Note: Descriptions are shown in the official language in which they were submitted.
2~
METHOD OF MAKIHG ABSORBENT ARTICLE HAVIHG FLAPS
AND ZONES OF DIFFERENTIAL EXTENSIBILITY
FIELD OF THE INVENTION
The present lnventlon relates to ~ethods of mak1ng absorbent
art1cles such as fe~ale san1tary napklns adult 1ncontlnence
dev1ces and the llke. St111 ~ore partlcularly the present
lnventlon concerns methods of mak1ng absorbent art1cles havlng flaps
whlch prov1de ~ones of d1fferent1al extenslblllty for retlev1ng the
stresses that develop in the flaps when the flaps are folded down
and under a wearer s undergar~ent.
BACKGROUND OF TNE INVENTION
All manner and varlety of absorbent art1cles conf19ured for the
absorpt10n of body flulds such as ~enses ur1ne and feces are, of
course well known. Absorbent art1cles parttcularly san1tary
napk1ns hav1ng ~1ngs or flaps are d1sclosed ln the 11terature and
are available ln the marketplace.
Generally the flaps extend laterally fro a central absorbent
means and are 1ntended to be folded around the edges of the ~earer s
pant1es 1n the crotch reg10n. Thus, the n aps are d1sposed between
--- 2 2 ~ L
the edges of the wearer's pantles ln the crotch reglon and the
wearer's thlghs. Commonl~, the flaps are provlded wlth an
attachment means for aff1xlng the flaps to the underslde of the
wearer's pantles.
The flaps serve ~t least two purposes. F1rst, the flaps
prevent exudates whlch otherw1se would so11 the edges of the
wearer's pantles from dolng such. Second, the flaps help stablllze
the napk1n from sh1ftlng out of place, espec1ally when the flaps are
afflxed to the unders1de of the pant1es.
Sanitary napk1ns havlng flaps of the var1Ous types are
dlsclosed 1n U.S. Patent ~,687,~78, ent1tled ~Shaped San1tary Hapk1n
~lth flaps~, whlch 1ssued to Van T11burg on August 18, l987, U.S.
Patent 4,608,04~, entltled ~Sanltary Napkln Attachment Means~, ~h1ch
1ssued to Matt1ngly on August 26, 1986, U.S. Patent ~,589,876,
ent1tled ~Sanltary Napk1n~, wh1ch 1ssued to Van Ttlburg on ~ay 20,
1986, U.S. Patent ~,285,3~3, ent1tled ~San1tary Napk1n~, ~h1ch
lssued to McNa1r on August 25, 1981, U.S. Patent 3,397,697, ent1tled
~D1sposable Sanltary Shleld for Undergarments~, whtch lssued to
Rlckard on August 20, 1968, and U.S. Patent 2,787,271, ent1tled
~Sanltary Napk1n~, wh1ch lssued to Clark on Apr11 2, l95~.
~ h11e s~n1tary napk1ns hav1ng flaps are commonly vlewed as
prov1d1ng better protect1On aga1nst so111ng ~s compared to sanltary
napklns w1thout flaps, the flapped napk1ns commonly exper1ence
problems that keep them from belng opt1mally effect1ve. ~hese
problems generally result fro~ the stresses exerted on such flaps
when the sanltary napk1ns are worn.
When the flaps are folted down along the edges of the wearer's
pant1es, stresses are created 1n the flaps. ThQ stresses are
espec1ally h1gh along the fold 11ne at the edges of the wearer's
pant1es where the flaps are bent from the bodys1de of the pant~ to
the unders1de of the panty. ~hese stresses are caused by f1tt1ng a
flap around the curved outl1ne of a panty crotch. ~hese stresses
are magn1f~ed when a wearer s1ts or crouches because the edges of
3 2 ~ 5 L~l
the pantles are pulled outward agalnst the flaps thus lncreaslng the
forces agalnst thls fold llne. ~hen the stresses become too hlgh
the flaps may become detached from the panty and some portlon of the
aforementloned beneflts of the flaps may be lost. In addltlon even
~f the stresses are not sufflclent to detach the flaps they may
still be sufftclent to cause the flaps to bunch longltudlnally
lnward. Thls effectlvely reduces the slze of the flaps and the area
of the wearer s undergarments that the flaps are able to cover.
Thus there ~s a commerclal need for a way of ellmlnatlng or at
least reduc~ng the stresses that develop ln the flaps when folded
so as to prevent the~ from becomlng detached f~o~ the wearer s
pantles and losing ablllty to cover a g1ven area of the pant1es.
A number of varlatlons on the types of flaps descrlbed above
have been presented ln an attempt to solve var10us problems. U.S.
Patent 4 900 320 lssued to ~cCoy on Februar~ 13 l990 dlscloses a
sanltary napkln having flaps afflxed at po1nts lnward from the
longltud1nal edge of the napkln. U.S. Patent ~ 911,701 lssued to
Mavlnkurve on Harch 2~ 1990 t1scloses a sanltary napkln havtng
elast1c means for provldlng greater convex shape to the body-fac1ng
port~on of the central absorbent and for enabl1ng adhes1ve--ree
placement of the flaps of the napk1n. U.S. Patent ~ 940 462 lssued
to Salerno on July IO l990 d1scloses a san1tary napkln w1th
long1tudlnally expandable flaps. A sanltary napkln hav1ng flaps
w1th stress rel1ef means ln the for~ of a notch or a sllt ls
descr1beJ ln U.S. Patent ~ 917 697 wh1ch lssued to Osborn III, et
al. on Apr11 17 I990. Although thls latter sanltar~ napk1n works
qulte well the search for san1tary napklns having 1mproved flaps
has cont1nued.
The stresses descrlbed above can also unduly 11mlt the s1ze of
the flaps used w1th an absorbent artlcle s1nce the stresses are
typlcally greater ln products havlng large flaps (that 1s flaps
hav1ng a relat1vel~ large longltud1nal d1~enslon). There 1s thus
also a need for absorbent art1cles wlth an lmproved stress rel1ef
means for rellevlng the stresses that develop 1n the flaps that
- 4 207951 1
does not limit the size of the flaps that can be used,
and methods for making such absorbent articles.
Therefore, it is an object of an aspect of the
present invention to provide a method for making an
absorbent article, such as a sanitary napkin, having
flaps that provide the absorbent article with zones of
differential extensibility for relieving the stresses
that develop in the flaps when they are folded down along
the edges of the crotch of the wearer's undergarments and
affixed to the underside of the undergarments.
It is an additional object of an aspect of the
present invention to provide a method of making an
absorbent article having flaps that provides the
absorbent article with zones of differential
extensibility that allow larger flaps to be used on the
absorbent article, than those of prior products.
These and other objects of an aspect of the present
invention will be more readily apparent when considered
in reference to the following description and when taken
in conjunction with the accompanying drawings.
SUMMARY OF THE lNv~NLlON
The present invention is directed to a method of
making an absorbent article, such as a sanitary napkin,
having flaps and zones of differential extensibility for
relieving the stresses that develop in the flaps when the
flaps are folded down along the edges of the crotch of
the wearer's undergarments.
Aspects of the invention are as follows:
A method of making an absorbent article having flaps
and zones of differential extensibility, said method
comprising the steps of:
(a) providing an absorbent article comprising a
main body portion, said main body portion having a body-
facing side, a garment side, a principal longitudinal
centerline, a principal transverse centerline, two spaced
apart longitudinal edges, said main body portion
~ .,
A-
4a 2 0 7 9 5 1 1
comprising a liquid pervious topsheet, a liquid
impervious backsheet joined to said topsheet, and an
absorbent core positioned between said topsheet and said
backsheet, said absorbent core having a pair of spaced
apart longitudinal side edges that define a widest
portion of said absorbent core at least at one place
between said longitudinal side edges of said absorbent
core, said absorbent article comprising:
(i) a pair of flaps, said flaps having a
garment side, and each flap being associated with said
main body portion at a juncture and extending laterally
outward beyond a longitudinal edge of said main body
portion, said junctures each having a pair of ends, said
flaps being divided into a front half and a back half by
a flap transverse centerline, and having a fastener
located on the garment side of said flaps for attaching
each flap to the underside of an undergarment or to the
other flap; and
(ii) two corner regions for each flap, said
corner regions being located in the regions of the ends
of each juncture, wherein portions of said flaps lie
along said flap transverse centerline and portions of
said flaps lie in said corner regions, and the portions
of said flaps that lie along said flap transverse
centerline lie transversely further outward from the
principal longitudinal centerline than the longitudinal
side edges of the absorbent core at the widest portion of
said absorbent core and are disposed further outward in
the transverse direction from the longitudinal said edges
of said main body portion than the portions of said flaps
located in said corner regions; and
(b) forming zones of differential extensibility in
said corner regions of said absorbent article, said zones
comprising portions of at least one of said topsheet,
backsheet, absorbent core, and flaps, said zones of
differential extensibility being capable of greater
A
,c~. '
4b 207q 5 1 1
extensibility outward in a generally transverse direction
than the surrounding portions of said absorbent article
whereby said zones of differential extensibility provide
material to cover a wearer's undergarment to prevent
exudates from soiling the wearer's undergarment through
said zones of differential extensibility.
A method of making an absorbent article having flaps
and zones of differential extensibility, said method
comprising the steps of:
(a) providing an absorbent article comprising a
main body portion, said main body portion having a body-
facing side, a garment side, a principal longitudinal
centerline and a principal transverse centerline, said
main body portion having two spaced apart longitudinal
side edges, said main body portion comprising a liquid
pervious topsheet, a liquid impervious backsheet joined
to said topsheet, and an absorbent core positioned
between said topsheet and said backsheet, said absorbent
core having a pair of spaced apart longitudinal side
edges that define a widest portion of said absorbent core
at least at one place between said longitudinal side
edges of said absorbent core;
(b) providing at least one component in the form of
a pair of flaps, said flaps each having a garment side, a
flap transverse centerline, a proximal end, a distal end,
two corner regions, said corner regions being located in
portions of said flaps that are at the proximal ends of
said flaps and spaced away from said flap transverse
centerline, and a fastener located on the garment side at
the distal end of said flaps for attaching each flap to
the underside of an undergarment or to the other flap
wherein portions of said flaps lie along said flap
transverse centerline;
(c) forming zones of differential extensibility in
said corner regions of said flaps, said zones comprising
portions of at least one of said topsheet, backsheet,
absorbent core, and flaps, said zones of differential
A
~ 4c 207951 1
extensibility being capable of greater extensibility
outward in a generally transverse direction than the
surrounding portions of said flaps while the portions of
the flaps that lie along the flap transverse centerline
have a greater dimension in the transverse direction from
the proximal ends of said flaps than the portions of the
flaps located in the corner regions whereby said zones of
differential extensibility provide material to cover a
wearer's undergarment to prevent exudates from soiling
the wearer's undergarment through said zones of
differential extensibility; and
(d) attaching said at least one component that
comprises said flaps to said main body portion so that
the proximal ends of said flaps are affixed at a juncture
with the main body portion, said flaps each extend
laterally outward beyond a longitudinal edge of said main
body portion and lie transversely further outward from
the principal longitudinal centerline than the portions
of the longitudinal side edges of the absorbent core at
the widest portion of said absorbent core.
A method of making a sanitary napkin having flaps
and a zone of extensibility, said method comprising the
steps of:
(a) providing a sanitary napkin comprising:
a main body portion comprising an absorbent
core, said absorbent core having two spaced apart
longitudinal side edges that define a widest portion of
said absorbent core at least at one place between said
longitudinal edges of said absorbent core;
a pair of flaps extending laterally outward
from a juncture with said main body portion to a distal
edge, said flaps each having a garment side with a
fastener thereon, a flap transverse centerline, and
points along said flap transverse centerline at the
distal edge of said flaps, wherein said points along said
flap transverse centerline lie transversely outboard of
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4d 207951 1
the longitudinal side edges of the widest portion of said
absorbent core; and
(b) forming a zone of extensibility in said
sanitary napkin, said zone of extensibility comprising
portions of said flaps that are spaced longitudinally
away from said flap transverse centerline, said zone of
extensibility having slack therein and being capable of
greater extensibility outward in a generally transverse
direction than the points of said flaps located along
said flap transverse centerline whereby said zones of
differential extensibility provide material to cover a
wearer's undergarment to prevent exudates from soiling
the wearer's undergarment through said zones of
differential extensibility.
