PACKAGE WITH LID MADE BY DEEP DRAWING METHOD

Abstract: A package (1) made by the deep drawing method, comprising a container part (2) and a lid (3). The edges of the lid (3) and the container part (2) are designed so that the inner wall (3a) of the edge of the lid (3) is tightly against inner wall (2a) of the edge of the container part (2), and correspondingly, the outer wall (3b) of the edge of the lid (3) is tightly against the outer wall (2b) of the edge of the container part (2). Curved parts (2c, 3c) are arranged on the outer walls (2b, 3b), said curved parts locking the lid (3) into the container part (2) and sealing the seam between the lid (3) and the container part (2), so that the package (1) may also be used for storing strong-odoured and liquid substances.

Description: Package with lid made by deep drawing method. The invention relates to a package made by the " deep drawing method, comprising a container part and a lid, the edge of the container part having an inner wall, the upper part of the inner wall having an upper edge inclined outwards from it, and an outer wall inclined downwards from the outer edge of the upper edge; the edge of the lid having an upwardly inclined inner wall, the upper part of said inner wall having an upper edge inclined outwards from it, and an outer wall inclined downwards from the outer edge of the upper edge, whereby the container part and the lid may be laid one on top of the other so that they are substantially tightly sealed against each other. A prior art package made by the deep drawing method is a box having a container part whose edge is bent outwardly, inclining downwards. The lid to be placed on the box is shaped so that its middle part is below the edges of the container part, the edges of the lid being bent in accordance with the edges of the con¬ tainer part. Furthermore, the edge of the lid is bent to fit below the outermost part of the edge of the con¬ tainer part, whereby the lid is locked in place. The container part is sealed against the lid by the outer¬ most tip of its edge, and there is thus a line-shaped contact surface between the lid and the container part. A line-shaped contact surface of this kind is not suff¬ icient, however, to ensure tightness when the box is being handled, and odours and liquid products are thus allowed to escape the box. Deep drawing method has also been used for making packages in which the edge of the container part is bent substantially rectangularly, first outwards, then downwards, and once more outwards. The lid to be placed onto the box is designed in the corresponding manner. For securing the lid, recesses have been made in the corners of the lid, the insides of said recesses being pressed against the outer edges of the container part. A box of this kind, whose container part and lid are supported by linear surfaces, is not sufficiently tight either for packing strong-odoured substances and liquids. The object of this invention is to achieve a package made by the deep drawing method, which package is so tight that it can be used for storing strong-od¬ oured substances and liquids. The package of the invention is characterized in that at least one pair of curved parts is arranged on the outer wall of the edge of the container part and on the outer wall of the edge of the lid, the contacting surfaces of said curved parts being substantially of the same shape and size, and, upon the package being closed, substantially in the same position. The essential idea of the invention is that a cross-sectionally curved part surrounding the box is correspondingly arranged at the outermost part of the edge of the lid. The curved part of the edge of the container part and the curved part of the edge of the lid are arranged to be substantially of the same size and shape, and situated in the same position. The essential advantage of the invention is that the curved parts of the container part and the lid form a large contact surface between each other, which results in a tight package. A contact surface of this kind, formed by two curved surfaces, also allows toler¬ ances in manufacturing the package, however, without the tightness of the package remarkably suffering. The invention will be disclosed in greater detail in the attached drawing, in which Figure 1 shows an perspective view of the pack¬ age of the invention, Figure 2 shows a cross-section of the edge of the package in accordance with Figure 1, and Figure 3 shows a cross-section of the edge of a package in accordance with a second embodiment of the invention. Figure 1 shows a package 1 in accordance with the invention, made of thin plastic material. The pack- age 1 comprises a container part 2 and a lid 3. At the edge of the lid 3, there is a projecting part 3f in one corner, and lifting the projecting part is the easiest way to open the package. The container part 2 and the lid 3 are made by the deep drawing method. In the deep drawing method, a plastic film is first warmed. Thereafter, the warmed plastic film is brought between moulds, whereby air is sucked from one side of the film, and air is led to the other side of the film, as a result of which the plastic film is shaped in accordance with the mould. Thereafter, the moulded plastic film is removed from the mould, and the moulded objects are cut out of the film. Figure 2 shows a cross-section of the edge of the package 1 of the invention. The numbering in Figure 2 corresponds to that in Figure 1. The entire cross- section of the edge of the package 1 is substantially of the same shape. The edge of the container part 2 of the package 1 is shaped so that the inner wall 2a is first bent outwards, and then downwards to form an outer wall 2b, and once more outwards to form a flange 2e. An inwardly curved part 2c is formed on the outer wall 2b. The middle part of the lid 3 is below the upper edge of the container part 2. The edge of the lid 3 is bent so that the inner wall 3a of the lid is parallel with the inner wall 2a of the container part 2, and said inner walls 3a and 2a are substantially tightly against each other. The upper part of the edge of the lid 3 is further bent so that it is parallel with the upper edge of the container part 2. The edge of the lid 3 is furth- er bent to form an outer wall 3b parallel with the outer wall 2b of the container part 2 and so that it is firmly against it. The outer wall 3b of the edge of the lid 3 is further bent so that it forms a corresponding flange 3e as the one at the edge of the container part 2. Flanges 2e and 3e stiffen the structure of the outer wall 2b of the edge of the container part 2 and the lower part of the outer wall 3b of the edge of the lid 3. On the outer wall 3b of the lid 3, an inwardly curved part 3c corresponding to the curved part 2c of the cont- ainer part is arranged. The contacting surfaces of the curved parts 2c and 3c are substantially of the same shape and size, and in addition, upon the lid being closed, substantially at the same level. Since inner walls 2a and 3a rest against each other, they form an integral structure that supports the entire package. Thus, e.g. when squeezing the container part 2 of the package 1 from outwards, the inner wall 2a of the container part 2 pushes the inner wall 3a of the lid 3 and further the outer wall 3b of the lid 3 inwards, whereby the seam between the outer wall 2b of the container part 2 and the outer wall 3b of the lid 3 remains tight. Upon pressing the lid 3 onto the container part 2, the curved part 3c of the lid 3 fits in the curved part 2c of the container part 2, whereby the lid 3 is locked into the container part 2. Curved parts 2c and 3c compose a curved sealing face between each other, whereby the package is made so tight that it can also be used for storing strong-odour- ed substances and liquids. A curved sealing face of this kind also allows tolerance and handling of the package, without the tightness substantially suffering. The curved parts 2c and 3c are advantageously shaped like a curve of a circle. The curved parts 2c and 3c may be curved inwards, as shown in Figure 2, or they may be curved outwards. Figure 3 shows the cross-section of the edge of another package 1 of the invention. The numbering in Figure 3 corresponds to that in Figures 1 and 2. On the outer wall 2b of the edge of the container part 2, and correspondingly on the outer wall 3b of the edge of the lid 3, there are curved parts 2c and 3c, and above them other curved parts 2d and 3d. Curved parts 2c and 2d, as well as 3c and 3d may be curved to the opposite dir- ections, as shown in Figure 3, or they may also be curved to the same direction. Curved parts 2c and 2d, as well as 3c and 3d may also be situated some distance away from each other vertically, as shown in Figure 3, or they may follow immediately one after another. Pro- vided that curved parts 2c and 2d as well as 3c and 3d are curved to the opposite directions and follow immedi¬ ately one after another in the vertical direction, they will form a structure having a substantially s-shaped cross-section. The drawing and the explanation associated therewith are only intended to illustrate the idea of the invention. The invention may vary in its details within the scope of the attached claims. Thus, the material of the package 1 may be any plastics formable by means of the deep drawing method. The shape of the package may also vary freely; it may be e.g. round, rectangular or quadrangular. Curved parts 2c and 2d as well as 3c and 3d may further be of a parabolic or un- symmetrical shape.

