Corner block

Abstract

 A corner block for vertical corners of a structure built from natural rock, such as a soapstone furnace, to connect a first and a second wall element (1,2) forming the wall surfaces of the structure together at an angle exceeding 90°. The wall elements comprise vertical straight edge surfaces (3,5). The corner block comprises a first joint surface (4) parallel to the vertical edge surface (3) of the first wall element (1) and having a vertical inner edge (7) and a vertical outer edge (10), and a second joint surface (6) parallel to the vertical edge surface (5) of the second wall element (2) and having a vertical inner edge (8) and a vertical outer edge (11). According to the invention, the corner block comprises a straight planar inner surface (9) connecting the inner edges (7,8) of the first and second joint surfaces (4,6), and an outer surface (12) connecting the outer edges (10,11) of the first and second joint surfaces and consisting of a first sub-surface (13) parallel to the inner surface (9) and a second sub-surface (14) at right angles to the second joint surface (6), all outer surface corners connecting vertical surfaces of the corner block being in the range of [90° - 180°).

Description

[0001] The present invention relates to a corner block as defined in the preamble of claim 1. The invention exclusively concerns structures manufactured from natural rock, especially soapstone, such as furnaces and other fireplaces built from soapstone, but also other structures of natural rock.

[0002] In stone structures, such as soapstone furnaces, exterior corners exceeding 90° are currently generally produced by working an edge of one of the wall elements into an oblique angle such that, when the elements are joined together, a desired exterior corner is formed in the shell of the furnace. Various corner structures of this type are known, but a feature common to them all is that at least one, and in some cases even both, of the opposite surfaces of the elements to be joined must be separately worked into a suitable bevel or other shape. Thus, the manufacture of elements leads to individual production of parts for each furnace and therefore to high production cost.

[0003] In some applications, a source of problems are stones with sharp angles, e.g. 45°, which are used when an exterior corner of 135° is to be made. Such a sharp corner in a stone is very susceptible to damage during manufacture, transport and assembly, requiring extra precautions. For this same reason, when making exterior corners exceeding 90°, it has not been possible to use small, wedge-like corner blocks to join wall elements together.

[0004] The object of the present invention is to eliminate the drawbacks described above. A specific object of the invention is to present a new type of corner block for stone furnaces and corresponding stone structures, which allows a maximum degree of modularity in the design of wall elements and exclusively rectangular cuts in working them.

[0005] As for the features characteristic of the invention, reference is made to the claims.

[0006] The corner block of the invention is manufactured from natural rock and is intended for use in vertical corners of structures built from natural rock, such as a stone furnace, to join together adjacent first and second wall elements forming the wall surfaces of the structure, at an angle exceeding 90°. The corner block comprises a first joint surface parallel to a vertical edge surface of a first wall element, i.e. a stop face for said vertical edge surface, and a second joint surface parallel to a vertical edge surface of a second wall element, i.e. a stop face for this vertical edge surface. Both joint surfaces have a vertical inner edge and a vertical outer edge. According to the invention, the corner block comprises a straight and planar inner surface connecting the inner edges of the first and second joint surfaces, and an outer surface connecting the outer edges of the first and second joint surfaces, said outer surface consisting of a first sub-surface parallel to the inner surface and a second sub-surface at right angles to the second joint surface. Thus, according to the invention, all outer surface corners connecting vertical surfaces of the corner block are in a half-open range [90 - 180°).

[0007] The basic idea of the corner block of the invention is that the bevel surfaces needed in a corner are made in the corner block, thus permitting all wall elements to be manufactured as rectangular bodies and using standard parts as much as possible. Another essential feature of the corner block is that no sharp corners susceptible to damage are present, at least on the outer surface of the structure.

[0008] In a preferred case, the first and second joint surfaces of the corner block are at an angle to each other and at a distance from each other so that only the imaginary extensions of the surfaces intersect at a distance from the corner block inside the structure.

[0009] Another significant feature of the design of the corner piece is the first sub-surface parallel to the inner surface, which allows the corner block to be worked with a single straight cut into a suitable size, so that it is possible to use only modular-sized elements in the walls themselves.

[0010] In an embodiment of the invention, the first and second joint surfaces are parallel to each other, in which case the corner block forms in the wall structure a corner or bend between two parallel wall elements.

