BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates to a pack for containing articles, such as a backpack.
2. Description of the Background and Other Information
[0002] Backpacks typically comprise a bottom, a front side, and a back side. The front side
and the back side are adjacently connected to each other at their lateral right and
left edges. Further, the lower edges of the front side and of the back side are both
directly connected to the bottom, whereas the upper edges remain free of permanent
connection. Between the upper edges a top opening is defined.
[0003] The front side, back side, and bottom form a compartment adapted to receive a load
to be carried and the top opening allows insertion and removal of the load.
[0004] The front side, the back side, and the bottom are usually made of a relatively flexible
(i.e., non rigid) material, such as a panel of textile fabric.
[0005] Various closures for the top opening are used in packs. Backpacks, for example, typically
use the hem-and-draw-cord type closure, possibly covered by an upper lid.
[0006] The roll-top type closure is also used for packs, such as backpacks. In particular,
roll-top type closures are used for waterproof packs.
[0007] A roll-top closure includes two flaps, each of which originates from one of the front
side and the back side of the pack. To perform the closing of the top opening of the
pack, the two flaps are pressed against each other and then rolled down together until
a "rolled state" of the two flaps in reached.
[0008] Roll-top closures further include a retaining mechanism for retaining the two flaps
in their "rolled state".
[0009] One of the weakness of the packs having roll-top closures is that they have a relatively
small top opening.
SUMMARY OF THE INVENTION
[0010] The invention improves the comfort and efficiency in using a pack having a roll-top.
[0011] A pack according to the invention has an improved construction technique which achieves
yet unseen performance.
[0012] More particularly, the invention is directed to a pack having a roll-top closure.
In addition, the invention is directed to articles, such as bags, packs, and backpacks
which are be carried by strap, such as shoulder straps.
[0013] Any embodiment of a pack according to the invention includes an improved structure,
and/or a construction technique, not heretofore known to those skilled in the art.
[0014] Such improved structure and construction technique further allow improvements in
the convenience of use of a pack.
[0015] According to the invention, a pack is provided that includes the following:
a bottom, a front side, a back side, and a top opening for allowing insertion and
removal of articles inside the pack;
the front side and the back side are adjacent to each other at their left and right
edges;
the pack further includes a closure arrangement for closing the top opening;
the closure arrangement includes an upper front flap, adjacently connected to the
front side, and an upper back flap adjacently connected to the back side;
the pack is closed when the upper front flap and the upper back flap are pressed against
each other and then rolled down together along the pack until a "rolled state" of
the upper front flap and the upper back flap is reached;
the pack further includes an expansion device that allows, on one hand, separation
of the front side from the back side when the expansion device is in an "open state"
and, on the other hand, abutment of the front side to the back side when the expansion
device is in a "closed state"; the expansion device having a lower extremity and a
upper extremity;
the upper extremity of the expansion device is positioned at the junction between
the front side and the upper front flap and respectively between the back side and
the upper back flap.
[0016] By having the upper extremity of the expansion device extend to the upper front flap
and the upper back flap, the expansion device allows the top opening to be enlarged,
thereby facilitating access to the interior of the pack.
[0017] According to a first embodiment of the invention, a pack is further provided by which
the expansion device includes a slit provided between the front side and the back
side, as well as a gusset positioned between the edges of the slit.
[0018] According to a second embodiment of the invention, a pack is further provided by
which the expansion device includes a slide fastener, such as a zipper.
BRIEF DESCRIPTION OF DRAWINGS
[0019] Other aspects of the invention will be set forth in the following detailed description
which refers to the appended drawings in which
FIG. 1 is a perspective front view of a pack according to a first exemplary embodiment
of the invention, showing the pack is an open state;
FIG. 2 is a perspective front view of the pack of FIG. 1, showing the pack in a closed
state;
FIG. 3 is a perspective front view of a pack according to a second exemplary embodiment
of the invention, showing the pack in an open state;
FIG. 4 is a perspective front view of the pack of FIG. 3, showing the pack in a closed
state.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 and FIG. 2 show a pack according to a first embodiment of the invention.
[0021] The pack 1 comprises a bottom 2, a front side 3, and a back side 4. The front side
3 and the back side 4 are adjacently connected to each other at their lateral right
and left edges, such as by stitched seams or otherwise according to techniques known
in the art. The assembly of the front side 3 and of the back side 4 forms a tubular
sleeve.
