Volume expansion element

Abstract

 Volume expansion element (1) for a piece of luggage (2) comprising a longitudinal closure element (3) with a first closing side (4) and a second closing side (5) and a gusset (6) which is in connection with said first closing side (4) and said second closing side (5) and extends between said first closing side (4) and said second closing side (5), wherein in a non-expanded state the first closing side (4) is in direct engagement with the second closing side (5) and wherein in an expanded state the first closing side (4) and the second closing side (5) are disengaged from each other such that they are positioned at a distance (D) to each other, which distance (D) is bridged with said gusset (6). Further at least one tensile element (7) is in connection with the first closing side (4) and the second closing side (5) such that with the tensile element (7) a tightening force can be provided between said first closing side (4) and said second closing side (5) in the expanded state.

Description

TECHNICAL FIELD

[0001] The present invention relates to a volume expansion element for a piece of luggage according to the preamble of claim 1 and to a piece of luggage comprising such a volume expansion element according to the preamble of claim 12.

PRIOR ART

[0002] Volume expansion elements in the technical field of luggage are well known. Such volume expansion elements serve to expand the volume of a piece of luggage, whereby the user decides, if it an expansion is necessary or not. Typically such expansion elements comprises a gusset and a zipper, whereby when the zipper is opened the gusset is in its expanded state and when the zipper is closed the gusset is in its non-expanded state.

[0003] The volume expansion elements as known from prior art have the drawback that the degree of expansion is limited to a few centimeters. This enhances the volume, but usually not to a degree as it is required by the user.

[0004] Larger expansions require mechanical parts to operate as a variable extension between the two suitcase shells to stabilize the two shells against each other so that the case remains stable on four wheels. These mechanical adjsutments are heavy, expensive, source for mechanical failure and difficult to operate.

SUMMARY OF THE INVENTION

[0005] It is therefore an object of the present invention to provide a volume expansion element that can be expanded according to the intention of the user, in particular to a larger degree. In particular the volume expansion shall have no negative effect on the overall stability of the piece of luggage in particular to allow maneuvering on four wheels under the provision that the overall weight of the piece of luggage without items to be carried will be optimised.

[0006] This object is solved by the volume expansion element according to claim 1. Accordingly a volume expansion element for a piece of luggage comprising a longitudinal closure element with a first closing side and a second closing side and a gusset which is in connection with said first closing side and said second closing side and extends between said first closing side and said second closing side. The volume expansion element can take two states, namely an expanded state and a non-expanded state. In the non-expanded state the first closing side is in direct engagement with the second closing side and in the expanded state the first closing side and the second closing side are disengaged from each other such that they are positioned at a distance to each other. Said distance is bridged with said gusset. The distance defines the degree of expansion. At least one tensile element is in connection with the first closing side and the second closing side such that with the tensile element a tightening force can be provided between said first closing side and said second closing side in the expanded state.

[0007] With the tightening force the piece of luggage can be compressed such that the user is provided with a piece of luggage having a firm structure in the expanded state. The tightening force acts such that the closing sides will be tightened together. In particular it is possible to compensate shearing movement in the gusset.

[0008] The gusset is preferably provided as flexible gusset such as a nylon, coated nylon, coated cotton, polyester or coated polyesterfabric.

[0009] The connection between the gusset and said closing sides is preferably a direct and firm connection, however, it can also be indirect for example via the piece of luggage. In a very preferred embodiment the closing sides, the gusset and the tensile element are connected to the piece of luggage with the same connection means, preferably with sewing stitches riveting, gluing and/or welding.

[0010] Preferably the tensile element is arranged relative to said closing sides and said gusset such that in said non-expanded state the tensile element is embedded in said gusset and said engaged closing sides. In other words: the tensile element is in the non-expanded state arranged within said closing sides and said gusset. The gusset and the closing sides in the non-expanded state limit a space or loop in which said at least one tensile element is located. This has the advantage that the tensile element is hidden in the non-expanded state and therefore the risk of damaging the tensile element will be reduced. Further the tensile element is in this embodiment preferably arranged such that in the expanded state it is accessible from the outside as seen from the interior space of the piece of luggage. This has the effect that the user can act on the tensile element after packing.

[0011] The gusset extends thereby towards and into the interior space of a piece of luggage.