A method of making a sanitary napkin having flaps
and a zone of extensibility, said method comprising the
steps of:
(a) providing a sanitary napkin comprising:
a main body portion comprising an absorbent
core, said absorbent core having two spaced apart
longitudinal side edges that define a widest portion of
said absorbent core at least at one place between said
longitudinal edges of said absorbent core;
a pair of flaps extending laterally outward
from a juncture with said main body portion to a distal
edge, said flaps each having a garment side with a
fastener thereon, a flap transverse centerline, and
points along said flap transverse centerline at the
distal edge of said flaps, wherein said points along said
flap transverse centerline lie transversely outboard of
the longitudinal side edges of the widest portion of said
absorbent core; and
(b) forming a zone of extensibility in said
sanitary napkin, said zone of extensibility comprising
portions of said flaps that are spaced longitudinally
away from said flap transverse centerline, said portions
of said flaps comprising material that is extensible and
A-''J'''
-~ 5 207951 1
capable of greater extensibility outward in a generally
transverse direction than the points of said flaps
located along said flap transverse centerline whereby
said zones of differential extensibility provide material
to cover a wearer's undergarment to prevent exudates from
soiling the wearer's undergarment through said zones of
differential extensibility.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a top plan view of a preferred sanitary
napkin embodiment made by the method of the present
invention.
Figure lA is a lateral cross-sectional view taken
along line lA-lA of Figure 1 through the corner region of
one of the flaps of the sanitary napkin.
Figure lB is a lateral cross-sectional view taken
along line lB-lB of Figure 1 through the center portion
of one of the flaps.
, .
A~
Flgure 2 ls a top plan vlew of a sanltary napkln havlng flaps
wlth an alternatlvely preferred type of ~ones of d~fferentlal
extenslblllty.
Figure 2A ls a lateral cross-sectlonal vlew taken along llne
2A-2A of Flgure 2 through one of the flaps of the sanltary napkln.
Flgure 3 ls a perspectlve vlew of the crotch portlon of a
women s pantles.
Figure ~ ls the same perspectlve vlew of the women s pantles
shown ln Flgure 3 wlth the sanltary napkln of Flgure l belng placed
thereln for use.
Flgure 5 ls a top plan v1ew of an alternatlvely preferred
sanltary napkln made by the method of the present lnventlon.
Flgure 6 ls a cross-sectlonal vlew of the sanltary napkln shown
ln Figure 5 taken along llne 6-6 of Flgure 5.
Flgure 7 ls a cross-sectlonal vlew taken from an angle slm11ar
to that of Flgure 6 of a san1tary napk1n hav1ng a pleat ~olned to
its backsheet made by the method of the present lnvent10n.
Flgure 8 ls plan vlew of a sanltar~ napk1n showlng a curved
pattern of ~o~nlng the flap to the maln body portlon of the sanltary
napk1n.
Flgure 8A ls plan vlew of another san1tary napk1n showlng a
curved pattern of ~olntng the flap to the ma1n body portlon of the
sanitary napkln.
Flgure 8B 1s a plan vlew of a ~ethod of mak1ng flaps for the
embod1ment shown ln Flgure 8A.
Flgures 8C - 8E are varlous top and bottom plan vlews of still
another sanltary napkln ln whlch the flaps are ~olned to the maln
body portlon of the sanltary napkln along a curved ~uncture.
Flgure 9 ls a top plan vle~ of a sanltary napkln ln whlch the
maln body portion of the sanltary napkln ls folded.
Flgure lO ls a slmpllfled cross-sectlonal vlew of the sanltary
napk~n shown 1n Flgure 9 taken along 11ne 9-9 of Flgure 9.
F19ure 11 ls a bottom plan vlew of the santtary napkln shown 1n
Flgure 9.
Flgure 12 ls a slmpllfled transverse cross-sectlonal vle~ of
another alternatlvely preferred sanltary napk1n ln whlch the ~a1n
body port10n ls folded only once.
Flgure 13 ls a slmpllfled transverse cross-sectlonal vlew of
another sanitary napk1n 1n ~h1ch the ~a1n body portlon conta1ns
mult1ple folds.
Flgure 1~ ls an exploded perspecttve v~ew show1ng the asse~bly
of a san1tar~ napk1n wh1ch contalns a preferred absorbent core and
panty fastening adheslve pattern for use 1n the present lnvent10n
(but whlch does not 1nclude flaps and the zones of dlfferent1al
extens1b111ty provlded b~ the the method of the present lnventlon).
Flgure 15 1s a d1agram whlch 111ustrates some of the ter~s and
concepts descr1bed ln Table 1.
Flgure 16 ls a top plan vlew of a san1tary napk1n havlng flaps
provlded w1th an opt10nal barrler feature.
DETAlLFn DESCRIPTION OF PREFERRED _MBaDl~F~TS
The present 1nvent10n relates to ~ethods of maklng absorbent
art1cles such as female san1tary napk~ns. ~ore part1cularly the
2~1f ~
present lnventlon relates to ~ethods of maklng absorbent artlcles
havlng flaps ~hlch provlde 20nes of dlfferentlal extenslblllt~ for
rel1eYlng the stresses that develop ln the flaps when the~ are
folded down along the edges of the crotch of the wearer's
undergarments and attached to the underslde of the underganments.
~ he term ~absorbent artlcle~, as used hereln, refers to
artlcles wh1ch absorb and contaln body exudates. More speclflcally,
the term refers to art1cles whlch are placed agalnst or ln proxlmlty
to the body of the wearer to absorb and contaln the ~arlous exudates
d1scharged from the body. The term ~absorbent artlcle~ ls lntended
to 1nclude san1tary napklns, pantlllners, and lncontlnent pads (and
other artlcles worn ln the crotch region of a garment). The ten~
~dtsposable~ refers to artlcles wh~ch are lntended to be d1scarded
after a s1ngle use and preferably recycled, composted, or otherwlse
d1sposed of ln an environmentally compatlble ~anner. (That ls, the~
are not lntended to be laundered or otherwlse restored or reused as
an absorbent artlcle.) In the preferred embodlment lllustrated, the
absorbent artlcle ls a sanltary napkln des1gnated 20.
The term ~sanltary napkln', as used hereln, refers to an
artlcle wh1ch 1s worn by females ad~acent to the pudendal reg~on
that ls lntended to absorb and contaln the varlous exudates whlch
are dlscharged from the body (e.g., blood, menses, and urlne). ~he
method of the present lnvent10n, however, 1s not llmlted to the
product10n of the partlcular types or conflguratlons of absorbent
artlcles shown ln the drawlngs.
A preferred embodlment of a sanitary napkln 20 made by the
present lnventlon ls shown ln Flgure 1. As shown ln F~gure 1, the
sanltary napkln 20 bas k all~ comprlses an absorbent means
represented by central absorbent pad (or ~maln body portlon') 22,
and two flaps 2~. (In the d1scuss10n that follows, unless otherw1se
noted, the sanitary napkln descrlbed here1n wlll have two flaps.
~h11e lt ls not necessary that the napk1n have two flaps, two flaps
are preferred over one flap. Also, wh11e ~t 1s not necessar~ that
the flaps be m1rror lmages of one another, they preferably are.
2 ~
Thus, the descrlptlon of one flap wtll be a descrlptlon of the
other, and, for clarlty, dlscusslon of the second flap ~ay be
omltted.)
~ he sanltary napkln 20 has two centerllnes, a prlnclpal
longttudlnal centerllne l and ~ pr1nc1pal transverse centerllne t.
The term ~longltudlnal~, as used hereln, refers to a 11ne, axts or
dlrectlon ln the plane of the san1tary napk1n 20 that ls generally
allgned wlth (e.g., approxlmately parallel to) a vertlcal plane
whlch blsects a standtng wearer tnto left and rtght body halves when
the santtary napktn 20 ls worn. The terms ~transYerse' or ~lateral~
used hereln, are ~nterchangeable, and refer to a llne, ax1s or
dlrectlon whlch lles wtthln the plane of the sanltary napkln 20 that
1s generally perpendlcular to the long1tud~nal dtrect10n.
The san1tary napkln 20 1s compr1sed of a topsheet ~0,
backsheet 42, an absorbent core 4~, and a pa1r of flaps 2~. At
least a part of the topsheet 40, backsheet 42, and absorbent core
comprlse the maln body portlon 22. The flaps 24 shown tn Flgures l
and lA are compr1sed of separate pteces of materlal wh1ch ~re
attached to the maln body portton 22. (In alternattve embodtments,
such as those shown tn U.S. Patent 4,917,697 lssued to Osborn, the
flaps 24 may be tntegral wtth the ma1n body portton 22. In such a
case, the topsheet 40 ma~ form one surface of both the n aps 2~ and
the matn body port10n 22, and the backsheet 42 may form the other
surface of the same. In addttton, the absorbent matertal of the
santtary napk1n 20 m-y extend tnto the flaps 24 to form ~ flap
absorbent core, as descr1bed ln greater deta11 1n U.S. Patent
4,917,697.)
The flaps 24 are each assoctated wtth ma1n body portton 22
along a ~uncture. Th1s ts typ1cally a 10ng1tudtnally-ortented (or
~longttudtnal~) ~uncture, such as ltnes of ~uncture 30. As used
heretn, the terms ~uncture~ (or ~ltne of ~uncture~) refer to
regtons where the flaps 2~ extend fro~ or are ~otned to the ~n
body portlon 22. These regtons can be any of var~ous curved or
stratght ltnes, but they are not ltmtted to llnes. Thus, these
2~f~
- lo
reglons can comprlse flanges strlps lntermlttent llnes and the
llke. In the sanltary napkln 20 lllustrated ln flgure 1 llne of
~uncture 30 ls ~ rel~tlvely stralght llne.
The flaps 2~ have a proxlmal edge 32 ad~acent the l~ne of
Juncture. A dlstat edge (or ~free end~) 34 1s remote fro~ the llne
of ~uncture 30. As shown ln Flgure l each flap 2~ 1s dlvlded lnto
a front half 26 and a back half 28 b~ a flap transverse centerllne
tI. The flap transverse centerllne tl m~y cotnclde wlth the
pr1nclpal transverse centerllne t of the san1tary napk1n but thls
ls not absolutely requ1red. The flap transverse centerllne tl
extends through the pr1nclpal longltudlnal centerllne l to dlvlde
the sanltary napk1n 1nto four quarters A B C and D.
The quarters comprlse a flrst portlon or zone (such as Al Bl
Cl and Dl) ad~acent at least a port10n of the prlnclpal
longltudlnal centerllne l and the flap transverse centerllne tl. A
second portlon or zone (A2 B2, C2 and D2) ls outboard of and
complementary ~th the f1rst port10n. (The ter~s ~outboard~ or
~outward~ as used hereln mean generally spaced ln ~ d1rectlon away
from these centerl1nes. ~he ten~ ~co~plementary- ~s used here1n
means that the f1rst and second port10ns form an ent1re quarter.)
The san1tary napk1n 20 has at least one zone of d1fferentlal
extens1blllty (or ~zone of extenslb111ty~ or s1mply ~zone~) 50.
Preferably as sho~n 1n Flgure l the san1tary napkln 20 has four
zones of d1fferent1al extenslbll1ty 50 one ~n each quarter of the
san1tary napk1n 20. The zones of d1fferentl-1 extens1btllt~ 50
relleve the stresses wh1ch tevelop ln the flaps 2~ when the~ are
folded around a panty crotch. S1nce the zones of dlfferentlal
extenslb11ity 50 rel1eve stresses 1n the flaps they may be referred
to hereln as a type of ~stress rellef means~.
The ter~ ~zone of d~fferentl~l extens1b111ty~ as used herein
refers to a port10n of the san1tary napk1n 20 ~h1ch 1s capab1e of
extendlng ~ d1ffer1ng amount (preferably ~ greater a~ount), th~n
surroundlng port10ns of the san1tary napk1n 20. These ~surround1ng
portlons~ of the sanltary napkln comprlse the flrst portlons of the
~uarters. The zones of dtfferent1-1 extenslblllty 50, thus,
comprtse the second portlons of each quarter.
The zones of d1fferent1al extenslblllty 50 ~re preferably
prlmarlly extenslble 1n a greater amount generally outward ln the
transverse dlrectlon. Thls ls generally 1n the dlrectlon of the
arrows shown ln Flgure 1. As used here1n, ~generally ln the
transverse dlrect10n~ means that the extenslb111ty has a transverse
component. All of the extenslon, however, need not be exactly
parallel to the pr1nc1pal transverse centerllne of the san1tary
napkln. The extenslb11lty ls preferably or1ented more ln the
transverse dlrectlon than ln the long1tudlnal dlrect10n.
