EP2668868B1 - Stiffening element for a backpack and backpack with such a stiffening element - Google Patents

Description

The present invention relates to a backpack with a stiffening element. From the US 5,320,262 A is already known a backpack, which has a grid as a stiffening element, which may also be made of wood and is fully inserted in a closable bag. This document does not show a strip-shaped stiffening element, the surface of which is protected against weathering with a wood preservative, preferably linseed oil, the stiffening element engaging only in the upper portion and the lower portion of an insertion pocket and the central portion of the stiffening element being visible.

From the DE 199 32 498 A1 is a stiffening element made of wire, which is partially exposed. The wire-shaped stiffening element has a plurality of support members in its corner areas, which engage in receiving chambers. For this purpose, the stiffening element in the corner regions, for example, a double-T-shaped configuration.

In the prior art support and stiffening elements are known which serve to stiffen a backpack and in particular the back of a backpack. In principle, embodiments are known in which the backpack is fastened by additional fastening elements on a frame-shaped stiffening element, for example in the form of a Kraxe. But there are also known stiffening elements, which are preferably integrated into the backpack and in particular in the back part.

Such stiffening elements integrated in the backpack are usually made of metal or plastics. One advantage of metal is its high strength, which makes it possible to produce filigree stiffening elements. Although such metallic stiffening elements basically fulfill their function sufficiently, these metallic and often thin metal components have sharp edges and corners. The sharp edges and corners result in movement or stress that the envelope of the backpack, which usually consists of flexible fabrics, can be scoured, cut or pierced. Furthermore, there is a risk of injury to the user.

As a countermeasure, it is also not possible to make the stiffening element made of metal simply thicker and thus avoid the formation of sharp edges, since in this case the stiffening element would become too heavy and too stiff due to the high specific gravity of metals. Consequently, it is necessary to round the thin corners and edges of stiffening elements by Aufkantungen so that there are no possibilities of damage to the backpack material or injury to the user. Depending on the effort that needs to be done to post-cure the stiffeners, so does the cost of production. A not to be neglected aspect is the deformability of metallic stiffening elements due to greater load. However, metallic materials do not enjoy a good reputation for sustainability in resource use, especially when made of lightweight aluminum.

A common alternative today for the production of stiffening elements for backpacks is the use of plastics or composite materials. These materials have quite advantages over metallic stiffening elements. So they can be produced in almost any shape and have a significantly lower weight. Also plastics do not have a good reputation regarding the sustainability in the use of resources and the recyclability at the end of the life cycle of the backpack and thus the integrated stiffening element. In addition to the ecological problems, the use of plastics also entails mechanical disadvantages. A common problem with plastics is the tendency to stress cracking due to stress during use and residual stress states. The source of residual stress states lies in the production process of the plastic parts, in particular the injection molding process. The high load of the backpack when carrying stems from the fact that the wearer does not move completely linearly while walking, but both horizontal and vertical accelerations occur. Due to the inertia of the load carried these accelerations cause shocks, which are comfort-reducing transmitted to the carrier. Ideally, a stiffening element absorbs these shocks by resilient movements and thus contributes significantly to the wearing comfort. However, this also means that the stiffening element is subject to constant stress. This continuous load, together with residual stress states from the production of the stiffening element, can then lead to component failure, ie to fatigue and finally to breakage of the stiffening element.

Also disadvantageous is the only insufficient resistance of plastics to UV light irradiation, conditions such as occur, for example, in direct sunlight. Rucksacks are mainly worn outside closed rooms and are therefore subject to usage due to high UV radiation exposure. In the mountains, a frequent environment of use, the radiation intensity increases due to the thinner altitude air additionally. The irradiation of plastics with UV radiation leads not only to a color change but also to a change in the mechanical material properties that embrittle plastics. This also favors the component fatigue described above and the subsequent failure.