[0012] Alternatively or additionally to the arrangement as just mentioned the tensile element is arranged behind the gusset on the opposite side of said closing sides. The tensile element is thereby oriented towards the interior space.

[0013] The tensile element can be provided in various variants. The various variants have in common that the tensile element provides a tensile force from the first closing side to the second closing side.

[0014] Preferably the tensile element has the shape of a strip-like element extending transverse over the gusset from the first closing side to the second closing side.

[0015] In a preferred variant the tensile element is a strap with at least one length adjusting element with which the length of the strap can be adjusted and thereby a tensile force between the closing sides can be provided. The length adjusting element is preferably a ladder lock.

[0016] In a further preferred variant the tensile element is an elastic strap and/or a spring-like band providing a tensile force between the closing sides.

[0017] In a further variant several bearing points are arranged at a distance to each other in the vicinity of the first closing side and the second closing side. A tensile band is then guided trough said bearing points whereby the tensile band connects alternatively the bearing points of the first closing side and bearing points of the second closing side. When the tensile element is put under tension the first closing side and the second closing side will be moved together. The bearing point is preferably an eyelet. Hence a similar system as a shoe lace system can be provided.

[0018] The different variants of the tensile elements can be used in one single volume expansion element.

[0019] Preferably the tensile element is, in particular apart from its end regions, separate from said gusset. The end regions are typically in connection with the gusset. The term "separate" means that there is preferably no connection between the tensile element and the gusset in a region between said first closing side and said second closing side. This region is the region that is visible in the expanded state.

[0020] Alternatively it may also be possible that the tensile element is an integral part of the gusset or that the tensile element is provided by said gusset. In these two cases the gusset is preferably elastic or comprises an elastic portion.

[0021] Preferably the gusset is provided as non-interrupted gusset which completely bridges the gap between the first closing side and the second closing side. Hence the gusset is, when used in a piece of luggage, a part of the wall defining the housing. The gusset is preferably provided such that no access to the interior space of the piece of luggage can be provided. Alternatively the gusset can also be provided such that it is part of closure element providing access to the interior space of the piece of luggage; preferably a zipper can be arranged in connection with said gusset.

[0022] Preferably the width of the gusset between the first closing side and the second closing side in the expanded state is larger than 5 cm, in particular larger than 8 cm, preferably larger than 12 cm. This width defines also the amount of expansion.

[0023] Preferably the longitudinal closure element is a zipper, wherein the first closing side comprises a first row of teeth, wherein the second closing side comprises a second row of teeth and wherein a slider is present between said first row of teeth and said second row of teeth. In the non-expanded state the teeth of the first row engage with the teeth of the second row.

[0024] Preferably the first closing side and a first edge region of the gusset are connectable to a first housing part of a piece of luggage and the second closing side and a second edge region of the gusset are connectable to a second housing part of a piece of luggage. In a very preferred embodiment the first closing side and the first edge region are connected along the same axis to the housing. The same applies to the second closing side and the second edge region.

[0025] Preferably the first closing side and the second closing side extend along the edge regions of the gusset. Hence they limit the gusset towards its side. At a starting point between said edge regions the first closing side and the second closing side go together. At this starting point the zipper is located in the non-expanded state.

[0026] Preferably the closing sides are in a firm connection with the gusset in a starting segment of the longitudinal closure element. The starting segment extends from said starting point to the regions in which the closing sides extend parallel to the edge regions. Preferably the closing sides are sewn to the gusset in said starting segment.

[0027] A piece of luggage comprises a housing with a first housing part and a second housing part and a volume expansion element according to the description above. Preferably the first closing side is in connection with the first housing part and the second closing side is in connection with the second housing part. Said gusset bridges the gap or distance between said first housing part and said second housing part.

[0028] In the non-expanded state the closing sides engage with each other and the gusset extends from the closing side towards and into the interior of the piece of luggage. In the expanded state the gusset extends between the first housing part and the second housing part and provides a wall-like structure between the two housing parts. Furthermore the at least one tensile element extends also between the first housing part and the second housing part. The gap or distance between the first housing part and the second housing part is thereby bridged with said gusset and said at least one tensile element.

