-burning section is moved up and down with the aid of a scissor- like linkage mechanism, which comprises a longitudinal plate that extends along a front side-wall of the housing in a basically horizontal direction, with a slot in it, and a guide that can be moved in the slot, together with a lever that has an operating end, which can be moved along a top longitudinal edge of a front lateral surface of the housing, and an actuating end, which is connected to the guide at a pivoting point. The scissor-like linkage mechanism can be moved up and down without much effort on the part of the user, for which purpose its actuating end is shifted along the front side-wall of the housing. Owing to the reliable vertical displacement, the burner elements of the gas-fire remain in the right position, so that they can be retracted into the housing and extended again without affecting the flame distribution in an undesirable way. As a result, the components of the telescopic gas pipe can also be easily moved in and out of each other in the vertical direction.

According to a second aspect the invention provides a fireplace system comprising a housing with side walls that bound a receiving space and a top surface lying perpendicularly to the side walls, wherein the top surface has a positioning opening at the top, a gas-burning section with a gas-fire and a gas inlet pipe, which gas-burning section can be moved up and down between a retracted position, in which the gas-burning section is located under the positioning opening inside the housing, and an operating position, in which the gas-burning section is situated in or near the positioning opening, and a wood-burning platform, wherein the wood-burning platform is provided with an ash- collecting space, which is so arranged that it can be inserted into the positioning opening essentially vertically and can be taken out of it when the gas-burning section is in the retracted position.

The ash-collecting space is preferably formed by the first circumferential edges of the wood-burning platform.

The presence of an ash-collecting space that can be easily inserted vertically into the positioning opening and can be removed from it in the same way prevents the ash and other, unburnt residues of a log fire from easily dropping below the wood-burning platform when the mode of operation is being changed, thereby fouling the gas- burning section or the surroundings.

In an embodiment the wood-burning platform is in the "parking position" inside the housing, being placed along the front side-wall of the housing. There is preferably also a receiving opening next to the positioning opening, which receiving opening is provided to accommodate and/or store the wood-burning platform, and it is preferably fitted with a covering element. This arrangement makes the wood-burning platform both easily accessible for the user and invisible when the gas-fire is in use, which improves the aesthetic appearance of the fireplace.

In an embodiment the wood-burning platform comprises one or more removable gratings, situated above the ash- collecting space.

The gratings are arranged in particular within the second circumferential edges of the wood-burning platform.

Since the wood-burning platform is integral with the grating and the ash-collecting space, the ash, soot and wood particles are collected in the ash-collecting space when wood is being burned on the grating. If after burning wood, the fireplace is to be brought into the gas- burning position again, the user will remove the wood- burning platform from the positioning opening in a vertical movement, and put this unit in a place that is the most suitable for keeping the ash-collecting space and for cleaning the grating. Fouling the surroundings is prevented here, since soot and ash are enclosed in the ash-collecting space. At the same time, the collection of soot and ash in the ash-collecting space under the grating ensures that these particles of dirt cannot enter the gas- fire, which guarantees the safe operation of the latter. After the cleaning operation, the wood-burning platform is replaced into its parking position inside the housing. To prevent the gratings from getting loose and falling below, the wood-burning platform is preferably provided with second circumferential edges, inside which the grating or gratings can be arranged.

The grating and the ash-collecting space are preferably provided with grippable points to make it easy to handle the wood-burning platform and to be able to remove it from the housing in the horizontal position without having to touch it with one's hands. A gripping device that is fitted with corresponding gripping elements can therefore be used to raise the grating and the ash- collecting space.

In an embodiment a second wood-burning platform is provided in the receiving opening between the first wood-burning platform and the base of the gas-fire, and since an extra space is created under the grating to collect the ashes, an insulating effect is obtained, which improves with the degree of filling of the ash-collecting space. This protects the gas pipe under it from the high temperatures reached when wood is burned.