[0011] In the manner described above, the corner block of the invention significantly simplifies the making of corners exceeding 90° in stone furnaces and other structures of natural rock, bringing considerable cost savings, because by simply fitting corner blocks the same results are achieved for which in prior it has been necessary to manufacture wall elements of several different sizes and to work them so as to make the required bevels. The invention eliminates all corners below 90°, which are easily damaged, for all outer corners and in a preferred embodiment for all corners of the corner blocks. Moreover, the corner blocks are easy to manufacture because they can be produced from plate-like bars of rock of uniform thickness only by sawing or cutting straight through the whole rock blank. This eliminates the need to make interior corners in the stone, which always require a cut into a certain depth from two directions.

[0012] In the following, the invention is described in detail by referring to the attached drawings, in which

Fig. 1 presents a corner block according to the invention and its use at an angle of 135°,

Fig. 2 presents another practical application of the invention,

Fig. 3 presents a third practical application of the invention,

Fig. 4 illustrates a use of a corner block as provided by the invention in a stone furnace,

Fig. 5 illustrates another use of a corner block as provided by the invention in a stone furnace,

Fig. 6 presents another corner block according to the invention.

[0013] The corner block in Fig. 1 has been produced from a stone having the shape of a rectangular parallelopiped, one edge of which has been bevelled from both sides to produce planar surfaces in desired directions. Thus, the corner block comprises a first joint surface 4 parallel to a vertical edge surface 3 of a first wall element 1 and a second joint surface 6 parallel to a vertical edge surface 5 of a second wall element 2. The first and second joint surfaces 4 and 6 are at an angle of 45° to each other. The inner edges 7 and 8 of the first and second joint surfaces are connected by a straight inner surface 9, while the outer edges 10 and 11 of the first and second joint surfaces are connected by an outer surface 12, which consists of a first sub-surface 13 parallel to an outer surface of the first wall element 1 and a second sub-surface 14 parallel to an outer surface of the second wall element 2.

[0014] In this way, a corner 15 is formed between the first and second sub-surfaces 13 and 14, which in the embodiment presented is 135° or, if measured on the outside from surface to surface, 225°.

[0015] Thus, the corner block has a first joint surface 4 at right angles to the first sub-surface 13 and to the inner surface 9. As stated above, the second sub-surface 14 is at an angle of 135° to the first sub-surface, while the second joint surface 6 is at right angles to the second sub-surface 14. Both end surfaces of the corner block are planar surfaces at right angles to all the above-mentioned surfaces.

[0016] The corner block of the invention can thus be used to join wall elements 1 and 2 having the shape of a rectangular parallelopiped to each other at an angle other than 90° without making bevels in the wall elements, just by selecting and working the corner 15 of the corner block, or rather the angle between the joint surfaces 4 and 6, into a desired angle. Since the first sub-surface 13 and the inner surface 9 are parallel to each other, the corner piece can be produced in a simple manner from a straight stone bar of uniform thickness by only making suitable bevels (joint surface 6 and second sub-surface 14) in its one edge.

[0017] As shown in Fig. 2, two corner blocks can be joined by placing a first joint surface against a second joint surface, thus producing an outer corner nicely bevelled and rounded instead of a conventional rectangular corner. It is to be noted that the corner blocks can be as high as the wall elements used, so they can be linked to each other and to wall elements in each tier by means of hooks and other connecting elements 16 known in themselves. However, it is also possible to use solid corner blocks that are lower or higher than the wall elements, even as high as the fireplace itself.

[0018] Fig. 3 shows how a bevelling corresponding to Fig. 2 is made on a rectangular corner by using two corner blocks as provided by the invention. In this embodiment, however, the two corner blocks are placed with their first joint surfaces abutting against each other, the second joint surfaces being joined with wall elements. In this way, by using corner blocks of the same size, a somewhat larger bevel is produced than in the application in Fig. 2. It is to be noted that a desired bevel length can be achieved in both applications by only making a straight cut through the corner block e.g. along the broken line 17, i.e. in the area of uniform thickness of the corner block.

[0019] Fig. 4 presents the tier layout of the stone elements in a soapstone furnace using corner blocks as provided by the invention. In this application, the back wall and side walls of the furnace have been built from conventional corner blocks 18 and modular-sized wall elements 19 and 20, with corner blocks 21 according to the invention extending from the side wall elements obliquely forward toward the centre, with their first joint surfaces abutting against each other. This arrangement leaves in the front side of the furnace a suitable space for a furnace door 22 between the corner blocks. In this application, too, the lengths of the corner blocks 21 have been chosen so as to leave a space of exactly the right width for the furnace door.