[0029] Preferably the housing comprises a front wall, a back wall, a top wall, a bottom wall and side walls, wherein said front wall and said back wall forming major faces of the housing, wherein said side walls forming side faces of the housing and extend between the front wall and the back wall and wherein said top wall and said bottom wall forming top and bottom ends of the housing and extend between the front wall and the back wall. The volume expansion element extends in a circumferential manner around said housing in the top wall, the side walls and the bottom wall. Therefore the top wall, the side walls and the bottom wall are divided and linked with the volume expansion element that is in connection with said walls.

[0030] In a preferred embodiment the first housing part is a front shell comprising at least the front wall and the second housing part is a back shell comprising at least the back wall. Front shell and back shell are connected with the volume expansion element. The first closing side, the gusset and the tensile element are in connection with the front shell, whereas the second closing side, the gusset and the tensile element are in connection with the back shell.

[0031] The shells are preferably rigid shells which are more rigid than the gusset.

[0032] In a preferred embodiment the first housing part comprising the front wall and parts of said side wall, parts of said top wall and parts of said bottom wall and the second housing part comprising the back wall and parts of said side wall, parts of said top wall and parts of said bottom wall. The parts extending from the back wall and the front wall have preferably the same length, so that two similar shells can be provided. The volume expansion element is then connected to said parts and is therefore arranged centrically between the front wall and the back wall.

[0033] Preferably at least one of, in particular exactly one of, said tensile elements links the first housing part with the second housing part in the area of said bottom wall.

[0034] Further or alternatively at least one of, in particular exactly two of, said tensile elements links the first housing part with the second housing part in the area of each of said side walls.

[0035] Further preferably in the area of said top wall no tensile element is arranged.

[0036] In a very preferred embodiment exactly one tensile element is arranged in the region of the bottom wall, exactly two tensile elements are arranged in the region of each of the side walls and no tensile element is arranged in the region of the top wall.

[0037] Preferably in said front wall a closure element is arranged giving access to the interior space of said housing. With regard to this closure element it has to be noted that it is fully arranged in said front wall and that there is no interaction at all with regard to the volume expansion element. Hence the closure element is not in connection with the volume expansion element.

[0038] In a preferred embodiment a plate is arranged in said housing at the bottom end, which plate is in firm connection with one of said first housing part or said second housing part and extends in the expanded state over the gap between the first housing part and the second housing part. The plate is arranged in the interior of said housing and comes in contact with that side of the gusset facing towards the interior space. The plate has the advantage that it provides a support for the items in the interior space in case the piece of luggage stands upright.

[0039] The plate has a length such that it extends over the gap in the expanded state.

[0040] Preferably the piece of luggage comprises in the region of the bottom end wheels, in particular caster wheels. In the top end the piece of luggage preferably comprises a handle.

[0041] Further embodiments of the invention are laid down in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

Fig. 1

shows a detailed view of an embodiment of the volume expansion element according to the invention;

Fig. 2

shows a view of a piece of luggage with the volume expansion element according to figure 1, wherein the piece of luggage is in its non-expanded state;

Fig. 3

shows a view of a piece of luggage with the volume expansion element according to figure 1, wherein the piece of luggage is in its expanded state;

Fig. 4

a detailed view of Fig. 3; and

Fig. 5

a detailed view of the interior space at the bottom.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0043] Figure 1 shows a view of a volume expansion element 1 for a piece of luggage 2. The piece of luggage 2 here is shown as a trolley, but it can be any other piece of luggage, such as a duffle bag, a backpack, a suitcase, etc.. Hence, the volume expansion element 1 can be used in a wide variety of types of luggage in order to enhance the volume of the piece of luggage.

[0044] The volume expansion element 1 comprises a longitudinal closure element 3 and a gusset 6. The volume expansion element 1 comprises with a first closing side 4 and a second closing side 5. The gusset 6 is in connection with the first closing side 4 and the second closing side 5. The connection can be directly or via the piece of luggage. The gusset 6 extends between the first closing side 4 and the second closing side 5.

[0045] In an expanded state, as it is shown in figure 1, the first closing side 4 and the second closing side 5 are disengaged from each other such that they are positioned at the distance D to each other. The distance D, which can also be designated as gap, is then bridged with said gusset 6.

[0046] In a non-expanded state as it is shown in figure 2, the first closing side 4 is in direct engagement with the second closing side 5. Therefore there is no gap or distance between the first closing side 4 and the second closing side 5.