In an advantageous embodiment, the gas-burning section is moved up and down with the aid of a scissor- like linkage mechanism, which comprises a longitudinal plate that extends along a front side-wall of the housing in a basically horizontal direction, with a slot in it, and a guide that can be moved in the slot, together with a lever that has an operating end, which can be moved along a top longitudinal edge of a front lateral surface of the housing, and an actuating end, which is connected with the guide at a pivoting point. The scissor-like linkage mechanism can be moved up and down without much effort on the part of the user, for which purpose its actuating end is shifted along the front side-wall of the housing. Owing to the reliable vertical displacement, the burner elements of the gas-fire remain in the right position, so that they can be retracted into the housing and extended again without affecting the flame distribution in an undesirable way. As a result, the components of the telescopic gas pipe can also be easily moved in and out of each other in the vertical direction.

According to a third aspect the invention provides a fireplace system comprising a housing with side walls and an upper positioning opening, a gas-burner section with a gas-fire and a gas pipe, and a pilot-light unit with a gas pipe for the pilot light, which gas-burning section can be moved up and down between a retracted position, in which the gas-burning section is located under the positioning opening inside the housing, and an operating position, in which the gas-burning section is situated in or near the positioning opening, wherein the gas pipe for the pilot light is fitted with a constriction.

This constriction ensures that the gas stream in the gas pipe for the pilot light is restricted, so that - if this pipe is ruptured or if it springs a leak - only a small gas stream can emerge from it, which does not create a dangerous situation.

In an embodiment the diameter of the gas pipe for the pilot light is in the range of 1-10 mm, while the diameter of the constriction is in the range of 0.1-5 mm. The outside diameter of the gas pipe for the pilot light is preferably about 4 mm, while the diameter of the constriction is preferably about 0.4 mm.

In an embodiment the inside diameter of the gas pipe (101) for the pilot light is chosen from 2-4 mm, and the diameter of the constriction (102) is chosen from 0.4-1 mm.

Since the cross-section of the constriction is only about one-eighth of that of the gas inlet pipe, an advantageous ratio is obtained, so that a gas leak from a leaking flexible gas pipe for the pilot light does not cause the formation of an explosive air-gas mixture in the fireplace. Owing to the constriction, the amount of gas flowing into the pilot- light unit is only slightly more than the amount of gas consumed by the pilot light. A small gas leak will therefore quickly extinguish the pilot light and turn off the gas inlet.

The gas pipe for the pilot light in the fireplace system preferably comprises a first pipe section that is made of a stiff but bending material, and a second pipe section, made of a supple, flexible material.

By using a combination of a bendable material and a flexible material, one obtains a gas pipe for the pilot light that is safe and easy to maintain and to connect up, in the case of which the bendable pipe section can be connected up to the gas regulating unit in the usual way, while the flexible pipe section can be moved with the gas-burner section.

In an advantageous embodiment the constriction is formed near the site where the first, bendable pipe section is joined to the second, flexible pipe section. Since the constriction is near the joint between the two pipe sections, a leak from the flexible pipe section only produces a small amount of gas, and the formation of explosive mixtures is prevented.

The constriction is made in the first, bendable pipe section, and preferably near the point where it joins to the second, flexible pipe section.

Since the constriction is made in the bendable pipe section, it continues operating undiminished after a maintenance operation and the possible replacement of the flexible pipe section, and the formation of an explosive gas mixture in the fireplace is prevented.

In particular, the connection between the first and the second pipe section is fitted with a coupling device. More especially, the constriction is provided in this coupling device.

Since a coupling device is used, it is simply to join the first and second pipe section together The second, flexible pipe section can also be easily removed in order to replace it or carry out maintenance work on it. By arranging the constriction in the coupling device, it can be guaranteed that the constriction is always present between the first and the second pipe section. This arrangement also makes it possible to minimize the internal gas volume that rapidly emerges from the gas pipe for the pilot light when it springs a leak.

In an embodiment the lifting mechanism for the gas-burner section is fitted with a pilot-light interrupter, and the end of the second, flexible pipe section is joined to this pilot-light interrupter. The pilot-light interrupter turns off the gas inlet to the pilot flame when the gas-burner section is removed from its operating position. Consequently, the pilot flame goes out, after which the gas regulating block turns off the gas inlet to the gas-fire and to the pilot light. The constriction ensures that, if a leak occurs in the flexible pipe section of the gas pipe for the pilot light, this leak is minor, not dangerous and only lasts a short time.

