U.S. patent application number 13/126295 was filed with the patent office on 2011-08-25 for inflatable cell for anti-eschar mattresses.
Invention is credited to Thaddee Mulliez.
Application Number | 20110203053 13/126295 |
Document ID | / |
Family ID | 41450011 |
Filed Date | 2011-08-25 |
United States Patent
Application |
20110203053 |
Kind Code |
A1 |
Mulliez; Thaddee |
August 25, 2011 |
INFLATABLE CELL FOR ANTI-ESCHAR MATTRESSES
Abstract
The invention relates to an inflatable cell for anti-eschar
mattresses, including an inflatable housing having an elongate
shape and two main opposed side surfaces, as well as several oblong
welds that have a main longitudinal axis substantially
perpendicular to the main longitudinal axis of the housing, which
are spaced apart along the length of the housing, and which connect
two main opposed side surfaces of the housing together.
Inventors: |
Mulliez; Thaddee; (Marcq en
Baroeul, FR) |
Family ID: |
41450011 |
Appl. No.: |
13/126295 |
Filed: |
November 4, 2009 |
PCT Filed: |
November 4, 2009 |
PCT NO: |
PCT/FR2009/001275 |
371 Date: |
April 27, 2011 |
Current U.S.
Class: |
5/712 |
Current CPC
Class: |
A61G 7/05769
20130101 |
Class at
Publication: |
5/712 |
International
Class: |
A47C 27/10 20060101
A47C027/10 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 2008 |
FR |
0806193 |
Nov 3, 2009 |
FR |
0957775 |
Claims
1. An inflatable cell for anti-eschar mattresses, said cell
comprises an inflatable housing having an elongate shape and two
main opposed side surfaces, as well as several oblong welds whereof
the main longitudinal axis is substantially perpendicular to the
main longitudinal axis of the housing, which are spaced apart along
the length of the housing, and which connect two main opposed side
surfaces of the housing together.
2. The cell according to claim 1, comprising an inner sheet that is
positioned between the two main surfaces using said oblong welds,
and which makes it possible to limit the expansion of the cell.
3. The cell according to claim 2, wherein the length (L.sub.3) of
each oblong weld is at least equal to 50% of the height (H.sub.4)
of the inner sheet.
4. The cell according to claim 1, wherein the two main opposed side
surfaces are welded directly to each other using said oblong
welds.
5. The cell according to claim 1, comprising an upper surface that,
when the housing is inflated, forms an upper support surface,
wherein the two main side surfaces of the cell are welded together
over at least three sides of the periphery thereof using at least
one lower longitudinal weld and two side welds, said lower
longitudinal weld having a curve profile made so that when the
housing is inflated, the support surface is deformed so as to have
a basin-shaped fall prevention curve profile with raised ends.
6. The cell according to claim 5, wherein said lower longitudinal
weld has a bowed curve profile whereof the apex is oriented towards
the support surface, so that when the housing is inflated, the
support surface is deformed so as to have a basin-shaped fall
prevented curve profile with raised ends.
7. The cell according to claim 6, wherein when the housing is
deflated, the height H.sub.1 between the apex of said lower
longitudinal weld is smaller than the height H.sub.2 at the ends of
the housing.
8. The cell according to claim 5, wherein said lower longitudinal
weld has a curve profile such that the height at the center H.sub.1
of the deflated housing is smaller than the height H.sub.2 at the
ends of the deflated housing.
9. The cell according to claim 7, wherein the height difference
.DELTA.H (.DELTA.H=H.sub.1-H.sub.2) between the heights H.sub.1 and
H.sub.2 is at least equal to 3 cm, and preferably at least equal to
5 cm.
10. The cell according to claim 1, wherein said housing is made up
of a sheet folded in two lengthwise, and welded on three sides of
the periphery thereof using at least one lower longitudinal weld
and two side welds, the support surface being free of welds.
11. The cell according to claim 10, wherein the distance (e.sub.1)
between each oblong end weld and the adjacent side weld of the
housing, measured along the longitudinal axis of the housing, is
greater than or equal to the distance (e.sub.2) between said oblong
end weld and the upper bend line of the sheet forming the
housing.
12. The cell according to claim 1, wherein the housing is made up
of two separate sheets welded together over the entire periphery
thereof using at least four welds: a lower longitudinal weld, two
side welds, and an upper longitudinal weld.
13. The cell according to claim 12, wherein the distance (e.sub.1)
between each oblong end weld and the adjacent side weld of the
housing, measured along the longitudinal axis of the housing, is
greater than or equal to the distance (e.sub.2) said oblong end
weld and the upper weld line.
14. The cell according to claim 1, wherein the upper support
surface of the deflated housing has a substantially rectilinear
profile over the entire length of the housing.
15. The cell according to claim 1, wherein the oblong welds are
substantially centered over the height (H.sub.1) of the housing of
the cell.
16. The cell according to claim 1, wherein the length (L.sub.3) of
each oblong weld is at least equal to 30% of the maximum height
(H.sub.1) of the deflated housing.
17. An inflatable cell for anti-eschar mattresses, said cell
comprising an inflatable housing having an elongate shape and two
main opposed side surfaces, as well as an upper surface which, in
the inflated state of the housing, forms an upper support surface,
the two main opposed side surfaces of the cell being welded to each
other on at least three sides of their periphery using at least one
lower longitudinal weld and two side welds, and said lower
longitudinal weld having a curve profile that is made so that when
the housing is inflated, the support surface is deformed so as to
have a basin-shaped fall prevention curve profile with raised
ends.
18. The cell according to claim 17, wherein said lower longitudinal
weld has a bowed curve profile whereof the apex is oriented towards
the support surface, so that when the housing is inflated, the
support surface is deformed so as to have a basin-shaped fall
prevention curve profile with raised ends.
19. The cell according to claim 18, wherein when the housing is
deflated, the height H.sub.1 between the apex of said lower
longitudinal weld is smaller than the height H.sub.2 at the ends of
the housing.
20. The cell according to claim 17, wherein said lower longitudinal
weld has a curve profile such that the height at the center H.sub.1
of the deflated housing is smaller than the height H.sub.2 at the
ends of the deflated housing.
21. The cell according to claim 19, wherein the height difference
.DELTA.H (.DELTA.H=H.sub.1-H.sub.2) between the heights H.sub.1 and
H.sub.2 is at least equal to 3 cm, and preferably at least equal to
5 cm.
22. The cell according to claim 17, comprising one or more
additional welds that make it possible to connect the two main
opposed side surfaces of the housing together.
23. The cell according to claim 22, wherein the additional weld(s)
are oblong.
24. The cell according to claim 23, wherein the additional oblong
weld(s) are oriented so that their main longitudinal axis is
substantially parallel to the main longitudinal axis of the
housing, and define at least two superimposed inflation chambers
that communicate with each other.
