CHANNEL SYSTEM WITH A CROSS-SECTION WITH ROUNDED CORNERS AND METHOD FOR MANUFACTURING ELEMENTS THEREIN

Abstract: The invention relates to a channel system with a cross-section with rounded corners, comprising various elements, such as straight, branch, corner, reducing fittings and/or the like. The elements have planar (1) and arched (2), such as convex, concave or corresponding wall parts, and which elements are manufactured of a material preferably with thin walls, such as sheet metal, plastic or the like. For achieving a cross-section with rounded corners, the elements of the channel system are formed by using joining arrangements to connect at least arched wall parts (2) with each other, preferably substantially the edges thereof, wherein the elements connected with each other form a flow or wiring channel or the like. The elements of the channel system, having different sizes and/or shapes, are formed by combining basic parts (1a, 1a', 2a, 2b, 2c) forming planar (1) and arched (2) wall parts.

Description: Channel system with a cross-section with rounded corners and method for manufacturing elements therein The invention relates to a channel system with a cross-section with rounded corners, comprising various elements, such as straight, branch, corner, reducing fittings and/or the like with planar and arched, such as convex, concave or corresponding walls, and which elements are manufactured of a material preferably with thin walls, such as sheet metal, plastic or the like. For achieving a cross-section with rounded corners, at least part of the elements of the channel system are formed by using joining arrangements to connect at least arched wall parts with each other, preferably substantially the edges thereof, wherein the elements connected with each other form a flow or wiring channel or the like. Particularly as flow channels, channels with a cross- section with rounded corners are more advantageous for flowing than acute-angled, e.g. rectangular or quadratic channels. In a channel with acute angles, the flow is naturally not evenly distributed onto all parts of the wall, as compared with a channel with rounded corners, but turbulence is induced by acute angles. Thus for example in ordinary ventilation systems, impurities are slowly accumulated in the ducts. Commonly used channels with rounded corners are spiral tubes which are manufactured for each standardized tube size. In a channel system made of spiral tubes, the various branch, corner, reducing and corresponding fittings are manufactured by applying ordinary sheet working techniques. Thus the manufacture of the said elements requires good professional skills and/or specially tailored equipment, such as moulds, templates or the like. For reasons of manufacturing techniques, it is usually necessary to provide certain elements of a channel system having a cross-section with otherwise rounded corners with partly sharp edges, whereby it is not possible to maintain the advantageous cross-section with rounded corners in all parts. Naturally, for different elements needed for each tube size, tools for each size must be used. In practice, such channel systems made of spiral tubes usually have a clumsy general appearance due to elements manufactured with most various techniques and skills. The publications GB-1,301,858 and GB-1, 552,916 disclose elements formed by planar parts joined together, applicable for use in a channel system with a cross- section with sharp edges. GB-1,301,858 presents a fireproof channel element, the wall being formed by flat plates joined together by corrosion-resistant connecting means fixed at the inner edges and the outer surfaces of the joints being welded. GB-1,552,916 presents a solution for forming the walls of an element of flat plates notched and bent into a right angle, which are fixed to each other by U-shaped connecting means and support frames. The solutions of both publications are only applicable for manufacturing elements with a cross-section with sharp edges. Further, the application requires precise dimensioning of the wall parts and the use of particular connecting means. Consequently, the said solutions are demanding with respect to both their manufacturing - to secure sufficient compatibility of elements - and their installation - because several operations are needed. Finnish Patent Application No. 497/71 presents a method and device for connecting elements in ventila¬ tion systems with high requirements for tightness. The method presented in the publication can also be applied for manufacturing elements of a channel system with a cross-section with rounded corners. The inven¬ tion of the publication relates to manufacturing elements of