In particular, a third, bendable pipe section is arranged between the pilot-light interrupter and the pilot-flame unit. The leak will therefore occur in this pipe section. By fixing the pilot-light interrupter on the lifting mechanism, a solid pipe made of a bendable material can be used.

In an embodiment the first, bendable pipe section is made of copper or aluminium metal. The second, flexible pipe section is preferably made of teflon (PTFE) . The third, bendable pipe section is preferably made of copper or aluminium metal.

Copper and aluminium pipes withstand the heat of a gas-fire or a log fire. Teflon (PTFE) pipes are also resistant to heat, but they quickly tear or spring a leak if they are regularly bent.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which : Fig. 1 is a perspective view of a fireplace system according to the invention, with a housing, a wood-burning platform and a storage cassette;

Fig. 2 shows a fireplace system according to Fig. 1 in the gas-burning mode;

Fig. 3 shows a fireplace system with a gas-burner base in the retracted position;

Fig. 4 shows a fireplace system in a partially exploded form, with the scissor-like linkage mechanism and an operating lever for moving the gas-burner base, in the raised position;

Fig. 5 shows the removal of the wood-burning platform from its parking position, inside the storage compartment;

Fig. 6 shows the fireplace system according to

Fig. 1, with the wood-burning platform placed above the positioning opening, with the cover strip in the folded-up (open) position;

Fig. 7 shows the fireplace system according to Fig. 6, with the cover strip in the folded-down position over the wood-burning platform;

Figs. 8 and 9 show perspective views of the wood- burning platform according to the invention;

Fig. 10 shows the wood-burning platform according to Figs. 8 and 9, in the open position;

Fig. 11 shows a detail of an ash barrier formed by an overlap between the inner circumferential edge of the frame edge and the outer circumferential edge of the log fire grating;

Fig. 12A shows an embodiment of the fireplace system with the telescopic gas pipe in the operating position;

Fig. 12B shows the item according to Fig. 12A, with the gas pipe in the retracted position;

Fig. 13A shows a perspective detail of the telescopic gas pipe;

Fig. 13B shows a longitudinal cross-section of the item shown in Fig. 13A;

Fig. 13C shows a transverse cross-section of the item shown in Fig. 13B;

Fig. 14A shows the wood-burning platform with removable gratings;

Fig. 14B shows a gripping device for the wood- burning platform shown in Fig. 14A;

Fig. 15A shows a side view of the fireplace system;

Fig. 15B shows the fireplace system illustrated in

Fig. 1A, with the gas-fire in the retracted position; and

Fig. 16 shows the connection with the constriction in the coupling device in detail. DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a combined wood-and-gas fireplace system 1 in the gas-burning mode. This fireplace system 1 comprises a box-like housing 2 with an essentially rectangular bottom, together with a rear side-wall that extends perpendicularly to the bottom, a front side-wall 4, and transverse side-walls 5 and 6. The housing 2 has a top surface 7, with a positioning opening in it to accommodate the wood-burning platform 8. When the wood-burning platform 8 is in the parking position, it is located in a flat box ^¬ like cassette 10, which is placed inside the housing 2, along the front side-wall 4.

In the gas-burning mode illustrated here, the gas- burner base 12 lies in the positioning opening made in the top surface 7, which gas-burner base 12 carries the stone burner elements 14 which act as flame distributors. The gas-burner base 12 can be moved up and down in the housing 2 with the aid of a scissor-line linkage system 15, actuated by a lever 16.

As can be seen from Fig. 2, an embodiment of the gas-burner base 12 comprises a supporting surface 20 with a gas-fire 21, which is connected to a flexible gas pipe 22. A pivoting cover strip 23 with a central opening 24 is placed above the top surface 7, so that it covers the edges of the positioning opening, made in the top surface 7.

Fig. 3 shows the fireplace with the gas-burner base 12 in the partly retracted position. To make the drawing clearer, the cassette 10, with the wood-burning platform 8 in it, has been removed from the storage compartment 26, which is accessible from the receiving opening 27, made in the strip 28 that runs around the top circumferential edge 33 of the housing 2. The gas-burner base 12 can be moved inside the housing 2, between a top operating position (in which this base lies in the positioning opening 25 made in the top surface 7) and a position retracted into the housing, shown in Fig. 3.