[0047] Furthermore the volume expansion element 1 comprises at least one tensile element 7 which is in connection with the first closing side 4 and the second closing side 5 such that the tensile element 7 can be used to provide a tightening force F between said first closing side 4 and said second closing side 5 in the expanded state. This means that the tensile element 7 as it is shown in figure 1 can be tightened such that the first closing side 4 will be moved against the second closing side 5 and vice-versa. This in order to tighten the piece of luggage 2 in the expanded state such that a compact structure can be achieved. Upon tightening of the tensile element 7 the distance D becomes smaller than in the maximal expanded state. The force of the tensile element 7 acts against the items which are stored in the interior space of the piece of luggage.

[0048] The tensile element 7 is arranged between said closing sides 4, 5 and said gusset 6 such that in said non-expanded state the tensile element 7 is fully embedded within said gusset 6 and side engaged closing sides 4, 5. The gusset 6 and the engaged closing sides 4, 5 provide closed loop or space in which said tensile element 7 is embedded. With reference to figure 1 this means that in case the first closing side 4 will be engaged with the second closing side 5 the tensile element 7 will be no longer visible, since it is then covered by the gusset 6 and said engaged closing sides 4, 5.

[0049] The tensile element 7 has the shape of a strip-like element. The strip-like element extends transverse over the gusset 6 from the first closing side 4 to the second closing side 5. The width of the strip-like element in is thereby smaller than the maximal distance D. The strip-like element can have various appearances.

[0050] In the present embodiment the tensile element 7 is a strap 8 with at last one length adjusting element 9. With the length adjusting element 9 the length of the strap can be adjusted and thereby a tensile force F can be provided between the closing sides 4, 5.

[0051] In the present case the length adjusting element 9 is a buckle that is arranged in connection with the strap 8. The strap 8 comprises here a first segment 28 which is in connection with the first closing side 4. Furthermore the strap 8 comprises a second segment 29 which is in connection with the second closing side 5. The first segment 28 and the second segment 29 are linked together with said length adjusting element 9, which has the shape of a buckle. In the present case the second segment 29 is in a firm connection with the buckle 9 and the first segment 28 forms a loop around the buckle 9. Thereby the second segment 29 comprises a free end 30 with which said change in distance of the strap 8 can be achieved. Thereby one can pull the free end 30 towards the second closing side 5 in order to provide tightening force.

[0052] As one can clearly understand the tensile element 7 can also be provided in other form, in particular as an elastic strap and/or a spring-like band. Both the elastic strap and the spring-like band provide a tensile force F. It is also possible to mix several embodiments of the tensile elements 7 in one piece of luggage 2.

[0053] In the present embodiment the tensile element 7 is a separate part from said gusset 6. This means that over the distance D there is no physical connection between the gusset 6 and the tensile element 7. However, in the end region 10 of the tensile element 7 there can be a connection between the tensile element 7 and the gusset 6 as well as with said first closing side 4 and said second closing side 5 depending on how the tensile element 7 is connected to the closing sides 4, 5 and the gusset 6.

[0054] In an alternative embodiment that is not shown in the figures the tensile element 7 is an integral part of the gusset or it can be provided by the gusset.

[0055] The gusset 6 is provided as a non-interrupted gusset which completely bridges the distance D or gap between the first closing side 4 and the second closing side 5. Hence in the expanded state the gusset 6 provides a part of the wall of the housing 18 of the piece of luggage 2.

[0056] The distance D is a preferred embodiment larger than 5 centimetres, in particular larger than 8 centimetres, preferably larger than 12 centimetres.

[0057] As it can be seen from figure 1 the longitudinal closure element 3 is a zipper. The first closing side 4 comprises a first row of teeth 10 and the second closing side 5 a second row of teeth 11. A slider 12 is present between said first row of teeth 10 and said second row of teeth 11. Upon movement of the slider 12 the row of teeth 10 and the row of teeth 11 can be engaged or disengaged.

[0058] With regard to the arrangement towards the interior space 27 of the piece of luggage 2 one can say that the longitudinal closure element 13 is the outermost element with regard to the tensile element 7 and said gusset 6. The gusset 6 is thereby preferably the innermost element and therefore the tensile element 7 is arranged between said longitudinal closure element 3 and said gusset 6.