[0020] Fig. 5 shows another layout of stone elements, in which the back and sides of a corner fireplace are composed of conventional modular-sized wall elements 23 and corner blocks 24. In the front part of the fireplace there are two corner blocks 25 as provided by the invention, whose length has been so chosen as to leave a suitable space for a door 26 between them.

[0021] Thus, in both applications in Fig. 4 and 5, the walls themselves can be built from modular-sized standard blocks, while precise fits and dimensions are achieved using corner blocks according to the invention by working them into the required lengths by cutting off a suitable piece from one end with a straight cut.

[0022] Fig. 6 presents an embodiment of the invention in which the first joint surface 34 and the second joint surface 36 of the corner block 30 are parallel to each other. In this case, the wall elements 31 and 32 joined by the corner block are parallel but in different vertical planes. In this embodiment, both edges of the corner block have been bevelled with straight cuts, but although a sharp angle is formed at the inner edge of the first joint surface 34, it does not cause any problems as it remains inside the structure. Thus, the corner block in this embodiment, too, is made from a stone bar of uniform thickness so that no corners below 90° are formed in the outer surface of the structure.

[0023] In the foregoing, the invention has been described by the aid of examples by referring to the attached drawings, but different embodiments of the invention are possible within the scope of the inventive idea defined by the claims.

Claims

1. Corner block for vertical corners of a structure built from natural rock, such as a soapstone furnace, to connect a first and a second wall element (1,2) forming the wall surfaces of the structure together at an angle exceeding 90°, which wall elements comprise vertical straight edge surfaces (3,5) and the corner block comprises a first joint surface (4) parallel to the vertical edge surface (3) of the first wall element (1) and having a vertical inner edge (7) and a vertical outer edge (10), and a second joint surface (6) parallel to the vertical edge surface (5) of the second wall element (2) and having a vertical inner edge (8) and a vertical outer edge (11),
   characterized in that the corner block comprises

- a straight planar inner surface (9) connecting the inner edges (7,8) of the first and second joint surfaces (4,6), and

- an outer surface (12) connecting the outer edges (10,11) of the first and second joint surfaces and consisting of a first sub-surface (13) parallel to the inner surface (9) and a second sub-surface (14) at right angles to the second joint surface (6), all outer surface corners connecting vertical surfaces of the corner block being in the range of [90° - 180°).

2. Corner block as defined in claim 1, characterized in that the first sub-surface (13) and the second sub-surface (14) meet each other at a corner (15) at an angle exceeding 90°.

3. Corner block as defined in claim 1, characterized in that the first sub-surface (13) meets the second sub-surface (14) via a round curvature.

4. Corner block as defined in claim 1, characterized in that the first joint surface (4) and the second joint surface (6) are at an angle to each other such that their imaginary extensions intersect each other at a distance from the corner block inside the structure.

5. Corner block as defined in claim 1, characterized in that the first sub-surface (13) is at right angles to the first joint surface (4).

6. Corner block as defined in any one of claims 1 - 5, characterized in that two corner blocks are placed side by side with the first joint surface (4) of one block abutted against the second joint surface (6) of the other block to form a relatively short wall between two corners exceeding 90°.

7. Corner block as defined in any one of claims 1 - 5, characterized in that two corner blocks are placed side by side with the first joint surface (4) of one block abutted against the second joint surface (6) of the other block to form two corners exceeding 90° close to each other in the structure.

8. Corner block as defined in any one of claims 1 - 7, characterized in that the first joint surface (4) and the second joint surface (6) are at an angle of 45° to each other.

9. Corner block as defined in any one of claims 1 - 8, characterized in that all corners connecting vertical surfaces in the corner block are in the range of [90-180°).

10. Corner block as defined in claim 1, characterized in that the first joint surface (34) and the second joint surface (36) are parallel to each other, in which case the first and second wall elements (31,32) are parallel to each other but in different vertical planes.

11. Corner block as defined in any one of claims 1 - 10, characterized in that the corner (15) is 135°.

12. Corner block as defined in any one of claims 1 - 11, characterized in that the corner block has been worked from a straight soapstone bar of uniform thickness by sawing or cutting etc. straight through the whole soapstone bar.

Drawing