Packaging element placed over an edge of an object for its protection against shocks, and corresponding assembly and method

Abstract: The present invention comprises an assembly of a substantially block-shaped object (O) and four packaging elements (1) for placing over one or more edge parts formed by a short edge of the object, wherein the packaging elements are each manufactured from one piece of at least slightly flexible foamed plastic and each comprise: a first engaging surface (2) for engaging on a surface of the object which extends on one end of the edge substantially transversely thereof, and a second engaging surface (4) for engaging on a second surface of the object which extends substantially parallel to the first surface on the other end of the edge.

Description: The present invention relates to an assembly of a relatively thin and substantially block-shaped object having shorter and longer edges and four packaging elements for placing over said shorter edges of the object and protecting said shorter edges, wherein the packaging elements are each manufactured from one piece of at least slightly flexible foamed plastic and each comprise: a first engaging surface for engaging on a surface of the object which extends on one end of the edge substantially transversely thereof, and a second engaging surface for engaging on a second surface of the object which extends substantially parallel to the first surface on the other end of the edge. Relatively vulnerable objects, for instance a housing with electronic components such as medical equipment, parts for photocopiers, video recorders and personal computers, must be provided in a cardboard box with buffer elements at the corners or edge parts thereof in order to absorb the forces occurring in a fall from a height of 70 cm. Such packaging elements are usually manufactured from foamed plastic, such as polystyrene. Polystyrene has the drawback however that it is rather brittle and, partly for this reason, not re-usable. In addition, emission of environmentally unfriendly gases can take place in the production of polystyrene. Known from the American patent 3.695.421 is a packaging assembly of an object and four packaging elements that are placed over the short edges of the substantially block-shaped object. The four packaging elements are placed with simple handle portions over the edges of the object, after which the assembly is placed in a container. Although the packaging elements have the advantage that they cover the (short) edge parts of the object, they have the drawback that for every new object to be handled, for example a new electronic device, a new mould adapted to the new device has to be developed, which implies a considerable investment. Furthermore the known assembly needs a large amount of packaging material, of which a large part is not effective for absorbing shocks and vibrations. Further known from the French patent specification 2.651.747 is a packaging assembly of a substantially block-shaped object and two packaging elements that are slightly expandable. These packaging elements cover two full side surfaces of the block-shaped object leaving the edges of the object exposed or uncovered. This not only implies a unnecessary large amount of packaging material to be used, which is undesirable from the point of view of environment, but also renders the block-shaped objects vulnerable to damages of the edge parts thereof. Moreover the complicated actions or operations needed to handle the packaging process, i.e. arrange the packaging elements over long as well as short edges of the object, render this packaging assembly practically unusable for existing practice of quickly packaging such objects. It is an object of the present invention to solve these problems. The present invention therefore is characterized in that each of the for packaging elements is provided with an expandable structure which only extends between the first engaging surface and the second engaging surface and is substantially meander-shaped. The assembly, packaging elements and method according to the present invention permit to use the same packaging elements for objects of different sizes within certain limits, while still covering edge parts of the block-shaped objects. Furthermore, the present invention facilitates the recycling of such packaging elements, because sorting the packaging elements according to the size of the corresponding object can be dispensed with. Besides, as the expansion of the expandable structure of the packaging elements is only in one direction, i.e. in the direction of the (short) edges to be covered, it is also easy to (automatically) package the block-shaped object. The present invention further provides a packaging element for use in the above-mentioned assembly, wherein preferably used as foamed plastic is a polypropylene, which is at least slightly flexible and less brittle than polystyrene and thus well suitable for re-use. Because these packaging elements are re-usable, they can be used first of all by a manufacturer of empty housings for electronic equipment and subsequently by a manufacturer who fits the electronic components in such housings. The foamed polypropylene has preferably a density of 18-35 grams per liter, even more preferably 22-28 grams per liter, even more preferably 24 grams per liter. In a preferred embodiment of the present invention a packaging element is provided, wherein the meander-shaped structure has a length of 100-200 mm, which length can be enlarged by about 50 mm by stretching and which length preferably amount to about 160 mm. In a preferred embodiment of the present invention a packaging element is provided having such dimensions and thickness that the bottom and a side of a block-shaped object having a weight of 15 kg experiences a maximum acceleration of respectively 37g or 30g during a fall from a height of 70 cm. The present invention further provides a method for packaging an object, wherein four packaging elements as mentioned above are placed successively over a short edge of the object, if necessary by slightly expanding each thereof and wherein the object is placed together with the packaging elements in a packing box. In a further preferred embodiment a method is provided wherein the object is a housing for a personal computer. In a further preferred embodiment a packaging element is provided wherein the meander structure comprises two or more U-shaped mutually connected parts. Further advantages, features and details of the present invention will be elucidated on the basis of the following description of a preferred embodiment thereof with reference to the annexed drawing, in which: fig. 1 shows by way of illustrating the method according to the present invention a top view of an object packaged by using four preferred embodiments of the packaging element according to the present invention; fig. 2 shows a perspective view of a packaging element of fig. 1; fig. 3 shows a side view from the inside of the packaging element of fig. 2; and fig. 4 is a sectional view along the line IV-IV of fig. 3. A substantially block-shaped object 0 (fig. 1) is provided at the corners, along the shortest sides or edges thereof, with four packaging elements 1 according to the present invention. Such an object 0 is pushed together with the four packaging elements 1 into a cardboard box in the usual manner, wherein the packaging elements 1 serve to absorb shocks or forces which occur if the cardboard box should happen to fall onto the ground from a determined height during transport. As shown particularly in fig. 2, a packaging element 1 comprises four engaging surfaces 2, 3, 4 and 5, wherein engaging surfaces 3 and 5 extend roughly in the same plane and engaging surfaces 2 and 4 are roughly parallel, are situated at a mutual distance and are roughly perpendicular to the surfaces 3 and 5. In the position designated with 1' the engaging surfaces 2-5 engage on substantially flat walls of the object 0, for instance a housing for a personal computer. The packaging element 1, which is preferably manufactured from foamed polypropylene which is slightly flexible and suitable for re-use, extends in four directions from the surfaces 2-5 over a distance d, so that the forces occurring in an unforeseen fall can be absorbed by this foamed plastic mass. The distance d depends on the density of the foamed plastic and the weight of the object 0. Extending between the engaging surfaces 2 and 5 are two meander-shaped parts 6 and 7 respectively which, since the plastic is slightly flexible, are stretched over a determined distance like a kind of concertina in order to adapt to the length of the side or edge of the object. The length L in non-stretched situation of the packaging element 1 is shown In fig. 3. In a first realized embodiment this dimension L amounts to 160 mm, wherein it can be stretched over a distance of 40-50 mm, and wherein the absorbing power of the foamed polypropylene with a density of 24 grams per litre remains preserved at such a stretch. With this realized embodiment, wherein the distance d amounted to 50 mm, drop tests over a drop height of 70 cm were performed out with a block-shaped object of 15 kg in weight. Acceleration transducers were placed on the object 0. The acceleration transducers placed on the bottom and side of the object recorded a maximum acceleration of respectively 37 g and 30 g over a period of respectively 24 and 27 milliseconds, wherein g is the gravitational acceleration. These measurements confirm the calculations made beforehand that the accelerations occurring with this embodiment amount to less than 40 g. The accelerations measured on the side, which are lower than the accelerations measured at the bottom, can be attributed to the absorbing power of the meander-shaped or zigzag-shaped parts of the packaging element which is increased by bending. In addition to the reduced use of material due to this meander shape as well as the possibility of stretching thereof, this absorbing bending is an added advantage of the packaging element according to the present invention. It is the expectation that with the packaging element according to the present invention (block-shaped) objects with a shortest side of 100-200 mm can be packed at a weight of the object of 10-30 kg. Depending on the weight and the dimension, foamed polypropylene with a density of 18-35 grams per litre can be used. In accordance with set requirements the distance d (and the distance L) of the packaging element according to the present invention can of course also be varied. In addition to re-usable polypropylene, polyethylene can likewise be used with a slightly greater mass due to the smaller absorbing power, or another slightly flexible plastic which can be stretched and which has sufficient absorbing power, such as for instance possible forms of polystyrene. The present invention is therefore not limited to the above described embodiment; the requested rights are determined in the first instance by the following claims.