The zone(s) of dlfferent1al extenslb11tty 50 can compr~se any
structure capable of extendtng a greater amount 1n the transverse
dlrectlon than the surround1ng port10ns of the sanltary napkln. The
d1fferentlal extens1b11ity referred to here1n, however, must be
elast1cless. That 1s, 1t must be accompl1shed w1thout the use of
separate elastlc pteces, strands, or mater1als to contract one or
more port10ns of the sanltary napktn. The zones of d1fferent1al
extens1btl1ty must also be accompltshed ~tthout sl1ttlng or notch1ng
portlons of the san1tar~ napk1n that cover the wearer's
undergarments. Th1s w111 have the advantage that exudates w111 not
be able to travel through the s11ts or notches to so11 the wearer's
underqarments.
Su1table structures for the zones of dlfferentlal extenslbl1ty
lnclude, but are not llm1ted to zones of mater1al that are
mechan1cally stratned, corrugated, ~r1ng rolled~, folded, pleated,
or ~olned along a curved ~uncture. These structures (although
sometlmes shown only as be1ng part of the flaps 2~), can compr1se
portlons of the matn body port10n 22, portlons of the n aps 2~, or
both. They can be tntegral parts of these components of the
san1tary napk1n, or separate elements, such as p1eces of mater1al,
~otned to the san1tary napk1n.
--- 12 2a?~3~ ~
~ he ~ones of dlfferentlal extenslblllty 50 are more
speclflcally located 1n the corner reglons 52 of the san1tary napkln
20. (~hus, the second porttons A2, B2, C2, and ~2 Of the quarters
preferably comprise the corner reg10ns 52 of the san1tary napkln
20.) ~he sanltary napkln 20 preferably has four corner reglons 52
(two by each flap, and one 1n each quarter).
The ten~ ~corner reglons~ 52, as used hereln, refers to
portlons of the san~tary napk1n 20 th~t are generally located ~long
or ad~acent a portlon of the long1tudlnal ~uncture of each flap 24.
The corner regions 52 for each flap 24 are located ln two areas ln
the reglons of the ends 30a and 30b of each ~uncture 30. One corner
reg10n 52 ls located ad~acent the longltudinal ~uncture 30 ln the
front half 26 of the flap 2~. The other ls ad~acent the
longltudlnal ~uncture 30 ln the back half 28 of the flap 2~. The
corner reglons 52 are preferabl~ at least part1-11y d1sposed
longltudlnally away from the flap transverse centerl1ne tl ln each
d1rectlon. (Thus, the corner reg10ns 52 may be descr1bed as be1ng
longitudlnally ~remote~ fro~ the flap transverse centerl1ne tl.)
In the most preferred case (as ~111 be subsequently descr1bed
ln greater detall), the zones of d1fferentlal extens1b111ty 50 are
located along a port10n of the fold 11ne where the flaps 2~ are
folded around the wearer's panty crotch. The fold 11ne w111
typ1cally be located along or ad~acent the long1tud1nal ~uncture 30
of each flap 2~. S1nce the terms ~portions~, ~zones~, and
~reg10ns~, as used here1n, refer to general areas, the zones of
different1al extens~b111ty 50 and the corner reg10ns 52 are, thus,
not llm1ted to po1nts wh1ch 11e prec1sely on the 11nes of ~uncture
30. Typ1cally, they w~ll 1nclude both those po1nts wh1ch 11e on the
11nes of ~uncture 30 as well as the surround1ng areas of the
san1tary napk1n 20 (wh1ch 1nclude the aforement10ned fold 11nes).
The long1tudlnal ~unctures, thus, typlcallr serve as good
approxlmat10ns for the locat10n of the zones of d1fferent1al
extenslb111ty 50.
_ 13 2 ~f~ L
The corner reglons 52 are deslgnated as such because they
typlcally lnclude the ~corners~ formed ~long the perlphery 23 of the
sanltary napkln 20. The ~corners~ occur where the edges 35 of the
flaps 24 lntersect wlth the longltudlnal slde edges 22- of the maln
body port~on 22 when the sanltary napkln 20 ls shown ln a plan vlew.
It ts not necessary for there to be a sharp angle formed at the
1ntersectlon of these edges or for llnes of demarcatlon to
deslgnate the same however. (Another ~ay to descr1bQ the corner
reglons 52 ls wlth reference to U.S. Patent 4 917 697 lssued to
Osborn III, et al. The corner reglons 52 descrlbed hereln are
typlcally comprlsed at least of those areas shown as hav1ng sllts or
notches in the Osborn et al. patent. (For slmpllclty these areas
may be referred to hereln as ~notch reglons~). However the corner
reglons 52 ln the present lnventlon preferably encompass a larger
area than the sllts or notches shown ln the Osborn patent.)
The portlons of the flaps 2~ ln the corner reg10ns 52 of the
sanltary napkln 20 may be referred to as the ~corner reg10ns of the
flaps or ~flap corner reglons~. These ~a~ be separately deslgnated
52 although they are st111 consldered to comprtse the corner
reglons 52 per se.
Flgures l and lA show a sanltary napkln 20 whlch has one
preferred type of zones of d1fferent1al extenslb11lty 50. In the
sanltary napk1n 20 shown 1n F1gures l and lA the zones of
d1fferent1al extens1b111ty 50 comprlse portlons of the san1tary
napkln 20 that have slack provlded thereln. These port10ns of the
sanltary napk1n 20 comprlse at least the flap corner reg10ns 52 .
The slack 1s prov1ded to the san1tary napk1n 20 1n the
embodlment shown 1n Flgures l and lA by pre-stretch1ng (or
~pre-straln1ng~) the corner reg10ns of the flaps 52 . Th1s can be
accompl1shed by heat1ng and then stretchlng the flap corner reglons
generally ln the transverse d1rect10n. Th1s heat1ng and stretchlng
1ncreases the s1ze of the flap corner reglons 52'. Thus when the
sanltary napk1n ls la1d out as shown ln Flgures 1 and lA wlth the
flaps 2~ extended there 1s excess mater1al 1n the flap corner
2 ~7 ~ J~L
reglons 52'. Thls excess materlal (as described ln greater deta11
below) allows the flaps 24 to be folded around the crotch of the
wearer's pantles w1thout stresses being created ln the corner
reg1ons 52.
Any known method of stretch~ng mater1als can be used to
pre-stretch the corner reg10ns 52. (It ls expressly not adm1tted,
however, that the use of zones of differentlal extens1bll1ty 50 1n
the corner reglons of an absorbent artlcle ls known or the method of
mak1ng an absorbent artlcle hav1ng zones of d1fferentlal
extensibll1ty 1s known.) Any suitable process that stretches the
mater1al of the corner reglons 52 beyond the1r polnt of plast1c
deformatlon to permanently deform (or elongate) the corner reglons
52 can be used. For lnstance, lt ls not necessary for the corner
reglons 52 to be heated pr10r to stretchlng the same. Heatlng may
make the stretchtng eas1er, however. In add1t10n to pre-stretchlng,
a number of alternatlve ways of prov1ding 20nes of d1fferent1al
extenslbll1ty are descrlbed ln greater detall belo~ 1n con~unctlon
~ith the embodl~ents shown 1n the remalning dra~1ng f19ures.
The 1ndlvldual components of the san1tary napk1n 20 ~111 flrst
be looked at 1n greater deta11.
The topsheet 40 1s 11qu1d permeable and when the san1tary
napk1n 20 ls 1n use, the topsheet 40 1s 1n close prox1m1ty to the
sk1n of the user. The topsheet ~0 ls compl1ant, soft feel1ng, and
non-1rr1tat~ng to the user's sk1n. It can be made from any of the
mater1als convent10nal for th1s type of use. Nonllm1t1ng examples
of sultable mater1als that can be used as topsheet 40 are ~oven and
nonwoven polyester, polypropylene, nylon, and rayon and formed
thermoplastlc f11ms, ~1th formed f11ms belng preferred.
Su1table formed f11ms are descr1bed 1n U.S. Patent 3,929,135,
ent1tled ~Absorptlve Structure H~vlng Tapered Cap111~r1es~, ~hlch
1ssued to Thompson on December 30, 1975, U.S. Patent 4,324,426,
ent1tled ~D1sposable Absorbent Art1cle Hav1ng A Sta1n-Res1stant
Topsheet~, ~h1ch 1ssued to ~ullane and Sm1th on Apr11 13, 1982, U.S.
207951 1
Patent ~ 3~2 31~ ent1tled ~Resltlent Pl~stlc ~eb Exhlbltlng
Flber-Llke Propertles~ whlch lssued to R~del ~nd rhompson on August
3 1982 and U.S. Patent ~ 463 0~5 entltled ~Macroscoplcally
Expanded ~hree-Dlmenslonal Pl~stlc ~eb Exhlb1tlng Non-610ssy Vlslble
Surf~ce and Cloth-Llke ~act11e Impresslon~ wh1ch 1ssued to Ahr
Louls Mullane and Ouellette on July 31 1984. Formed fll~s are
preferred for topsheet ~0 because they are perY10us to 11qulds and
yet non-absorbent. Thus the surface of the formed fll~ ~hlch ls ln
contact wlth the body rema1ns dr~ ~nd 1s more co~fortable to the
wearer.
In one partlcularly preferred embod~ment (shown ln Flgure l~
wlthout the ~ones of dlfferentlal extenslblllty of the present
1nventlon) the sanltary napk1n 20 1s comprlsed of components that
are extenslble (l.e. capable of stretchlng part1cularly 1n the
longltudlnal dlrect10n) when the sanltar~ napktn ls ~orn.
Preferably the sanltary napkln 20 ls capable of elongatlng between
about 15X and about ~OX of lts unstretched length. ~h1s
extens~blllty prov~des better ln-use flt comfort, and decreased
sta1n1ng. In other embodl~ents onl~ l~mlted port10ns of the
components of the s~nltary napkln 20 are c~pable of stretch1ng.
A part1cularly preferred topsheet ~0 for use ln such an
embodlment ls one wh1ch 1s mad~ ln accord-nce w1th U.S. Patent
~ 63 0~5 and r1ng rolled to prov1de 1t ~lth ~ degree of
longltud1nal extenslblllty. Sultable processes for r1ng roll1ng or
~pre-corrugatlng~ are descr~bed ln U.S. Patent ~ l07 36~ lssued to
Sisson on August 15, 1978, U.S. Patent 4,834,741 issued
to Sabee on May 30, 1989 and in co-pending, commonly
assigned Canadian Patent Application Serial No. 2 103 822
entitled "Improved Method And Apparatus For Incrementally
Stretching A Zero Strain Stretch T ~mi n~te Web To Impart
Elasticity Thereto" filed by Gerald M. Weber et al. on
January 28, 1992, Canadian Patent Application Serial No.
2 101 277 entitled "Improved Method And Apparatus For
Incrementally Stretching Zero Strain Stretch Laminate Web
In A Non-Uniform Manner To Impart A Varying Degree of
Elasticity Thereto" filed by Kenneth B. Buell et al. on
January 28, 1992, and Canadian Patent Application
_~,
, .
A.
16 2 0 7q5ll
Serial No. 2 104 236 entitled "Improved Method And
Apparatus For Sequentially Stretching Zero Strain Stretch
T.~mi nAte Web To Impart Elasticity Thereto Without
Rupturing The Web" filed by Gerald M. Weber et al. on
January 28, 1992. The fold lines in the corrugations of
the topsheet ~hould run in the transverse direction so
the topsheet is longitudinally extensible.
Such a topsheet is described in greater detail in
the following patent applications which were filed on
July 24, 1992: Canadian Patent Application Serial No.
2 073 815 entitled "Absorbent Articles, Especially
Catamenials, Having Improved Fluid Directionality,
Comfort and Fit" filed in the names of Thompson, et al.;
Canadian Patent Application Serial No. 2 073 849 entitled
"Fluid Handling Structure for Use in Absorbent Articles"
filed in the names of Thompson, et al.; and, Canadian
Patent Application Serial No. 2 113 416 entitled
"Absorbent Core for Use in Catamenial Products" filed in
the names of Buenger, et al. These patent applications
may be referred to collectively as the "Capillary Channel
Fiber" patent applications.
- In add1t10n 1n preferred san1tary napk1n embod1~ents at least
a port10n of the outer surface 40a of the topsheet ~0 1s treated
w1th a surf~ctant. It 1s preferred that the surfactant be
substant1ally evenly and completel~ d1stributed across at least the
port10n of the outer surface ~Oa of topsheet 40 that overla~s the
ma1n body portton 22. Th1s can be accompl1shed b~ ~n~ of the common
techn1ques well known to those sk111ed 1n the art. For example the
surfactant can be appl1ed to topsheet 40 by spraylng by paddtng or
by the use of transfer rolls.
