Note: Descriptions are shown in the official language in which they were submitted.
CA 02112688 2005-11-04
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l
CUSHIONING STRUCTURE
FIELD OF THE INVENTION
This invention relates to a fluid inclusive,
composite, cushioning structure in which a
plurality of elements are formed to enclose a fluid
that is responsive to outside impsct forces and to
reduce the damaging effects of such forces. xore
particularly, it relates to structures having
pliable cells that are filled with air or other
gaseous fluids to cushion impacts, such as air
bubble and air bag devices, in which the air
compresses under the forcos of suddenly applied
impact loads to resist the forces, thereby
cushioning the load. Even more particularly, the
interval flow of fluid is in a controlled manner to
reduce the rebound of the impacting body.
WO 93/00845 PGT/U592/05533
. e. r,l ~ 1
2
The general problems of damage caused by
suddenly applied impact loads era wall recognised.
Such damages include breakage and destruction of
property as wall as injury to persons.
Eecause the occurrence of such impact loads is
beyond the control of those who have a need to ship
products in commerce by rail, truck, or air and
other common carrier transportation, a most coon
approach ~to the problem is to provide packaging
io material and cushioning material i~ ~ positi~n
ar~u~nd -the ~ o~ j ant in v a ~ shipping ~ c~ntainsr 'to sbs~rb,.~;
;; ._.
the - impacts baf~re ~ -tBse~r ' have a damaging effect on ~.,
the contents rieing~snipped. ,
In a like menHaer, pexsons who are likely to be
subjected to impacts either by falling or contact
in sports Such as football and other "contact's .
sports often employ cushioning materials in the
forrr~n of padding t~ absorb hoe impacts:
Elderyy persons aye particularly susceptible
2~ to injury~ primarily broken bones; through falls
and sudden a~~pac°ts. h maj~r problem for the
elderly; wh~ are f~x~aing an increasing, p~rtion of
the populati~n; is ~uscegtibility to broken bones
from falls andl sudden pacts: Pe~eons of a~
2 ~ ~dvancad age f iaad it veer di f f icult to r~covar from
such injuries, and br~k~n hips mnd ,j~ints ~sft~n
' ~ lead to c~mpli~~tiora~ shortening l~.fe:
7Cn still. ~ther instances s~me items or
:products ragulerly receive and resist impacts: in
3~ chair normal operation. For instance, the soles of
~sh~es .:..mmnd the treads ~f tires ~r ob j ects which
repetitively rec~iv~ imparts in n~ra~al operation. '
In recant ~esrs; a~ called "athletic" oz° "walking~'
shoes have b~~n provided with soles snd insol~as
35 that are thought to ba helpful in cushioning the
WO 93/00845 P~'/LJS92/05533
3
impacts of walking. dogging, and other strenuous
endeavor. The cushioning structure ~f this
invention is especially useful for this
application.
7Cn still other instances~ design and
construction efforts have been directed to
cushioning the impacts of automobile collision with
cushioning materials that are particularly light in
weight but offer good cushioning perfor~aanca if
such i~apaet collisions occur. ~pacfal mat~riala ~ pct
the 'framework . . of v~hieles are prov$~~d lor.~'-:,this
purpose r The cushioning : atruct~ira of .;. this ''
invention is especially a~s~ful' . ' for this
application.
Because packing materials add to the weight
and volume of the. freight and obj~cts being
shipped, lightweight and compactness are ob3ective
features addressed by the prior art as well a~ aaany
of the products presently in use. ~Iowever, such
objectiv~ss should be ideally sought . wfout a
reduction in the perf~rmance of the mater~.sl. It
is era object of the present invention to achi~ve a
~~acimum capability f~r the abs~rptiora bf impact 8nd.
energy impa~°ted t~ the material by the forces
impacting ors the structure with a ~ainimum energy
available for ra~bound. It ~s a further objeet to
provide an improvedl ratio of material ussge,
material cost, and energy absorptibn by means of
the unicpae f~rr~ and geometrieal shapes of the
3~ elements in the structure and their rtlation to
sash other. While prior practitioners have used
some of the form and features of the present
invention their unicgue combination presented he~c~in
has not been previously taught.