[0022] The lower edge of the front side 3 and the lower edge of the back side 4 are both
adjacently connected to the bottom 2, thereby forming a compartment adapted to receive
a load to be carried.
[0023] Between the upper edge of the front side 3 and the upper edge of the back side 4
a top opening 13 is provided, through which the load can be inserted or removed by
the user.
[0024] The pack is made of flexible material, such as woven textile fabric. In a particular
construction, this fabric is coated and/or laminated with at least one water-repellent,
water resistant, and/or waterproof material.
[0025] In order to give the front side and the back side of the pack a better upholding
while maintaining its flexibility, the woven textile fabric can be assembled with
a structural sheet. Such structural sheet, which can be positioned along one surface
of the back side and/or front side and/or sandwiched between opposing panels of either/both
of the sides, can be made of any semi-rigid material such as a plastic composite material,
foam, etc. Such structural sheet would, in such embodiment, have an appropriate thickness
to exhibit enough strength to enhance the ability of the pack to maintain an upright
orientation, particularly when empty, without adding excessive weight to the pack.
[0026] A roll-top closure arrangement is provided to close the top opening 13. The roll-top
closure arrangement includes an upper front flap 5 and an upper back flap 6.
[0027] In particular embodiments of the invention, the upper front flap 5 mainly includes
two portions, i.e., a front supple portion 7 and the front firm portion 8 or, stated
another way, a front flexible portion and front rigid portion, with the terms flexible
and rigid at least merely describing the portion 8 being more rigid - or less flexible
- than the portion 7. The front supple portion 7 and the front firm portion 8 have
the contours of strips placed parallel to each other, the front supple portion 7 being
positioned between the front side 3 and the front firm portion 8.
[0028] The front supple portion 7 and the front firm portion 8 extend transversely of the
pack along the entire length of the upper front flap 5, and the width of the front
supple portion 7 is at least equal of the width of the firm portion 8.
[0029] As mentioned above, the front rigid portion 8 is more rigid than the front flexible
portion 7. In a particular embodiment, the front rigid portion includes a stiffener.
Typically, the stiffener may be a plastic plate or any other material that is flexible,
such as elastically flexible, i.e., having the ability to return to its original shape
after having been flexed.
[0030] Similarly, the upper back flap 6 includes a back supple/flexible portion 9 and a
back firm/rigid portion 10. The properties of the back supple portion 9 with respect
to the back firm portion 10 are the same as the properties just described above for
front supple/flexible portion 7 with respect to the front firm/rigid portion 8 and,
therefore, they are not further described here.
[0031] The stiffeners of the front firm portion 8 and of the back firm portion 10 have an
identical, or substantially identical, width and length.
[0032] An expansion device is provided between the front side 3 and the back side 4. This
device allows a widened separation of the front side 3 from the back side 4 when they
are in an "open state". On the other hand, when the front and back sides are in a
"closed state", access to the top opening 13 is blocked and the front side 3 and the
back side 4 are brought towards one another. In a particular embodiment, such as the
illustrated embodiment, the front and back sides are brought into abutment in the
closed state.
[0033] In the first exemplary embodiment of the invention, the expansion device includes
a structure on both the right and on the left of the pack. Further in the detailed
description of this embodiment, reference to "expansion device" is intended to refer
to the expansion structures on both the left and right of the pack. That is, the left
and right expansion structures of the expansion device have at least the following
attributes in common.
[0034] When in the "open state," the expansion device widens the top opening 13. When the
expansion device is in the "closed state," the size of the top opening is reduced
and the roll-top closure arrangement may be operated.
[0035] In the first embodiment of the invention, the expansion device comprises a slit 14
positioned between the front side 3 and the back side 4 extending down from their
upper edges.
[0036] According to the invention, the upper extremity of the expansion device, i.e., in
this case, of the slit 14, coincides with the junction of the upper front flap 5 with
the front side 3.
[0037] The expansion device further includes a locking mechanism 15 to maintain the expansion
device, and the slit 14, in the "closed state," as well as a gusset 11 to improve
the waterproof and/or the airtight qualities of the pack. The gusset 11 also prevents
articles stored within the pack to be expelled while the pack is closed.