Claims: Claims : 1. A package made by the deep drawing method, comprising a container part (2) and a lid (3) , the edge of the container part (2) comprising an inner wall (2a) , the upper part of the inner wall (2a) having an upper edge inclined outwards from it, and an outer wall (2b) inclined downwards from the outer edge of the upper edge; the edge of the lid (3) having an upwardly inclined inner wall (3a) , the upper part of said inner wall (3a) having an upper edge inclined outwards from it, and an outer wall (3b) inclined downwards from the outer edge of the upper edge, whereby the container part (2) and the lid (3) may be laid one on top of the other so that they are substantially tightly sealed against each other, c h a r a c t e r i z e d in that at least one pair of curved parts (2c, 3c) is arranged on the outer wall (2b) of the container part (3) and on the outer wall (3b) of the edge of the lid (3) , the contact- ing surfaces of said curved parts being substantially of the same shape and size, and, upon the package (1) being closed, substantially in the same position. 2. A package as claimed in claim 1, c h a r ¬ a c t e r i z e d in that at least two pairs of curved parts (2c, 2d, 3c, 3d) are arranged on the outer wall (2b) of the container part (3) and on the outer wall (3b) of the edge of the lid (3) , the contacting surfaces of said curved parts being substantially of the same shape and size, and, upon the package (1) being closed, substantially in the same position. 3. A package as claimed in claim 1 or 2, c h a r a c t e r i z e d in that at least one pair of curved parts (2c, 3c) is inwardly curved. 4. A package as claimed in claim 2 or 3, c h a r a c t e r i z e d in that the curved parts (2c, 2d, 3c, 3d) are curved to the opposite directions. 5. A package as claimed in any one of the pre¬ ceding claims, c h a r a c t e r i z e d in that the curved parts (2c, 2d, 3c, 3d) are substantially shaped like the curve of a circle. 6. A package as claimed in any one of the pre¬ ceding claims, c h a r a c t e r i z e d in that in the lower part of the outer wall (2b) of the edge of the container part (2) and in the lower part of the outer wall (3b) of the edge of the lid (3) , there are flanges (2e, 3e) inclined outwards from the outer walls (2b, 3b) .

Inventors: AROMAA JUHANI, SAARINEN JYRKI, AROMAA, JUHANI, SAARINEN, JYRKI
Applicants: AROMAA JUHANI, SAARINEN JYRKI, SATATUOTE OY, AROMAA, JUHANI, SAARINEN, JYRKI
Application year: 1995
Main classification: B65D43
IPC codes: B65D43