Note: Descriptions are shown in the official language in which they were submitted.
CA 02608673 2007-11-21
TAMPON APPLICATOR BARRELS HAVING GRIPPING STRUCTURES AND
METHODS OF FORMING
This application is a divisional of Canadian Patent Application No. 2,528,676.
FIELD.OF THE INVENTION
The present invention relates to tampon applicators. More particularly, the
present invention
relates to tampon applicator barrels having gripping structures and methods of
forming.
DESCRIPTION OF RELATED ART
A tampon assembly is used to inject an absorbent or hygienic material, known
as a tampon
pledget, into the vaginal vault. The pledget of commercial tampon assemblies
is typically
positioned in a tampon applicator. Tampon applicators typically include a
barrel and a plunger.
The pledget is housed in the barrel for expulsion therefrom through the action
of the plunger.
During use, an end of the barrel is inserted into the vaginal vault. Once the
end of the barrel has
been inserted, the plunger can be used to expel the pledget from the end of
the barrel into the
vaginal vault. Once the pledget is in position, the pledget expands upon
contact with moisture to
conform to contours of the body and, thus, provide leakage protection.
Comfort to the user during insertion of the barrel and expulsion of the
pledget is an important
aspect for the commercial success of the tampon assembly. The ease with which
the barrel can
be gripped by the user during insertion of the applicator and/or expulsion of
the pledget can
increase the comfort associated with the use of the tampon assembly.
Tampon applicators (e. g., barrels and/or plungers) can be made from a variety
of materials. For
example, tampon applicators have traditionally been made of polymers or
cardboard. During the
molding of polymer-based applicators, gripping structures of the desired size
and shape can
easily be formed.
The gripping structures on cardboard-based applicators are typically formed
after the cardboard
has been formed into a tube-like shape.
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Various gripping structure configurations for cardboard applicator barrels
have been proposed to
facilitate gripping of the applicator and/or expulsion of the pledget. One
approach is to emboss a
raised portion into the barrel, where the raised portion can take the form of
a series of raised
circumferential rings or a series of discrete raised areas aligned in several
circumferential rows.
However, there is a continuing need for tampon applicator barrels having
gripping structures that
increase the user's ability to grip the applicator and methods of forming such
barrels.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide tampon. applicator barrels
having gripping
structures and methods of forming.
It is another object to piovide cardboard applicator barrels having gripping
rings and methods of
forming.
It is another- object to provide methods of defining such gripping structures
having a selected
height without piercing through the outennost layer of the cardboard
applicator barrel..
These and other objects and advantages of the preseni invention are provided
by compressing a
barrel between a free-spinning pliable pressure wheel and a rotating mandrel
to form the raised
grippirxg structures on the barrel.
These and other objects and advantages are also provided by controlling the
number of rotations
of a mandrel.
These and other objects and advantages are also provided by controlling a rate
of travel of a
pressure wheel into a barrel with respect to a number of rotations of a
mandrel.
Further objects and advantages are provided by shaping a number of protrusions
on a mandrel
with a pair of sloped sides and a flat top portion to control, limit, or
mitigate (hereinafter "
mitigate") instances of "pierce through".
Still further objects.and advantages are provided by a method that controls
the hardness (e. g. ,
durometer) of a pressure wheel, the speed of descent of the pressure wheel
with respect to the
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number of rotations of a mandrel, the shape of protrusions on the mandrel, and
any combinations
thereof to provide gripping structures having a desired height while
initigating instances. of
piercing through the applicator barrel.
Other objects and advantages are provided by a gripping structure having
airline separations
formed therein and methods of forming.
In.one einbodiment of the present invention, a tampon applicator barrel is
provided. The barrel
includes a cardboard tube having a first end and a second end and at least one
gripping stru.cture
-being defined from the cardboard tube proximate the second end. The cardboard
tube has a wall
thickness of between about 0.015 and about 0.020 inches, while the gripping
structure has a
height of upto about 0.035 inches.
In another embodiment of the present invention, a tampon applicator barrel
having a cardboard
tube, a circumferential ring, and an epoxy- coating is provided. The
circumferential ring is
defined from the cardboard tube. The epoxy coating being disposed on the
cardboard tube. The
airline separations are defined in the cardboard tube andlor the epoxy coating
to provide a rough
surfaee to at least the circumferential ring.
A method of forming a cardboard tampon applicator barrel is also provided. The
method
includes: moving a mandrel having a selected number of protrusions into
contact with an inner
surface of the tampon applicator barrel; moving a pressure wheel having a
corresponding number
of recesses into contact with an outer surface of the tampon applicator barrel
so that the
protrusions and recesses are.opposite one another; and rotating at least one
of the mandrel and
the pressure wheel a desired number of revolutions while moving the mandrel
and the pressure
wheel toward one another a distance equal to or greater than a desired
gripping structure height.