[0038] In addition, the gusset 11 also limits the amplitude of the opening of the slit 14.
In another embodiment, in order to benefit from an even wider top opening, the gusset
11 could be removed.
[0039] Operation of the pack 1 is next described.
[0040] In FIG. 1, the pack is shown to be open, whereby items can be inserted or removed
from within the pack. The roll-top closure arrangement is wide open and the expansion
device is in its "open state". As described above, the upper extremity of the expansion
device coincides with the lower extremity of the roll-top closure arrangement, i.e.,
there is a junction of the upper front flap and the front side. Therefore, the expansion
device and the roll-top closure arrangement work in conjunction with each other to
provide the widest possible top opening, thereby facilitating access to the inside
of the pack.
[0041] Consequently, the user may insert articles within the pack or remove them.
[0042] Subsequently, the expansion device is closed by the user. During this step, the upper
segment of the front side 3 and of the back side 4 are brought together, and placed
in abutment, the segments of the gusset 11 are folded and project into the pack, and
the locking mechanisms 15 on the left and right sides of the pack are closed.
[0043] The locking mechanism 15, in the illustrated embodiment, includes a male and female
snap fastener. The male part is fixed on the upper segment of the front side 3 whereas
the female part is fixed on a tab that protrudes from the back side 4. Other forms
of locking mechanisms are also encompassed by the invention, such as hook-and-loop
fasteners, etc.
[0044] The next step is the actual closing of the pack by actuation of the roll-top closure
arrangement. The upper back flap 6 and the upper front flap 5 are pressed against
each other such that the back firm portion 10 and the front firm portion 8 are placed
face-to-face.
[0045] The upper back flap 6 and the upper front flap 5 are then rolled down. In the first
embodiment, the front firm portion 8 and the back firm portion 10 are folded down,
one time, against the back supple portion 9.
[0046] When the user wants to close the top opening 13, he/she presses the upper front flap
5 and the upper back flap 6 against each other and then rolls down the flaps together
until a "rolled state" of the flaps in reached.
[0047] Due to the presence of a firm portion in the upper front flap 5 and in the upper
back flap 6, the rolling down of the roll-top closure can be easily operated. This
advantage is enhanced when the firm portions of the upper front flap 5 and of the
upper back flap 6 are both equipped with a stiffener. Indeed, with the help of the
stiffeners, the user has a great easiness to snugly fit the two upper flaps 5, 6 when
he/she presses them against each other. Secondly, when the user performs the rolling
down of the upper flaps, the lower edges of the stiffeners provide a clear-cut and
straight folding line around which the rolling down can begin.
[0048] When the "rolled state" of the upper front flap 5 and the upper back flap 6 is reached,
such state is held by a retaining mechanism. In the first embodiment, the retaining
mechanism includes two straps 16, one on the left side of the pack and one on the
right side of the pack.
[0049] Each of the straps 16 is attached by one of its ends to the external face of the
upper front flap 5, the other end of which is provided with one part 16a of a self-gripping
tape, i.e., a first part of a hook-and-loop fastener, such as that of a Velcro
® fastener. On each of the left and right of the front side 3 of the pack, a second
part 16b of the hook-and-loop fasteners is provided. Consequently, by attaching the
free end of the strap 16 to the front side 3, the roll-top closure mechanism is maintained
closed.
[0050] A handle 12 is attached to the external face of the upper front flap 5 to carry the
pack.
[0051] A second embodiment of the invention is described with reference to FIGS. 3 and 4.
The pack is a backpack 17. For making reference to aspects of the invention common
to both the first and second embodiments, identical reference numbers are used in
the drawing figures.
[0052] The backpack 17 includes a bottom 2, a front side 3, and a back side 4. The front
side 3 and the back side 4 are adjacently connected to each other at their lateral
right and left edges. The backpack 17 further includes a pair of shoulder straps 18,
attached to the back side 4, and a belt 19.
[0053] The backpack 17, in the exemplary illustrated embodiment, is also equipped with a
front pocket 26, an inside pocket 27, and with any other accessory commonly used for
packs.
[0054] The assembly of the front side 3 and of the back side 4 forms a tubular sleeve.
[0055] The lower edge of the front side 3 and the lower edge of the back side 4 are both
adjacently connected to the bottom 2, thereby forming a compartment adapted to receive
a load to be carried.