separate wall surfaces, the edges being equipped with joint arrangements. The joint arrange¬ ments are formed by a U-shaped joint part at the edge of another wall surface, the edge of the opposite wall surface being placed therebetween. The publication discloses applications with a cross-section with rounded corners of a straight element, a T-branch and an angle of 90°, each being formed by two arched wall surfaces placed against each other. The joint solution presented in the publication is useful in principle, but it does not, however, offer a comprehensive solution for manufacturing elements with different shapes and sizes. Consequently, it is not possible to manufacture different parts of a channel system by present tech- niques in a way that all parts of the channel system be based on a cross-sectional shape with rounded corners. Thus, for channel systems presently manufac¬ tured, combinations must usually be made of both rounded and angulated components, whereby the whole is unsatisfactory in appearance. Aiming at a uniform appearance, the costs of manufacturing rise onto ■ an extremely high level when present solutions are applied, because separate tools are needed for each size and shape. It is an aim of the channel system with a cross-section with rounded corners according to the invention to achieve a decisive improvement to the disadvantages presented above and thus to improve the state of prior art in the field substantially. For achieving this aim, the channel system with a cross-section with rounded corners according to the invention is primarily characterized in that the elements of the channel system, having different sizes and/or shapes, are formed by combining basic parts forming wall parts with planar and arched shapes, such as convex, concave or the like. The most important advantages of the channel system of the invention are the simplicity and uniformity of the basic parts used therein, whereby the entire channel system with elements of different sizes and shapes can be composed of the same basic parts. There is thus no need e.g. to manufacture separate tools to correspond to each element size or shape as in the present methods. The channel system of the invention is thus also uniform in appearance, whereby it has, most preferably, rounded corners in all elements. Advantageous embodiments of the channel system of the invention are presented in the other, dependent claims. The invention relates also to a method for manufactur¬ ing elements of a channel system of the said type. The method is defined more closely in the preamble of the independent claim related to the method. The features primarily characterizing the method are presented in the characterizing part of the correspond¬ ing claim. The method of the invention makes it possible to manufacture elements of the channel system by a simple set of tools, because a uniform channel system of the invention can be composed of basic parts having the same basic shapes. The elements of different sizes and shapes are formed simply by combining planar basic parts and arched basic parts, the latter being most preferably made in only three shapes. The appli¬ cation of the method does not require difficult or additional operations, but all elements can be assembled and joined to each other by simple joining arrangements suitable for each purpose. An advantageous embodiment of the method of the invention is presented in a dependent claim related to the method. In the following description, the invention is il¬ lustrated in detail with reference to the appended drawings. In the drawings, Fig. la shows a sample of a straight element of a channel system according to the invention, Fig. lb is an explosion view of the element shown in Fig. la, Fig. 2a shows a corner piece in a 90° angle, Fig. 2b is a partial explosion view of the corner fitting shown in Fig. 2a, Fig. 3 shows a corner piece in a 45° angle, and Fig. 4 shows a channel system with a uniform appearance, formed by a channel system of the invention. The embodiments shown in Figs. 1 to 4 are examples of a channel system of the invention having a cross- section with rounded corners and including different elements, such as straight, branch, corner, reducing fittings and/or the like. The elements have planar 1 and arched 2, such as convex, concave or corresponding walls, and they are manufactured of a material prefer¬ ably with thin walls, such as sheet metal, plastic or the like. For achieving a cross-section with rounded corners, the elements of the channel system are formed by connecting at least arched wall parts 2 by their edges with each other using joining arrangements, wherein the elements connected with each other form a