In addition, a method of forming. a cardboard tampon applicator barrel is
provided that includes:
defining a mandrel having a selected number of protrusions depending
therefrom; defming
pressure wheel having a corresponding number of recesses defined therein, the
pressure wheel
having a Type A durometer in a range preferably between about 45 and about 95,
moving the
selected number of protrusions into contact with an inner surface of the
tampon applicator barrel
moving the corresponding number of recesses into contact with an outer surface
of the tampon
applicator barrel so that the protrusions and recesses are opposite one
another; and rotating at
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least one of tlie ma.ndrel and the pressure wheel a desired number of
revolutions while moving
the mandrel and the pressure wheel toward. one another a distance equal to or
greater than a
desired gripping structure height.
The above-described and other features. and advantages of the present
invention will be
appreciated and understood by those skilledin the art from the following
detailed description and
drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a side view of an exemplary embodiment of a tampon assembly;
FIG. 2 is an enlarged sectional view of circle 2 of FIG. 1 illustrating an
exemplary embodiment
of a gripping structure;
FIG. 3 is a schematic depiction of an exemplary embodiment of a method of
forming the
gripping structure of FIG. 2; FIG. 4 is a side view of an exemplary embodiment
of a pressure wheel;
FIG. 5 is an end view of the pressure wheel of FIG. 4;
FIG. 6 is an enlarged view of circle 6 of FIG. 4;
FIG. 7 is a side view of an exemplary embodiment of the mandrel of FIG. 4;
FIG. 8 is an en.larged view of circle 8 of FIG. 7;
FIG. 9 is an alternate exemplary embodiment of the gripping structure of FIG.
2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings and in particular to FIGS.. 1 and 2, a tampon
assembly generally
represented by reference numeral 10 according to the present invention is
shown. Assembly 10
has a pledget 12 and an applicator 14. Applicator 14 includes a barre1.16 and
a plunger 18.
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Barrel 16 has a generally tubular shape having has a.first end 20 and a second
end 22. First end
20 defines the insertion end of barrel 16 and includes a number or a plurality
of petals 24. Petals
24 are defined in first end 20 by a number or plurality of slits 26. Barrel 16
is illustrated by way
of example as including six petals 24. Of course, it is contemplated by the
present invention for '
barrel 16 to have more or less than six petals. For example, barrel 16 can
have any number of
petals between about two and eight petals, such as, for example, three, four,
five or six petals.
Plunger 18 can expel pledget 12 from barre116. Plunger 18 is positioned to
slide in barrel 16 at
second end 22. Pledget 12 is expelled through first end 20 through the
movement of plunger 18
in the direction of arrow 28, which is parallel to a longitudinal axis 30 of
barre116. As plunger
18 moves in the direction of arrow 28, the plunger can urge pledget 12 into
petals 24 until the
petals open along slits 26 and the pledget is expelled from barre116 through
first end 20.
Barre116 preferably includes one or more layers of cardboard. The layer (s) of
barrel 16 can be
convolutedly or spirally wound as is known in the 'art. Alternately, 'the
layer (s) of barrel 16 can
be rolled. Of course, barrel 16 can be formed of any combination of convolute
and/or rolled
cardboard layers.
As used herein, the term "cardboard" shall include materials such as, but not
limited to,
cardboard, paper, paper or cardboard laminate, paper slurry, pulp slurry, pulp-
molded paper, or
any combinations thereof.
Barre116 preferably has a wall thickness of between about 0.008 inches and
about 0.020 inches,
more preferably at least about 0.011 inches, with between about 0.015 and
about 0.020 inches
being most preferred.
In some embodiments of the present invention, barrel 16 includes one or more
coatings and/or
polymer film layers or laminates (not shown) disposed thereon. For example,
barrel 16 can
include an epoxy coating as set forth in commonly owned and assigned U. S.
Patent No.
5,931,803 to Jackson.
In order to assist the user in gripping barrel 16, second end 22 includes one
or more gripping
structures 32 defined thereon. Gripping structures 32 are raised portions of
barrel 16 that
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facilitate control of the.barrel. Specifically, gripping structures 32 have a
height 34 that imparts a
selected gripability to barrel 16.
Height 34 is defined as the distance from an outside surface 36 of barrel 16
to a top or apex 38 of
gripping structure 32. For example, height 34 can be up to about 0.035 inches,
preferably
between about 0.012 and about 0.030 inches, and most preferably between about
0.015 and about
0.024 inches. Thus, height 34 provides gripping structure 32 with a pronounced
ring-like s,hape.
Barrel 16 is illustrated by way of example as having three evenly spaced,
circumferential (e. g.,
generally perpendicular to axis 30) grippirig structures 32. In addition,
gripping structures 32 are
illustrated by way of example as being continuous about the circumference of
barrel 16.