Claims: Assembly of a relatively thin and substantially block-shaped object (O) having shorter and longer edges and four packaging elements (1) for placing over said shorter edges of the object and protecting said shorter edges, wherein the packaging elements are each manufactured from one piece of at least slightly flexible foamed plastic and each comprise: a first engaging surface (2) for engaging on a surface of the object (O) which extends on one end of the edge substantially transversely thereof, and a second engaging surface (4) for engaging on a second surface of the object (O) which extends substantially parallel to the first surface on the other end of the edge, characterized in that each of the four packaging elements (1) is provided with an expandable structure (6,7) which only extends between the first engaging surface (2) and the second engaging surface (4) and is substantially meander-shaped. Packaging element for use in an assembly as claimed in claim 1, wherein the foamed plastic is polypropylene. Packaging element as claimed in claim 2, wherein the foamed polypropylene has a density of 18-35 grams per litre. Packaging element as claimed in claim 3, wherein the density amounts to 22-28 grams per litre, preferably 24 grams per litre. Packaging element as claimed in any of the claims 1-4, wherein the meander-shaped structure has a length of 100-200 mm, which length can be enlarged by about 50 mm by stretching. Packaging element as claimed in claim 5, wherein the length amounts to about 160 mm. Packaging element according to any of the preceding claims, having such dimensions and thickness that the bottom and a side of a block-shaped object (O) having a weight of 15 kg experiences a maximum acceleration of respectively 37g and 30g during a fall from a height of 70 cm. Method for packaging an object, wherein four packaging elements as claimed in any of the claims 2-7 are placed successively over a short edge of the object (O), if necessary by slightly expanding each thereof and wherein the object is placed together with the packaging elements in a packing box. Method as claimed in claim 8, wherein the object is a housing for a personal computer. Packaging element as claimed in any of the claims 2-7, wherein the meander structure comprises two or more U-shaped mutually connected parts (6,7).

Inventors: FREDRIKS JAN, FREDRIKS, JAN
Applicants: BESTPAK HOLDING BV, BESTPAK HOLDING B.V.
Application year: 1996
Main classification: B65D81
IPC codes: B65D81