The lever mechanism used for moving the gas-burner base 12 consists of a scissor-like linkage mechanism 15 with two scissor arms 30 and 31, which are mounted on bearings in a bottom guide slot 32 and in a top guide slot 32', formed in a longitudinal plate 34, so that the two arms can be displaced in the horizontal direction by a sliding movement. The lever movement of the scissor-like linkage mechanism 15 is actuated manually with the aid of the lever 16 by gripping its operating end 35, which can be moved to and fro along the top longitudinal edge 36 of the housing 2. An actuating end 37 of the lever 16 is hinged on a sliding block 38, which can be horizontally moved in a guide slot 39 formed in the top longitudinal plate 34. When the lever 16 is moved to the left in Fig. 3, the gas-burner base 12 is raised to its operating position in or near the positioning opening 25. A torsion spring 45 is included here to help the lever move the gas-burner base.

In the position shown in Fig. 3, the frame edge 40 of the cover strip 23 is pivoted upward, this cover strip being connected to the rear longitudinal edge 43 of the housing 2 at the pivot points 41 and 42. A supporting arm 44 has to prop up the frame edge 40 in the open position and prevent its closure by pivoting down, since this frame edge is made of metal and is relatively heavy. The width of the frame edge 40 is such that it fully covers the strip 38 in the horizontal position and protrudes beyond the boundaries of the positioning opening 25. In the horizontal position of the frame edge 40, the inside edge 47 of this frame edge 40 protrudes beyond the circumferential edge 33 of the strip 28 towards the central part of the positioning opening 25. In the horizontal position, the outer edge 48 of the frame edge 40 is level with the top outer circumferential edge 56 of the housing 2.

Fig. 4 shows the lever action of the scissor-like linkage mechanism 15 of the gas-burner base 12 when the lever 16 is actuated in order to raise the gas-burner base 12 to its operating position. A further displacement of the lever 16 to the left by the user secures the position of the gas-burner base 12 in its operating position, after which the cover strip 23 can be folded down, and the fireplace can be used as a gas-fire.

Fig. 5 shows how, with the cover strip 23 in the up position, the wood-burning platform 8 can be taken out of the storage compartment 26 with the aid of a carrying handle 50. This carrying handle 50 can be moved with respect to the wood-burning platform 8 in the direction indicated by the arrow A, so that it lies against the longitudinal edge 51 when the wood-burning platform 8, in its parking position, is concealed in the internal storage compartment 26 of the housing 2.

Fig. 6 shows how the wood-burning platform 8 is placed into its operating position in the positioning opening 25. This platform is supported here on a carrier 53, shown in Fig. 4. The frame edge 40 of the cover strip 23 can then be pivoted into the horizontal position, with the spacer lugs 54 and 55 resting on the cover strip 28. In this case, the frame edge 40 is situated above the wood-burning platform, and the inside edge 47 extends over the grating 59 of the wood-burning platform 8, as shown in Fig. 7. This prevents wood particles, soot and ash from entering into the housing 2 along the grating 59.

Fig. 8 shows the wood-burning platform 8 shaped like a flat box, with the grating 59 being removably fixed to an ash-collecting space or ash-collecting section or ash- pan 60. Two hand-grips 61 and 62 are mounted on the ash-pan 60 to make it possible to put the wood-burning platform easily into a suitable position for emptying the ash-pan and cleaning the grating 59. Fig. 9 shows how the grating 59 is removably fixed to the ash-pan 60 with the aid of the carrying handle 50, and how it can be removed by tilting the ash-pan backward. Fig. 10 shows the grating in the out position, in which the ash-pan 60 can be emptied.

Fig. 11 shows a detail of the outer circumferential edge 65 of the grating 59 and the inner circumferential edge 47 of the frame edge 40. The downward- pointing fin 63 on the circumferential edge 47 and the upward-pointing fin 64 on the circumferential edge 65 of the grating 59 create an efficient ash barrier to prevent the ash from migrating into the housing 2 from the area between the bottom of the frame edge 40 and the grating 59. The length D of the overlap is at least 1 cm, while the height of the fins 63 and 64 is for example about 0.5 cm.