However, it is contemplated for barrel 16 to have more or less than three
gripping structures 32,
for the gripping structures to be discontinuous about the circumference of the
barrel, for the
gripping structures to be unevenly spaced, and any combinations thereof.
In the past, gripping structures 32 having=height 34 in the aforementioned
ranges have been
difficult, if not impossible, to achieve without piercing through outer
surface 36 of barrel 16.
Advantageously, it has been determined that gripping structures 32 having
heigbt 34 can be
formed using a method 40 illustrated in FIG: 3 without the pierce through of
prior methods. For
purposes of clarity, various components (e. g., petals 24, slits 26, etc.) of
barrel 16 are omitted
from FIG. 3.
Method 40 uses a pressure wheel 42 and a mandrel 44 to form structures 32.
Pressure wheel 42 is
illustrated in FIGS. 4 through 6, while mandrel 44 is illustrated in FIGS.. 7
and 8.
Pressure wheel 42 has a number of recesses 46 defined in its outer
circumference, and mandrel
44 has a corresponding number of protrusions 48 defined in its outer
circumference. The number
of recesses 46 and protrusions 48 correspond to the number of desired gripping
structures 32.
Mandrel 44 and barrel 16 are moved into contact with one another in a first
direction 50 that is
parallel to axis 30. For example, mandre144 can inserted into second end 22 of
barrel 16, the
second end can be moved over the mandrel, or any combinations thereof. In this
position,
mandrel 44 is positioned in barrel 16 so that protrusions 48 are in contact
with the barrel.
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Next, pressure wheel 42 is moved into contact with outside surface 36 of
barrel 16 in a second
direction 52 that is perpendicular to axis 30. In this position, indentations
46 are positioned.
opposite protrusions 48.
Once pressure wheel 42 is in contact with barrel 16, mandrel 44 is rotated in
a third direction 54,
which is generally parallel to axis 30. While mandrel 44 is being rotated,
pressure whee142 is
moved along second direction.52 a distance substantially equal or greater to-
height 34. In this
manner, indentations 46 and protrusions 48 are compressed together about
barrel 16, while the
barrel is rotated eccentrically by mandrel 44 to form gripping structures 32
in the barrel.
It should be recognized that method 40 is described by way of example as
rotating mandrel 44.
Of course, it is contemplated that pressure wheel 42 can be the driving
member, barre116 can the
driving member, or any combinations thereof. It should also be recognized that
method 40 is
described by way of example as moving rotating pressure wheel 42 in second
direction 52. Of
course, mandrel 44 and barrel 16 can be moved in a direction opposite second
direction 52.
Advantageously, pressure wheel 44 is formed of a materials of various hardness
and frictional
15. properties to mitigate instances of "pierce through" of outer surface 36
during formation of
gripping structures 32. It believed that using pliable pressure wheel 44
reduces the sheer on
barrel 16 as it is being formed by .the pressure wheel and mandrel 44. In one
embodiment,
pressure wheel 44 is formed of a pliable material having a Type A durometer in
a range
preferably between about 45 and about 95 as measured by.ASTM D2240, more
preferably
between about 55 and about 85, and most preferably about 85 on the absolute
scale. For
example; pressure wheel 44 can be formed of urethane, rubber, plastics, and
other materials in
the aforementioned durometer ranges.
It has also been determined that the rate of travel of pressure wheel 42 in
direction 52 with
respect to the rotation of mandrel 44 in direction 54 can mitigate instances
of "pierce through".
Namely, it has been determined that sheer forces on barrel 16 can be reduced
by moving pressure
whee142 in direction 52 while mandre144 is rotated a selected number of
rotations in direction
54. For example, mandrel 44 can be rotated in third direction 54 between about
four (4) and
about twenty (20); and preferably between about eight (8) and about twelve
(12) revolutions,
while pressure wheel 42 is moved height 34 in second direction 52. Thus,
method 40 can control
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the number of revolutions of mandrel 42 with respect to the speed of travel of
pliable pressure
wheel 44 in second direction 52 to mitigate instances of "pierce through".
Pressure whee142 can be moved in second direction 52 at the desired rate with
a cam, a
pneumatic cylinder, a hydraulic cylinder, a linear motor, or other components.
In addition, method 40 can control the shape of protrusions 48 on mandrel 44
to mitigate
instances of "pierce through". For example in one embodiment, protrusions 48
on mandrel 44
can have a pair of sloped sides 56 and a top portion 58., Sides 56 are sloped
with respect to a
plane 60 in a range of about 7.5 degrees to about 11.5 degrees, preferably
about 9.5 degrees. In
this example, plane 60 is perpendicular to axis 30. Top portion 58 is,
preferably, flat. Namely,
top portion is preferably parallel to axis 30.