35 lrlthough the prior art addresses many of the
WCD 93/10&65 ~'C'I'/dJ~9~/05533
_., »J
r;:~ ~ ~~ ~ ~ ii i'~ ~,3
relevant factors that bear on the construction of
an improved cushioning structure, none teach the
unique form found in the cushioning structure of
this invention.
~ Y ~F ~E Il~EN2~~N
. In summary, this invention is a cushioning
structure for dampening shocks comprising one or
more planar stratum or sheets of pliable material
having a~plurality of cell structures bonded and
ltd seal~d~thereto with each cell, structure comprisi
a polygon including ~a. plurality - of : ,° walls ita -:.~r.
upstanding. relationship r:-::.t~ : ~ the: plane ~f a ::
stratum.. Each c~11 is cl~s~d and sealed at each
end, with at least hne end being one stratum, so
that each cell structure comprises a sealsad
enclosure having a fluid the;~°ein. Each cell is
connected to adjacent cells by way of a restricting
airway that acts as a va7.ve which can be varied
during fabrication by ad~u~ting the gatio of the
2A cell volume to he cross~sehti~n of the connecting
airway cross sectional area.
In a preferred Saab~diment; the structure
includes two s~~et~ of plastic material such as
polyethylene or pol~vinylsthyler~e Qf a thin plialale
compounding composition; with heatagonally shaped
cells that are boaa~ed t~ an overlay seccand sheet in
such a way as to permit controlled airflow between
adjacent cells. ~lith the proper spacing of the
hexagonal cells, two of the described assemblies
3~ can .be meshed or ~aated together with the inside
cell: oW one assembly nesting into the spaces
between the cells of the second as~eambly. the cell
walls are bonded to the outside sheets and
co~unication aneans are provided between adjacent
35 cells so that the air or gas may pass from bne cell
CA 02112688 2005-11-04
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to the next when an impact force strikes a
localized area on the surface of the structure and
the air is restricted or slowed from re-entering
the original cell in order to reduce the nor~o~al
5 rebound.
In another embodiment, the invention includes
a cushioning material structure of resilient
material~formed into the structure comprising: (a)
a plurality of generally planer and oppoainq
1o lateral sides, having a plurality of indentures
formed in one or more of the opposing sides in the
general configuration of a grid like surface on the
sides: (b) the indentures are constructed in
geometric shapes with walls of structural integrity
resulting from thair.shape and arranged in a grid
in repeating patterns that provide a continuum
performance laterally throughout the structure.
Appropriate selection of material, wall
thicknesses, and the connecting cross-sectional
areas between the cells, provides the means for
optimizing the performance of the structure in
absorbing the energy of impact that is delivered to
the surface of the material while minimizing the
amount o! rebound from the structure. By using an
appropriately selected combination of different
connecting cross-sectional areas throughout the
structure, the resistance to different kinds and
quantities of impacts can be provided to produce
the del~ired deceleration.
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5a
In accordance with one aspect of the present
invention, there is provided a cushioning structure
including resilient foamed material having generally planar
and opposing first and second lateral sides and a plurality
of indentures formed in a repeating pattern in said first
side to provide a continuum of cushioning performance
throughout the structure, characterised in that: said
indentures in said resilient foamed material define
geometric shapes with structurally integral walls; the
cushioning structure further includes a first planar stratum
sealingly bonded to said first side of said foamed material
closing the indentures to form cells; and fluid passage
means are provided between adjacent cells for the transfer
of fluid therebetween resulting from a pressure increase in
one or more cells as a consequence of shock loads upon an
outer surface of said first stratum; whereby said cushioning
structure provides a continuum of cushioning performance
laterally throughout the structure.
The foregoing and other advantages of the
invention will become apparent from the following disclosure
in which preferred embodiments of the invention are
described in detail and illustrated in the accompanying
drawings. It is contemplated that variations and structural
features and
~Vfl 93/OO8d5 PCT/LJS92/05533
6
arrangement of parts may appear to the person
eltilled in the art, with~ut departing from the
scope of sacrificing any of the advantages of the
invention which is delineated in the included
claims.
BRIEF ~E~~~~2vnw n~ E DR w~~r-~
Figure 1 is a partial schematic sectional
perspective view of a portion of the structure ~f
this invention.
~ ,F~~re , ~~ is . ~ ,.T paxtial . ele~at3onal section .
view of the ~ structure on. the liaae ~,~r~~, of F'i
..y~.,; v.' 1 '..... ,. . . n . n W m Y, ~~'~.N .9 .. w .. , a a ' ,
..:. rz ,x
~ ~.I, ~ . .. ., , . ~ . ., ;.. .,' . ..
,:, , . , : : _ , : . . ~. .. . . . .
Fi~are ~B is a partial _'elevatfonal section
vi~w of another embodim~nt of this invention from
Z5 the sa9oae position as Figbare ~~.
Figure 3~ is a partial ~che~atic s~~tional
plan view of a portion ~f ~nr~ottaer odi~ent of the
structure of this invention.
Figure 38 i~ a partial ele~rational sect~:on
2~ view of a portion of the structure talon ont he
line 3E--3E of Figure ~~.
Fic,~r~ ~~ i~ a partial plan view -of another
ea~aodiment ~g his invents~n:
dire ~~ is ~ partial eleva~tional section
~~~~w ta~~n. ~n eline ~~°°~~of Figure 'UAe
F~:gure 5 as a sects~nal elevation view of
° another e~odi~ent of the inyenti~n:
figure ~ is a partial elevational section view
of araot3~er eadi~ent taf this invention.
3~ Figure 7 is a partial schematic sectional
perspee:tive va.ew of ~ p~rti~~ of mother embodiment
~f the structure ~f this in~venti~n.
Figure 7~ is a sohe~atic layout of the
organisation of the cells in the esnbodime~at sh~wn
3~ in Figure 7.
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7
Figure 8 is a typical load vs. time chart
representative of an impact load upon an undamp
cushioning structure.
Figure 9 is a graph showing tho velocity and
acceleration imparted to a test specimen in a
standard test when no cushioning structure is
provided between a bare floor and the specimen.
Figure l0 is a graph showing velocity and
acceleration imparted to a specimen droppod 36
to inches upon a cushioning structure of 1 inch thick
conventional commercial bubble pack.
Figure il is a graph showing velocity and
acceleration of a specimen that was dropped 36
inches upon a conventional sandwich structure of
dense elastic foam.
Figure 12 is a graph showing velocity and
acceleration of a specimen dropped upon the
prototype cushioning structure of this invention
from a height of 36 inches.
Figure 13 is a plan view of one side o! the
cushioning structure of this invention with a
transparent strata on the upper surface.
Figure 14 is a sectional view through the
composite assembled structure taken on the line 14
14 of the Figure 13.
Figure 15 is an exploded sectional view taken
on the line 15-15 of Figure 13.
Figure 16 is an exploded sectional view taken
on the lips 16-16 of Figure 13.
3o Figure 17 is a sectional view of a typical
multi layer composite structure taken on a line
similar to Figure 14.
Figure 18 is a sectional view of another typical multi
layer composite structure.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF
THE BEST MODE OF CARRYING OUT THE INVENTION
The strscture of this invention indicated
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8
generally as 19 includes an upper stratum or sheet
of pliable material 20, and a lower stratum or
sheet of pliable material 21 separated by a matrix
of hexagonal, hollow three-dimensional polygon
members 22 in juxtaposed or contacting relationship
one to the next.
As shown in Figure 1 and 2A, the cell members
22 are of hexagonal shape in cross-sectional plan.
In the finally assembled condition the edges 23 and
l0 24 of the individual hexagonal cells 22 are bonded
to the top stratum 20 and bottom stratum 21 at
edges 24 at one side and at edges 23 at the
opposite side, respectively. The bond formed at
the edges 23 and 24 is a substantially hermetically
sealed connection so that in the assembled
condition the matrix includes a plurality of
generally hexagonal cells 27 separately sealed one
from the next, except as specifically otherwise
provided and as hereafter defined.
Since the materials are heat sealable the
various seals described herein may be accomplished
by conventional heat sealing means. Adhesive could
also be used.
The structure l9 is hermetically closed at the
periphery by a closure means and an inlet is
provided for the admission of a fluid such as air
or other gas which may be at a pressure above
surrounding atmosphere or environment in which the
structure is placed. The structure 19 is
constructed. of generally pliable materials, usually
plastics, including vinyl and/or polyethylene type
films.
Dimensionally it is conceived that the
structure 19 could be between about 1 and 30
centimeters "thick", i.e. the distance from the
WO 93/OO~dS PCT/US92/05533
9
outside of one stratum to the other. The thickness
of the sheet materials from which the strata 2~ and
21 and matrix cells wall elements 22 are f~rmed may
be between about .~l and 1~0 mills.
~Cn the embodiment sho~m in Figures Z acrd 2A
the matrix cells comprise hexagonal polygons. Such
shape has been chosen because of the unicyue form of
a hexagon that permits complete nesting ef the
vertical surfaces of the cell one to the next.
Nevertheless, other forms ~f polyg~ns: may pr~vide
the:: advantages of.this, :~. invention:: and arm to; be.
considex~d'~ as ~wit99in~. the concepts; worthy o~ further
evaluat~.on arad usefulness' in the app7;ication of the
principles that are embodied in the structure l9.
For instance, the contacting wall between
polygons may be sloped rather than vertical,
providing tapered or truncated polygons, rather
than rectangular polygons as shoum in Figure a.
Figure- 28 shows tapered p~lygons acJ an exa~aple. 'In
2c? thin embodiment a plurality o~ dells 35 have
substantially u~astarading sides 3f bonded to an
upper planar sheet like ~tratu~ ~7 and 's similar
lows stratum 38:
Four sided polyg~ns or cubes are
representative of another p~lygon configuration
that may be useful in some circumstances, as seen
i~ gi~ures 3A a~ad 3S
in this embodiment a plurality of cells 4t~ are
cube-like rectangles, formed or m~lded into an
3~ a:nternal core member 4ls C~re member 4l, is bonded
t~ an ..upper ~ sheep 4 2 and a lower sheet ' ~ 3 at
pos3.ti~nr~l ~f c~ntact 44:.
Stall ~ther f~rans of polygons are w~aha~n ready
conception, fo= instance, pentagons or'cones.
Referring to'Figures 4A and vB a structure ~~
~1J~3~'a'Ti'~I,~TE S~(°'c~'~"
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includes an upper stratum 51 to which is bonded a
lower cellular matrix 52 on which is formed a
plurality of downstanding/upstanding truncated
polygon cells 53 selectively arranged in mutually
5 supporting and equally load distributing
relationship across the surface of the stratum 51.
In another aspect of this invention as shown
in Figure 5, a passage way conduit or aperture 30
is provided from a polygon to each of the adjacent
10 cells through which the fluid is conducted to pass
from one cell to the next. 8y the proper. selection
of the size of such conduits, the rate of fluid
flow may be controlled and serve to "valve" the
rate of the fluid passage from one cell to the
next. Such conduits 30 may be provided by allowing
unbonded areas between the end of a cell 60 and
the stratum 61. This controlled venting of the
compressed air spring within the impacted cell
serves to maximize the absorption of the impact
energy while minimizing the energy available for
rebound. The difference in pressure between the
impacted and the unimpacted,-adjacent cells aids
the controlled refnflation of the impacted cell in
order the provide protection from rspeated,impacts.
In the embodiment of Figure 5, an internal
matrix structure is sandwiched between an upper
stratum 61 and a lower stratum 62 and bonded there
between at the surfaces 63 and 64.
Referring to Figure 5, the internal matrix
structure is provided with substantially
upstanding walls that may also be designed to
provide one-way valve-like apertures 32 between the
walls of two mating hexagonal structures that aids
the reduction of rebound energy. The apertures 32
open upon an impact due to the columnar buckling of
'W~,193100~45 ~ ~ ~ ~ ~ Q ~ P~'/I~~92i05~33
13
the cell walls and pass fluid fro~a the impacted
area to adjacent areas when the pressure on the one
side increases t~ a value higher than the pressure
' on the other side. When the pressure equalises
during the structural rebound, the resilience of
the material in the member 61 causes the valved
opening to close or partially close thereby
restricting the reverse flow toy allowing the
pressure to gradually ecyualize.
Referring, to the Figures . 6, 7 and ,'7A, in the
further ;, . embodiment : :a~f .; the; ;: inventiora~ : :-.:, separate
substructures ~..; indicated;-.~en~rally; a~ ,T~; and- 71: end
constructed in: accordance with the embodiment~shown
in Figures ~4A and ~4~, are bro~xght together as shown
by the arrows in Figure 6 to fore a composite
structure 73. When s~ assembled the polygon ells
of substructure 7~ 'See Figure 7Aj mate with
polygon cells of substrucaure 71 leaving a
plurality of empty 'cells °72.
2~ In the as~~mbled position as shown in Figure 7
the composite structure 73 compresses an upper
stratum 74, internal cell polygons 75, shown as
truncated prismatic in slhape because of the
inherent columnar structural strength of such
configuration, of the upper substructures ~~, and
internal polyggn cells T6, of matdhing
configuration to the polygons 75, of the lower
substructure 71, as well as lower stratuan 77.
channels 8~ of the upper substructure 70 and
3~ channels ~l of the lower substructure 71 provide
the va~.ving actaon and dampening action in
composite straacture 73.
~y a~aans of a c~~.nation of the columnar
buckling of the supporting hexagonal walls, the
restricted airflow through the connecting passages
w~ a~roosas . ! ~ , ~~.-rlus92ross3~
,,
~J
I2
between the cells, and the valVed airflow between
mating structures, the rate is controlled at which
the force of impact an the surface srf the structure
is dissipated throughout the structure and the
energy available for rebound is minimized.
Tn use, structures 19, 50 and 73 are placed
external to a fragile body or between a wall such
as the side of a shipping carton, and an object
such as a ~ product to be shipped in comaaerce. It
may be expected that the object w313 encounter .
suddenv: loads: and v impacts during - the course '~~.:' its
ship~ia'ht~'t~~'its' destination. 'i='su~h impactsK~p~~duce .
sudden loader ~n one side ~f the f st~uctur~ l~ ~ and
ft>rC~S are Crated against one sl.dE: Stratum, which
depend upon the amount of force and the area of the
object that inputs on the surface. The x°ea~tion
created in the structure 1~ responds to the impact
load by co~apre~s~.ng the fluid through lateral
pressure forces radiating frog the place ~f ' i~a~act
0 form one cell. to the neat to disperse the l~~d and
reduce the foarcc at a rate which preVerats damage to
the object.
In an alternative sgtuat~~n, tae st~Cture l9
may be f~rmed' as we~rin~ appax°el ~r padding for the
projecting and more fragile components ~~ ~ persons
body. If-the padding were worn as a pmts bx skirt
about the hips of a person, and the persoa~ falls ~
the protruding hip joints are ~ load to wlai.ch the
strwctur~ 1~ reacts.
because of its unique constructs~n and the
lateral, ~ispers~l of the impact load, it had been
found that the energy absorption ~f this structure
exceeds prior art apparatus tested that are in use
for these purp~ses. In actual tests the energy
absorption has Daeen found to be 3p a 300 higher
.~~ca~~ t ~~~ 5~~~
W~ 93/00845 ~ ~, ~ ~ ~ ~ ~ ~c~reu~9~eoss~~
than such packing materials as '°bubble packs" or
foam materials such as rubber or plastic foam
materials that are presently in the marketplace for
this purpose.
Referring again to Figure 31~ and ~B, in still
another aspect of the invention, selected numbers
and positioned cells are filled with foam type
materials 45 to provide a further parameter of
dampening attenuation and energy absorption
reaction to the load as well as the restoration or
recovery of the cushioning ~ ;: structure, to : its
:~riginal or pre-unpacted state. . , .. ,
:, ;
~t is bel i~~ed ~ that the further enhancement of
the surprisingly outstanding results are provided
by the damping by the fluid as its' flow is
restricted to adjacent cells, by the valve action
between the mating hexag~nal structures, and the
strength end controlled dolvmnar buckling produced
by a the Crumpling.~f the inherently strong.pol~ygon
structures.
A pr~tntyp~- cushioning structure as shown in
Figure 7 according to this iawention was
constructed and tested in comparison with other
well known cushianing materials such as
c~mmerciall~r available bubble pack, which is a
connected plurality of semirspherical air cells
~ similar to that shown in ~7~~.-Patent 4,287,250, and
a f~am sandwich comprising two layers of foam,
manufactured by Dynamic systems, Inc. ~n these
tests an subject in the shape ~f a manikin head
weighiaag 7, pmured~ was dropped form a ~cli~tance of 36
inches upon a structure as defined in Table I which
1r~1 reprew~8ent&'~tlve,of .,theresslultse
r ';
. n;. . ' ~ ~.:: ~~'~_ ,.:~~ .. ~ ;~:':~ .,:;.., -..,,4 ,,, ,,; .w..~ .,...~,,
, . ,
r ,
n. , ~ r ,
.... .., , ~ . ....... .,.. ~,.,. ,. .,... . ...... ,. ... .. .r . ., ...~. ,
. ,. ., . .. ,. , : .,
dV0 93/00845 ~:~ ~ ~ , . , ' . P'd'd'/US92/05533
n~
TA87.~ 1 ° FORGE°ylKPtIIeSE ~,IvdD JE~ST1TLTTION
_~mt~u,~,~~scrit~ta.on Acce? ~xst9 on
t° ~estit~~ta.on
1 t~ ~
9's (En~rgY
. ~iff~r~nce
ya~pactlees
m '' ~a~ound j
p.~ ~ ~:.I
. 9 ::~ ~~w_~.:, ~a~e'Fl~~r~ 3S~ 252.3 ,.,.
~ ~
65
1~ 72 8ublala hack v~. 3~~ 321:5 .
~ ~ ,~ .;,
_ r~ ~
11 55 F'~am Sat~dwach 375.335. ~ 5a
20 law: ~4 : ynv~ntion ' ~2~~'' 371:2 ,
,4S
In Talble I ~~peak to peak: is the valt~a in g ~ s
ft/sec2 per 3~ ft/sec2 of maximum force in one cycle
25 from fir6t illl~act to r~~oLDJtld.
The it~p~.lse ie tye foxce ~ time in
pound,/second and the restitution co~gfici,~ht is the
percent of reb~tuad between the first impact acrd the
first rela~und: Tt is to be em~shasi~e~ th~~ tla~-
3~ prot~t~~e unit was ~~~h lighter (25% ~f the density
Or weight of the sandwich ~oam) and on~:y half ids
thicJ~ess. The packaging density of the invention
is also significantly higher than conventional
bubb~.e pack, i: e. the material is ~aor~led into the
3~ series of he~ca~onal cells to px°ovide a high
strength/weigh~ rati~ and still can be easily
aS~wa~~de ~~n~°~the~nt~rnal... ~tr~n~th ~~~ th~m-
dividing members can be variede °the invention can
also,. be ~~de to saapp~rt practically any we$g~,t end
40 still provide good shock abs~rption pr~tgc~tion ~ a
feattare of g~,~~,t importance to ~e sh~ppi~rg and
packing industry. This structu~e~ is also
~~'TITIt~'~ ~H~c"~°
~uvo 93i~o~a~ ~ ~, ~ ~crius~2ioss~3
r~A ~ 1..~ l3
compatible with traditional vacuum melding
technology and thus is relatively ine~tpensive to
mass produce. It is therefore apparent that there
are significant commercial improvements in his
5 cushioning structure as a lightweight, low bulk,
high performance packaging material for shipping.
Further evidence of the improved energy
absorption of this invention in comparison with
other cushioning materials tested is shown in
:10 F'igures_7-11, in which the aria under the neutral
.,. ..: , ::~ axis ~.; °°,zero°° : for ..; the .;
invention and = the : . depth ~.~ of ~ ..
.~ : ; .,..pe~et~ation of .tee:. rebound, a: s; yshown :by. the : first-~- a
::
rebound envelope (cross-hatched- belowv the neutral
axis) is drastically reduced in comparison with the
15 other materials.
TAB~E II - HEAD DR~P ENERGY CATaCiIhATI~NS
FIG G G V~ KE
Z
, Desc~ption ve ea_k V,~,2Vrz Vr tiff ~req
9 Hare Floor 9.71 15.45 198 106 1.87 9.93 4.57
_ ~~ ~~bble-Pack 8:98 13.45 169 45 3.'e'67.3.394.22
11. FOam
Sandwich 10.85 16.15 269 48 23.87 3.62
12 Inventi~n 11.13 15,64 308 64 4.81 26:353.62
where m = 7~32.2 _ :2~7 slugs
vi = Vel~eity of Impact
yr = Velocity of-Rebaund
c~ ) - ~ ~vi~ - Vrz) ft~-lb
(DIFF) 2
Further testing was conducted by GH Package/Product
Testing and Consulting, inc. of Cincinnati, Ahio aecording to
standard.....~ASTM 'American Society of Testing Materials)
criteria. In these tests the structure was subjected to
vibration and impact shock testing to determine its viable
characteristics as related to packaging. the vibration
W~ 93/00845 , ~ PCT/LJS92/05533
~.~..~~~va~~
testing encompassed a 0.5 g input sign wave sweep with the
cushioning structure of the invention loaded with incremental
loadings from 0.11 psi to 0.1°~ psi. The results indicated a
very low transmissibility characteristic to all testing
frequencies with all loads . This characteristic far
packaging protection is extremely beneficial in vibration
protection since shifting psi loadings can be costly by
requiring more cushioning material thereby increasing the
volume and cost. Also, when wrapping material, the uniform
vibration characteristics take place no matter what the.
results:_:of; loading :° in psi: In comparison ' t~~~ the'vibration
responses og~ a; double thickness: o~ bubble pabk-~ the-ycushioning~
material . of this invention performs lower in transmissibility
and much more consistent on all loads and frequencies.
3.5 The shock resistance characteristics produced by one
thickness of the cushioning structure of the invention was
typically greater than that generated by two thicknesses of
conventional bubble pack. This was true across the various
increased loadings that were impacted ont he material.
Another important characteristic noted was that after
the initial shock and rebound, the impactload incurred
almost no additional secondary rebounds or almost negative
g's. This indicates that a product which is packaged in the
cushioning structure of this invention will not incur
successive aftershock which may be more than damaging to
sensitive products than the initial impact even though the
initial impact even though the ina.tial impact g's may result
in lame amplitudes.
Since the structure is more "efficient" (i.e. energy
absorbing per unit of thickness) ~.t would be useful in
various ~~her appalications such as life jackets,. baseball
catcher protection, hockey ee~uipment, football helmets,
shoulder and chest protectors and seat cushions.'
The prototypes of the invention were constructed to
provide both a fast response and well regulated collapse
.,,.. ",._ . ..... . . ,, .. , , .. .. .....
,.,:,
..,.:.
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WO 931005 ~ PCT/US91/05533
17
while preventing the °°bottoming out°° of the
structure. The
invention presents a new and novel concept of distributed air
cell venting and the controlled deformation of its internal
structural members. Because of this combination, the wall
thickness of the structure can be constructed to withstand a
wide range of selected pre-loading. The pre-loading of the
prototype unity was established to provide for less than-ten
pounds without pre~riature collapse. This a~ay be selectively
increased iai other cushioning structures by increasing the
wall thickness of the cells and/or the orifices and cells.
:r , : . _, The :. ~ energy - absorption and - rebound is regulated by the
vent3latian rats ~f ~the~~~ ~tructure.w'~ . . . .~ . .. v . ... ' .
.. ~ , ~eEarring tow° Figures ' 13 - ' 26,' ar~other~ embodiment of a
cushioning structure 140 is shown including a formation of
foamed resilient material 141.. 1~s shown the foamed material
141 is sandwiched between the plurality of two strata 142 ar:~
143 respectively. The cushion material 141 is formed to
include nndentures 144.
In still another embodiment of the invention tire cushion
mater~.al 154 is formed to include indentures 144 on one side
rather than on opp~sing sides. In this embodiment, shown ira
Figure 1~, the cushion material 154 may preferably be
relatively smooth on the ur~indentured side 160 and comprises
continuous foam except for the side that t~uches ire contact
with a stratum 155. In this embodiment the indentured side
includes the passageways and grid lake structure of the
previous embodiments.
In same circumstances the cushion material 154 may be
b~nded to a structural componea~t 155 of the ~bject with which
it is used, such as. an insole or element of a shoe or a pane.
~or door of an autoanobile. In this situati~n; the insole or
structural eleme~,t serves as the counterpart of the opposiang
stratum 155. The structure of this embodiment is different
, from the dual str~~a structure of Figure 14, and is
distinguished from an unsandw~ched unindentured foam wkai~h
~t~~~l°iTIJ'f E ~hl°T
WO 93/00845 PC.'d'/US~2/05~33
C A
I1'~~' ,~, ~, It '~.~ ~~~ t,)
1$
has been conventionaly provided as an insole in shoes.
The term ''resilient material" 141~ 154 is intended to
include materials that by their internal structure have a
resilience that tends to bring them back to their original
. formed shape when a load on them is removed ( ie . elasticity) .
Such materials are often termed "foam" when the void space
ratio is high relative to denser material, although denser
materials may be "resilient" if they are elastic.