flow or wiring channel or the like. The elements of the channel system having different sizes and/or shapes according to the invention are formed by combining basic parts la, 2a, 2b, 2c forming planar 1 and arched 2 wall parts. A closed channel with a cross-section with rounded corners is shown in Fig. la and in an explosion view in Fig. lb. The planar wall parts 1 of the channel are formed by first basic parts which in this embodi¬ ment are rectangular flat plates la. The arched wall parts 2 are formed by second basic parts 2a which extend in the longitudinal direction s and are arched in the transverse direction, thus forming the rounded corners of the channel as their longitudinal edges are attached to plates la. A corner piece in a 90° angle is shown in Fig. 2a and in an explosion view in Fig. 2b. The edges of the internal angle 3 of the piece are formed by third basic parts 2b joining the two longitudinal direc- tions si, s2 in an arch and arranged in the transverse direction in an arch. These third basic parts 2b are connected at their first edges to a second basic part 2a joining them and at their second edges to side plates la ' . Further, the edges of the external angle 4 of the corner piece are formed by fourth basic parts 2c arranged to be continuously arched and connected at their edges to second basic parts 2a. The upper and back walls of the piece are formed by flat plates la joined with second basic parts. For achieving an advantageous assembly of a channel system according to the invention, the arches of the edges of second 2a, third 2b and fourth 2c basic parts forming arched wall parts 2, to be connected with each other, are formed using a substantially equal radius R of curvature. As shown in Figs. 2a and 2b, one edge of each third basic part 2b to be joined with a side plate la' is arranged to join the plane t defined by the side plate la' in an arch. Further, the said edge is formed by two flat edge parts in angles deviating from each other in the said plane t. The angle between the longitudinal directions si, s2 being 90° in the case in question, it is most advantageous to elect the angle between the straight edge parts also a right angle. Thus it is also simple to manufacture side plates la' by only deleting the rectangular pieces from the corners. In the embodiments presented, the second basic part 2a is preferably formed by 1/4 of a cylindrical surface and the fourth basic part 2c substantially of 1/8 of a spherical surface, correspondingly. Figure 3 shows a corner piece corresponding to the Figs. 2a, 2b, the longitudinal directions deviating in an angle of 45°. Thus the fourth basic part 2c' is formed by 1/16 of a spherical surface, whereby the third basic part 2b' and the second basic part 2a' are arranged in an angle of 45° correspondingly. Both side plates la" are formed of hexago 1 1 plates which are symmetrical in relation to their central line K. Figure 4 shows a channel system with a uniform ap¬ pearance, manufactured by the method of the inven¬ tion. The method of the invention can be used for manufacturing both closed channels and partly open channels. Open channels can be used, as presented, as wiring channels or cover plates. By the principle presented above, the method of the invention is thus used to form elements with different shapes by combining planar and arched wall parts suitably with each other in order to manufacture elements with different shapes. Thus, corresponding elements with different sizes in the channel system are manufactured by using the same basic parts, whereby the dimensions, such as the area and length, of the first and second basic parts are changed corresponding¬ ly- It is obvious that the invention is not limited to the embodiments presented above but it can be varied within the basic idea even to a great extent. For example, the corner piece shown in Figs. 2a, 2b can be simply modified into a T-piece open in three directions. The basic parts can naturally be connected to each other by a variety of joining arrangements depending on the material used and the purpose of the channel in question. Thus, for example when sheet metal is used, the basic parts can be formed e.g. by a joining principle of the type mentioned in the beginning of the description above. In a corresponding manner, the joining arrangements can be arranged to be disassembled e.g. for forming various cover plates of temporary art. It is naturally the purpose of the channel that sets the requirements for the tightness etc. of the joining arrangement. Consequently, the channel system of the invention can be used in a variety of applications, manufactured of " a variety of materials and by a variety of techniques.