Against this background, it is the object of the present invention to provide a backpack with an improved stiffening element that can be manufactured in a cost-effective and resource-saving manner compared with the known stiffening elements and at the same time eliminates the mechanical deficiencies of the known devices.

According to the invention, this object is solved by the features of claim 1. Preferred embodiments will be apparent from the dependent claims.

When indicating directions and in particular component portions of the subject invention, terms such as "top" or "bottom" in the following description of the invention are used in the manner as they are in a functional application of the subject invention, d. H. carrying a backpack by a wearer in a vertical orientation.

According to the invention, the stiffening element is made of wood or wood products, ie from a renewable raw material. The use of renewable resources for a stiffening element of a backpack contributes to a resource-saving end product. The disposal or recyclability at the end of the life cycle is significantly improved with the use of renewable resources.

According to the invention, the stiffening element is made of wood or wood products. One reason for this is that wood has a high rigidity at comparatively low density. In addition, wood can permanently remove repetitive bending stress with little creep. Preferably, in the stiffening element according to the invention, the fibers of the wood run parallel to the largest longitudinal extent of the stiffening element. Another reason for the preference of wood is the easy machinability. Particularly advantageous is the use of at least two, preferably a plurality of individual with wood layers that are interconnected. These are preferably permanently connected together with a suitable glue or connector. A layer number of 5 to 7 laminated wood layers has proven to be particularly advantageous. The individual layers preferably have a layer thickness of 1.5 mm.

The stiffening element preferably has a flat rectangular cross-section. Stiffeners with a flat rectangular cross section are easier to work out, for example by sawing, from a larger workpiece of the raw material than cross sections of other dimensions. In cross-sections with other shapes, such as round or oval shape, after a first cut, another processing step, such as milling or turning, required to obtain the final shape. In the present invention of a stiffening member having a flat rectangular cross section, therefore, the production cost is lowered.

According to the invention, the individual large-area, preferably rectangular, wooden layers are first laid one above the other, with a suitable connector, in particular adhesive or glue, being introduced between the layers to be joined. The desired permanent connection of the individual layers and the inventive shaping takes place simultaneously in a further step by applying a flat pressing force on the
layered layers, especially using a thermal component. The specific shaping is realized by the use of appropriately trained press top and bottom parts of the pressing tool. After the connector has hardened, a flat workpiece shaped in the form according to the invention has been produced from the connected large-area layers. In a further step, individual stiffening elements are then preferably separated in strips from the workpiece by means of a sawing device, before the surface treatment and sealing, including edge processing of the individual stiffening element, takes place in a last step. Preferably, the edge is broken with a radius of 4 mm in order to avoid damage and injury to the backpack material and the wearer.

Depending on the application, it makes sense that the width of the stiffening element can be from one centimeter to the maximum width of the back. Very wide stiffening elements can be used especially if only one stiffening element is provided for a backpack. The width of the stiffening element is limited by the width of the back part. Narrower stiffening elements are mainly used in backpacks which have a plurality of stiffening elements.

According to an advantageous embodiment, the thickness of the stiffening element is from one millimeter up to 30 millimeters. The ease of processing compared to metal stiffening elements and the cross section of the stiffening element made of renewable raw materials also makes it possible to round off edges or corners at low cost or to provide them with a phase, for example. Due to the cross-sectional dimensions, it is ensured that the material of the backpack on which the stiffening element rests is neither scoured, cut or punctured. There is also a significantly lower risk of injury for the user. In addition, depending on the width and thickness of the stiffening element, its mechanical properties can advantageously be changed and adapted to the requirements.