25. The cell according to claim 17, comprising several additional
oblong welds, whereof the main longitudinal axis is substantially
perpendicular to the main longitudinal axis of the housing, which
are spaced apart along the length of the housing, and which make it
possible to connect the two main opposed side surfaces of the
housing together.
26. The cell according to claim 25, wherein the length (L.sub.3) of
each additional oblong weld is at least equal to 30% of the maximum
height (H.sub.1) of the deflated housing.
27. The cell according to claim 22, comprising an inner sheet
positioned between the two main side surfaces of the housing, which
is welded to said main side surfaces via said additional welds, and
which makes it possible to limit the expansion of the cell.
28. The cell according to claim 25, wherein the length (L.sub.3) of
each additional oblong weld is at least equal to 50% of the height
(H.sub.4) of the inner sheet.
29. The cell according to claim 22, wherein the two main opposed
side surfaces are welded together directly via said additional
welds.
30. The cell according to claim 22, wherein the additional welds
are substantially centered on the height of the housing of the
cell.
31. The cell according to claim 17, wherein said housing is made up
of a sheet folded in two lengthwise, and welded on three sides of
the periphery thereof via the lower longitudinal weld and said side
welds, the support surface being free of welds.
32. The cell according to claim 31, wherein the distance (e.sub.1)
between each additional end weld and the adjacent side weld of the
housing, measured along the longitudinal axis of the housing, is
greater than or equal to the distance (e.sub.2) between said
additional end weld and the upper bend line of the sheet forming
the housing, so that when the housing is inflated, the support
surface is deformed so as to have a basin-shaped fall prevention
curve profile with raised ends.
33. The cell according to claim 17, wherein the housing is formed
by two separate sheets welded together on the entire periphery
thereof via at least four welds: a lower longitudinal weld two side
welds, and an upper longitudinal weld.
34. The cell according to claim 33, wherein the distance (e.sub.1)
between each additional end weld and the adjacent side weld of the
housing, measured along the longitudinal axis of the housing, is
greater than or equal to the distance (e.sub.2) between said
additional end weld and the upper weld, so that when the housing is
inflated, the support surface is deformed so as to have a
basin-shaped fall prevention curve profile with raised ends.
35. The cell according to claim 17, wherein the upper support
surface of the deflated housing has a substantially rectilinear
profile over the entire length of the housing.
36. An inflatable cell for anti-eschar mattresses, said cell
including an inflatable housing having an elongate shape and two
main opposed side surfaces, as well as an upper surface which, in
the inflated state of the housing, forms an upper support surface,
said housing being either (i) formed by a sheet folded in two
lengthwise, and welded on three sides of its periphery using a
lower longitudinal weld and two side welds, and the support surface
being free from welds, or (ii) formed by two separate sheets welded
to each other over the entire periphery thereof using at least four
welds: a lower longitudinal weld, two side welds, and an upper
longitudinal weld, said cell including one or more additional welds
that are spaced apart along the length of the housing, and that
make it possible to connect the two main opposed side surfaces of
the housing to each other, the distance (e.sub.1) between each
additional end weld and the adjacent side weld of the housing,
measured along the longitudinal axis of the housing, being greater
than or equal to the distance (e.sub.2) between said additional end
weld and (i) the upper bend line of the sheet forming the housing,
or (ii) the upper longitudinal weld, such that when the housing is
inflated, the support surface is deformed so as to have a
basin-shaped fall prevention curve profile with raised ends.
37. The cell according to claim 36, wherein the upper support
surface of the deflated housing has a substantially rectilinear
profile over the entire length of the housing.
38. The cell according to claim 36, wherein the additional weld(s)
are oblong.
39. The cell according to claim 38, wherein the oblong additional
weld(s) are oriented so that their main longitudinal axis is
substantially parallel to the main longitudinal axis of the
housing, and define at least two superimposed inflation chambers
that communicate with each other.
40. The cell according to claim 38 wherein the main longitudinal
axis of the oblong additional welds is substantially perpendicular
to the main longitudinal axis of the housing.
41. The cell according to claim 40, wherein the length (L.sub.3) of
each additional oblong weld is at least equal to 30% of the maximum
height (H.sub.1) of the deflated housing.
42. The cell according to claim 36, comprising an inner sheet
positioned between the two main side surfaces of the housing, which
is welded to said main side surfaces via said additional welds, and
which makes it possible to limit the expansion of the cell.
43. The cell according to claim 40, wherein the length (L.sub.3) of
each additional oblong weld is at least equal to 50% of the height
(H.sub.4) of the inner sheet.
44. The cell according to claim 36, wherein the two main opposed
side surfaces are welded together directly via said additional
welds.
45. The cell according to claim 36, wherein the additional welds
are substantially centered on the height of the housing of the
cell.
46. The cell according to claim 36, wherein said lower longitudinal
weld having a curve profile that is made so that when the housing
is inflated, the support surface is deformed so as to have a
basin-shaped fall prevention profile with raised ends.
47. The cell according to claim 46, wherein said lower longitudinal
weld has a bowed curve profile whereof the apex is oriented towards
the support surface, such that when the housing is inflated, the
support surface is deformed so as to have a basin-shaped fall
prevention curve profile with raised ends.
48. The cell according to claim 47, wherein when the housing is
deflated, the height H.sub.1 between the apex of said lower
longitudinal weld is smaller than the height H.sub.2 at the ends of
the housing.
49. The cell according to claim 46, wherein said lower longitudinal
weld has a curve profile such that the height at the center H.sub.1
of the deflated housing is smaller than the height H.sub.2 at the
ends of the deflated housing.
50. The cell according to claim 48, wherein the height difference
.DELTA.H (.DELTA.H=H.sub.1-H.sub.2) between the heights H.sub.1 and
H.sub.2 is at least equal to 3 cm, and preferably at least equal to
5 cm.
51. An inflatable cell for anti-eschar mattresses, said cell
includes an inflatable housing having an elongate shape and two
main opposed side surfaces, an upper surface that forms an upper
support surface when the housing is inflated, and one or several
oblong welds, the main longitudinal axis of which is substantially
parallel to the main longitudinal axis of the housing, and which
make it possible to connect the two main opposed side surfaces of
the housing to each other, so as to define, in the housing, at
least two superimposed inflation chambers that communicate with
each other, wherein the upper support surface of the deflated
housing has a substantially rectilinear profile over the entire
length of the housing, and the oblong weld(s) are made so that when
the housing is inflated, the support surface is deformed so as to
have a basin-shaped curved fall prevention profile with raised
ends.
52. The cell according to claim 51, wherein the welds in a line are
identical, and in that the spacing (d) between the welds of a line
is substantially constant.