Claims: Claims : 1. Channel system with a cross-section with rounded corners, comprising various elements, such as straight, 5 branch, corner, reducing fittings and/or the like with planar (1) and arched (2) , such as convex, concave or corresponding walls, and which elements are manu¬ factured of a material preferably with thin walls, such as sheet metal, plastic or the like, whereby for 10 achieving a cross-section with rounded corners, at least part of the elements of the channel system are formed by using joining arrangements to connect at least arched wall parts (2) with each other, preferably substantially the edges thereof, wherein the elements 15 connected with each other form a flow or wiring channel or the like, characterized in that the elements of the channel system, having different sizes and/or shapes, are formed by combining basic parts (la, 2a, 2b, 2c) forming wall parts with planar (1) and 20 arched (2) shapes, such as convex, concave or the like. 2. Channel system with a cross-section with rounded corners according to claim 1, characterized in that at least one planar wall part (1) of an element 25 in the channel system is formed of a first basic part (la) , such as a flat sheet, plate or the like, whereby at least one arched wall part (2) of the element is formed by a second basic part (2a) which extends in the longitudinal direction (s) and is 30 arched in the transverse direction, at least one of its longitudinal (s) edges being attached to the If, first basic part (la) . 3. Channel system with a cross-section with rounded 35 corners according to claim 1 or 2 , characterized in that at least one arched wall part (2) of an element in the channel system is formed by a third basic part (2b) joining two longitudinal directions (si, s2) in an arch and arranged in the transverse direction at least partly in an arch, the third basic part (2b) being connected at least at its first substantially longitudinal edge to a second basic part (2a), to a third basic part (2b) and/or the like and/or at its second substantially longitudinal edge to a first basic part (la ' ) . 4. Channel system with a cross-section with rounded corners according to claim 1, 2 or 3, characterized in that at least one arched wall part (2) of an element in the channel system is formed by a fourth basic part (2c) arranged to be continuously arched and connected at least at one of its edges to a second basic part (2a) , a third basic part (2b) and/or a fourth basic part (2c) . 5. Channel system with a cross-section with rounded corners according to any of claims 1 to 4 , charac- terized in that the arches of at least the edges, to be connected with each other, of second (2a) , third (2b) and fourth (2c) basic parts forming arched wall parts (2) of an element in the channel system, are formed using a substantially equal radius (R) of curvature. 6. Channel system with a cross-section with rounded corners according to claim 3, characterized in that the second edge of a third basic part (2b) to be joined with a first basic part (la') is arranged to join the plane (t) defined by the first basic part (la') in an arch, whereby the said edge is formed by two flat edge parts in angles deviating from each other in the said plane (t) . 7. Channel system with a cross-section with rounded corners according to claim 2 and 5, characterized in that the second basic part (2a) is formed substan¬ tially by 1/4 of a cylindrical surface. 8. Channel system with a cross-section with rounded corners according to claims 4 and 5, characterized in that the fourth basic part (2c) is formed substan¬ tially by 1/8 of a spherical surface. 9. Method for manufacturing elements of a channel system with a cross-section with rounded corners, wherein different elements of the channel system, such as straight, branch, corner, reducing fittings and/or the like with planar (1) and arched (2) , such as convex, concave or corresponding walls, are manu- factured of a material preferably with thin walls, such as sheet metal, plastic or the like, wherein, for achieving a cross-section with rounded corners, at least part of the elements of the channel system are formed by using joining arrangements to connect at least arched wall parts (2) with each other, preferably substantially the edges thereof, wherein the elements connected with each other form a flow or wiring channel or the like, characterized in that the elements of the channel system, having different sizes and/or shapes, are formed by combining basic parts (la, 2a, 2b, 2c) forming planar (1) and arched (2) , such as convex, concave or corresponding wall parts, wherein the arches of at least the edges, to be connected with each other, of the basic parts (2a, 2b, 2c) forming arched wall parts (2) of an element in the channel system, are formed using a substantially equal radius (R) of curvature. 10. Method according to claim 9, characterized in that at least one planar wall part (1) in an element of the channel system is formed of a first basic part (la, la') , such as a flat plate, flange or the like, wherein at least one arched wall part (2) of the element is formed of a second basic part (2a) extending in one longitudinal direction (s) and arranged to be arched in the transverse direction, such as one formed by 1/4 of a cylindrical surface or correspondingly, and/or a third basic part (2b) joining two longitudinal directions (si, s2) in an arch and arranged in the transverse direction in an arch, with the second edge that is to be connected to the first basic part (la 1 ) arranged to join the plane (t) defined by the first basic part in an arch, whereby the said edge is prererably formed by two flat edge parts in angles deviating from each other in the said plane (t) , and/or by a fourth basic part (2c) arranged to be con¬ tinuously arched, such as one formed substantially of 1/8 of a spherical surface.

Inventors: PERTTULA JUKKA, PERTTULA, JUKKA
Applicants: PERTTULA JUKKA, PERTTULA, JUKKA
Application year: 1993
Main classification: F16L9
IPC codes: F16L9