Depending on the application form, it makes sense that the stiffening element springs in different degrees depending on the cross-sectional dimensions of the stiffening element and thus can be adapted to the comfort requirements of the user the wearing properties of the backpack. The greater the width and thickness of the cross section, the stiffer the stiffening element becomes. In general, it can be determined that the stiffening element has to be all the stiffer, the heavier the load to be transported in the backpack, not least to prevent a fracture of the stiffening element. Due to the low specific density of renewable raw materials compared to metals, in particular the preferred material wood, an adaptation of the cross section of the stiffening element is readily possible, without increasing the weight excessively. In addition to the required stiffness for removing the load is the
Stiffening element depending on the cross-sectional dimensions of different degrees resilient. This allows the wearing properties of the backpack to be adapted to the user's comfort requirements. In practice, it has been found that a thickness of one millimeter, in particular with wide stiffening elements, up to a thickness of 30 millimeters, especially when using narrow stiffening elements, covers the necessary for the user spectrum of suspension hardness for the stiffening element of a backpack.

The spine of the human body has a double S-shaped curvature. The shape of the present invention is optimized based on the anatomical shape of the wearer so that the stiffener has an upper portion, a middle portion and a lower portion, the upper portion having an S-shaped bend and the lower portion having a kink. Shaped in such a way, the stiffening element brings the backpack into shape so that its back follows the course of the double S-shaped curvature of the spine. This significantly increases the wearing comfort. On the one hand, the support surface between the back and back of the wearer is increased. Pressure points as a result of punctiform contacts between the back and back are thus avoided. On the other hand, the back may be close to the back of the wearer. So it is possible to carry the load closer to the body in the backpack. As a result, the center of gravity of the load is located less far from the spine than would be the case for straight stiffeners with back-to-back clearance. The distance between the spine and the center of gravity of the load in the backpack creates a moment which the wearer must counteract so as not to fall backwards. As the distance between the spine and the center of gravity of the load decreases, so does the moment applied to the wearer's body. This makes it possible for the wearer to carry the load more comfortably because it must counteract a lower load torque. The shape can be easily achieved by using the material according to the invention.

To protect the wearer as well as the longevity of the backpack, the surface of the stiffening element is smooth in an advantageous embodiment. Through the use of wood preservatives, preferably linseed oil, an effective protection against weathering, especially moisture, is ensured. The use of linseed oil has the advantage that the linseed oil layer can be renewed at any time by the user by rubbing the stiffening element with linseed oil in case of damage to the protective layer or a wear due to use. In contrast to products containing synthetic resin, a coating with linseed oil does not burst when exposed to moisture or UV radiation. Also, in the treatment with linseed oil no pretreatment of the surface, for example by grinding or the like must be done. Advantageously, it turns out that the preferred material wood, has a high resistance to UV radiation. This causes only one some discoloration of the surface, which, however, has no significant influence on the mechanical properties.

The pocket is closed on one side and open on the other side. The open side of the pocket can be opened and closed again with a slide-in pocket closure. A preferred embodiment of the insertion pocket closure provides for the use of a hook and loop fastener. One possible embodiment is the formation of the insertion pocket closure as a flap provided with a hook-and-loop fastener. However, other closures are conceivable, for example by buttons or a zipper.

In that the stiffening element can be pulled out of the pocket and can be replaced by another stiffening element ensures that after opening the Einschubtaschenverschlusses the previously described different hard or stiff stiffening element to adjust the comfort of wear by the user without tools against another stiffening element can be replaced ,

The invention provides that the insertion pocket is partially recessed and the stiffening element engages only in the upper portion and the lower portion in the insertion pocket and in particular the central portion of the stiffening element remains visible. In addition to imprints for a visible marking of the stiffening element, a carrying device of the backpack can also be attached to this visible stiffening element. This can be done for example by a tubular bag open on both sides of the carrying device. The tubular bag includes the part of the visible stiffening element.

Fig. 1 :

Eine Aufsicht des erfindungsgemäßen Aussteifungselementes;

Fig. 2:

Eine seitliche Ansicht des erfindungsgemäßen Aussteifungselementes;

Fig. 3:

Die Anatomie einer menschlichen Wirbelsäule;

Fig. 4:

Eine seitliche Ansicht eines erfindungsgemäßen Rucksacks;

Fig. 5:

Eine vereinfachte Ansicht einer Rückenpartie eines Rucksacks, welcher nicht Teil ausmacht der vorliegenden Erfindung.