Ira Figure 13 the upper stratum 142 is depicted as
~'o.~~ansparent so that the internal, structure, grid Like
configuration of the.,formed res.~lient.~;dushi~ning material
. .._ t,y':~ .;.." ..: . . ., _ . ._ _, .
141 ~aay be discerned through .;the , stratum- 142: ; ~ ,
. , ~'he strata 142 and 143 ..may .be ~ of~: pliable or semi~-
yr . , . .. , ,
p~.iable, or even rigid, materiel such as polymer, formulated
to provide different degrees of flexibility, and other
physical properties. The strata 142, x:43 are bonded to the
cushion materiel 141 by well-known, conventional techniques
d.ncluding adhesille. and .heat sealing ~roceo~se~re , The b~nd.ing
may take place over ~~he entire exposed surface - 146 of the
. 2~ cushioning material 141 ~r it may be providedl at intermittent
points of contact betraeen the surt~aces.
When the structure is assembled the indentures form
ells with molded interconnecting passageways, channels or
~'r~ndu~ts 15 V s .
The indentures 144 are shown as truncated polygon in
shape, because it is believed that the~~ provide formations
that have exceptional structural integrity: ether forms of
indentures could be useful and selected depending on the
parameters of perfo~znance that are to be provided by the
3o total structures Semzspheres could be a useful form although
their spacing would k~e Less compact when the indentures ~r
provided~..in a grid like mating ~'elationship on opposite sides
146 of the foam cushioning material.
In the embodiment shown in Figures 13 and 14, a
plurality of tube~like apertures 147 are provided fr~m one
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CA 02112688 2005-11-04
73092-3
19
side 142 to the other side 143, and when constructed in the
vertical orientation, as shown, provide further structural
integrity to the foamed cushioning material, and/or
compressible fluid cells for their cushioning properties.
When the composite structural construction of the
Figures 13-17 are bonded and sealed together, the indentures
144 and the apertures 147 comprise a plurality of cells for
the containment of fluid, such as air, which may be
pressurized at assembly or at ambient atmospheric pressure as
l0 desired for the performance of the structure..
Referring to Figures 13 and 15, of special significance
are the passages 150 that provide fluid communication from
one cell to the next, and function as the passages described
with respect to previous embodiments such as Figures 5, 6 &
7. It has been found that the embodiments of the structure
as shown in Figures 13-17 are the equivalent or superior in
performance to that shown in Figure 12.
Referring to Figure 17, a structure comprising a
plurality greater than two of stratum 142, 143 and 145 are
shown with a plurality of formed cushion material 141 bonded
and sealed there between. In this embodiment, the benefits
of the invention are additive although the amount of material
for the equivalent performance is reduced.
As shown in Figures 13 and 16, the grid like matrix
includes the plurality of relatively ~~solid" portions 151 as
a further structural component.
Referring further to Figure 14, in another aspect it has
been conceived that the strata 142 and 143 may be provided
with small incontinui~ties, apertures or "pin-prick"-like
perforations 148 which open.when the strata 142 and 143 are
stretched by an impact force on the structure. The
perforations are constructed to perform like valves which
open or close depending on the characteristics of the
material of the strata, the thickness of the sheet and the
pressure to which it is subjected upon impact. Such
CA 02112688 2005-11-04
73092-3
controlled venting in and out of the structure to the
external atmosphere would be expected to provide a measure of
damping, but is not believed to provide controlled rebound
characteristics as shown in Figure 12.
5 The pin prick flap type pressure relief and transfer
system described in the previous paragraph may be embodied in
the apparatus shown in Figure 17 in which instance the
aperatures 185 and the aperatures 186 provide exchange of
fluid between the separate layers 188 and 189 to further
10 provide fluid transfer means between the separate layers.
This provides a further dampening effect in the "vertical Z
direction", as distinguished from the "lateral X-Y
direction", provided by, the channels 150 and the valves-like
aperatures 147.
15 It has been deemed important that the invention includes
the ability for mass production and low cost.
It is herein understood that although the present
invention has been specifically disclosed with the preferred
embodiments and examples, modifications and variations of the
2 0 concepts herein disclosed may be resorted to by those skilled
in the art. Such modifications and variations are considered
to be within the scope of the invention and the appended
claims.