Fig. 12A shows an embodiment (without a frame edge) , comprising the housing 2 and inside it (in the operating position) the scissor-like linkage mechanism 15, the gas-burning section 12 (with the gas-fire 21) , and the telescopic gas inlet pipe 70, which is essentially vertical. In this embodiment, the first pipe section 71 is fixedly connected to the bottom of the housing 2, while the second pipe section 72 is fixedly connected to the movable gas- burning section 12.

Fig. 12B shows the scissor-like linkage mechanism 15 and the gas-burning section 12 in the retracted position, where the first pipe section 71 of the telescopic gas inlet pipe 70 is pushed into the second pipe section 72. This figure also shows that the wood-burning platform 8 is inserted into the positioning opening 25 to make it possible to have a log fire in the fireplace. The ash-collecting section 60 is arranged under the wood-burning platform 8 to collect the ashes and other, unburnt residues formed when wood is being burned. The wood-burning platform 8 can be fitted either with a grating 59 shown in Fig. 9, or with a grating shown in Fig. 14A. The wood-burning platform 8 rests on the supporting edges 66 that are fitted to the housing 2.

Fig. 12B also shows a second wood-burning platform 80, which is mounted between the first wood-burning platform 8, the ash-collecting space 60 and the gas-burning section 12. This second wood-burning platform 80 creates an extra insulating space between the ash-pan 60 of the first wood- burning platform 8 and the second wood-burning platform 80.

Fig. 13A shows a perspective detail of the telescopic gas inlet pipe 70, with the first pipe section 71 and the second pipe section 72 in the operating position. The first pipe section 71 and the second pipe section 72 are both straight cylindrical with a constant wall thickness along the circumference. On the upper end of the first pipe section 71 a nozzle orifice 73 has been provided. The nozzle orifice 73 comprises a nozzle tube 78 and a wider cover. The wider cover comprises a cylindrical base having inner screw thread by means of which the nozzle orifice has been screwed onto the first pipe section 71.

Fig. 13B shows a longitudinal cross-section of the item illustrated in Fig. 13A, with a gas stream 79 and an air stream 77. The nozzle tube 78 is formed by a circumferential wall, but other constructions and designs can also be used. The nozzle tube 78 is a length of tube with a reduced cross-section, so that during use the gas stream 79 to the gas-fire leaves the nozzle tube 78 faster, owing to the reduced cross-section. This creates a sub- atmospheric pressure at that point, so that air 77 is aspirated in from the surroundings through the free space 76.

The dimensions of the first pipe section 71, the second pipe section 72 and the nozzle orifice 73 are indicated in Fig 13B. The inner diameter Dl of the second pipe section 72 is 22 mm. The largest outer diameter of the nozzle orifice 73 is 21 mm. The outer diameter D3 of the nozzle tube 78 is 13 mm. The inner diameter D4 of the nozzle tube 78 is 9.49 mm. The lower part of the second pipe section 72 extends parallel along the cylindrical base of the nozzle orifice 73 in vertical direction, wherein in the operative position only the lowest part of the second pipe section 72 still extends above the lowest part of the cylindrical base of the nozzle orifice 73. This configuration and these diameters represent particular design aspects that will be explained in the following paragraph .

The second pipe section 72 and the cylindrical base of the nozzle orifice 73 together define an annular space 150 ("D1-D2") having in transverse cross-section an area of 5-12 percent of the inner area ("Dl") of the second pipe section 72. The cross section of the annular space 150 is constant along the overlap between the second pipe section 72 and the cylindrical base of the nozzle orifice 73. This annular space 150 ensures that primary air 77 can be aspirated in and mixed with the gas stream 79, so that the gas burns in the gas-fire with the typical full red and dark orange flames like a wood fire. This effect is further enhanced by the relatively large cross sectional area of the passage of the nozzle tube 78 with respect to the area of the second tube section 72. The nozzle tube 78 has in transverse cross section an inner area ("D4") of 15-25% of the inner area ("Dl") of the second pipe section 72. The length of the overlap between the second pipe section 72 and the cylindrical base is at least 33 percent, preferably at least 66% of the inner diameter Dl of the second pipe section 72.