53. The cell according to claim 51, wherein the two main side
surfaces are welded together via a single oblong weld whereof the
main longitudinal axis is substantially parallel to the main
longitudinal axis of the cell.
54. The cell according to claim 51, wherein the superimposed
inflation chambers have substantially the same volume.
55. The cell according to claim 51, wherein the total length of the
welds of a line or the sole oblong weld is at least equal to 40% of
the total length (L.sub.2) of the inflation chambers.
56. The cell according to claim 51, wherein the maximum width
(L.sub.max) of the upper support surface of the inflated cell is
between 6 cm and 9 cm.
57. The cell according to claim 51, wherein the maximum width
(L.sub.max) of the upper support surface of the inflated cell is
smaller than the height (H') of the inflated cell.
58. The cell according to claim 51, comprising an inflation stem
for inflating/deflating the superimposed chambers of the
housing.
59. The cell according to claim 51, wherein the housing is formed
by a sheet folded in two lengthwise, and welded on three sides of
the periphery thereof using a lower longitudinal weld and two side
welds, the support surface being free of welds.
60. The cell according to claim 59, wherein the distance (e.sub.1)
between each end weld and the adjacent side weld of the housing,
measured along the longitudinal axis of the housing is greater than
or equal to the distance (e.sub.2) between said end weld and the
upper bend line of the sheet forming the housing.
61. The cell according to claim 51, wherein said housing is formed
by two separate sheets welded together over the entire periphery
thereof via at least four welds: a lower longitudinal weld, two
side welds, and an upper longitudinal weld.
62. The cell according to claim 61, wherein the distance (e.sub.1)
between each end weld and the adjacent side weld of the housing,
measured along the longitudinal axis of the housing, is greater
than or equal to the distance (e.sub.2) between said end weld and
the upper weld.
63. The cell according to claim 51, wherein said inflated housing
comprises two end surfaces, and the distance (e1) separating each
end surface from the closest longitudinal weld and which is
measured along the longitudinal axis of the housing, is greater
than or equal to the distance (e.sub.2) separating said
longitudinal weld and the support surface.
64. The cell according to claim 59, wherein said lower longitudinal
weld having a curve profile made so that when the housing is
inflated, the support surface is deformed so as to have a
basin-shaped fall prevention curve profile with raised ends.
65. The cell according to claim 64, wherein said lower longitudinal
weld has a bowed curve profile whereof the apex is oriented towards
the support surface, so that when the housing is inflated, the
support surface is deformed so as to have a basin-shaped fall
prevention curve profile with raised ends.
66. The cell according to claim 64, wherein when the housing is
deflated, the height H.sub.1, between the apex of said lower
longitudinal weld is smaller than the height H.sub.2 at the ends of
the housing.
67. The cell according to claim 64, wherein said lower longitudinal
weld has a curve profile such that the height at the center H.sub.1
of the deflated housing is smaller than the height H.sub.2 at the
ends of the deflated housing.
68. The cell according to claim 66, wherein the height difference
.DELTA.H (.DELTA.H=H.sub.1-H.sub.2) between the heights H.sub.1 and
H.sub.2 is at least equal to 3 cm, and preferably at least equal to
5 cm.
69. An anti-eschar mattress, comprising a plurality of the
inflatable cells according to claim 1, which are positioned
transversely to the longitudinal axis of the mattress, and which
are juxtaposed along said longitudinal axis.
70. An anti-eschar mattress, comprising a plurality of the
inflatable cells according to claim 36, which are positioned
transversely to the longitudinal axis of the mattress, and which
are juxtaposed along said longitudinal axis.
71. An anti-eschar mattress, comprising a plurality of the
inflatable cells according to claim 51, which are positioned
transversely to the longitudinal axis of the mattress, and which
are juxtaposed along said longitudinal axis.
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of inflatable
anti-eschar mattresses used in hospitals or similar settings or in
individual homes, for people confined to bed rest for long periods
of time. The object of the invention is a new inflatable cell for
anti-eschar mattresses, as well as an anti-eschar mattress
including a plurality of inflatable cells.
BACKGROUND OF THE INVENTION
[0002] When a person is bedridden for a long time on a traditional
mattress, the parts of the person's body that are in prolonged
contact with the mattress undergo compressions, which ultimately
cause eschars to form.
[0003] With the aim of offsetting this problem of eschar formation,
one solution known to date consists of proposing anti-eschar
inflatable mattresses, which include a plurality of juxtaposed
inflatable cells. This type of mattress is for example described in
U.S. Pat. No. 5,704,084.
[0004] The cells of an anti-eschar mattress can be inflated
individually using a compressor or equivalent means and according
to a so-called "dynamic" mode characterized by an inflation
sequence and cycle that are predefined, so as to reduce the
compression time of the body parts in contact with the cells of the
mattress. For example, the inflation of every other cell is done
cyclically. The characteristics of this dynamic mode are generally
configurable so as to best adapt them to the bedridden person.
[0005] In this type of anti-eschar mattress inflatable cell, for
the comfort of the bedridden person and for effective draining of
the eschars, it is important to optimize the support surface of the
cell designed to be in contact with the bedridden person. In
particular, if the width of the support surface of each cell of a
mattress is too large, in dynamic mode there is a risk of
tourniquet effect on the bedridden person. Conversely, if the width
of the support surface of each cell is too small, the dynamic
relief effect is no longer felt by the bedridden person.
[0006] Another problem encountered during confinement to bed of a
person in a hospital or similar setting is related to accidental
falls by the bedridden person. This problem is magnified and
becomes critical when the bedridden people have reduced motor
abilities, such as for example people having undergone surgery,
people who are completely or partially paralyzed, or the
elderly.
[0007] With the aim of reducing these risks of accidental falls, in
French patent application FR 2 883 728, a fall prevention
inflatable cell for anti-eschar mattresses has already been
proposed. This cell comprises two outer sheets welded on the
periphery thereof so as to form an inflatable housing, and which
are fastened by circular welding spots to an inner sheet making it
possible to limit the expansion of the housing. Once inflated, the
housing includes a support surface having a basin-shaped fall
prevention profile with raised ends.
[0008] With this type of cell including circular welding spots,
there is, however, a risk, under the repeated effects of
inflation/deflation cycles, of two adjacent individual cells
sliding vertically, relative to each other, resulting in poor
alignment and positioning of the cells, which is detrimental to the
proper operation of the anti-eschar mattress.
[0009] The positioning flaw is even more pronounced in the case
where inflatable cells with horizontal oblong welds are used as
described and illustrated in FIGS. 2 and 3 of U.S. Pat. No.
5,109,560. With this type of cells, to prevent this positioning
flaw, one is thus forced to fasten each individual cell on a
support, which complicates the structure and production of the
anti-eschar mattress.