Treat1ng the outer surface ~Oa of the topsheet ~0 w1th a
surfactant ~endeYs the surface of the topsheet ~0 more h~droph11tc.
Th1s results 1n 11qu1d penetrat1ng the topsheet ~0 faster than tt
would lf the surface ~ere not treated. Thts d1m1n1shes the
ltkel1hood that menstrual n u1ds wlll flow off topsheet ~0 r~ther
than be1ng absorbed b~ the absorbent core ~. Preferably an~
porttons of the topsheet ~0 that overlay the n aps 2~ are not
treated w1th the surfactant. Thts w111 mtn1-1ze an~ tendenc1es
~ ,;.,
flulds may have to spre-d laterally across the flaps ~nd to come ln
contact wlth the wearer's thlghs and other parts of the wearer's
body.
In preferred embodlments, the lnner surface ~Ob of topsheet 40
ls secured ln contactlng relatlon wlth the absorbent core ~ h1s
contactlng relatlonshlp results ln llquld penetratlng topsheet ~0
faster than 1f the topsheet ~0 were not ln contact ~lth absorbent
core U . The topsheet ~0 can be malntalned ln contact wlth
absorbent core 44 by applylng adheslve to the lnner surface ~Ob of
the topsheet 40. Sultable adheslves useful for thls purpose are
descrlbed ln U.S. Patent ~,917,697. The adheslves can be applled by
the same methods as the surfactant ls applled to the outer surface
40a of the topsheet 40.
The absorbent core U ls poslt~oned between the topsheet ~0 and
the backsheet ~2. The absorbent core ~ provldes the means for
absorblng menstrual fluld. The absorbent core 44 need not have an
absorbent capaclty much greater than the total amount of menstrual
flu1d antlc1pated to be absorbed. The absorbent core U 1s
generally compress1ble, conformable, and non-lrr1tatlng to the
user's skln. It can compr~se any materlal used ln the ~rt for such
purpose. Examples lnclude comm1nuted wood pulp whlch ls generally
referred to as a1rfelt, creped cellulose wadd1ng, absorbent foams,
absorbent sponges, synthet~c staple flbers, poly~erlc f1bers,
hydrogel-form1ng polymer gelllng agents, peat moss, or any
equ1valent materlal or comb1nat10ns of mater1als.
Polymer1c gelllng agents are those materlals wh1ch, upon
contact wlth flulds (1.e., llqulds) such as water or body flu1ds,
lmblbe such flulds and thereby for~ hydrogels. In th1s manner,
flulds d1scharged lnto the absorbent core U can be acqulred and
held by the polymer1c gelllng agent, thereby prov1d1ng the art1cles
hereln w1th enhanced absorbent capac1ty and/or lmproved fluld
retentlon performance.
_ l8 207951 1
~ he polymerlc gelllng ~gent ~hlch 1s employed 1n the absorbent
core U ~111 gener~ comprlse partlcles of ~ substant1ally
~ater-lnsoluble sl~ghtl~ cross-ltnked, partl~lly neutr~ ed
hydrogel-formlng polymer ~ater1~ he ter~ ~part1cles~ as used
here1n can refer to part1cles 1n any for~ such as tn the fon~ of
pellets flakes or f1bers. ~he characterlst1cs of the ~bsorbent
core U (1nolud1ng but not 11mlted to the preferred types of
polymer mater1als used thereln and types of methods wh1ch can be
used for prepar1ng these polymer part1cles) are descr1bed 1n greater
deta11 1n U.S. Patent 5 009 653 1ssued to Osborn.
In one preferred embod1ment the absorbent core ~ 1s
lam1nate compr1sed of a l~yer of superabsorbent pol~er ~ater1~1
such as 1n the fon~ of part1cles d1sposed between two a1r-1~1d
t1ssues f1rst and second t1ssue la~ers (or ~upper- and ~lower~
t1ssue l~yers). The f1rst and second t1ssue l~yers prov~de
contalnment of the super~bsorbent polymer ~aterl~ prove lateral
w1ck1ng of the absorbed exud~tes throughout the absorbent core U
and prov1de a degree of ~bsorbency.
A suitable laminate is the superabsorbent laminate
WATER-LOCK~ L-535 available from the Grain Processing
Corporation of Muscatine, Iowa (WATER-LOCK registered TM
by Grain Processing Corporation). Such superabsorbent
laminates are disclosed in U.S. Patent 4,467,012,
entitled "Composition For Absorbent Film and Method Of
Preparation", which issued to Pedersen et al. on August
21, 1984, and U.S. Patent 4,260,443, entitled "T,~m; n~ted
Absorbent Process", which issued to Lindsay et al. on
April 7, 1981.
In a part~cularly preferred embod1ment the absorbent core ~4
~s a lam~nate as descr1bed abovc wh~ch ~s s11tted or part1ally
sl1tted for long~tud1nal extenslb~l1ty as shown ~n FI6. 1~ ~n the
accompany~ng dra~1ng f~gures. ~h1s sl1tted or part1~11y sl~tted
core 1s descr1bed ~n greater deta~l 1n the Cap~llary Channel F1ber
patent appl1cat10ns.
As.
2 ~7 ~ L
The backsheet 42 ls lmpervlous to ltqulds and thus prevents
menstrual fluld from solllng the clothlng of the user. Any materl~l
used ~n the art for such purpose can be ut~llzed hereln. Sultable
materlals ~nclude embossed or nonembossed polyethylene fllms and
laminated tlssue. A sultable polyethylene f11m ls ~anufactured by
Monsanto Chemlcal Corporatlon and marketed ln the trade as Fllm No.
8020.
In one alternat1ve embodlment of the sanltary napkln 20
(typlcally ln whlch the topsheet 40 overlays only the maln body
portlon 22 and does not extend out to form the top surface of the
flaps) the backsheet 42 ~ay be comprlsed of two layers. In such a
case the backsheet 42 0ay comprlse a flrst layer of lofted mater1al
d1sposed on the core-faclng slde 42a of the backsheet. The purpose
of the flrst layer ls to provlde a comfortable non-1rr1tattng
surface aga1nst the body of the wearer. The lofted layer ~ay be
comprlsed of any su1table materlal such as a nonwoven mater1~1.
Preferably the lofted layer compr1ses a hydrophob1c nonwoven
material. ~he second layer may be dlsposed on the gan~ent slde 42b
of the backsheet 42 and ~ay comprlse a flu1d l~perv10us fllm. A
low denslty polyethylene matertal about 0.01 to about 0.05
milllmeters ln thlckness preferably about 0.02 m1111meters ln
thlckness has been found to work well as th1s second layer. A
polyethylene f11m such ~s 1s sold by the Ethyl Corporat10n
Vlsqueen D1v1s10n under ~odel XP-3938S has been found part1cularly
well suited for this second layer. The backsheet 42 ~ay also be
made of a soft cloth-llke mater1al wh1ch 1s hydrophob1c relat1ve to
the topsheet 40. A polyester or polyolefln1c flber backsheet 42 has
been found to work well. A part1cularly preferred soft cloth-llke
backsheet 42 materlal ls a lamlnate of a polyester nonwoven mater1al
and a f11m such as descrlbed ln U.S. Patent 4 476 180 1ssued to ~nuk
on ~ctober 9 1984.
A part1cularly preferred extens1ble backsheet 42 ls an extended
adheslve fllm Formula tl98-338 manufactured by the F~ndley Adhes1ves
2 ~ 7~ L
Company of ~auwatosa, ~lsconsln ~hlch ls descr1bed ln greater detall
ln the Caplllary Channel Flber patent appllcatlons.
As shown ln Flgures l and lA, the topsheet 40 ls secured to
backsheet ~2 along a flrst seam, such as seam 36. The seam 36 can
be formed by any means commonly used ln the art for thls purpose
such as by glulng, crlmplng, or heat-seallng. The sea~ 36 ls
lllustrated ln Figure l as extendlng completely around the perlphery
of the maln body portlon 22. Thls ls a preferred embodlment for
ease of constructlon. (Other means of unlt1ng the var10us elem~nts
can be used.)
The maln body portlon 22 ls the portlon of the san1tary napkln
20 that conta1ns an absorbent means, such as absorbent core U . The
ma1n body portlon 22 has a llqu1d pervlous body contact1ng surface
(represented ln Flgure lA by topsheet ~0) and an opposed 11qu1d
lmperv10us surface (represented ln F~gure lA by backsheet ~2). It
ls to be understood that the embod~ment 111ustrated 1s only one
posslble embodlment, albe~t a preferret one. Other poss1ble
embod~ments 1nclude one ~n ~h1ch an absorbent core U 1s essentlally
completely wrapped wlth topsheet before lt ls placed on a backsheet.
The ma1n body port10n 22 can also compr1se an absorbent core ~h1ch
possesses suff1c1ent 1ntegrlty to stand alone and 1s 11qu1d perv10us
on one surface wh11e the other surface has been treated to render 1t
11qu1d 1mperv10us.
The ma1n body port10n 22 may be relat1vely th1ck or relatlvely
narrow and th1n. A narrow ma1n body port10n 22 may be effect1ve
because the overall conf1gurat10n and use of san1tary napk1n 20
results 1n ma1n body port10n 22 be1ng ma1nta1ned 1n close prox1m1ty
to the body. Such prox1m1ty of ma1n body port10n 22 places tt
prec1sely where 1t should be: very near the boty at the vag1nal
open1ng. The ma1n body port10n 22 can then absorb the vast ~a~or1ty
of the menstrual flu1d (menses) before 1t has an opportun1ty to flo~
along the s1tes of the ma1n body port10n 22. A thln ma1n boty
port10n may also be des1red because 1t 1s typ1cally comfortable to
the user.
2~
F~gures 1 and lA ~lso show the fasteners, such ~s adheslve
attachment means, centr~l p~d adhes~ve 5~ and flap adhesive 56,
whlch are adapted to secure the sanltary napk1n 20 to the crotch
region of an undergarment.
The central pad adhes1ve 5~ provldes an adheslve attachment
means for securlng maln body portlon 22 ln the crotch portlon of a
panty. The outer surface of flap 2~, adJacent the dlstal edge 3~ of
the flap, 1s preferably coated w1th a flap adhes1ve 56. The flap
adhes1ve 56 1s used to ass1st 1n matntaln1ng the flap 2~ 1n pos1t10n
after lt ls wrapped around the edge of the crotch portton of the
panty as descr1bed below. The flaps 24 can be malnta1ned ln
pos1t10n by attach1ng the flaps 2~ to the undergarment, or to the
oppos1ng flap. Su1table adhes1ve fasteners are descrtbed ln greater
detatl ~n U.S. Patent ~,91~,69~.
The fasteners used w1th the absorbent artlcles made b~ the
method present lnvent10n are not ltm1ted to adhes1ve attachment
means. Any type of fastener used 1n the art can be used for such
purpose. For example, the san~tar~ napktn 20 could be secured to
the wearer's undergarment b~ the fastener descrtbed ln U.S. Patent
4,946,527 entltled ~Pressure-Senstt1ve Adheslve Fastener and Method
of Hak1ng the Same~ lssued to Battrell on August 7, l990. For
s1mpltc1ty, however, the fasteners w111 be descr1bed ln ter~s of
adhes~ve attachment means.
The adhes1ve attach~ent means are respect1vely covered by
removable release 11ners, central pad release ltner and flap release
11ner, both des1gnated S8. The pressure-sens1t~ve adhestves should
be covered w1th release ltners 58 to keep the adheslves from
st1ck1ng to extraneous surfaces pr10r to use. Su1table release
11ners are descr1bed 1n U.S. Patent ~,917,697.
~ htle a preferred san1tary napk1n e~bodtment has been
descr1bed, numerous other san1tary n-pktn embod1~ents hav1nq flaps
are avatlable and are d1sclosed 1n the ltterature. These could be
prov1deJ w1th the zones of d1fferent~al extens1bll1ty b~ the ethod
22 207951 1
of the present invention. In particular, sanitary
napkins having flaps are disclosed in Canadian Patent
Application Serial No. 2,028,288 entitled "Sanitary
Napkin Having Laterally Extensible Means for Attachment
to the Undergarment of the Wearer", filed October 25,
1990 in the name of Osborn, et al., U.S. Patents
5,009,653 and 4,950,264,
both ent1tled ~h1n ~lex1ble San1tary Napk1n ~h1ch 1ssued to
Osborn on Apr11 23 l991 and August 21 1990 respect1vel~ U.S.