In an alternative embodiment the two pipe sections are positioned in each other's line of continuation by means of the nozzle tube 78 even when the two pipe sections have been pushed so far out of each other that the lower end of the second pipe section 72 is located above the upper end of the first pipe section 71. The lower end of the second pipe section 72 extends to a point above the nozzle orifice 73, whereby the first and the second pipe section are not in contact with each other, so they enclose a free space 76 in between, as a result of which, when the gas-fire is in use, primary air 77 can be aspirated in and mixed with the gas stream 79, so that the gas burns in the gas-fire in the best possible way. These measures ensure a safe "open" connection between the two pipe sections of the telescopic gas inlet pipe 70. The gas 79 is injected as an upward jet and therefore does not easily flow out into the surroundings through the free space 76. Furthermore, the gas jet creates a slightly sub-atmospheric pressure at the outlet orifice of the nozzle tube, as a result of which air 77 is aspirated in through the free space 76, so that the gas 79 cannot flow out into the surroundings, due to this preferred route of flow .

In above mentioned embodiments, the nozzle tube 78 is formed by a circumferential wall, but other constructions and designs can also be used.

Fig. 13C shows a transverse cross-section of the alternative telescopic gas inlet pipe 70 with the second pipe section 72 being positioned around the first pipe section 71. The inner wall 75 of the second pipe section 72 is not in contact with the outer wall 74 of the first pipe section 71, so that the free space 76 is formed between the two pipe sections, which has the shape of an annular gap in the present case, since the cylindrical pipes have a circular cross-section. However, other shapes can also be used for the cross-sectional profile of the pipe sections, and the operation of the nozzle tube is hardly impaired, if at all, if the outer wall 74 is in contact with the inner wall 75 at one or more points.

The fireplace according to the invention can also be provided with safety devices or safety regulators, such as a gas interrupter or gas shut-off valve, which closes when the gas-burning section is in the parking position. Such a device can close off both the gas inlet pipe to the gas-burning section and the gas pipe to the pilot light.

If required, the gas inlet pipe to the pilot light can be in the form of a flexible pipe, in which case the diameter of the pipe is made sufficiently small, so that any leaks will only release so little gas into the surroundings that it does not constitute a hazard.

Fig. 14A shows a wood-burning platform 8 in detail, with three removable gratings 59. Under these gratings is located the ash-collecting space 60, which is formed by the first circumferential edges 67, extending in an essentially vertical direction. In this embodiment, the wood-burning platform 8 is also fitted with second circumferential edges 68, which extend in an essentially vertical direction and serve to support and fix the gratings 59. The gratings 59 and the wood-burning platform 8 are fitted with grippable points 90 and 91, so that they can be raised with the aid of a gripping device 95 (shown in Fig. 14B) , equipped with corresponding gripping elements 96, as a result of which, the wood-burning platform 8 can be raised without direct contact between the user' s hands and the wood-burning platform 8. The circumferential edges 67 and 68 ensure that the ash and the gratings cannot easily fall or slide out of the wood-burning platform 8, so that the fouling of the surroundings can be prevented.

Fig. 15A shows the fireplace system 1 with its housing 2, and inside it in the operating position the lifting mechanism 15, the gas-burner section 12, with the gas-fire 21, and the telescopic gas pipe 70 for the burner, which pipe extends essentially vertically. The gas-burner section 12 is provided with a pilot-light unit 100, whose pilot light lights the fire in the fire-place 21. The pilot- light unit 100 is supplied with gas by means of a gas pipe 101 for the pilot light. The gas pipe 101 for the pilot light and the gas pipe 70 for the burner are connected to the gas regulating unit 111. The gas regulating unit 111 is supplied with gas from the gas inlet pipe 112 present in the room of premises where the fireplace is installed. The gas regulating unit 111 controls the gas flow to the gas-fire 21 and to the pilot-light unit.