BRIEF DESCRIPTION OF THE INVENTION
[0010] One aim of the invention is to propose a new inflatable cell
for anti-eschar mattresses making it possible to obtain proper
operation, in dynamic mode, while preventing the aforementioned
risks of sliding and poor positioning of the cell, relative to an
adjacent cell, during repeated inflation/deflation cycles, and
without it being necessary to fasten the cell on a support.
[0011] The first object of the invention is therefore an inflatable
cell for anti-eschar mattresses defined in claim 1. This cell
comprises an inflatable housing having an elongate shape and two
main opposed side surfaces, as well as several oblong welds that
have a main longitudinal axis substantially perpendicular to the
main longitudinal axis of the housing, which are spaced apart along
the length of the housing, and which connect two main opposed side
surfaces of the housing together.
[0012] Another aim of the invention is to propose a new inflatable
cell for anti-eschar mattresses that makes it possible to reduce,
for bedridden people, both the risk of eschar formation and
accidental fall risks.
[0013] The second aim of the invention is therefore an inflatable
cell for anti-eschar mattresses, said cell comprising an inflatable
housing having an elongate shape and two main opposed side
surfaces, as well as an upper surface which, in the inflated state
of the housing, forms an upper support surface; the two main
opposed side surfaces of the cell are welded to each other on at
least three sides of their periphery using at least one lower
longitudinal weld and two side welds, and said lower longitudinal
weld has a curve profile that is made so that when the housing is
inflated, the support surface is deformed so as to have a
basin-shaped fall prevention curve profile with raised ends.
[0014] The third object of the invention is an inflatable cell for
anti-eschar mattresses, said cell including an inflatable housing
having an elongate shape and two main opposed side surfaces, as
well as an upper surface which, in the inflated state of the
housing, forms an upper support surface; said housing is either (i)
formed by a sheet folded in two lengthwise, and welded on three
sides of its periphery using a lower longitudinal weld and two side
welds, and the support surface being free from welds, or (ii)
formed by two separate sheets welded to each other over the entire
periphery thereof using at least four welds: a lower longitudinal
weld, two side welds, and an upper longitudinal weld, said cell
including one or more additional welds that are spaced apart along
the length of the housing, and that make it possible to connect the
two main opposed side surfaces of the housing to each other, the
distance (e.sub.1) between each additional end weld and the
adjacent side weld of the housing, measured along the longitudinal
axis of the housing, being greater than or equal to the distance
(e.sub.2) between said additional end weld and (i) the upper bend
line of the sheet forming the housing, or (ii) the upper
longitudinal weld, such that when the housing is inflated, the
support surface (SP) is deformed so as to have a basin-shaped fall
prevention curve profile with raised ends.
[0015] The fourth object of the invention is an inflatable cell for
anti-eschar mattresses, said cell includes an inflatable housing
having an elongate shape and two main opposed side surfaces, an
upper surface that forms an upper support surface when the housing
is inflated, and one or several oblong welds, the main longitudinal
axis of which is substantially parallel to the main longitudinal
axis of the housing, and which make it possible to connect the two
main opposed side surfaces of the housing to each other, so as to
define, in the housing, at least two superimposed inflation
chambers that communicate with each other; the upper support
surface of the deflated housing has a substantially rectilinear
profile over the entire length of the housing, and the oblong
weld(s) are made so that when the housing is inflated, the support
surface is deformed so as to have a basin-shaped fall prevention
curve profile with raised ends.
[0016] The invention also relates to an anti-eschar mattress
comprising a plurality of the previously cited inflatable cells,
which are positioned transversely to the longitudinal axis of the
mattress, and which are juxtaposed along said longitudinal
axis.
BRIEF DESCRIPTION OF THE FIGURES
[0017] Other features and advantages of the invention will appear
more clearly upon reading the following detailed description of
several preferred embodiments of the invention, this description
being provided as a non-limiting and non-exhaustive example of the
invention, and in reference to the appended drawings, in which:
[0018] FIG. 1 is a perspective illustration of an inflatable cell
for anti-eschar mattresses, made according to a first alternative
embodiment,
[0019] FIG. 2 is a diagrammatic view in transverse cross-section of
the cell of FIG. 1 in cutting plane II-II,
[0020] FIG. 3 is a diagrammatic and partial top view of the cell of
FIG. 1,
[0021] FIG. 4 is a diagrammatic flattened lateral view of the cell
of FIG. 1 (deflated state),
[0022] FIG. 5 is a diagrammatic flattened front view of an
inflatable cell for anti-eschar mattresses, done according to a
second alternative embodiment,
[0023] FIG. 6 is a diagrammatic flattened front view of an
inflatable cell for anti-eschar mattresses, done according to a
third alternative embodiment,
[0024] FIG. 7 is a perspective illustration of a cell of an
anti-eschar mattress, inflated and done according to a fourth
alternative embodiment of the invention,
[0025] FIG. 8 is a flattened diagrammatic illustration of the cell
of FIG. 7 in the deflated state,
[0026] FIG. 9 is a diagrammatic transverse cross-section of the
cell of FIG. 7 in plane IX-IX,
[0027] FIG. 10 is a top view of the cell of FIG. 7,
[0028] FIG. 11 is a transverse cross-section in plane XI-XI of the
cell of FIG. 8,
[0029] FIG. 12 is a longitudinal cross-section in plane XII-XII of
the cell of FIG. 6,
[0030] FIG. 13 is a diagrammatic side view of a set of cells
according to the invention that are juxtaposed, so as to form an
anti-eschar mattress,
[0031] FIG. 14 is a diagrammatic side view of a set of cylindrical
cells of the prior art that are juxtaposed, so as to form an
anti-eschar mattress,
[0032] FIG. 15 is a diagrammatic flattened side view of a cell in
the deflated state, done according to a fifth alternative
embodiment of the invention,
[0033] FIG. 16 is a diagrammatic flattened front view of an
inflatable cell for anti-eschar mattresses, done according to a
sixth alternative embodiment of the invention,
[0034] FIG. 17 is a diagrammatic flattened front view of an
inflatable cell for an anti-eschar mattress, done according to a
seventh alternative embodiment of the invention,
[0035] FIG. 18 shows a cell, in the inflated state, made according
to an eighth alternative embodiment of the invention,
[0036] FIG. 19 is a diagrammatic side view of the cell of FIG.
18.
DETAILED DESCRIPTION OF THE INVENTION
[0037] FIGS. 1 and 4 show an inflatable individual cell 1 for an
anti-eschar mattress, according to a first alternative embodiment
of the invention. In FIG. 1, the cell 1 is inflated. In FIG. 4, the
cell 1 is shown flat, deflated.