[0056] Between the upper edge of the front side 3 and the upper edge of the back side 4
a top opening 13 is provided, through which the load can be inserted or removed.
[0057] The pack is made of flexible material, such as woven textile fabric. In a particular
construction, this fabric is coated and/or laminated with at least one water-repellent,
water resistant, and/or waterproof material.
[0058] In order to give the front and the back side of the pack a better upholding while
maintaining its flexibility, the woven textile fabric can be assembled with a structural
sheet. As with the first embodiment, such structural sheet can be made of any semi-rigid
material such as plastic composite material, foam, etc. It would, in such embodiment,
have an appropriate thickness to exhibit enough strength without adding excessive
weight to the pack.
[0059] A roll-top closure arrangement is provided to close the top opening 13. The roll-top
closure arrangement includes an upper front flap 5 and an upper back flap 6.
[0060] The upper front flap 5 mainly includes two portions, i.e., the front supple portion
7 and the front firm portion 8. The front supple portion 7 and the front firm portion
8 have the contour of strips placed parallel to each other, the front supple portion
7 being positioned between the front side 3 and the front firm portion 8.
[0061] The front supple portion 7 and the front firm portion 8 extend transversely of the
pack along the entire length of the upper front flap 5, and the width of the front
supple portion 7 is at least equal of the width of the firm portion 8.
[0062] The front firm portion 8 is more rigid than the front supple portion 7. in a particular
embodiment, the front firm portion includes a stiffener. Typically, the stiffener
may be a plastic plate or any other material that is flexible, such as elastically
flexible, i.e., having the ability to return to its original shape after having been
flexed.
[0063] Similarly, the upper back flap 6 comprises a back supple/flexible portion 9 and a
back firm/rigid portion 10. The properties of the back supple portion 9 with respect
to the back firm portion 10 are the same as the properties just described for front
supple/flexible portion 7 with respect to the front firm/rigid portion 8 and, therefore,
they are not further described here.
[0064] The stiffeners of the front firm portion 8 and of the back firm portion 10 have an
identical, or substantially identical, width and length.
[0065] An expansion device is provided between the front side 3 and the back side 4. This
device allows a wider separation between the front side 3 and the back side 4 when
they are in an "open state". On the other hand, when they are in a "closed state",
the front side 3 and the back side 4 are brought closer together. In a particular
embodiment, such as the illustrated second embodiment, the front and back sides are
brought into abutment in the closed state.
[0066] In the second exemplary embodiment of the invention, the expansion device includes
a structure on both the right and the left of the pack. Further in the detailed description
of this embodiment, "expansion device" is intended to refer to the expansion structures
on both the left and right of the pack. That is, the left and right expansion structures
of the expansion device have at least the following attributes in common.
[0067] When in the "open state," the expansion device widens the top opening 13. When the
expansion device is in the "closed state," the size of the top opening is reduced
and the roll-top closure arrangement may be operated.
[0068] In the second embodiment of the invention, the expansion device comprises a slit
14 positioned between the front side 3 and the back side 4 extending down from their
upper edges.
[0069] According to the invention, the upper extremity of the expansion device, i.e., in
this case, of the slit 14, coincides with the junction of the upper front flap 5 with
the front side 3.
[0070] The lower extremity of the expansion device is positioned in the vicinity of the
bottom 2 of the pack. Moreover, the expansion device comprises no limitation of its
amplitude. Consequently, when the expansion device is in the "open state," the backpack
17 can be fully open, i.e., having the back side 4, the bottom 2, and the front side
3 laid on the floor/ground.
[0071] The expansion device further includes a locking mechanism to maintain the slit 14
in its "closed state." Such locking mechanism, in the illustrated second embodiment,
comprises a slide fastener in the form of a zipper 20.
[0072] Operation of the backpack 17 is next described.
[0073] In FIG. 3, the backpack 17 is shown to be fully open, whereby items can be inserted
or removed from within the pack. The roll-top closure arrangement is wide open and
the expansion device is in its "open state." As described above, the upper extremity
of the expansion device coincides with the lower extremity of the roll-top closure
arrangement, i.e., there is a junction of the upper front flap 5 and the front side
3. Therefore, the expansion device and the roll-top closure arrangement work in conjunction
with each other to provide the widest possible top opening, thereby facilitating access
to the inside of the pack.
[0074] Consequently, the user may insert articles within the backpack or remove them. Because
the lower extremity of the expansion means is placed in the vicinity of the bottom
2, it is possible to lay the back side of the backpack on the floor or ground, or
on any horizontal surface, and still have a top-down access to arrange the content
of the backpack 17.
[0075] Subsequently, the expansion device is closed by the user. During this step the upper
portion of the front side 3 and of the back side 4 are brought together, and placed
in abutment, by pulling up the sliders 21 of the slide fastener 20.
[0076] The next step is the actual closing of the backpack by actuation of the roll-top
closure arrangement. The upper back flap 6 and the upper front flap 5 are pressed
against each other such that the back firm portion 10 and the front firm portion 8
are placed face-to-face.
[0077] The upper back flap 6 and the upper front flap 5 are then rolled down. In this second
embodiment, the front firm portion 8 and the back firm portion 10 are folded down,
one time, against the back supple portion 9.
[0078] When the user wants to close the top opening 13, he/she presses the upper front flap
5 and the upper back flap 6 against each other and then rolls down the flaps together
until a "rolled state" of the flaps in reached.
[0079] Due to the presence of a firm portion in the upper front flap 5 and in the upper
back flap 6, the rolling down of the roll-top closure can be easily operated. This
advantage is enhanced when the firm portions of the upper front flap 5 and of the
upper back flap 6 are both equipped with a stiffener. Indeed, with the help of the
stiffeners, the user has a great easiness to snugly fit the two upper flaps 5, 6 when
he/she presses them against each other. Secondly, when performing the rolling down
of the upper flaps, the lower edges of the stiffeners provide a clear-cut and straight
folding line around which the rolling down can begin.
[0080] When the "rolled state" of the upper front flap 5 and the upper back flap 6 is reached,
such state is held by a retaining mechanism. In the second embodiment, the retaining
mechanism includes two compression straps 22, one on the left side of the pack and
one on the right side of the pack.
[0081] Each of the compression straps 22 includes an upper segment 23 attached to the front
supple portion 7; a lower segment 24 attached to the back side 4; and a buckle 25,
that connects the upper segment 23 to the lower segment 24. The free end of the lower
segment 24 is non-removably attached to the buckle 26, whereas the upper segment 23
is slidably attached to it. The upper segment 23 follows, in the various loops that
constitutes the buckle 25, a path that allows an easy sliding in one direction, and
a restrained sliding in the opposite direction.
[0082] By pulling down the free end of the upper segment 23, the length of the compression
strap is easily reduced. The length is automatically maintained. FIG. 4 shows the
backpack 17 when it is closed, with the compression strap 22 pulling down the left
and the right ends of the roll-top closure arrangement, thereby maintaining them in
the "rolled state". Indeed, so long as the roll-top closure arrangement is maintained
in an arched position, they are unable to come unrolled. This is particularly the
case when the firm portions of the upper front flap and the upper back flap include
stiffeners.
[0083] To again open the backpack 17, the user needs to unlock the locking mechanism by
lifting up the lower tip of the buckle 25. As a consequence, the compression strap
22 lengthens until the roll-top closure arrangement returns to its straight position.
When in the straight position, the roll-top closure arrangement naturally comes unrolled
and open.
[0084] At that stage, i.e., when the roll-top closure is opened, the size of the top opening
13 may be sufficient for the user if, for example, the user wishes to add a new item
on top of a plurality of items already loaded within the backpack 17.
[0085] On the other hand, the user may decide to expand the top opening 13 by operating
the expansion device. In that event, the user would then pull down the sliders 21
of the zippers 20.
[0086] It is important to note that the expansion device may also be used as a supplementary
opening for the backpack. Indeed, even when the roll-top closure arrangement is closed,
the zippers 20 provide lateral, left, and right access to the content of the backpack.
[0087] A handle 12 is attached to the external face of the upper front flap 5 to carry the
pack. To economize the use of material, the upper segment of the left compression
strap, the handle, and the upper segment of the right compression strap are various
portions of the same band that advantageously is attached on various locations of
the external face of the front supple portion 7.
[0088] The invention is not limited to the two particular exemplary embodiments described
by way of examples, and the invention can be implemented in all types of packs.
NOMENCLATURE
[0089]
- 1
- Pack
- 2
- Bottom
- 3
- Front side
- 4
- Back side
- 5
- Upper front flap
- 6
- Upper back flap
- 7
- Front supple portion
- 8
- Front firm portion
- 9
- Back supple portion
- 10
- Back firm portion
- 11
- Gusset
- 12
- Handle
- 13
- Top opening
- 14
- Slit
- 15
- Locking mechanism
- 16
- Strap
- 16a
- First part of fastener
- 16b
- Second part of fastener
- 17
- Backpack
- 18
- Shoulder strap
- 19
- Belt
- 20
- Zipper
- 21
- Slider
- 22
- Compression strap
- 23
- Upper segment
- 24
- Lower segment
- 25
- Buckle
- 26
- Front pocket
- 27
- Inside pocket
1. A pack (1) comprising:
a bottom (2), a front side (3), a back side (4), and a top opening (13) for allowing
insertion and removable of articles inside or from the pack (1);
said front side (3) and said back side (4) having respective edges adjacent to each
other;
a closure arrangement to close said top opening;
said closure arrangement comprising an upper front flap (5), adjacently connected
to said front side (3) and an upper back flap (6) adjacently connected to said back
side;
said closure arrangement being movable between a first position and a second position,
in said first position, the pack is open and in said second position, the pack is
closed;
in the first position of said closure arrangement, said upper front flap (5) and said
upper back flap (6) are pressed against each other and are together rolled along the
pack (1) into rolled state of the upper front flap (5) and the upper back flap (6)
;
an expansion device movable between an open state and a closed state;
in said open state, the expansion device allowing separation of the front side (3)
from the back side (4) and, in said closed state, the front side (3) and the back
side (4) are in abutment;
said expansion device having a lower extremity and an upper extremity;
said upper extremity of said expansion device being positioned between a junction
of said front side (3) and said upper front flap (5) and a junction of said back side
(4) and said upper back flap.
2. A pack according to claim 1, wherein:
said expansion device comprises a slit (14) provided between said front side (3) and
said back side (4).
3. A pack (1) according to claim 2, wherein:
said expansion means device comprises a gusset (11);
said gusset (11) limits opening of said slit (14) when said expansion device is in
the open state and provides a waterproof quality to said slit (14) when said expansion
device is in closed state.
4. A pack (1) according to claim 1, wherein:
said expansion device further comprises a slide fastener.
5. A pack (1) according to claim 1, wherein:
said expansion device includes a structure connected to the back side (4) and structures
connected to respective ones of a left upper edge and a right upper edge of the front
side (3) of the pack (1).
6. A pack (1) according to claim 1, wherein:
said upper front flap (5) comprises a front supple portion (7) and a front firm portion
(8), and said upper back flap (6) comprises a back supple portion (9) and a back firm
portion (10);
said front firm portion (8) and said back firm portion (10) are shaped as elongated
strips, each of said strips having a length at least equal to a width of the front
side (3) ;
said front supple portion (7) and said back supple portion (9) are shaped as elongated
strips, each of said strips having a breadth at least equal to a breadth of the front
firm portion (8).
7. A pack (1) according to claim 6, wherein:
in said first position of said closure arrangement, the front firm portion (8) and
the back firm portion (10) are pressed against each other and are folded together
against the back supple portion (9), thereby being in a rolled state of the upper
front flap (5) and the upper back flap (6).
8. A pack (1) according to claim 6, wherein:
the front firm portion (8) includes a stiffener and the back firm portion (10) comprises
a stiffener.
9. A pack (1) according to claim 7, wherein:
the closure arrangement further comprises a retaining mechanism to retain the upper
front flap (5) and the upper back flap (6) in their rolled state.
10. A pack (1) according to claim 9, wherein:
said retaining mechanism comprises a pair of tensioning straps, each of said tensioning
straps being attached on the front supple portion (7).
11. A pack (1) according to claim 1, further comprising:
a handle to allow the pack (1) to be carried with a hand of a user.
12. A pack (1) according to claim 1, further comprising:
a pair of shoulder straps (18) to allow the pack (1) to be carried by shoulders of
a user.
13. A pack (1) according to claim 1, wherein:
the lower extremity of the expansion device is positioned in a vicinity of the bottom
of the pack (1).