In the embodiment shown in Fig. 15A, the gas pipe

101 for the pilot light comprises a first pipe section 103 and a second pipe section 104. The gas pipe 101 for the pilot light contains a constriction 102, which limits the gas flow to the gas regulating unit through the gas pipe 101 for the pilot light to the pilot-light unit 100, owing to its reduced cross-section, or diameter, or area of cross- section. The diameter of the gas pipe 101 for the pilot light is generally chosen from values between 1 and 10 mm, so that this diameter or equivalent diameter is about a half to one-twentieth of the diameter of the pipe, having therefore a value between 0.1 and 5 mm. In an advantageous embodiment, the outside diameter of the gas pipe 101 for the pilot light is about 4 mm and its inside diameter is 2 mm, while the diameter of the region of constriction is about 0.4-1 mm. Owing to this constriction, the amount of gas that can flow to the pilot-light unit is slightly more than the amount of gas consumed by the pilot light. Therefore, a small gas leak will quickly extinguish the pilot light and close off the gas inlet through the gas regulating unit 111.

The first pipe section 103 is preferably made of a material that is stiff, rigid and difficult to bend (called here "a bendable material") , for example a metal that contains a substantial amount of copper or aluminium. This has the advantage that the gas pipe 101 for the pilot light can easily be firmly connected to the housing 2, and it can also be easily connected to the gas inlet pipe 112, using conventional coupling elements. The gas-burner section 12 is fitted with a displacing device, which is a lifting mechanism or a scissor-like linkage mechanism 15 in the embodiment shown in Fig. 1A, so that the gas pipe 101 for the pilot light has a flexible pipe section 104 that bends with the gas-burner section 12 as the latter is being moved up or down. The flexible material, which should also be heat-resistant, is preferably teflon (PTFE) .

Fig. 15B shows the scissor-like linkage mechanism

15 and the gas-burner section 12 in the retracted position, in which case the first pipe section 71 of the telescopic gas inlet pipe 70 is pushed into the second pipe section 72. This illustration also shows that the wood-burning platform

8 is introduced into the positioning opening in order to make a log fire in the fireplace. An ash-collecting part 60 is arranged under the wood-burning platform 8 to collect the ash and other, unburnt residues formed when wood is burned.

This illustration also shows that the gas pipe 101 for the pilot light is bent in a round downward curve, following the gas-burner section 12. The constriction 102 is preferably arranged near the connection between the first, bendable pipe section 103 and the second, flexible pipe section 104. This connection can also be in the form of a coupling device 110, in which case the first and second pipe sections are attached to it.

Owing the constriction 102, the gas flow through the flexible pipe section 104 is limited in the case of a leak .

Fig. 16 shows in more detail an embodiment of the coupling device 110 between the first, bendable pipe section 103 and the second, flexible pipe section 104. In this embodiment, the constriction 102 is arranged inside the coupling device 110 between the two pipe sections 103 and 104. This greatly reduces the gas flow inside the flexible pipe section 104, so that - if there is a leak in this second, flexible pipe section 104 - only a small leakage stream flows into the housing, so that the formation of explosive gas-air mixtures is prevented. In view of the small risk of a leak from the bendable first pipe section 103, the constriction is arranged near the joint between the first and second pipe section 103 and 104. The constriction 102 can also be arranged in the first, bendable pipe section 103, so that, when the second, flexible pipe section 104 is replaced, the constriction 102 is not removed or damaged. The constriction 102 can also be arranged further upstream in the first pipe section 103, but this has the disadvantage that, if there is a leak, more gas can flow into the housing, owing to the greater inner pipe volume.

The gas pipe 101 for the pilot light can also be fitted with a pilot-light interrupter 105, which shuts off the gas flow to the pilot-light unit 100 when the gas-burner section 12 is removed from its operating position. This can be done in a conventional way, for example with the aid of a gas valve, which is only opened when the gas-fire 21 is fully in its operating position. In Fig. 2, the pilot-light interrupter 105 is arranged on the displacing unit or scissor-like linkage mechanism 15 of the gas-burner section 12, so that a third, bendable pipe section 106 is fitted between the pilot-light interrupter 105 and the pilot-light unit 100. As a result, the second, bendable pipe section 104 extends from the coupling device with the constriction 102 to the pilot-light interrupter 105.

When the gas-burner section 12 is taken out of its operating position and moved down by the scissor-like linkage mechanism 15, the gas supply to the pilot flame is stopped, so the pilot flame goes out, and the sensor in the pilot-light unit 100 shuts off the gas flow from the gas regulating unit 111 to both the gas pipe 70 for the burner, and the gas pipe 101 for the pilot light.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the spirit and scope of the present invention .