[0059] In figure 1 the first closing side 4 and a first edge region 13 of the gusset 6 are connected to a first housing part 14 of the piece of luggage 2. The second closing side 5 and a second edge region 15 of the gusset 6 are in connection with a second housing part 16 of the piece of luggage 2. Likewise the tensile element 7 extends from the first housing part 14 to the second housing part 16 and is firmly connected to the housing parts 14, 16. In the preferred embodiments the first closing side 4, the first edge region 13 of the gusset and the tensile element 7 are connected in the same region with the first housing part 14. Likewise the second closing side 5 and the second edge region of the gusset as well as the tensile element 7 are connected at the same region with the second housing part 16. Preferably the tensile element 7, the gusset 6 and said closing sides 4, 5 are sewn with regard to the respective housing part 14, 16. Other connection means, such as riveting, gluing or welding are also possible. The connection means can also be combined with each other. In particular it may advantageous to use a rivet connection for the tensile element 7 in view of the forces that apply.

[0060] The longitudinal closure element 3 extends with its closing sides 4, 5 along the edge regions 13, 15 of the gusset. Furthermore the first closing side 4 and the second closing side 5 meet at the starting point 17 between said regions 13, 15. In the present case the starting point 17 is arranged in the middle of the gusset 6. The starting point 17 is also the end point for the zipper, when the volume expansion element 1 is in its expanded state. This is shown in figure 1. In case now the user would like to bring the volume expansion element 1 to its non-expanded state the slider 12 will be moved from the starting point 17 along the closing sides 4, 5 and thereby the latter will engaged. This is shown by an arrow C. The user has to move the slider 12 along arrow C in order to engage the first closing side with the second closing side.

[0061] In a starting segment 33 of the longitudinal closure element the closing sides 4, 5 are in a firm connection with the gusset 6. This starting segment 33 extends from said starting point 17 to the regions in which the closing sides 4, 5 extend parallel to the edge regions 13, 15 of the gusset 6. The end of the starting segment 33 is illustrated with reference numeral 34.

[0062] In figures 2 to 4 an embodiment of a piece of luggage 2 comprising said volume expansion element 1 as the described above is shown.

[0063] The piece of luggage 2 comprises a housing 18 with a first housing part 14 and a second housing part 15. The first housing part 14 and the second housing part 15 are connected with the volume expansion element 1. In the non-expanded state the first housing part 14 and the second housing part 15 are closer to each other than in the expanded state. The gap between the first housing part 14 and the second housing part 15 in the expanded state is, as described above, covered by the gusset 6.

[0064] In figure 2 the volume expansion element 1 is shown in its non-expanded state.

[0065] In figure 3 the volume expansion element 1 is shown in its expanded state. Thereby it can be seen that the gusset 6 extends fully over the distance D or the gap between the first housing part 14 and the second housing part 16. Also the tensile element 7 extends fully over the distance D between the first housing part 14 and the second housing part 16.

[0066] The housing 18 comprises, as it can be seen in figures 2 and 3 a front wall 20, a back wall 21, a top wall 22, a bottom wall 23 and side walls 24, 25. The front wall 20 and the back wall 21 form thereby major faces of the housing 18. The side walls 24 and 25 form side faces of the housing 18 and extend between the front wall and the back wall 21. The top wall 22 and the bottom wall 23 form top and bottom ends of the housing 18 and extend also between the front wall 20 and the back wall 21. The first housing part 14 in the present case is thereby provided by the front wall 20, parts of the back wall 21, parts of the top wall 22, parts of the side walls 24 and 25. The same applies to the second housing part 15. The second housing part 15 is provided in the present case by the back wall 21 and parts of the top wall 22, parts of the bottom wall 23 and parts of the side walls 24, 25. The volume expansion element 1 is thereby in connection with said parts of said top wall 22, said parts of said bottom wall 23 and said parts of said side walls 24, 25 extending from the front wall 20 or the back wall 21, respectively.

[0067] The volume expansion element 1 extends, as it can be seen in figures 2 and 3 in a circumferential manner around said housing 18 in the top wall 22, the side walls 24, 25 and the bottom wall 23.

[0068] The first housing part 14 in the present case is provided as a front shell and the second housing part is provided as a back shell. The shells are harder and stiffer with regard to the gusset 6 that links the two shells with each other.

[0069] With regard to the arrangement and the distribution of the tensile element 7 the following can be said. Depending on the length of the respective wall one or more than one tensile element 7 can be arranged.

[0070] In the present case each of the side walls 23, 25 comprise two tensile elements 7 which are arranged at a distance to each other. A further tensile element 7, which is not shown in the figures, is arranged in the area of the bottom wall 23. With regard to the top wall, which is shown in figure 4, no tensile element 7 is arranged. This can be seen in figure 4. The arrangement of the tensile element as just described provides a sufficient structure to obtain a compact piece of luggage. However in case the piece of luggage is provided at a larger or smaller or different size the number of the tensile element 7 can vary accordingly.

[0071] From figure 5 it can also be seen that within said housing a plate 32 is arranged. The plate 32 is arranged at the bottom end and is in a firm connection with one of said housing parts 14, 15. In the present case it is in connection with the second housing part 16. There is no firm connection with the first housing part 14 apart from a protection fabric 36. However, the plate 32 is moveably beared on said first housing part 14. The plate 32 serves as element to enhance stability of the gusset 6 in the area of the bottom end of the suitcase. It is preferable that the width W of the plate is chosen such that in the maximal expanded state the plate bridges the distance D between the two housing parts 14, 16.

[0072] Furthermore the piece of luggage comprises in the bottom region for wheels 35. Two wheels 35 are linked to the first housing part 14 and two wheels are linked to the second housing part 16. In such a piece of luggage the volume expansion element 1 is in particularly advantageous since with the tightened tensile elements 7 the two wheel pairs can be positioned in the same plane as a shear movement relative between the first housing part 14 and the second housing part 16 can be prevented.

LIST OF REFERENCE SIGNS

[0073] 

1	volume expansion element	27	interior space
2	piece of luggage	28	first segment
3	longitudinal closure element	29	second segment
4	first closing side	30	free end
5	second closing side	31	end regions
6	gusset	32	plate
7	tensile element	33	starting segment
8	strap	34	end of first segment
9	length adjusting element	35	wheels
10	first row of teeth	C	arrow
11	second row of teeth	D	Distance
12	slider	W	width
13	first edge region
14	first housing part
15	second edge region
16	second housing part
17	starting point
18	housing
19	gap
20	front wall
21	back wall
22	top wall
23	bottom wall
24	side wall
25	side wall
26	closure element

Claims

1. Volume expansion element (1) for a piece of luggage (2) comprising
a longitudinal closure element (3) with a first closing side (4) and a second closing side (5) and
a gusset (6) which is in connection with said first closing side (4) and said second closing side (5) and extends between said first closing side (4) and said second closing side (5),
wherein in a non-expanded state the first closing side (4) is in direct engagement with the second closing side (5) and
wherein in an expanded state the first closing side (4) and the second closing side (5) are disengaged from each other such that they are positioned at a distance (D) to each other, which distance (D) is bridged with said gusset (6), characterized in that
at least one tensile element (7) is in connection with the first closing side (4) and the second closing side (5) such that with the tensile element (7) a tightening force can be provided between said first closing side (4) and said second closing side (5) in the expanded state.

2. Volume expansion element (1) according to claim 1, characterized in that the tensile element (7) is arranged relative to said closing sides (4, 5) and said gusset (6) such that in said non-expanded state the tensile element (7) is embedded in said gusset (6) and said engaged closing sides (4, 5) and/or in that the tensile element (7) is arranged behind the gusset (6) on the opposite side of said closing sides (4, 5).

3. Volume expansion element (1) according to one of the preceding claims, characterized in that the tensile element (7) has the shape of a strip-like element extending transverse over the gusset (6) from the first closing side (4) to the second closing side (5).

4. Volume expansion element (1) according to one of the preceding claims, characterized in that the tensile element (7) is a strap (8) with at least one length adjusting element (9) with which the length of the strap (8) can be adjusted and thereby a tensile force (F) between the closing sides (4, 5) can be provided.

5. Volume expansion element (1) according to one of the preceding claims, characterized in that the tensile element (7) is an elastic strap; and/or a spring-like band providing a tensile force (F) between the closing sides (4, 5); and/or in that several bearing points are arranged at a distance to each other in the vicinity of the first closing side and the second closing side, wherein a tensile band is then guided trough said bearing points whereby the tensile band connects alternatively the bearing points of the first closing side and bearing points of the second closing side such that when the tensile element is put under tension the first closing side and the second closing side will be moved together.

6. Volume expansion element (1) according to one of the preceding claims, characterized in that the tensile element (7) is, in particular apart from its end regions (31), separate from said gusset (6); or in that the tensile element (7) is an integral part of the gusset (6); or in that the tensile element (7) is provided by said gusset (6).

7. Volume expansion element (1) according to one of the proceeding claims, characterized in that the gusset (6) is provided as non-interrupted gusset which completely bridges the distance (D) between the first closing side (4) and the second closing side (5) and/or in that the width of the gusset (6) between the first closing side (4) and the second closing side (5) in the expanded state is larger than 5 cm, in particular larger than 8 cm, preferably larger than 12 cm.

8. Volume expansion element (1) according to one of the proceeding claims, characterized in that the longitudinal closure element (3) is a zipper, wherein the first closing side (4) comprises a first row of teeth (10), wherein the second closing side (5) comprises a second row of teeth (11) and wherein a slider (12) is present between said first row of teeth (10) and said second row of teeth (11).

9. Volume expansion element (1) according to one of the proceeding claims, characterized in that the first closing side (4) and a first edge region (13) of the gusset (6) are connectable to a first housing part (14) of a piece of luggage (2) and second closing side (5) and a second edge region (15) of the gusset (6) are connectable to a second housing part (16) of a piece of luggage (2).

10. Volume expansion element (1) according to claim 9, characterized in that the first closing side (4) and the second closing side (5) extend along the edge regions (13, 15) of the gusset (6) and meet at a starting point (17) between said edge regions (13, 15).

11. Volume expansion element (1) according to claim 10, characterized in that the closing sides (4, 5) are in a firm connection with the gusset (6) in a starting segment (33) of the longitudinal closure element (3), which starting segment (33) extends from said starting point (17) to the regions in which the closing sides (4, 5) extend parallel to the edge regions (13, 15) of the gusset (6).

12. Piece of luggage (2) comprising a housing (18) with a first housing part (14) and a second housing part (15) and a volume expansion element (1) according to one of the preceding claims, wherein said first closing side (4) is in connection with the first housing part (14) and the second closing side (5) is in connection with the second housing part (15) and wherein said gusset (6) bridges a gap (19) between said first housing part (14) and said second housing part (15).

13. Piece of luggage (2) according to claim 12, characterized in that said housing (18) comprises a front wall (20), a back wall (21), a top wall (22), a bottom wall (23) and side walls (24, 25), wherein said front wall (20) and said back wall (21) forming major faces of the housing (18), wherein said side walls (24, 25) forming side faces of the housing (18) and extend between the front wall (20) and the back wall (21) and wherein said top wall (22) and said bottom wall (23) forming top and bottom ends of the housing (18) and extend between the front wall (20) and the back wall (21),
wherein the volume expansion element (1) extends in a circumferential manner around said housing (18) in the top wall (22), the side walls (24, 25) and the bottom wall (23).

14. Piece of luggage (2) according to claim 12 or 13, characterized in that the first housing part (14) is a front shell comprising at least the front wall (20) and the second housing part (16) is a back shell comprising at least the back wall (21).

15. Piece of luggage (2) according to one of the claims 13 to 14, characterized
in that at least one of, in particular exactly one of, said tensile elements (7) links the first housing part (14) with the second housing part (16) in the area of said bottom wall (23); and/or
in that at least one of, in particular exactly two of, said tensile elements (7) links the first housing part (14) with the second housing part (16) in the area of each of said side walls (24, 25); and/or
in that in the area of said top wall (22) no tensile element (7) is arranged.

16. Piece of luggage (2) according to one of claims 13 to 15, characterized in that in said front wall (20) a closure element (26) is arranged giving access to the interior space (27) of said housing (18).

17. Piece of luggage (2) according to one of claims 12 to 16, characterized in that a plate (32) is arranged in said housing (18) at the bottom end, which plate is in firm connection with one of said first housing part (14) or said second housing part (16).

Drawing