In another embodiment, mandrel 44 can include pliable regions 49 positioned
adjacent
protrusions 48. Pliable regions 49, preferably, are undercut portions of
mandrel 44 adjacent to
sloped sides 56 protrusions 48, where the undercut regions are filled with
pliable material. It has
been determined that pliable regions 49 can also reduce the sheer on barrel 16
as it is being
formed-by pressure wheel 42 and mandrel 44. In one embodiment, the pliable
material of pliable
regions 49 have a Type A durometer in a range preferably between about 45 and
about 95 as
measured by ASTM D2240, more preferably between about 55 and about 85, and
most
preferably about 85 on the.absolute scale. For example, regions 49 can be
formed of urethane,
rubber; plastics, and other materials in the aforementioned durometer ranges.
It has been found that the combination of gently sloped sides 56, flat top
portion 58, and/or
regions 49 can aid method 40 in mitigating instances of "pierce through".
It should be recognized that protrusions 48 are illustrated by way of example
only as semi-
circular. Of course, it is contemplated by the present disclosure for
protrusions 48 to have other
shapes, such as, but not limited to polygonal, ovoid, circular, or any
combinations thereof.
Accordingly, method 40 can control the hardness of pressure wheel 42, the
speed of descent of
the pressure wheel with respect to the number of rotations of mandre144, the
shape of
protrusions 48 on the mandrel, and any combinations thereof, to provide
gripping structures 32
having the desired height 34 while mitigating the instances of piercing
through barrel 16.
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Refeiring now to FIG. 9, an alternate embodiment of a gripping structure 132
is illustrated. Here,
component parts performing similar and or analogous functions are numbered in
multiples of one
hundred.
Gripping structure 132 is defined in barrel 116 having plunger 118 slidably
disposed therein.
Barrel 116 include a coating 162 disposed on an oater layer or laminate 164.
In addition, barrel
116 can include one or more inner layers or laminates 166 (only one shown).
For example,
coating can be an epoxy coating as set forth in commonly owned and assigned
U.S.
Patent No. 5,931,803 to Jackson.
Gripping structure 132 has a height 34 that is defined as the distance from an
outside surface 136
of barrel 116 to a top or apex 138 of the gripping structure. For example,
height 134 can be up to
about 0.035 inches, preferably between about 0.012 and about 0.030 inches, and
most preferably
between about 0.015 and about 0.024 inches.
It has been determined that controlling the process conditions used during
manufacture of
gripping structure 132 can cause one or more micro or airline separations 168
in coating 162
. andJor outer layer 164.
Separations 168 can provide gripping structure 132 with a rough surface that
can supplement the
gripping benefit of the gripping structures themselves. However, separations
168 terminate prior
to actually extending entirely through outer layer 164, or only slightly
pierce through the outer
layer.
Iri one embodiment, separations 168 can be formed in coating 162 and provide
edges (not
shown) that directly contact the user's finger (not shown) to enhance the
gripability of gripping
structures 132.
In an alternate embodiment, separations 168 can be=formed in outer layer.164.
Here, coating 162
has a thickness sufficient to allow the edges of separations 168 to be felt
through the coating and,
.25 thus, provide enhanced gripability to gripping structures 132.
In yet another embodiment, separations 168 can be formed in both coating 162
and outer layer
164 to provide both direct and indirect edges to enhanced gripability of
gripping structures 132.
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For example, it has been found that the moisture content of coating 162 and/or
layers 164, 166
can be controlled during creation of the gripping structures 132 to cause
formation of separations
168. In addition, other process conditions in addition to or in lieu of
moisture content can be
controlled during manufacture of gripping structure 132 to form separations
168. For example,
process conditions such as, but not limited to, .the hardness (e. g.
durometer) of a pressure
wheel, the speed of descent of the pressure wheel with respect to the number
of rotations of a
mandrel, the shape of protrusions on the inandrel, thickness and/or
composition of coating 162,
thickness and/or composition of layer 164 and/or 166, or any combinations
thereof.
It should also be noted that the terms "first" ,"second", "third", "upper",
"lower", and the like
may be used herein to modify various elements. These modifiers do not imply a
spatial,
sequential, or hierarchical order to the modified elements unless specifically
stated.
While the present invention has been described with reference to one or more
exemplary
embodiment., it will be understood by those skilled in the art that various
changes may be made
and equivalents may be substituted for elements thereof without departing from
the scope of the
present invention. In addition, many modifications may be made to adapt a
particular situation or
material to the teachings of the disclosure without departing from the scope
thereof. Therefore, it
is intended that the present invention not be limited to the particular
embodiment(s) disclosed as
the best mode contemplated.for carrying out this invention, but that the
invention will include all
einbodiments falling within the scope of the present disclosure.