Fig. 6:

Eine Ansicht der Rückenpartie des erfindungsgemäßen Rucksacks mit einer Tragevorrichtung;

Fig. 7:

Eine perspektivische Ansicht eines erfindungsgemäßen Aussteifungselementes; und

Fig. 8:

Ein Herstellungsverfahren der Aussteifungselemente mit seinen einzelnen Fertigungsschritten.

Further features and advantages of the subject matter of the invention will become apparent from the following description of specific embodiments with reference to FIGS. Show it:

Fig. 1:

A plan view of the stiffening element according to the invention;

Fig. 2:

A side view of the stiffening element according to the invention;

3:

The anatomy of a human spine;

4:

A side view of a backpack according to the invention;

Fig. 5:

A simplified view of a back part of a backpack, which does not form part of the present invention.

Fig. 6:

A view of the back part of the backpack according to the invention with a carrying device;

Fig. 7:

A perspective view of a stiffening element according to the invention; and

Fig. 8:

A manufacturing process of the stiffening elements with its individual manufacturing steps.

Fig. 1 shows a stiffening element (1) with the tripartite in an upper portion (5), a central portion (10) and a lower portion (15). The fiber path (A) of the wood is aligned along the longitudinal extension of the stiffening element (1).

Fig. 2 shows a stiffening element (1), with the tripartite in an upper portion (5), a middle portion (10) and a lower portion (15). The upper portion has (5) an S-shaped bend (20), the middle portion (10) is straight and the lower portion (15) has a kink (25).

Fig. 3 shows the anatomy of a spine (65) with the double S-shaped curve (70). Optimized is the shape of the stiffening element (1) with an S-shaped bend (20) in the upper portion (5), a rectilinear middle section (10) and a bend (25) in the lower section (15). This shape of the stiffening element (1) causes the back part (45) over the entire surface of the back of the wearer. In this way, bruises are avoided and at the same time the load of the backpack (40) worn as close to the body. As a result, the moment occurring due to the distance between the back and load is minimized. This is decisive for the wearing comfort, since otherwise the wearer must counteract this moment by force application.

Fig. 4 shows an embodiment variant of the backpack (40) according to the invention with the stiffening element (1). In the illustrated embodiment, the backpack (40) has an insertion pocket (30) which has a recessed portion. The stiffening element (1) is designed as a visible stiffening element (2) in the middle section (10). In the upper section (5) and in the lower section (15), the stiffening element is not visible (3) inserted into the insertion pocket (30). Another alternative embodiment (not shown), which does not form part of the present invention, does not provide a recessed portion of the insertion pocket (37). In both embodiments, the insertion pockets (30) have a closed side (31) and an open side (32). The open side (32) of the insertion pocket (30) is provided with a slide-in pocket closure (35), which preferably opens with a hook-and-loop fastener (36) and can be closed again. In principle, it is irrelevant whether the open side (32) and the insertion pocket closure (35) are located at the top or bottom of the insertion pocket (30). At the in Fig. 4 illustrated embodiment, the open side (32) and the insertion pocket closure (35) are mounted below, whereas the closed side (31) of the insertion pocket (30) is above. It is also conceivable a third embodiment with Einschubtaschenverschlüssen (35) on two opposite open sides (32) of the insertion pocket (30).

In Fig. 4 a backpack (40) with carrying device (50) is shown. At the recessed portion of the insertion pocket (37), the visible stiffening member (2) is carried in a tubular bag (60) attached to the carrying device (50), and thus the carrying device (50) is attached to the back part (45).