Patent 4 9~0 ~62 ent1tled ~San1tary Napkln ~1th Expandable Flaps~
wh1ch 1ssued to Salerno on Jul~ l0 1990 U.S. P~tent ~ 91~ 697
ent1tled ~San1tary Napk1n Hav1ng ~laps and Stress Rel1ef Means~
wh1ch 1ssued to Osborn III, et al. on Aprtl l~, l990, U.S. P~tent
~ 91l 70l entltled ~Sanltar~ Napk1n Hav1ng Elast1c Shap1ng Heans~
whlch 1ssued to Mav1nkurve on March 2~ 1990 U.S. Patent ~ 900 320
ent1tled ~San1tary Napk1n ~1th Pant~ Gather1ng Flaps- ~h1ch 1ssued
to McCoy on February 13 1990 U.S. Patent ~ 68~ ~8 ent1tled
~Shaped San1tary Napk1n ~lth Flaps , ~hlch 1ssued to Van ~11burg on
August 18 l98~ U.S. Patent ~ 608 0~ ent1tled ~San1tary Napk1n
Attachment Means- wh1ch 1ssued to ~att1ngl~ on August 26 1986
U.S. Patent ~ 589 876 ent1tled ~S-n1tary Napk1n~ ~h1ch 1ssued to
Van ~1lburg on Ma~ 20 1986 U.S. Patent ~ 285 3~3 entltled
~San1tary Napk1n- ~h1ch 1ssued to ~cNa1r on August 25 1981 U.S.
Patent 3 397 697 ent1tled ~D1sposable San1tar~ Sh1eld For
Undergarments~ ~h k h lssued to R1ckard on August 20 1968 and U.S.
Patent 2 78~ 2~1 ent1tled San1tary Napk1n~ ~h1ch 1ssued to Clark
on Apr11 2 195~.
Su1table absorbent artlcles 1n the for~ of pant111ners ~re
dlsclosed 1n U.S. Patent ~ ~38 6~6 ent~tled ~Pant111ner~ 1ssued to
Osborn on Apr11 19 l988. Su1table absorbent art1cles at least
some of which are in the form of adult incontinence
products, are described in Canadian Patent Application
Serial No. 2,098,502 entitled "Absorbent Article Having
Rapid Acquiring Wrapped Multiple Layer Absorbent Body"
filed by Barry R. Feist, et al. on December 20, 1991.
, .
A i~.
207951 1
The characterlst1cs of the flaps 2~ w111 now be looked ~t ln
greater deta11. The general constructlon of flaps 24 su1table for
use 1n the present 1nvent10n (w1thout the zones of d1fferent1al
extens1b111ty) 1s descr1bed 1n greater deta11 1n the patents
lncorporated by reference here1n.
The overall slze of the flaps 2~ can be read11~ selected by
those sk111ed 1n the art. Prefer-bly, the flaps 2~ ~re s1zed so
that the san1tary napk1n 20 1s fro~ ~bout lO to ~bout 23 centlmeters
wide between the d1stal edges 3~ of the flaps at the1r greatest
separat10n. Preferably each flap 2~ 1s from about 5 to at least
about 19 cent1meters long 1n the d1rect10n par~llel to the pr1nc1pal
long1tud1nal centerl1ne ~ of the san~tary napkln.
~ he shape of the flaps 2~ can be selected b~ those sk111ed 1n
the art. Preferabl~ not only are the flaps 2~ m1rror 1mages of
each other the two halYes of each fl ~p 26 and 28 are also
symnetr1cal about the flap transverse centerl1ne tl. (It should be
understood th-t the shape and or1entat10n of the flaps descr1bed
here1n are those of a preferred embod1ment. ~hey are not mandatory
des1gn features.)
In the preferred embodlment 111ustrated 1n F1gure l the flaps
24 are pos1t10ned s11ghtl~ fon~ard of the pr1nc1p~1 transYerse
centerl1ne t of the san1tar~ napk1n. (In such a case the flap
transverse centerl1ne tl toes not co1nc1de w1th the pr1nc1p~1
transverse centerl1ne t of the san1tar~ napk1n 20.) ~he flaps 2~
however are preferabl~ evenl~ spaced from the pr1nc1p~1
long1tud1nal centerl1ne 1 of the san1tar~ napk1n.
";
2~
The flaps 2~ can be ~ssoclated wlth the maln body portlon 22 ln
a number of dlfferent manners. Many of the dlfferent ways a
component (such as the flaps 2~) can be ~olned to~ or ~assoclated
w1th~ etc. another component whlch are set forth ln the def1nltlons
of these terms cont~lned ~n U.S. Patent S 00~ 906 entltled
~Decoupled San1tary Hapk1n~ wh1ch lssued to Osborn et al. on Aprll
16 l991. ~hen the flaps comprlse separ-te elements they can be
~olned to the maln body portlon 22 by any techn1ques known to those
skllled 1n the art. Such techntques 1nclude but are not ltmlted to
adhes1ves heat and/or pressure ultrasonlcs etc.
~ he flaps 24 are assoc1ated wlth the ma1n body portton 22 along
11nes of ~uncture 30. The llnes of ~uncture can be concave
stralght (or but preferably not convex) relatlve to the prtnclpal
longitudlnal centerllne l. The ltnes of ~uncture 30 m~y compr1se
those llnes or areas where separate flap elements are ~olned to the
ma1n body portlon 2~. Alternat1Yely when the flaps 2~ ~re lntegral
wlth the matn body port1On 22 the ltnes of ~uncture 30 may
represent llnes of demarcatlon between the maln body portlon 22 and
the flaps 2~ (although lt ls not necessary that there be a prec1se
llne of demarcatlon).
It ls also not necessary that the flaps 2~ extend from (or be
~olned along) the longttudlnal edges 22a of the matn body portlon
22. The flaps 24 can ~ o1ned tnward (or ~tnboard~) fro~ the
longttudtnal edges 22a toward the longltudtnal centerltne such as 1s
shown 1n U.S. Patent ~ 900 320 lssued to McCoy on February 13 1990.
The flaps 24 can thus each be ~otned to the maln bod~ portlon 22
along the pr1nctpal long1tud1nal centerltne l or along the
long1tud1nal edges 22a of the matn body port~on 22 or at any place
between the prtnc1pal longttudtnal centerltne l and the longttudtnal
edges 22a of the maln body portton 22. The flaps 24 wtll of
course generally be on oppos1te stdes of the prtnctpal longttud1nal
centerltne l.
Hav1ng now descr1bed some sanltary napktns that can be provlded
wtth zones of dtfferenttal extens1bll1ty by the ~ethod of the
present lnventlon these sanltary napklns wlll now be descrlbed ln
greater detall wlth relatlon to the functlon of the same ln the
wearer s underganments.
flgure 3 ls a deplctlon of the crotch portlon 1~ of an
undergarment 11 of the type commonly worn by many women and well
known as a panty. A panty 11 comprlses a front sect10n 10 a back
sectlon 12 and a crotch portlon 1~ whlch ~olns the front and back
sectlons. The crotch portlon 1~ compr1ses two s1de edges l6 and
center crotch portlon 18.
The san1tary napkln 20 ls ut11lzed by removlng the release
llners 58 and placlng ~he sanltary napkln 20 ln a panty 11 as shown
~n Flgure ~. The center of maln body portlon 22 1s placed ~n crotch
portlon 1~ of the panty wlth one end of ma1n body port10n 22
extendlng towards the front sect10n lO of the panty and the other
end towards the back sectlon 12. The backsheet ~2 1s placed 1n
contact wlth the lnner surface of center crotch port10n 18 of the
panty. Central pad adheslve 54 ~atnta1ns ma1n body port10n 22 1n
posltlon. ~he dlstal portlons of flaps 2~ are folted around the
slde edges 16 of the panty. The flap adhes1ves secure the n aps 2
to the underside of the panty.
~ hen the flaps 2~ are folded down around the edge 16 of the
crotch portlon l~ of the pant~ stresses are developed 1n the ~ aps
part1cularly 1n the corner reg10ns 52 of the same. These stresses
are magnlf1ed when the flaps 24 are folded under the panty and
attached to the panty s underslde. The stresses are further
magn1fled when the panty 1s pulled up lnto pos1t10n and the elast1cs
ln the panty edges 16 force the folded port10n of the flaps 1nto the
uppermost part of the wearer's crotch and th19h.
The stresses are most h1ghly concentrated along the fold 19
where the flap 2~ changes from belng d1sposed on the bodys1de of the
panty to be1ng located on the unders1de of the panty. In other
words the stresses are concentrated at the edge 16 of the crotch
port10n l~ of the panty 11. The stresses ln the flaps 2~ generally
2~'~ t ~e~'ff 1
26
follow the arc formed by the edges 16 of the crotch portlon l~.
~hese stresses may cause the corner reglons 52 of the flaps 2~ to
bunch longltudlnally lnward. ~h1s reduces the area of the wearer's
undergarments the flaps ~re able to cover. If the stresses are
great enough the flaps 2~ can become detached from the panty and
the flaps 2~ wlll be less than optlmally effectlve. Dependlng on
the deslgn of the sanltary napk1n the arc of concentrated stresses
may or may not co1nclde wtth the llnes of ~uncture 30 between the
flaps 2~ and the maln body port10n 22.
In order to ellmlnate, or at least reduce these stresses the
sanltary napkln 20 ls prov1ded w1th zones of d1fferent1al
extensib111ty 50. The zones of d1fferentlal extenslb111ty 50
preferably reduce the stresses along the fold 19 to such a degree
that the flaps 2~ wlll rema1n attached to the unders1de of the panty
and wlll not lose thelr ab111ty to cover a g1ven area of the
wearer s undergarments.
Referr1ng agaln to Flgure l one preferred t~pe of zone of
dlfferentlal extenslb111ty 50 whlch was descr1bed br1efly above
compr1ses the slack ln the corner reg10ns 52 of the flaps. ~he
characterist1cs of the zones of d1fferent1al extens1b111ty 50 are
descr~bed ln greater deta11 below. That ls followed by a dtscuss10n
of some alternat1vely preferred types of zones of d1fferent~al
extenslbll1ty.
~ he zones of d1fferent1al extens1bll1ty S0 are as noted above
most preferably located at those po1nts where the edges 35 of the
flaps 2~ 1ntersect the edges 16 of the panty when the san1tary
napk1n 20 1s worn.
The po1nts of lntersect10n can generally be determ1ned by
hav1ng a person wear a part1cularly des19ned napk1n havlng n aps and
a fa1rly commonly des1gned panty. Commonly pant1es have a crotch
wldth of about 5.0 to about 9.0 cent1meters. Marks can then be made
on the bottom surface of the san~tary napk1n 20 where the sanitary
napk1n 20 1ntersects the panty. ~he po1nts of 1ntersect10n between
2~
the flap 2~ and the edge l6 of the panty generally colnclde wlth the
ends of the fold l9. Assumlng the napkln has two flaps, the four
marks ~lll mark the gener~l loc-tlons for the zones of dlfferentlal
extenslb11tty SO. ~he zones of dlfferentlal extenslblllty 50 m~y be
located along the llnes of ~uncture 30, outboard of the llnes of
~uncture ln the flaps 2~, or lnboard of the llnes of ~uncture.
Commonly, the zones of differentlal extenslblllty SO wlll begln at a
polnt located between the area of the flap transverse centerllne tl
and about l.S centlmeters 1n the longltudlnal dlrectlon fro~ the
flap transverse centerllne tI.
The zones of dlfferentlal extenslblllty SO may be of any shape.
Typlcally, they wlll for~ a three-slded flgure (roughly tr1angular,
ple-shaped, or fan-shaped) ln plan vlew when they are fully
extended. Often, the flgure deflned by the zones of dlfferentlal
extenslblllty wlll have two sldes that are of approx1mately equal
length and a shorter slde. The edge 35 of the flaps 2~ usually
forms the shorter s1de. It should be understood, however, that the
prec1se shape of the zones of dlfferentl?l extenslblllt~ 50 1s not
always as cr1t1cal as the locatlon and extens1b111ty propertles of
the same. L1kew1se, lt ls not crlt1cal for there to be preclse llne
of demarcatlon that marks the boundrles of the zones of dlfferentlal
extensiblllty SO (or the boundr1es of the complementary f1rst
portlons of the quarters of the sanltary napkln). Thus, there can
be a gradual trans1t10n bet~een the zones of dlfferent1al
extenslblllty SO and the f~rst portlons of the quarters of the
san1tary napkln.
The zones of dlfferentlal extenslblllty SO may be bounded on
one s~de by the 11ne of ~uncture 30. Alternatlvely, the boundary
may be ad~acent the llne of ~uncture 30. If the zones of
dlfferentlal extenslblllty SO are provlded ln the ma1n body port~on
22 (for lnstance, tf they are for~ed by a fold made through the ma1n
body portlon 22 (as descr~bed belo~)), however, th~s boundar~ eay be
as far lnboard as the pr1nc1pal long1tudlnal centerl1ne 1. The
zones of dlfferent1al extens1b111ty 50 are typlcally bounded ~t the
ends by at least a portlon of the edge 35 of the flap 2~. ~h1s ls
23?