[0038] This cell 1 includes an inflatable housing 2 having an
elongate shape and a longitudinal main axis 2a. In the illustrated
example, this housing 2 is made up of a substantially rectangular
sheet 20 made from a heat-weldable material, and for example
polyurethane. When the cell is deflated, this sheet 20 is folded
over in two lengthwise along a substantially rectilinear
longitudinal upper bend line 20a (diagrammed by a broken line in
FIG. 3). In FIG. 3, the two longitudinal edges of the sheet 20 that
are folded one on top of the other are referenced 20b, and the two
side edges of the sheet 20 that are folded one on top of the other
are referenced 20c.
[0039] The folded sheet 20 is heat-welded on three sides of its
periphery using a lower longitudinal weld 4 (opposite the upper
weld 20a) with length L.sub.2, smaller than length L.sub.1 of the
sheet 20, and two side welds 5 that extend said longitudinal weld 4
at both of its two, and that extend to the upper longitudinal bend
line 20a of the sheet 20.
[0040] The two surfaces 20d, 20e of the sheet 20 (FIGS. 1 and 4)
that are folded one on top of the other form the two main side
surfaces of the inflatable housing 2.
[0041] The lower longitudinal weld 4 has a particular curved bowed
profile whereof the apex 4a is oriented towards the upper bend line
20a. In reference to FIG. 4, the distance H.sub.2 between this apex
4a of the weld 4 and the upper bend line 20a that corresponds to
the upper longitudinal edge of the deflated housing 2, is smaller
than the height H.sub.1 of the side welds 5. Dimension H.sub.2
corresponds to the height at the center of the deflated housing 2,
and dimension H.sub.1 corresponds to the height at the ends of the
deflated housing 2.
[0042] The housing 2 also contains an inner sheet 6 made from a
heat-weldable material, and for example polyurethane, that has been
positioned between the two surfaces 20d, 20e of the sheet 20 folded
one on top of the other, before heat-welding of the two surfaces
20d, 20e.
[0043] Each main surface 20d, 20e of the housing 2 is fastened to
the inner sheet 6, using vertical oblong heat welds 7A and 7B, with
main longitudinal axis 7a, length L.sub.3 and width l.sub.3
(L.sub.3>l.sub.3). The main longitudinal axis 7a of the welds
7A, 7B is substantially perpendicular to the main longitudinal axis
2a of the housing 2, and the welds 7A, 7B are spaced apart along
the length of the housing 2. Each weld 7A, 7B includes a peripheral
edge 7b forming a closed oblong contour.
[0044] Preferably, for better solidity, at a weld 7A or 7B, the
surface 20d or 20e of the sheet 20 is welded on the entire surface
situated inside the peripheral edge 7b. In another alternative, the
surface 20d or 20e of the sheet 20 can be welded only along a thin
weld corresponding to said oblong peripheral contour 7b.
[0045] In reference to FIGS. 1, 3 and 4, the oblong heat welds 7A
correspond to the welds of the surface 20d of the housing 2 with
the inner sheet 6, and the oblong heat welds 7B (in broken lines in
FIGS. 1 and 4) correspond to the welds of the other surface 20e of
the housing 2 with the inner sheet 6. These welds 7A and 7B
alternate along the length (direction Y) of the housing 2.
[0046] The welds 4 and 5 and the oblong welds 7A, 7B are for
example made by high frequency welding.
[0047] In the alternative of FIG. 4, the welds 7A and 7B are all
identical. This feature is not, however, essential.
[0048] In the alternative of FIG. 4, the welds 7A (7B,
respectively) of a surface 20d (20e, respectively) are
substantially equidistant along the longitudinal axis 2a of the
cell. This feature is not, however, essential.
[0049] The invention is not limited to the particular number of
welds 7A, 7B of FIG. 4, the cell according to the invention being
able to include more welds 7A, 7B or fewer welds 7A, 7B than the
alternative of FIG. 4. The number of welds 7A, 7B and their spacing
depends in particular on the length of the inflatable housing.
[0050] In one 20d of the main surfaces of the housing 2, an opening
3 is formed to allow air to pass. The cell 1 includes an inflation
stem 8, for example made from plastic, that can integrate a valve,
and that allows fast inflation and deflation of the housing 2. This
stem 8 is fastened, for example by gluing, on the housing 2 at the
opening 3. This stem 8 is intended to be connected to a compressor
(not shown), for example using a flexible tubing to allow the
inflation and deflation of the housing 2 of the cell 1.
[0051] When the cell is inflated, the upper surface of the inflated
cell that extends on either side of the bend line 20a forms an
upper support surface SP (FIGS. 1 and 2) with which the body of the
bedridden person comes into contact.
[0052] In the particular alternative of FIGS. 1 to 4, this support
surface SP is for example free from welds, and is advantageously
smooth.
[0053] To make an anti-eschar and fall prevention mattress M
according to the invention, a plurality of cells 1 are juxtaposed
against each other along longitudinal axis X, each cell 1 being
positioned perpendicular (axis Y) to this longitudinal axis X, and
the main surface 20d of a cell being in contact with the main
surface 20e of an adjacent cell.
[0054] Also, preferably fastened on the housing 2 of the cell is a
means 9, for example snap fasteners, making it possible, if
necessary, to quickly assemble two adjacent cells 1 together, when
the mattress is formed. The cells 1 are placed on a support plane
such as a box spring, without being fastened to said planar
support.
[0055] In a known manner, when the mattress M is used, all of the
cells 1 are not inflated at the same time, but are inflated and
deflated individually according to a programmed cycle, so as to
cyclically modify the compression points on the body of the person
lying on the mattress, which makes it possible to reduce the risk
of eschar formation.
[0056] When a cell is inflated, each portion 20f of the main
surface 20d (20e, respectively) of the housing 2 situated between
two adjacent welds 7A (7B, respectively) advantageously forms,
owing to the implementation of vertical oblong welds 7A (7B,
respectively), a mat whereof the outer surface is only convex over
the entire height of the housing 2, and does not include a concave
portion, unlike what can be obtained with a cell according to FIG.
1 of application FR 2 883 728, for example, or from the cells
according to FIGS. 2 and 3 of U.S. Pat. No. 5,109,560. The risks of
vertical sliding and poor height positioning of a cell 1 relative
to an adjacent cell are thus avoided during repeated
inflation/deflation cycles of the cells of the mattress.
[0057] Preferably, but not necessarily, the oblong welds 7A, 7B are
substantially centered between the lower longitudinal weld 4 and
the upper longitudinal edge of the deflated housing 2, i.e. in the
alternative of FIG. 4, the upper weld 20a.
[0058] The length L.sub.3 of each weld 7A, 7B is chosen so as in
particular to obtain the formation of the aforementioned mats 20f
with the solely convex surface. Preferably, but not necessarily,
the length L.sub.3 of each weld 7A, 7B is at least equal to 30% of
the maximum height H.sub.1 of the deflated housing 2 (FIG. 4)
and/or preferably at least equal to 50% of the height H.sub.4 of
the inner sheet 6 serving to limit displacement.
[0059] In the alternative of FIGS. 1 to 4, the inner sheet 6 serves
to limit the expansion of the housing 2 in direction X, which is
perpendicular to the two main surfaces 20d, 20e of the housing 2,
and thereby makes it possible to limit the width of the inflated
housing 2. It also makes it possible, combined with the oblong
welds 7A, 7B, to obtain a cell 1 that is mechanically robust, and
whereof the welds 7A, 7B are not altered after intensive use.
[0060] In another alternative embodiment, the cell could be
provided without an inner sheet 6 and the main surfaces 20d, 20e
could be welded to each other directly using vertical oblong welds
7A, 7B in a manner comparable to the cell of FIG. 7 described below
whereof the two main surfaces 20d, 20e are welded together using
horizontal oblong welds 7.
[0061] In the alternative of FIGS. 1 to 4, owing to the use of a
bowed lower longitudinal weld 4 with a height H.sub.2 smaller than
the height H.sub.1, when the housing 2 is inflated, the upper
support surface SP is advantageously automatically deformed so as
to have a curved fall prevention profile forming a basin oriented
along the longitudinal axis 2a of the cell with raised ends 20g
(FIG. 1). This basin-shaped profile with raised ends 20g
advantageously makes it possible to hinder the sliding in direction
Y of a person lying on a mattress M including cells juxtaposed in
direction X, and thus to laterally stabilize said person in a
central position on the mattress M. The risk of accidental fall is
thereby greatly reduced.
[0062] The larger the height difference .DELTA.H between the
heights H.sub.1 and H.sub.2 (.DELTA.H=H.sub.1-H.sub.2), the greater
the deformation of the basin-shaped support surface SP. To obtain
an effective fall prevention effect, the height difference .DELTA.H
between the heights H.sub.1 and H.sub.2 is preferably, but not
necessarily at least equal to 3 cm, and still more preferably at
least equal to 5 cm.
[0063] The longitudinal weld 4 may have another curve profile
making it possible to obtain the basin-shaped fall prevention
profile for the support surface SP, when the housing 2 is inflated.
In particular, the longitudinal weld 4 could have another curve
profile making it possible to obtain a height H.sub.2 at the center
of the housing smaller than the height H.sub.1 at the ends of the
housing 2.
[0064] In the particular embodiment of FIG. 4, the apex 4a of the
lower longitudinal weld 4 is substantially centered relative to the
housing 2 along the longitudinal axis 2a of the housing. This
feature, although preferable, is not, however, essential.
[0065] In the alternative of FIG. 4, the smallest distance e.sub.1
between each end weld 7A and the adjacent side weld 5 of the
housing, measured along the longitudinal axis 2a of the housing, is
greater than or equal to, and preferably greater than, the smallest
distance e.sub.2 between said weld 7A and the upper bend line 20a
of the housing 2. This advantageously results in increasing the
raising of the ends 20g of the basin-shaped support surface SP,
when the housing 2 is inflated. In FIG. 4, the distance e1 is
substantially equal to the distance e2. If one wishes to more
substantially increase the raising of the ends 20g of the support
surface SP, one will preferably use a distance e1 greater than the
distance e2, as is done for example for the alternative of FIG. 16
described below.
[0066] This dimensional characteristic (e1.gtoreq.e2) is, however,
optional to obtain the fall prevention profile, when a lower weld 4
having the curve profile of FIG. 4 is used. As an example, FIG. 5
shows another alternative embodiment in which the distance e1 is
smaller than the distance e2, and which nevertheless makes it
possible to obtain a basin-shaped fall prevention profile for the
support surface SP of the cell, owing to the use of the curved
longitudinal lower weld 4.
[0067] The table below provides, as an example of an embodiment,
specific values (in mm) for the main dimensions of the cells shown
in FIGS. 4 and 5. These specific values are not limiting for the
invention. For these specific dimensions, the inner sheet 6 used is
for example a rectangular sheet with a length L.sub.4 of 950 mm, a
width H.sub.4 of 180 mm, and a thickness of 0.2 mm.
TABLE-US-00001 FIG. L1 L2 H.sub.1 H.sub.2 L.sub.3 l.sub.3 e.sub.1
e.sub.2 4 990 910 300 250 102 20 90 90 5 990 910 300 250 102 20 70
90
[0068] FIG. 6 shows another alternative embodiment, which makes it
possible to obtain a support surface having a basin-shaped fall
prevention profile. In particular, this alternative of FIG. 6 uses
a lower longitudinal weld 4 having a curve profile that makes it
possible to obtain a support surface SP with a basin-shaped fall
prevention profile, when the housing 2 is inflated.
[0069] More particularly, the alternative of FIG. 6 differs from
the alternative of FIG. 4 mainly by the use of pairs of circular
welds 7'A (7'B, respectively) replacing the oblong welds 7A (7B,
respectively). Unlike the alternative of FIG. 4, this alternative
does not, however, make it possible to obtain the aforementioned
mats 20f with a solely convex surface.
[0070] FIGS. 7 and 8 show an individual inflatable cell 1' for an
anti-eschar mattress, according to another alternative embodiment
of the invention. In FIG. 7, the cell 1 is inflated. In FIG. 8, the
cell 1' is shown flat and deflated.
[0071] Identically to the cell 1 of FIG. 1, this cell 1' includes
an inflatable housing 2 having an elongate shape and a longitudinal
main axis 2a. This housing 2 is made up of a substantially
rectangular sheet 20 made from a heat-weldable material, and for
example polyurethane. This sheet 20 is folded over in two
lengthwise following a longitudinal upper bend line 20a. Out of a
concern for simplification, the shared elements between this cell
1' of FIG. 6 and the cell 1 of FIG. 1 use the same references.
[0072] The folded sheet 20 is heat-weldable on three sides of the
periphery thereof using a lower longitudinal weld 4' with length
L.sub.2, smaller than length L.sub.1 of the sheet 20, and two side
welds 5 that extend said longitudinal weld 4' at both ends thereof,
and which extend to the upper longitudinal bend line 20a of the
sheet 20.
[0073] Unlike the cell 1 of FIGS. 1 and 3, the lower weld 4' is not
curved, but rather is substantially rectilinear.
[0074] Unlike the cell 1 of FIGS. 1 and 3, the cell 1' does not
have an inner sheet 6 serving to limit displacement, and the two
main side surfaces 20d, 20e of the inflatable housing 2 are
heat-welded directly to each other using an oblong weld 7, with
longitudinal axis 7a, length L.sub.3 and width l.sub.3
(L.sub.3>l.sub.3). Each weld 7 includes a peripheral edge 7b
forming a closed oblong contour.
[0075] Preferably, for better solidity, at a weld 7, the two
surfaces 20d, 20e of the sheet 20 are welded over the entire
surface situated inside the peripheral edge 7b. In another
alternative, the two surfaces 20d, 20e of the sheet 20 can be
welded only along a thin weld corresponding to said oblong
peripheral contour 7b.
[0076] The welds 7 are oriented so that the main longitudinal axis
7a thereof is substantially parallel to the main longitudinal axis
2a of the housing 2. The welds 7 are also positioned relative to
each other spaced apart and aligned along the main longitudinal
axis 2a of the housing 2.
[0077] The welds 7 make it possible to define, in the housing 2,
two superimposed chambers, i.e. a lower chamber 2b and an upper
chamber 2c (FIG. 10), which extend over the entire length L.sub.2
of the housing 2, and which communicate with each other owing to
spaces E (FIG. 7 and FIG. 11) between the welds 7.
[0078] During inflation of the housing 2, the air that is blown
into the lower chamber 2b, via the inflation stem 8, spreads in
said chamber 2b and, owing to the spaces E (FIGS. 7 and 11) between
the welds 7, this air also easily penetrates the upper chamber 2c
of the housing 2 while being advantageously distributed over the
entire length of the housing 2. Once the housing 2 is inflated with
air, said housing 2 forms two superimposed air cushions C1, C2
(FIG. 11) corresponding respectively to the two chambers 2b and 2c
defined by the weld 7.
[0079] Conversely, when the housing 2 is deflated, the air
contained in the upper chamber 2c can be evacuated quickly through
the stem 8 by passing through the lower chamber 2b, which allows
fast deflation of the two cushions C1 and C2.
[0080] In the alternative embodiment of FIGS. 7 and 8, the welds 7
are identical and the distances d between two adjacent welds 7,
measured along the longitudinal axis 2a of the housing, are
identical. In another alternative, the welds 7 can have a different
oblong shape, and can also not be identical; the spacing d between
welds 7 is not necessarily constant. In the alternative embodiment
of FIGS. 7 and 8, four aligned and spaced welds 7 are used. This
particular number of welds 7 is not limiting.
[0081] In the alternative shown in FIGS. 7 and 8, the weld 7 is
made substantially at mid-height H of the housing 2, such that the
cushions C1, C2 advantageously have substantially the same volume.
In another alternative of the invention, the height position of the
weld 7 may nevertheless be different, and the volumes of the two
cushions C1 and C2 may thus be different.
[0082] It is understood that the distance d between two adjacent
welds 7 influences the ability of the air to pass more or less
easily from one chamber 2b to the other 2c, and thereby influences
the ease and speed of inflation of the cushions C1 and C2. The
larger this distance d between two welds 7, the easier the
inflation and deflation of the two cushions C1, C2. Conversely, the
length of the welds 7 must be long enough to obtain a mechanical
strength of the welds 7 that is both sufficient and reliable over
time. It is therefore appropriate to select the length L.sub.3 of
the welds 7 and the distance d between welds 7 taking these two
contradictory constraints into account. In the alternative
embodiment of FIGS. 1 and 2, this distance d between two adjacent
welds 7 is slightly larger than the length L.sub.3 of a weld 7. In
another alternative, this distance d between two adjacent welds 7
could be equal to or smaller than the length L.sub.3 of a weld 7.
Preferably, but not necessarily, the total length of the welds 7
(sum of the lengths L.sub.3) is at least equal to 40% of the total
length L.sub.2 of the inflation chambers 2b, 2c.
[0083] For reasons of vertical stability of the cell during
inflation/deflation operations, it is preferable for the housing 2
of the cell 1 to include only two superimposed chambers 2b, 2c
corresponding to the superimposed cushions C1 and C2. However, in
the context of the invention, it is also possible to consider
making a cell including at least two oblong welds 7, which are
spaced apart along the height H of the cell, so as to define at
least three superimposed inflation chambers (or three superimposed
air cushions), each chamber communicating with the adjacent chamber
via spaces between welds.
[0084] FIG. 13 diagrammatically shows an anti-eschar mattress M
according to the invention made using a plurality of cells 1' that
are juxtaposed against each other along the longitudinal axis X of
the mattress, each cell 1' being positioned perpendicular to said
longitudinal axis X (longitudinal axis 2a of each cell 1
perpendicular to axis X).
[0085] In a known manner, when the mattress M is used, all of the
cells 1' are not inflated at the same time, but are inflated and
deflated individually according to a programmed cycle, so as to
cyclically and dynamically modify the compression points on the
body of the person lying on the mattress, which makes it possible
to reduce the risks of eschar formation, and makes the bedridden
person feel a dynamic relief effect. In this particular example of
FIG. 13, but non-limitingly, during each cycle, every other cell 1
is inflated and the remaining cells 1 are deflated. This particular
dynamic mode corresponds to a use of the mattress for anti-eschar
preventive care with 50% lift. It is also possible in another
dynamic mode to divide the mattress into several groups of n cells
(n.gtoreq.3), and during successive cycles to deflate, in each
group of cells successively, one cell out of the n cells, the other
cells in the group being inflated. This dynamic mode corresponds to
a use of the mattress for curative care. In this particular dynamic
mode, the use of cells according to the invention allows better
vascularization of the cutaneous tissue of the bedridden
person.
[0086] The weld 7 of each cell 1' advantageously makes it possible
to limit the lateral expansion of the cell 1, i.e. in the
longitudinal direction X of the mattress, and advantageously to
obtain a cell 1 that, once inflated, has an upper support surface
SP with a small maximum width L.sub.max (FIGS. 10, 11) and a height
H' when inflated that is larger than said maximum width L.sub.max.
Advantageously, the upper support surface SP is free from
welds.
[0087] By using cells 1' whereof the maximum width L.sub.max of the
support surface SP of the inflated cell is small, it is
advantageously possible, for a same mattress length M, to use a
larger number of juxtaposed cells, compared to inflatable cells C,
for example (FIG. 14), requiring the same volume of inflation air
and forming cylindrical rolls when inflated. During each cycle, the
width e of the spaces between two adjacent inflated cells 1 is
advantageously reduced, and the total contact surface between the
bedridden person and the support surfaces SP of the inflated cells
is increased. A better distribution is thus obtained of the weight
of the bedridden person over the entire length of the mattress M of
cells 1', and excessive localized compressions are avoided on the
bedridden person. In this way, unlike the prior art solution shown
in FIG. 14, the risks of "tourniquet effect" are advantageously
eliminated at the bearing zones of the body on the cells 1.
Moreover, owing to the use of at least two superimposed air
cushions C1, C2 on each cell, the height H' of the inflated cell 1
is increased, and one significantly improves the comfort of the
bedridden person and the eschar treatment.
[0088] It should be noted that the maximum width L.sub.max of an
inflated cell 1' must preferably also not be too small. Indeed, if
this width L.sub.max is too small, the total contact surface in
each cycle between the bedridden person and the support surfaces SP
of the inflated cells can become too large, and eliminate the
dynamic relief effect for the bedridden person. In practice, it is
preferable for this total contact surface to be between 50% and
75%.
[0089] For information and non-limitingly, the cell 1' according to
the invention is preferably designed to have a maximum width
L.sub.max when inflated between 6 cm and 9 cm. More particularly,
in one preferred embodiment, the cell 1' has been designed to have
an optimized maximum width L.sub.max in the vicinity of 7 cm to 8
cm.
[0090] In reference to FIG. 7, according to another advantageous
feature of the invention, the two main side surfaces 20d, 20e of
the housing 2 are welded to each other so that once inflated, the
housing 2 includes an upper support surface SP having a
basin-shaped fall prevention profile with raised ends 20g. These
raised ends 20g advantageously make it possible to hinder lateral
sliding (FIG. 7/axis Y) by a person lying on the mattress M, and to
laterally stabilize the person in a central position on the
mattress M. Accidental fall risks are thereby very significantly
reduced.
[0091] In the particular alternative embodiment shown in FIGS. 7
and 8, when deflated, the upper support surface SP of the housing 2
is substantially rectilinear (FIG. 7). The two main side surfaces
20d, 20e of the housing 2 are welded together so that the inflation
of the housing 2 causes a deformation of the support surface SP of
the housing 2 in the form of a basin with raised ends 20g (FIG. 7).
To obtain this deformation of the housing 2, the two end welds 7
should be carefully positioned as close as possible to the side
welds 5, so that when the housing 2 is inflated, these end welds 7
exert, relative to the side welds 5, a traction making it possible
to raise the upper ends 20g, as illustrated in FIG. 7. In this
alternative, this is obtained in particular by providing, between
each end weld 7 and adjacent side weld 5, a distance e.sub.1
measured along the longitudinal axis 2a of the housing that is
equal to or slightly larger than the distance e.sub.2 (measured
perpendicular to the longitudinal axis 2a) between said weld 7 and
the upper bend line 20a of the sheet 20 forming the housing 2.
Specific Example of Sizing of the Cell 1'
[0092] As a non-limiting example of the invention, in one specific
embodiment, the cell 1' had the following main dimensions:
L.sub.1=100 cm; L.sub.2=90 cm; L.sub.3=10 cm; l.sub.3=1.8 cm; d=11
cm; H=26 cm; H'=18 cm; H''=23 cm; L.sub.max=8 cm; L.sub.min=7 cm;
e.sub.1=11.5 cm; e.sub.2=11 cm.
[0093] FIG. 15 shows another alternative embodiment of a cell 1'
according to the invention including a single oblong weld 7.
[0094] FIG. 16 shows another alternative embodiment of a cell 1''
according to the invention, which, comparably to the alternative of
FIG. 7, includes an oval oblong weld 7 whereof the longitudinal
axis 7a is substantially parallel to the longitudinal axis 2a of
the cell, and which differs from the alternative of FIGS. 7 and 8
mainly by the use of a lower longitudinal weld line 4 that has a
curve profile similar to that of the alternative of FIG. 1, so as
to obtain the basin-shaped fall prevention profile for the support
surface SP. In this alternative, the distance e1 is also much
larger than the distance e2 so as to increase the raising effect of
the ends 20g of the housing 2 during inflation thereof, and to
improve the fall prevention effect.
[0095] FIG. 17 shows another alternative embodiment of a cell 1'''
according to the invention, which differs from the cell of FIG. 16
only by the use of two separate sheets 20d, 20e, instead of a
single sheet 20 folded in two. These two separate sheets 20d, 20e
are welded together over the entire periphery thereof using four
welds: the three welds 4, 5 previously described, and an additional
upper longitudinal weld 11, which replaces the bend line 20a. When
the housing 2 of this cell of FIG. 17 is inflated, the support
surface SP extends on either side of this upper weld 11.
[0096] Similarly to this alternative of FIG. 17, the cells of FIGS.
1, 5, 6, 7 and 15 previously described may also be modified so as
to replace the sheet 20 folded in two (with upper bend line 20a)
with two separate sheets 20d, 20e welded along a closed contour by
a lower longitudinal weld 4 (or 4') extended at both ends thereof
by two side welds 5, which themselves are connected to each other
by an upper longitudinal weld 11.
[0097] FIG. 18 shows another alternative embodiment of a cell
according to the invention including an inflatable housing 2
having, when inflated, two main side surfaces 20d, 20e, an upper
support surface SP, a lower bottom surface F, and two end surfaces
F'. This cell also has a substantially rectangular inner sheet 6',
which makes it possible to limit the expansion of the thickness of
the cell (direction X). The main surface 20d of the cell is welded
to one of the longitudinal edges of the inner sheet 6' using an
oblong longitudinal weld 7. The other main surface 20e of the cell
is welded to the other longitudinal edge of the inner sheet 6'
using an oblong longitudinal weld 7.
[0098] In this alternative, the housing of the cell also includes
outer reinforcing welds S (shown in thicker lines) that, at the two
end surfaces F' of the cell, have a -shaped profile and allow the
cell to be shaped. When the housing of the cell is inflated, the
inner sheet 6' is substantially horizontal, i.e. substantially
perpendicular to the two main side surfaces 20d, 20e, and the
housing forms two superimposed cushions C1, C2.
[0099] The oblong side welds 7 do not extend to the two end
surfaces F' and each have a length L.sub.3 small enough that when
the housing is inflated, the upper support surface SP is deformed
so as to have a basin-shaped fall prevention profile with raised
ends 20g (smaller volume at the center of the housing than the
volume of the housing at its ends). More particularly, to obtain
this fall prevention profile, the distance e1 separating each end
of a longitudinal weld 7 from the adjacent end surface F' and that
is measured along the longitudinal axis 2a of the housing, is
greater than or equal to the distance e.sub.2 separating said end
of the weld 7 and the support surface SP, and which is measured
along direction (Z) perpendicular to the longitudinal axis 2a.
[0100] The cell of FIGS. 18 and 19 can also be modified by
replacing a longitudinal weld 7 with several shorter longitudinal
welds 7 spaced apart in the longitudinal direction 2a of the cell,
in a manner comparable to the alternative previously described in
FIG. 7.
* * * * *