Fig. 5 shows the back portion (45) of a variant with two stiffening elements (1) and insertion pockets (30), which does not form part of the present invention. Notwithstanding the illustrated embodiment, however, other (not shown) variants with only one stiffening element (1) are conceivable or more than two stiffening elements (1), which form part of the present invention, insofar as they fall within the scope of the claim. For better clarity, the carrying device (50) in Fig. 5 not shown. In the illustrated embodiment, the insertion pocket (30) is not recessed. The closed side (31) is located at the top of the back (45), the open side (32) together with the insertion pocket closure (35) below. Not shown here are embodiments with an open side (32) and a slide-in pocket closure (35) on top of the back (45) or variants with two open sides (32) and two Einschubtaschenverschlüssen (35) top and bottom of the back (45).

Fig. 6 shows the complete back part (45) with the support device (50) of a backpack (40) with wrapping (55) and an additional hip belt (53) and visible stiffening elements (2). The non-visible stiffening elements (3) are located in the insertion pocket (30). In the illustrated variant, two stiffening elements (1) are used.

Fig. 7 shows a stiffening element (1) in the preferred embodiment of wood and its fiber profile (A), which extends along the longitudinal extent of the stiffening element.

The production method of the stiffening elements 1 according to the invention with its individual manufacturing steps is shown in FIG Fig. 8 shown. First, the individual large-area and rectangular-shaped wood layers are superimposed, with a suitable adhesive or glue is introduced between the layers to be joined. The desired permanent connection of the individual layers and the shaping according to the invention take place simultaneously in a further step by applying a flat pressing force to the layered layers. The specific shape in the side profile - the upper portion 5 has the S-shaped bend 20, while the middle portion 10 is rectilinear and the lower portion 15 has a kink 25 - is realized by the use of appropriately trained Pressober- and -unterteil of the pressing tool. After the connector has hardened, a flat workpiece shaped in the form according to the invention has been produced from the connected large-area layers. In a further step, individual stiffening elements 1 are then separated in strips from the workpiece by means of a sawing device. In a final step (not shown), the surface treatment and sealing including edge processing of the single stiffening element 1 takes place.

LIST OF REFERENCE NUMBERS

1

stiffening

2

Stiffening element visible

3

Stiffening element not visible

5

Upper section

10

Middle section

15

Lower section

20

S-shaped bend

25

kink

30

insertion pocket

31

closed page

32

open side

35

Insertion pocket closure

36

velcro fastener

37

Sawed out section of the sling pocket

40

backpack

45

back part

50

carrying device

53

hip belt

55

wrapping

60

Tubular bag

65

spinal column

70

Double S-shaped curvature

A

grain

Claims (6)

1. Backpack (40) with a back part (45) and a stiffening element (1), wherein the stiffening element (1) is made from wood or wood products, the stiffening element (1) is stripe-shaped and comprises an upper section (5), a middle section (10) and a lower section (15), wherein the upper section (5) has an S-shaped bend and the lower section (15) has a kink, wherein the backpack (40) comprises a slide-in pocket (30) on the back part (45) and the stiffening element (1) can be accommodated in the slide-in pocket (40), characterized in that the surface of the stiffening element (1) is protected against atmospheric influences by a wood preservative, preferably linseed oil, and the slide-in pocket (30) is recessed in part and the stiffening element (1) only engages in the upper section (5) and in the lower section (15) into the slide-in pocket (30) and the middle section (10) of the stiffening element (1) is visible.
2. Backpack (40) according to one of the foregoing claims, characterized in that the stiffening element (1) has a flat rectangular cross-section.
3. Backpack (40) according to one of the foregoing claims, characterized in that the width of the stiffening element (1) can be from one centimeter to the maximum width of the back part (45).
4. Backpack (40) according to one of the foregoing claims, characterized in that the thickness of the stiffening element (1) can be from one millimeter to 30 millimeters.
5. Backpack (40) according to one of the foregoing claims, characterized in that the surface of the stiffening element (1) is made smooth.
6. Backpack (40) according to claim 1, characterized in that the slide-in pocket (30) is provided with slide-in pocket closure, preferably in the form of a Velcro fastener, so that the slide-in pocket (30) can be opened and closed.

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