28
often a curved l~ne. (~he ~ones of dlfferentlal extenslblllty 50
can also be bounded at the ends by a portlon of the longltudlnal
edges 22a of the maln body portlon and/or transverse or end edges
22b of the maln body portlon 22.) The thlrd slde of the zones of
dlfferent~al extens~blllty ls typlcally formed by a boundary 51
whlch may be an lmaglnary llne that runs from the po~nt of the zone
of d~fferentlal extenslblllty 50 whlch ls elther located on the flap
transverse centerllne tl (or nearest to the same), to a po1nt on the
edge 35 of the flap 2~.
The total area covered by the zones of dlfferent1al
extens~b~l~ty 50 can vary w1dely. The area can cover a relat1vely
large port~on of the sanltary napkln, prov1ded there rematn so~e
port10ns of the sanltary napkln ad~acent at least portlons of the
princlpal longltudlnal centerllne and the flap transverse centerl1ne
that are less extens1ble. The zones of dlfferent1~1 extens1b111t~
50 can be provlded along the ent1re ~uncture 30 of the flaps 2~ w1th
the ma1n body port10n 22. In alternatlve embodlments, the zones of
dlfferentlal extenslblllty 50 can be prov1ded throughout the ent1re
flap (for lnstance, lf the ent~re flap ls pleated ~1th
longltudlnally-orlented pleats). Preferabl~, however, ln the
present lnventlon, zones of dlfferentlal extenslblllt~ 50 ~re not
provlded elther along the ent1re ~uncture 30 or throughout the
entlre flap. There are several reasons for th1s.
f~rst, due to the curvature of the panty crotch, all port10ns
of the flaps are not stressed the same amount when the flaps are
wrapped around a panty crotch. Typ1cally, the port10n of the n aps
located ad~acent the flap transverse centerllne tl (the center
portlon 27 of the flap) w111 not be sub~ected to stresses that are
as great as those exerted on the flap corner reglons 52'. Thus, 1t
1s posslble that the center portlon 27 of the flaps (and poss1bly
also the ad~acent reg10ns of the ma1n body portlon 22) could ~e
constructed so that lt ls not provlded w1th any extenslb111ty
propert1es. Alternatlvely, the center port10n 27 (and ad~acent
reg10ns) could merely be less extens1ble than the corner reglons 52
of the san1tary napk1n.
~r~
29
Second, lt ls prefer~ble that the corner reglons 52' of the
flaps 2~ stretch a greater dlstance ln the transverse dlrectlon than
the center portlon 2~ of the flaps for thè best f~t and for the
flaps 2~ to adapt properl~ to the curvature of the crotch of the
wearer's undergarments. Thls allo~s the boundary 51 deflned by the
zones of dlfferentlal extens1blllt~ to correspond to the
conflguratlon of the edges of the crotch of the wearer's pantles.
Thlrd, dependlng on the process used to create the ~ones of
d1fferentlal extens~blllty 50, 1t may be less expenslve to prov1de
dlfferentlal extenslblllty ln only certaln portlons of the san1tary
napklns.
The amount of dlfferent1al extens1blllt~ needed can vary
dependlng on a number of factors. ~hese lnclude, but are not
llmlted to the slze and conflguratlon of the wearer's pantles, the
s1ze and conf1gurat10n of the flaps, etc. Any a~ount of
d1fferentlal extenslb111ty tn the corner reglons 52 ~111 prov1de
some beneflt versus a sanitary napk1n that ls not prov1ded ~th
zones of dlfferentlal extenslb111ty. The amount of dlfferent1al
extens1blllty should not be so great, however, that the excess
mater~al that compr1ses the zones of dlfferentlal extenslb111ty 50
causes the sanltary napkln to f1t slopplly ad~acent the ~earer's
pant~es and her body.
Preferably, the amount of d1fferentlal extenslblllt~ 1s
suff1clent to substant1ally reduce the stresses on the flaps when
the sanltary napk1n ls ~orn. Typ~cally " conservatlvely conflgured
zone of dlfferentlal extenslblllty 50 ~s one wh~ch when fully
extended, deflnes a llnear boundary 51 (1.e., one wh1ch fonms a
stralght llne) that runs from the lntersectlon of the flap
transverse centerllne tl and the l~ne of ~uncture 30 to the po~nt on
the edge 3S of the flap 2~ ~here the flap 2~ lntersects the edge 16
of the panty crotch. A ~one of d1fferent1al extenslbll1ty 50 ~1th a
11near conflguratlon 1s sa1d to be conserv~t1vely conflgured because
lt w111 ordlnarlly prov1de a suff1c1ent amount of extens1b111t~ 1n
~ost cases to rel1eve the stresses ~n the flaps 2~. In an 1deal
2~
case the boundary 51 ~111 correspond to the conflgur-tlon of the
edges l6 of the crotch of the wearer s pantles.
Flgures 2 and 2A show a san1tary napkln havlng another type of
zone of dlfferentlal extenslblllt~. The sanltary napkln 20 shown ln
Figures 2 and 2A has flaps wlth corner reglons 52 that have been
prov1ded w1th dlfferent1al extenslblllty by rlng rolllng these
corner reglons ln accordance ~lth the above-descrlbed rlng rolllng
patents and patent appllcatlons. The rlng rolllng (or
pre-corrugat1ng) should be appl1ed so that the fold llnes 60 ln the
corrugatlons are orlented generally ln the longltudlnal dlrectlon.
The phrase ~generall~ ln the longltud1nal dlrectlon~ (and s1m11ar
phrases) as used hereln means or1ented more ln the longltudlnal
dlmenslon than ln the transverse dlmens10n. Thus the fold 11nes 60
may angle awa~ from the prlnclpal longltudlnal centerllne l. Th1s
wlll also provlde the deslred transverse dlrectlon extenslblllty.
In var1atlons of the embodlments of the present 1nventlon (such
as the embodtment shown ln Flgure 2 and 2A) the amount of
extenslbll1ty provlded can be var1ed throughout dlfferent port10ns
of the zones of d1fferent1al extens1b11lty 50. For lnstance the
number or amplltude of the corrugatlons formed by the rlng roll1ng
could be var1ed so that elther or both these characterlstlcs are
greater further from the flap transverse centerllne tl. Thls w111
allow the sanltar~ napk1n to be provlded wlth dlfferent1al
extens1b11lty charactertst1cs that most closely match the
conflguratlon of a panty crotch.
F1gures 5 and 6 sho~ another varlatlon of the sanltary napk1n
made by the method of the present 1nvent10n. The san1tary napk1n 20
shown 1n F1gures 5 and 6 has been prov1ded ~1th zones of
dlfferent1al extenslb111ty 50 by pleatlng and then gather1ng 1n
port10ns of the flaps.
The flaps 2~ are pleated or folded ~1th generally
long1tud1nally-or1ented fold llnes 62. The fold 11nes 62 can run
along and/or outboard (or even 1nboard) of the ~uncture 30 of the
_ 3l
flaps and the maln body portlon 22. The pleats preferably run the
length of the Juncture 30. ~he pleated sectlons of the flaps (the
~pleats-) 6~ are preferably folded on top of each other (th-t ls
stacked perpend1cular to the plane of the sanltary napk1n). In
alternatlve embodiments they may be folded and arranged
s~de-by-s~de. The pleated sect10ns are gathered 1n or restra1ned
from openlng by a flap pleat restra1nt 66 located along the flap
transverse centerllne tl Th1s prov1des the san1tary napkln and
part1cularly the flaps 2~ w1th corner reg10ns wh1ch arc extenslble
1n the transverse dlrect10n and w1th center port10ns 27 (along the
flap transverse centerllne tl) wh1ch are not.
In such a pleated embodlment the flaps 24 can be provlded w1th
any number of fold llnes. For lnstance ln the most baslc for- of
the pleated embodlment the flaps can slmply be folded lnward toward
the prlnclpal longltud1nal centerl1ne 1 along a s1ngle llne along
the ~uncture 30 and tacked to the ~aln body port10n 22 at a po1nt
1nboard of the ~uncture 30 (wh1ch 1s preferably 1n the are~ of the
flap transverse centerllne tl). Typ1cally however as sho~n 1n
Flgure 6 the flaps w111 have at least two pleat fold llnes 62.
The flap pleat restralnt 66 can be any su1table type of element
capable of keep1ng a port10n of the pleated mater1al from unfoldlng.
~he flap pleat restra1nt 66 can be located along the flap transverse
centerllne tI or lt can be spaced some d1stance away from the flap
transverse centerl~ne tl. The flap pleat restralnt 66 ls ho~ever
preferably located at some place along the flap transverse
centerl1ne tl. Th1s creates flaps with pleats whlch are able to
open up an equal amount ln both the front and back halves 26 and 28
for a preferred f1t around the panty crotch. The flaps 2~ can have
two flap pleat restra1nts 16 one located along (or spaced some
dlstance away from) the flap transverse centerllne tl for each flap
or they can have a s1ngle flap pleat restra1nt that spans froa one
flap to the other.
2~r~ ~1
32
The flap pleat restr-lnt 66 shown ln Flgure 6 1s an ~lnterlor~
restralnt l.e. ~t ls located ln between two ple-ted or folded
sectlons 6~ of the flaps 2~. In alternatlve embodl~ents the flap
pleat restralnt 66 can be of a type whlch secures the pleated
sectlons 6~ of the flaps 2~ from outslde (or exterlor) of the
pleated sections.
The flap pleat restralnt 66 may be of any si~e provlded lt ls
no larger than the length of the ~uncture 30. Th1s allows the
pleated sectlons 64 of the flaps 2~ to open properl~. Thls ls the
case slnce the pleated sect10ns 64 of the flaps 2~ w111 typ1cally
open from the ends 30a and 30b of the llnes of ~uncture to the flap
pleat restralnt 66. It may therefore be preferable for the flap
pleat restraint 66 to be as small as posslble to m1n1m1ze
lnterference wlth the openlng of the pleated sect10ns 64. The flap
pleat restralnt 66 should also be located at a polnt on the pleated
sectlon 6~ that ls relat1vely close to the pr1nc1pal longltudlnal
centerllne l. Th1s w111 ensure that the pleat w111 not unfold ~nd
lose lts effecttveness.
The flap pleat restra1nt 66 can be of any sultable
construct1on. Su1table flap pleat restralnts 66 lnclude but are
not limlted to adhes1ves ultrason1c bonds heat and/or pressure
bonds tapes etc. These dlfferent types of flap pleat restralnts
can be ln an unl1m1ted number of conf1gurat10ns. Such
conf1guratlons can 1nclude spots l~nes patches etc.
The dlmens10ns of some sultable pleats for embod1ments such as
those shown ln F~gures 5 and 6 are set forth 1n the followlng Table
1:
33
TABLE l -- PLEAT SIZES
Length of Flap ~ldth of Pleat Effectlve Pleat
~ln ) (ln ) S~ze ~ln )
3 0 ~3 0 1~
3 5 0 50 0 19
0 58 0 26
0 65 0 33
0 ~3 0 40
5 5 0 81 0 50
6 0 90 0 60
6 5 1 00 0 72
~ 1 11 0 86
7 5 1 23 1 03
8 1 40 1 2~
The d~menslons ln Table 1 are non-llm1t1ng examples of the
slzes of pleats ~hlch may be useful ln provldlng ~ san1tary napk1n
wlth sultable zones of differentl-l extenslb111t~ 50 The
d1menslons are based on a sanltary napkln embodlment whlch has a
pleat 9 lnches long The length of the pleat (des1gnated Pl ln
Flgure 15) ls measured from one end of the llne of ~uncture to the
other (from 30a to 30b) tn a d1rect10n parallel to the prlnclpal
longltudlnal centerllne 1
The length of the flaps 2~ referred to 1n Table 1 ls measured
along the ple-t 11ne 62 that ls closest to the dlstal edge 3~ of
the flap 2~ ~hen the pleat restr-lnt 66 ls removed and the flap 1s
unfolded The dlstance bet~een these t~o po1nts 62a and 62b 1s
deslgnated Fl ln Flgure 15 The ~ldth of the pleat Pw ls the
d1stance between fold llnes 62. The ~effect1ve pleat slze- refers
to a number calculated by multlplylng the ~ldth of the pleat t1mes
the ratlo def1ned by the length of the flap over the length of the
pleat
The effectlve pleat slze serves as an approx1mat10n of the
amount the pleat ~111 open ln the corner reg10ns 52 of the
san1tar~ napkln. Flgure lS shows thls schemat1call~. The 11ne
deslgnated 0 ln Flgure I5 represents the approx1mate locat10n of
Z3~ t q~
_ 3~
edges of the pleated sectlons when the pleat ls ln a fully opened
or extended conflguratlon. Flgure lS shows that ln thls
embodlment the polnts on the pleated sectlons spaced
longltudlnally farthest from the flap transverse centerllne tl
wlll generally fan open fully (approxlmately to po1nt ~l) ~h11e
the polnts such as 62- ln the corner reglons 52 of the sanltary
napkln wlll only open partlally (to po1nt ~2)- ~he effectlve
pleat slze recognlzes that the lesser amount whlch the pleated
sectlons wlll open ln the corner reglons ls dlrectly proportlonal
to the relatlonshlp between the length of the flaps and the length
of the pleat (l.e. perhaps better understood and more
speclflcally as belng proportlonal to the ratlo deflned by 1/2 F
over 1/2 Pl)-
The wldth of the pleat and the number of folds ln the pleats
determlnes the amount of extenslblllt~ of the pleated materlal.
