Portable and foldable fireplace

Technical Field The present invention generally relates to a collapsible and portable fireplace having a combustion chamber in an elongate pipe. More specifically, the invention relates to such a fireplace having a combination of collapsibly assembled parts that in a raised position form an elongate pipe having a combustion chamber, a foot and a bottom.

Background

Concurrently with increasing outdoor life and ecotourism, more people move about in woods and fields. Thereby, also the demand for providing heat and cooking facilities under active-service conditions increases. It is natural and common to use fire, and then the risk of unintentional ignition of inflammable material in the surrounding terrain also increases. There are also similar demands and risks in materially less developed countries or in emergency situations where heating and cooking equipment is lacking. In said connections, generally there is also a transport problem.

Therefore, there is a need of a simple, effective and safe fireplace that is flexible, easy to transport and formed in such a way that the risk of fire spreading decreases.

Prior Art

It is well known to form a fireplace as an elongate pipe having a round or four-sided cross-section. Air-intakes in the lower and upper edge provide an effective incinera- tion. Collapsibility and portability are provided by the selection of design, composition and choice of material for the different parts of the product. In the patent documents US 7,107,893, WO 03/042598 and US 3,384,066, there are a couple among numerous examples of prior art of this kind of fireplace, and in these publications, also the fundamental operating principles are explained.

The known tubular fireplaces have in common that a stand or foot and a bottom member often are lacking, and are insufficient or involve additional parts that affect portability and collapsibility in a disadvantageous way.

Object of the Invention

It is an object of the present invention to provide a portable fireplace having an improved combustion efficiency, collapsibility and stability.

Summary of the Invention According to the invention, the object is attained by a fireplace having a tubular combustion chamber that is constructed from flat wall members that are mutually foldable. In the developed state, the combustion chamber has a hexagonal-shaped combustion chamber.

Brief Description of the Drawings

The invention is explained in more detail in the accompanying figures, wherein: Figs. 1-6 show in different views an embodiment of a portable fireplace according to the invention.

Detailed Description

The figures show an embodiment of the invention in the form of a fireplace (1 ) having a tubular combustion chamber. The combustion chamber is constructed from six elongate wall members (2), each wall member at each one of the long sides (6) thereof being attached to a long side of an adjacent wall member in such a way that the wall members together form a pipe having a hexagonal cross-section. Fig. 1 shows the fireplace in a perspective view obliquely from the side.

The wall members are essentially rectangular and are, in the upper edge, provided with a recess 14. In the embodiment illustrated, the upper edge has the form of a crown with points on which cooking-vessels can be stably placed. The recesses have the purpose of letting out combustion gases when a cooking-vessel covers the opening of the upper portion.

Fig. 4 shows the fireplace from above and the cross-section of the combustion chamber is clearly seen. The thus hexagonal-shaped cross-section affords a volume of the combustion chamber that is optimized in relation to the material consumption for the wall members. The length of the combustion chamber, which for instance may be 20- 50 cm, provides a draught that increases the combustion efficiency.

The long sides of the wall members are attached to each other in hinges 18, 20 (refer to Fig. 3) in such a way that the polygon-shaped combustion chamber can be folded together into an almost flat cross-section, as is shown in Fig. 6. The hinges are, for instance, realised by intermittently repetitive short pipe sections 18 being arranged at the long sides of the wall members in a mutually offset pattern of the respective adjacent wall member. When the wall members are fitted to each other, the pipe-section patterns are brought together and form a chain of continuous pipes that are con- nected by means of a pivot pin 20.

Furthermore, the fireplace comprises three elongate foot members (4A, 4B, 4C), each of which has an edge (5A, 5B, 5C) that is articulately attached to a short side (7A, 7B, 7C) each of three ones of the wall members (2A, 2B, 2C) selected in such a way that each pair of said wall members (2A, 2B, 2C) has one of the other three wall members placed between. The respective foot member is foldable under the end of the combustion chamber in such a way that a first portion (2OA, 2OB, 20C) of the foot member forms a bottom of the combustion chamber as well as that a second portion (22A, 22B, 22C) forms a foot. The first portion 20 of each foot member is rectangular and covers a portion of the hexagonal-shaped end opening, and together the foot portions cover the entire end opening and accordingly forms a bottom.

A hexagonal-shaped grate 16, refer to Figs. 3 and 4, is articulately suspended to a wall member at the inside of the tubular combustion chamber and arranged in such a way that it is lowerable against a shoulder (not shown) in such a way that the grate can form a bottom in the combustion chamber. In the lowered position, the grate stabilizes the fireplace and keeps the combustion chamber expanded in the hexagonal-

shaped cross-section thereof. When the grate is retracted, simultaneously the combustion chamber collapses by the fact that the hinged wall members are folded against each other and the flat cross-section in the collapsed position shown in Fig. 6 is assumed.

Furthermore, the fireplace comprises a recess (8) in one of the wall members arranged for letting air into the combustion chamber. In different embodiments, this is arranged in such a way that it can let in air under and/or over the grate. The recess can also be used to bring in an igniting flame for ignition of the combustible in the combustion chamber. As is shown, furthermore there is preferably an adjustable door (10) that can be slid over the air-inlet recess (8). In order to allow manoeuvring of the door when the fireplace is hot, the door is preferably provided with one or more latticed handles 12.

Preferably, the parts of the fireplace are manufactured from thin sheet-metal plate, for instance sheet iron of a thickness of 2 mm.