The amount of extenslblllty (or slack mater1al) ln the corner
reglons 52 can, thus be calculated by multlplylng the number of
folded sectlons of the pleated sectlon tlmes the effectlve pleat
s1ze. Thus ln embodlments shown ln Flgure 15 hav1ng two folded
sectlons 6~a and 6~b the amount of slack ln each corner reglon 52
ls approx1mately equal to tw1ce the effectlve pleat s1ze.
In add1tlon to belng useful for determ1n1ng the amount of
extenslb111ty ln thc corner reglons of pleated sanltary napkln
embodlments, the effectlve pleat s1ze and other measurements
provided here1n can even be used more broadly. The effectlve
pleat slze flgures provlded can be used as guldellnes for
determ1nlng the amount of extens1blllty for the embodlments
descr1bed hereln havlng d1fferent types of zones of d1fferent1al
extenslblllty. The relatlonsh1p between the d1mens10ns of the
pleats provlded above and the d1mens10ns of 1nterest 1n the other
embod1ments descr1bed here1n can be arrlved at b~ one sk111ed ln
- 35 2 ~?~ ~3 ~ 3L
the art. (for example flgure lS sho~s ~n example of the use of
pleat ~ldths. The curved dotted llne shown ln Flgure 15
represents a suttable loc~tlon for the curved ~uncturc ln the
embodlment (descrlbed below) ln whlch zones of dlfferent1al
extenslblllty 50 are provlded by ~ttachlng the flaps 2~ along a
curved ~uncture. The curved ~uncture curves lnward ln an amount
equal to the wldth of the pleat.)
Flgure ~ shows an ~lternat1ve embodlment of a san1tary napkln
havlng pleated flaps ln whlch the f1~ps 2~ are pleated folded
oYer and secured to the garment slde 20b of the san1tary napkln
20 rather than the body-faclng slde 20a (as 1n the embod1ment
shown ln Flgure 6).
Flgure 8 shows an alternattve embodt~ent of a sanltary napk1n
20 made by the method of the present tnvent10n 1n wh1ch the ~ aps
2~ are attached ~long 11nes of ~uncture that are curved concave
lnward toward the prtnc1p~1 longitudln~l centerl1ne 1. ~hen the
flaps 2~ ln such an embodl~ent are folded outward excess fl~p
material ls present 1n the corner reg10ns 52.
In th1s embodl~ent the san1tar~ napk1n 20 may have two
longltudlnal ~unctures such as 30 and 30 adJacent e~ch
longltudinal edge of the ma1n body port10n.
The san1tar~ napk1n 20 can have a ftrst long1tud1nal ~uncture
(or an ~outboard~ longltudlnal ~uncture) 30 where the flap 2~ 1s
attached to or extends from the ma1n bod~ port10n 22. A second
long1tudlnal ~uncture can be present (or ~lnboard~ long1tudlnal
~uncture) 30 that 1s used to prov1de the santtary napkln 20 wlth
the des1red zones of d1fferentlal extenslb111ty 50.
The flrst longltudlnal ~uncture 30 1s shown as be~ng a curved
ltne ln Flgure 8. However, 1t need not be curved. It can be 1n
any form descr1bed above as be1ng su1table for the l~nes of
~uncture. The second longttud1nal Juncture 30' h~ ve. ~tl
2~
generally always be curved concave lnward toward the prlnclpal
longltudlnal centerllne l.
rhe sanltary napkln 20 shown ln F~gure 8 can be made fro~ any
sanitary napk~n that ls provlded wlth flaps. A securement means
such as a llne of adheslve 68 ls lald down on elther the
body-faclng s~de 20a or the garment slde 20b of the sanltary
napkln ln the pattern deslred for the second longltudlnal ~uncture
(or ~curved ~uncture-) 30 . ~he flaps 2~ are then folded over
onto the aforementloned slde of the sanltary napkln and sealed by
the securement means. The securement means can comprlse any means
known ln the art for securlng such materlals together lncludtng
but not l~mlted to heat and/or pressure seallng ultrason1cs and
of course adhes1ves.
In a preferred embod1ment the excess flap ~atertal betweem
the flrst and second long1tud1nal Junctures 30 and 30 can be
trlmmed to provlde the sanltary napkln 20 ~1th curved longltudlnal
slde edges. The format10n of the zones of d1fferent1al
extenslblllty ln th1s manner allows locat10n and curvature of the
curved ~uncture 30 to be controlled. In a preferred e~od1~ent
the curvature of the curved ~uncture 30 can be establ1shed to
colnclde ~lth the curvature of the panty crotch.
F1gure 8A shows an example of a sanltary napk1n that employs
another ~ay of attach1ng the flaps 2~ along a curved 11ne of
~uncture 30.
In the embod1ment shown 1n Flgure 8A the flaps 2~ are only
attached along a s1ngle curved ~uncture 30. As shown 1n F1gure
8A the longltud1nal s1de edges 22a of the ma1n bod~ port10n 22
are curved concave 1nward toward the pr1nc1pal long1tud1nal
centerllne l. The flaps 2~ are attached along the s1ngle ~uncture
30 that runs along the curvature of the long1tudlnal s~de edges
22a of the ma1n body port10n 22.
_ 37
f~gure 8A also shows that the curved Juncture 30 only needs
to be curved concave lnward ln the central reglon lO4 of the
sanltary napkln. (The s~me ls true for vlrtually all of the
curved ~uncture embodlments descrlbed hereln.) The curved
~uncture 30 can be ln any sultable conflguratlon ln the end
reglons of the sanltary napkln. For lnstance the Juncture 30 can
be stralght or (as shown ln Flgure 8A) curved convex outward ln
the end reglons lO0 and l02. (The terms ~central reglon~ and ~end
reglons~ are deflned ln U.S. Patent ~ 690 680 lssued to Hlgglns on
September l 198~.)
In fact the ~uncture 30 need not be curved at all to provlde
some of the deslred beneflts obtalned when uslng a curved
~uncture. The ~uncture 30 only needs to haYe some polnts such as
106 ln the central reglon lO~ of the sanltary napkln that are
more lnwardly dlposed than the polnts such as lOB that lle along
the ~uncture 30 ln the end reglons 102 and 104 of the san1tary
napkln. Thus the ~uncture 30 could be formed by two or more
stralght llnes or segments (and/or curved segments). The llnes
wlll typlcally be angled lnwardl~ toward the prlnclpal
longltudlnal centerllne l as they approach the central reglon 10
of the sanltary napkln. Curved ~unctures are preferred however
because they correspond most closely to the shape of the edges of
the panty crotch.
The proxlmal edges 32 of the flaps 2~ shown ln flgure aA are
either on or slightly laterally outboard of the securement ~eans
68. The proxlmal edges 32 of the flaps 2~ can be of varlous
dlfferent conflguratlons as long as thls relat1Onshlp ls
malntalned. Preferably the curvature of the proxlmal edges 32 of
the flaps 2~ closely matches the curvature of the longltudlnal
slde edges 22a of the maln body portlon 22.
~ he flaps 2~ can be attached to e1ther slde (20a or 20b) of
the sanltary napkln 20 (as ln the case of many of the embod1~ents
descrlbed hereln). Preferably however the flaps 2~ are attached
to the body-faclng slde 20a of the sanlt~ry napkln. Thls has the
38 2~ J~
advantage that the sanltary napkln can be placed ln the wearer s
underganments ~ith the flaps 2~ ln the folded lnward conflguratlon
shown ln F~gure 8A. ~he user does not have to unfold or
otherwlse man1pulate the flaps 2~ before ~ttach1ng the ma1n body
portlon 22 to the panty crotch. The flaps 24 are then folded back
outward around the edges of the panty crotch and attached to the
underslde of the panty. Preferably ln cases such as th1s where
the flaps are lnltlally ortented 1nwardly they are compr1sed of a
materlal sufflclently flex1ble that the flaps wlll not tend to
fold back lnward when they need to be folded back for attach~ent
to the underslde of the wearers pantles.
Flgure 8A also prov1des an example of flaps 2~ that can be
manufactured wlth a mlnlmu~ of wasted mater1al. Th1s ts
partlcularly lmportant ln cases where the flaps are made of a
relatlvely expens1ve materlal.
The flaps 2~ for the embodlment shown ln f19ure 8A ~re
preferably cut pr10r to the attachment of the same to the ~1n
body portlon 22. As shown 1n Flgure 8B the flaps 2~ are
preferably both cut from the same web of materlal 110. The web of
materlal 110 need only be as w1de as the lateral wldth of one flap
(or only sllghtly w1der than the wldth of a flap). The edges of
the web of mater1al or1ented 1n the mach1ne d1rect10n can be
tr1mmed to the des1red curvature for the prox1~al edges of the
flaps. After the edges are tr1~ed the edges 35 of the flaps can
be formed by cutt1ng the web along a slnuso1dal path.
The s1nuso1dal cutttng path can have an amplltùde that
extends from one edge of the web to the other. ~he s1nuso1dal
cuttlng path fonms flap p1eces wh1ch are ~nested~ wlth each other.
The cutt1ng path can thus, s1multaneously fon~ the edges of two
d1fferent flaps. For 1nstance the web of flap mater1al can be
cut so that the mater1al fonu1ng the port1on of the edges
des1gnated 35 and 35 " 1s abutt1ng and the slnuso1dal cutt1ng
path forms both flap edges.
Z ~ A ~
.
F~gures 8C - 8E show an example of ~ sanltar~ napkln that
employs st111 another wa~ of attachlng the flaps 2~ along curved
llnes of ~uncture 30 to create sl~ck ln the corner reglons 52.
~he attachment ls acco~pllshed ln the follow1ng ~anner.
In the embodlment shown ln Flgures 8C - 8E the san1tary
napkin 20 flaps 2~ that comprtse separate pleces attached to the
backsheet ~2 (these p1eces could of course be attached to
another component of the sanitary napkln 20). ~he longltudlnal
side edges 22a of the ma1n body portlon 22 of the sanltary napkln
prlor to the attachment of the flaps 24 are relatlvely
stralght.
A plece of ~aterlal extenslon 70 ls provlded whlch 1s
attached along each longltudlnal edge 22a of the ~aln body portlon
22. The extenslon 70 extends the longltudlnal slde edges 22a of
the maln body port10n 22 of the san1tary napk1n 20 outward fro~
the dlrectlon of the pr1nc1pal longltudlnal centerl1ne l. The
extenslon 70 can be any sultable matertal. Preferabl~ the
extens10n co~prtses backsheet materlal. In one preferred
embodlment the extenslon 70 comprlses ~ nonwoven/fluld lmpervlous
fll~ laminate slmllar to that descr1bed above as be1ng sultable
for use as the backsheet.
~ he extens10n 70 h~s two long1tud1nal edges 70a and two
transverse edges 70b. ~he long1tud1nal edges 70a comprlse
proxtmal long1tudlnal edge (or s1mply ~prox1mal edge-) 70a and a
d1stal longltudtnal edge (or s1mply ~dtstal edge~) 70a . ~n the
embodlment shown the proxlmal edge 70a of the extens10n 70 ts
preferably a relat1vely stra1ght 11ne and the dtstal edge 70a 1s
curved concave lnward toward the pr1nc1pal longltudlnal centerltne
l of the sanltary napktn. ~he rad1us of curvature of the dtstal
edge 70a ls des1gnated ln Ftgure 8F as the flrst rad1us of
curvature. rl-
~ he transYerse edges 70b of the extens10n 70 can be of anysu1table conflguratton. Preferably the transverse edges 70b are
of a curved convex outward conf1gurat10n sl~llar to that shown ln
the drawlngs so that they wlll present a comfortable shape for
the wearer
~ he flaps 2~ are proYlded ln the for~ of separate
crescent-shaped pleces of mater1al 72. The crescent-shaped p1eces
72 each have two curved edges 72a and 72b. One of the edges
72a has a smaller radlus of curvature (second r~d~us of curvature
r2) than the other edge 72b (whlch has a thlrd radlus of curvature
r3). The edges 72a w1th the smaller radlus of curvature r2 (l.e.
the edge ~ith more curvature) form the d1stal edge 3~ of the flaps
24. The edges 72b wlth the larger radlus of curvature r3 fon~ the
proxlmal edges 32 of the flaps.
The radti of curvature are establlshed so the th1rd radlus of
curvature r3 ~s less than the radlus of curvature rl (the radtus
of curvature of the dlstal edge 70a ' of the extenslon p1ece 70.)
There ls a zone along the edge 72b w1th the larger radlus of
curvature that has a plural1ty of spaced apart notches 76 cut lnto
lt (shown ln Flgure 80). The zone comprlses the fl-nge 7~ of the
flaps 2~. The flange 7~ can be of any su1table d1mens10ns wh1ch
allows the flaps 2~ to be attached to the extens10n 70. In the
embotlment shown the flange 1s about 1/~ lnch (about 0.6 m .) 1n
wldth. The notches 76 are preferably about 0.2 1nch (about 0.5
m~.) ln depth and ~bout 0.15 1nch (about 0.~ ~a.) 1n w1dth at
the1r w1dest polnt. The notches 76 allow the flange 7~ to spread
out suff1clently so that the flrst and th1rd rad11 of curvature
rl and r3 become approx1mately the same. Th1s allows the flaps
2~ to be attached along the flange 7~ to the edge of the extenslon
plece 70 ~lthout pucker1ng etc.
The flange 7~ can be attached to the extens10n 70 by any
su1table securlng element or attachment ~eans. for 1nstance as
shown tn Flgure 80 the secur1ng element used to ~ttach the flaps
2~ to the extens10n 70 can 1nclude but 1s not llm1ted to a
plurallty of spaced apart p1eces of double-slded tape 80 th-t are
placed along those areas of the n ange 7~ des1gnated 78 that 11e
. ~1
between the notches 76 (~he double-slded tape pleces are placed
along the unnotched portlons of the flange )
In an alternatlve embodlment whlch ls some~hat preferred
over the embodlment descrlbed above the extenslon ~0 can be made
lntegral wlth the ma~n body portlon 22 ~hat ls rather than
attachlng a separate extenslon plece to each longltudlnal slde
edge of the sanltary napkln 20, the longltudlnal slde edges of the
ma1n body portlon 22 (or a component thereof such as backsheet
~2) could merel~ be extended further outboard away fro~ the
prlnclpal longltudlnal centerl1ne l ~he longltudlnal slde edges
22a of the ~aln body portlon 22 could then be cut to form a curved
edge slmllar to that of the dlstal edge 70a" of the extenslon ~0
descrlbed above
Flgures 9-11 show st111 another alternatlve embodlment of a
sanltary napkln 20 ~ade by the method of the present lnventton
In thls embodlment the entlre sanltary napk1n 20 ls folded or
pleated through the ~a1n body port10n 22 of the san~tary napk1n
~he sanltar~ napkln 20 ls folded or pleated ~long two long1tud1nal
llnes 90 one of whlch 1s located on each slde of the pr1nc1pal
longltudlnal centerllne l The pleated sect10n of the ma1n body
portlon 22 ls restralned from openlng along the flap transverse
centerllne tl.
-
~ hls also creates ~ones of dlfferentlal extenslblllty S0 (orslack) ln the corner reglons 52 of the sanitary napk~n 20 The
zones of dlfferent~al extenslbtl1ty 50 are formed 1n the fl-ps 2~,
as well as ln port10ns of the ma1n body portlon 22 partlcularl~
those portlons wh~ch 11e between the corner reglons of the flaps
52 and the prlnc1pal long1tud1nal centerllne l ~he zones of
d1fferentlal extenslb111ty 50 are for~ed because the port10ns of
the components of the san1tary napk1n 20 are all gathered 1n along
the flap transverse centerl1ne tl (shown best 1n F1gure 10) ~h11e
the port10ns of the components of the san~tary napk~n spaced
long~tudlnally away fro~ the flap transverse centerl1ne tl are
gathered 1n to a lesser extent the farther they are spaced
2 ~7 ~e~
~2
tongltudlnally awa~ fro~ the flap transverse centerllne tl. (Note
that the cross-sectlon of Flgure 10 ls not taken through the ~ones
of dlfferentlal extenslblllty S0).
The foldlng or pleattng of the sanltary napk~n 20 also forms
a hump 92 1n the center of the ma~n bod~ port10n 22. ~hls hump 92
(although not necessar11y drawn to scale ln the drawlng flgures)
ls preferably made of such a sl~e and shape that lt 1s capable of
f~ttlng ln the space between the wearer s labla.
In the embodlment shown ln Figures 9-ll the pleated sectlon
of the sanltary napk~n 20 (or hump) 1s gathered ln and restra1ned
by a pad restralnt 9~. ~he pad restralnt 9~ ls preferably
relatlvel~ lnextens1ble so that lt prov1des the deslred zones of
d1fferent1al extens1b111t~ 50 1n the corner reg10ns 52 of the
san1tary napk1n 20. The pad restra1nt 9~ ma~ be 1n dlrect contact
w1th the gathered ln portlons that form the hump or lt may brldge
the hump. In the latter case, the pad restralnt 9~ na~ extend
outward as far as the proxlmal edges 32 of the flaps and restraln
the gathered ln portlons laterally outs1de the hu~p.
The pad restra1nt 9~ can be made of an~ su1table ~ater1al.
Some non-llm1t1ng examples of su1table materlals 1nclude paper
(prov1ded the same ls not located where 1t can be wetted) tapes
nonwoven mater1als and p1eces of pol~eth~lene fll-. The pad
restralnt 9~ can also lnclude any type of restr~lnt descrlbed
above as be1ng suitable for the flap pleat restra1nt 66 and v1ce
versa.
The san1tar~ napkln 20 as shown ln F1gures 9-11, can also
have opt1cnal elastlcs 96 on or ad~acent lts flaps 2~. ~n a
preferred embodlment the elastlcs 96 are located along the llnes
of ~uncture 30 ad~acent the center port10n 2~ of the flaps 2~.
These elast1cs 96 are attached to the sanltar~ napkln 20
(preferabl~ on the backsheet ~2) ln an elast1call~ contract1blQ
condlt10n. The elast1cs 96 ass1st the unrestralned pleated
port10ns of the san1tary napk1n 2~ ln openlng so that the pleats
~3
are fully effectlve. ~he zones of dlfferentlal extenslblllty 50
created ln such an embodlment are st111 cons1dered to be
~elastlcless.~ ~he elastlcs 96 are not used to gather ln portlons
of the san1tary napk1n to create the zones of dlfferentlal
extenslbll1ty 50 only to asslst the unrestralned pleated portlons
ln open1ng.
S~mllarly posltloned elastlcs can be used for the same
purpose ln the other sanltary napkln embod1ments descr1bed here1n.
~he use of elast1cs 96 1n the embodlment shown 1n Flgures 9-11,
however ls partlcularly lmportant because lt opens the
unrestralned pleated port1On of the napk1n 20 prlor to the
attachment of the sanltary napkln 20 to the wearer s undergarments
wlth the central pad adhes1ve 5~. (If the elastlcs 96 were not
used the central pad adheslve 54 may tend to remaln ln the fon~
of two parallel strlps rather than two concave lnwardly orlented
strlps as shown 1n F~gures 9 and 11. If the strlps of adhes1ve
are parallel when they are attached to the wearer s undergan~ents,
the effect of pleatlng and the gatherlng 1n the restralned port1On
of sanltary napk1n 20 ~ould be negated.)
flgure 12 shows an alternat1ve embod1ment of the san1tary
napk1n 20 of the present lnventlon ln wh1ch the san1tary napkln 20
ls folded or pleated only along one long~tudlnal llne 90. In th1s
case the fold 11ne 90 should preferably run along the pr1nc1pal
long1tud1nal centerl1ne 1.
Flgure 13 shows an alternatlve embod1ment of the san1tary
napk1n 20 ln whlch the san1tary napkln 20 ls folded or pleated
along a plurallty of fold llnes 90. In thls case the fold 11nes
90 are centered about the pr1nclpal longitudlnal centerllne 1.
It should be apparent to one sk111ed 1n the art that ln st111
other alternat1ve embod1ments the flaps 2~ (rather than the ma1n
body port1On 22) could bc prov1ded ~1th a s1ngle fold or mult~ple
folds. For 1nstance the flaps 2~ could be prov1ded ~lth folds
s1m11ar to the folds through the ent1re pad shown 1n F1gures 12
~ 2a~ J~ ~L
and l3. It ls also apparent that ln other ~lternatlve
embodlments the zones of d1fferentlal extenslblllty 50 of the
sanltar~ napkln 20 rather than belng lntegral ~lth the less
extenslble flrst port10ns of the sanltar~ napk1n 20 could
comprlse separate pleces of mater1al (such as separate slack
materl-l or rlng rolled corrugated or pleated materlal)
assoclated wlth the sanltary napkln.
Flgure 16 shows an alternatlve embod1ment 1n whlch the
sanltary napkln 20 1s prov1ded w1th a barrler 98 along the
proxlmal edges 32 of the flaps 2~. ~he barrler 98 stands up to
serve as a wall to retaln exudates flowlng ln the transverse
dlrectlon toward the flaps 24 (shown ln the flap 24 located near
the top of the sheet contalnlng flgure 16). ~he barrler 98 may
stand up before (and after) the san1tary napk1n 1s placed 1n the
wearer s undergarments or 1t ~ay 1n1t1ally 11e relat1vely ftat
agalnst the topsheet and use the forces exerted b~ fold1ng of the
flaps down under the wearer s undergan~ents to stand up. In other
alternatlve embodlments the barrler 98 may have 1ts ends tacked
down near the ends of the ~unctures so that 1t slants 1nwardly
durtng use rather than stand1ng stra19ht up.
The barr1er 98 may be provlded on ~ost of the embodtments
descr1bed here~n. (The barr1er may also be prov1ded on other
sanltary npak1n embod1ments. For 1nstance the flaps of the
san1tary napk1n 20 shown are completely extens1ble. In add1t10n
the san1tary napk1n could even be prov1ded w1th such a barr1er 98
lf 1t dld not have flaps 24.J The barrler 98 may be constructed
1n any su1table manner. F1gure l6 shows one preferred
construct10n 1n wh1ch the barr1er 98 ~s formed b~ prov1d1ng ~ aps
24 that compr1se non-1ntegral (or separate) elements. ~he barr~er
98 1s formed by prov~d1ng these flap elements w1th an extens10n of
excess mater1al 1nboard of the ~unctures 30. ~he barr~er 98 ~y
be made of the same mater1al as the rema1nder of the flaps 2~.
Alternat1vely ~t may (and/or the port~ons of the n aps ad~acent
the barr1er) may be made of a stlffer materlal to a1d the barr1er
1n stand1ng up.
~5 2 ~ c~-4~ ~L
In stlll other alternatlve embodlments the sanltary n~pk1n
could be provlded ~lth addltlonal components. For lnstance the
sanltary napkln could be provlded wlth the ~et-lald tlssue and/or
the llquld permeable ~lpe acqu1sltlon sheet descr1bed ln greater
detall ln U.S. Patent 5 009 653 lssued to Osborn. In addlt1On
such sanltary napk1ns could be prov1ded w1th add1tlonal types of
stress rel1ef means such as those descrlbed 1n U.S. Patent
917 697 at varlous locatlons around the perlphery of the
sanltary napkln.
Thus the present lnventlon provldes a method of mak1nq a
sanltary napkln havlng flaps and ~ones of dlfferent1al
extens1b111ty for relievlng the stresses that develop ln the flaps
when the flaps are folded down and under a ~earer s undergan~ent.
~ h11e partlcular embodlments of the present 1nventlon have
been lllustrated and descr1bed lt would be obv1Ous to those
sk111ed 1n the art that var1Ous other changes ~nd ~cd1flcat1Ons
can be made ~1thout depart1ng from the sp1r1t and scope of the
lnventlon.
~ hat ls clal~ed 1s:
