U.S. patent application number 09/851017 was filed with the patent office on 2001-08-30 for domed compressed tampons.
Invention is credited to Baer, Wilfried, Hull, Raymond J. JR., Kasahara, Masaki, Rex, Gerd R., Sonoda, Toshio.
Application Number | 20010018391 09/851017 |
Document ID | / |
Family ID | 25254347 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010018391 |
Kind Code |
A1 |
Hull, Raymond J. JR. ; et
al. |
August 30, 2001 |
Domed compressed tampons
Abstract
An improved apparatus and method compresses a cylindrical blank
into a tampon which is dimensionally stable and which is provided
with a domed insertion end. A cylindrical blank is radially
compressed and then introduced into a cylindrical axial compression
chamber. The blank is then subjected to an extreme axial
overcompression. The closed insertion end of the compression
chamber has a bore formed therethrough. The bore is generally
coaxial and is adapted to accept a reciprocating ejection ram
having a ram surface facing into the chamber. When the ram is
seated in the first position, the ram surface and the insertion end
wall of the compression chamber together form a smooth doming
surface. The bore periphery is of a smaller diameter than the
chamber and hence radially spaced from the side walls of the
chamber, and the ram has sufficient clearance to move through the
chamber and eject the tampon without interference from the walls of
the chamber.
Inventors: |
Hull, Raymond J. JR.;
(Hampton, NJ) ; Rex, Gerd R.; (Somerset, NJ)
; Baer, Wilfried; (Princeton, NJ) ; Kasahara,
Masaki; (Hiroshima, JP) ; Sonoda, Toshio;
(Hiroshima, JP) |
Correspondence
Address: |
AUDLEY A. CIAMPORCERO JR.
JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
25254347 |
Appl. No.: |
09/851017 |
Filed: |
May 8, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09851017 |
May 8, 2001 |
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09369572 |
Aug 6, 1999 |
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09851017 |
May 8, 2001 |
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08829369 |
Mar 31, 1997 |
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6003216 |
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Current U.S.
Class: |
493/337 |
Current CPC
Class: |
B30B 11/007 20130101;
Y10S 604/904 20130101; A61F 13/2085 20130101 |
Class at
Publication: |
493/337 |
International
Class: |
B05C 001/00 |
Claims
What is claimed is:
1. An apparatus for axially compressing a cylindrical blank into a
tampon having a domed insertion end, said apparatus comprising: a
cylindrical axial compression chamber having cylindrical side
walls, an insertion end, and an opposed withdrawal end; said
withdrawal end being open for the introduction of the cylindrical
blank into said chamber and for accepting a reciprocating
compression ram adapted to exert compression force against the
withdrawal end of the so introduced blank; said insertion
comprising an immovable insertion end wall having a bore
therethrough; said bore being coaxial with the compression chamber
and having a periphery at the insertion end wall of a smaller
diameter than that of the cylindrical compression chamber; said
bore being adapted to accept a reciprocating ejection ram, said ram
being capable of reciprocating through said bore and through said
compression chamber for ejecting the axially compressed blank; said
rejection ram having a ram surface facing into said compression
chamber; said ram surface and said insertion end wall of said
compression chamber together forming a smooth doming surface for
imparting a smooth surface dome to the insertion end of the blank
when said blank is compressed by the action of the compression
ram.
2. The apparatus of claim 1 wherein said bore has a diameter
ranging from about 40 to about 95% of the diameter of the
compression chamber.
3. The apparatus of claim 1 wherein said bore has a diameter
ranging from about 70 to about 90% of the diameter of the
compression chamber.
4. The apparatus of claim 1 wherein said ejection ram terminates in
a ram head having said ram surface thereon; said ram head tapering
axially away from said chamber.
5. A method for axially compressing a cylindrical blank having an
insertion end, a withdrawal end, and cylindrical walls
therebetween, into a dimensionally stable tampon comprising:
introducing said blank coaxially into a cylindrical compression
chamber having a closed insertion end, a withdrawal end and
cylindrical walls therebetween wherein the cylindrical walls of
said blank make frictional contact with the cylindrical walls of
the compression chamber; axially over-compressing said blank, said
overcompression being applied to the extent that, through the
action of the frictional contact, a plurality of circular pleats
are formed around the axially compressed blank, said compression
being sufficient to fold said pleats, in the direction of the
withdrawal end of the axially compressed blank, to overlie the next
adjacent portion of the cylindrical wall of the axially compressed
blank.
6. The method of claim 5 wherein said overcompression is to the
extent that the blank is axially compressed to about 15 to about
30% of its length prior to compression.
7. The method of claim 6 wherein the axially compressed blank is
allowed to expand after axial compression to about 50-80% of the
length of the blank prior to axial compression.
8. A dimensionally stable tampon comprising a cylindrical fibrous
body having an insertion end, a withdrawal end and cylindrical side
walls therebetween, said tampon being axially compressed from a
blank, said tampon having a plurality of circular pleats formed
around the axially compressed blank, said pleats being folded to
overlie the next adjacent portion of the cylindrical wall of the
tampon.
Description
BACKGROUND OF THE INVENTION
[0001] This invention concerns apparatus and methods for providing
dimensionally stable absorbent bodies which comprise cellulose
fibers and, in particular, concerns providing such bodies
compressed into cylindrical tampons having a rounded or domed tip.
Specifically, this invention provides methods and apparatus for
manufacturing dimensionally stabilized tampons with a domed tip
having a smooth surface.
[0002] Absorbent, cylindrical tampons are now widely used for a
number of absorbent purposes in the medical and dental field but
are primarily used in the field of feminine hygiene as catamenial
tampons. In this latter field, there are two basic types: digitally
inserted tampons, inserted with the fingers, and applicator tampons
inserted with the aid of an applicator. Both types are usually made
by folding or rolling a loosely associated, generally rectangular
strip of absorbent material, usually fibrous and cellulosic in
nature, into a blank and then compressing the blank into a
cylindrically shaped product. In the case of digital tampons, the
product is then wrapped and packaged and, in the case applicator
tampons, the product is first inserted into the applicator and then
wrapped and packaged.
[0003] In both instances it is highly desirable that the tampon
maintains its final compressed shape and presents a smooth outer
surface at the dome whereby both the removal from the applicator
and/or packaging and the insertion into the vagina are facilitated.
To this end, the art has provided various suggestions for attaining
shape stability and surface smoothness of the dome tip. In U.S.
Pat. No. 4,081,884 for example, it has been suggested that a tampon
blank be first radially compressed and then axially compressed and,
while in the axially compressed state, heated to impart a set to
the compressed body. The axial compression is applied to the extent
that the axially compressed tampon is about 90 to about 98% of the
desired length of the tampon in its final state. Owing to the heat
setting technique described therein, the tampon is said to "grow"
only moderately i.e. 2-10%, based on the final length. While this
technique does indeed produce a relatively dimensionally stable
tampon, unfortunately the required heating step entails expensive
equipment and is particularly difficult to carry out at the high
production speeds (of up to fifteen hundred tampons per minute)
required for practical commercialization.
[0004] The art has also made suggestions with respect to presenting
a smooth forward or insertion end for the tampon and, in particular
for presenting a tapered, domed, or hemispherical end for a tampon
to facilitate insertion. Such a suggestion may be found in U.S.
Pat. No. 3,738,364 wherein a ram having a recess designed to impart
a tapered shaped to a tampon blank is described. Most recently, in
European Patent Application 94/102244.4 filed on Feb. 14, 1994,
there is described a tampon blank which is axially compressed in a
cylinder between two rams with the insertion end ram having a cup
like recess to impart a hemispherical shape to the insertion end of
a tampon. Such a system is found to work well for a moderate degree
of axial compression. On the other hand, as will be described in
greater detail herein drawbacks are inherent in such systems. This
is particularly true in seeking to obtain dimensional stability
without resorting to a heat setting step and at the same time
attempting to dome the insertion end of the tampon.
SUMMARY OF THE INVENTION
[0005] This invention therefore concerns providing an improved
apparatus and method for compressing a cylindrical blank into a
tampon which is dimensionally stable and is provided with a domed
insertion end. Specifically, the invention comprises introducing a
cylindrical blank into a cylindrical axial compression chamber
having an insertion end, an opposed withdrawal end and cylindrical
side walls therebetween. The withdrawal end of the chamber is open
and adapted for the introducing the cylindrical blank into the
chamber and for accepting a reciprocating compression ram. The
compression ram is adapted to axially reciprocate into the chamber
and exert axial compression force against the withdrawal end of the
so introduced cylindrical blank. The insertion end of the chamber
presents an immovable closed insertion end wall to the cylindrical
blank when it is introduced into the chamber. Upon introducing the
blank into the chamber and urging the axial compression ram toward
the insertion end to axially compress the blank therebetween, the
insertion end of the blank is forced against the closed inner
surface of the insertion end of the chamber and takes the shape of
this inner surface; preferably, a smooth surfaced dome, e.g., a
hemispherical shape.
[0006] In accordance with this invention, shape stability is
achieved, not as in the prior art by slight overcompression and
recovery in conjunction with heat setting, but instead, by an
extreme axial overcompression step. In the axial compression step
of an embodiment of this invention the blank is pressed from its
original length to a length ranging from about 15-30% of its
original length. Blank is then allowed to recover to a finished
compressed tampon with the recovery length ranging from about
50-80% of the original blank length. Blank length is chosen to
produce a finished tampon which has the desired finished length,
e.g., about 45 millimeters.
[0007] The high degree of axial overcompression has been found to
result in a dimensionally stable tampon without the need for heat
setting. While the precise reasons for the remarkable stability of
the tampon is not entirely known, it is believed to be the result
of circular pleats forming on the cylindrical surface of the blank
during the compression step. These pleats tend to fold over the
cylindrical surface. When constrained from opening, as when the
finished tampon is packaged and/or placed in an applicator, the
pleats retard axial growth. It has been discovered however that the
high degree of compression in combination with conventional doming
techniques and apparatus, does not result in a smooth surfaced
domed insertion end. Accordingly, the closed insertion end of the
compression chamber is, in accordance with this invention, uniquely
designed to insure such smooth surface. Specifically, the closed
end wall of the chamber comprises a bore therethrough. The bore is
generally coaxial with the chamber and has a periphery, at the
insertion end wall, having a smaller diameter than that of the
cylindrical compression chamber. The bore is adapted to accept a
reciprocating ejection ram having a ram surface facing into the
chamber. The ram may be seated, in a first position, with the ram
surface contiguous with the insertion end wall. Further, the ram
may be axially reciprocated out of such first position, through the
bore and through the compression chamber to eject the axially
compressed blank. When the ram is seated in the first position, the
ram surface and the insertion end wall of the compression chamber
together form a smooth doming surface for imparting a smooth
surfaced dome to the insertion end of the blank when the blank is
compressed by the action of the compression ram. The smooth doming
surface may be accomplished as a result of having the ram closely
fitted to the bore at the periphery so as to present essentially no
gap between the bore periphery and the ram surface. The dome shape
may be imparted by machining the insertion end wall with the seated
ram in place, thereby obtaining a continuous smooth doming surface.
Because the ram is closely fitted within the bore, no ridges are
formed on the insertion end of the tampon, notwithstanding the high
degree of axially compression. Notwithstanding the tight fit of the
ram within the bore, because the bore periphery is of a smaller
diameter than the chamber and hence radially spaced from the side
walls of the chamber, the ram has sufficient clearance to move
through the chamber and eject the tampon without interference from
the walls of the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a domed tampon of this
invention having a generally a hemispherical insertion end;
[0009] FIG. 2 is a perspective view of a domed tampon of this
invention having a generally tapered end;
[0010] FIG. 3 schematically illustrates, in perspective view, a
method for producing a blank for compression in accordance with
this invention;
[0011] FIG. 4a schematically illustrates, in cross-sectional end
view a first step in the method for radially compressing a
blank;
[0012] FIG. 4b schematically illustrates, in cross-sectional end
view a second step in the method for radially compressing the
blank;
[0013] FIG. 4c schematically illustrates, in cross-sectional end
view a third step in the method for radially compressing the
blank;
[0014] FIG. 5a schematically illustrates, in longitudinal
cross-sectional view, a first step in a method of axially
compressing and doming a tampon blank employing, in part, the
teachings of the prior art;
[0015] FIG. 5b schematically illustrates, in longitudinal
cross-sectional view, a second step in the method of axially
compressing and doming a tampon blank employing, in part, the
teachings of the prior art;
[0016] FIG. 5c illustrates the compressed tampon resulting from the
methods of FIGS. 5a and b;
[0017] FIG. 6a schematically illustrates, in longitudinal
cross-sectional view, the apparatus and the first step in a method
incorporating the teachings of this invention for axially
compressing and doming a tampon blank;
[0018] FIG. 6b is a enlarged fragmented view of the insertion end
of the apparatus shown in FIG. 6a;
[0019] FIG. 6c schematically illustrates, in longitudinal
cross-sectional view, a second step in the method of this
invention;
[0020] FIG. 6d schematically illustrates, in longitudinal
cross-sectional view, a third step in the method of this invention;
and
[0021] FIG. 7 schematically illustrates, in longitudinal,
fragmented, cross-sectional view, a pleated axially compressed
blank, constrained by cylindrical walls.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring now to the drawings, FIG. 1 illustrates a domed
tampon 10 in its final desired shape, exhibiting a smooth,
hemispherical insertion end 12 and a rear or withdrawal end 14. A
withdrawal string 16 is affixed to the withdrawal end 14 for
removal of the tampon after use. FIG. 2 illustrates an alternative
design for a tampon 18 characterized by a smooth tapered insertion
end 20. It will be understood that the descriptions hereinafter
will primarily be focused on the embodiment of a tampon illustrated
by FIG. 1 but will be equally applicable to a tampon such as that
illustrated in FIG. 2 as well as other such variations in shape or
proportions.
[0023] FIG. 3 schematically illustrates one method for preparing an
uncompressed blank for manufacturing a tampon illustrated in FIGS.
1 and 2. A rectangular pad 22 of absorbent material is rolled into
a spiral configuration to form a generally cylindrical blank 24.
The pad 22 may comprise any of a number of absorbent materials or
combinations thereof. Generally, however, such a pad comprises
fibrous cellulosic materials and, in particular, cellulosic fibers
of, for example, wood pulp, cotton or rayon. Other materials, both
fibrous and nonfibrous (e.g., granulated, powdered, foamed, and the
like) may be incorporated to increase absorbency or provide other
functions such as odor control or antimicrobial activity. When the
absorbent material is primarily fibrous, rectangular pads of these
fibers will generally maintain sufficient integrity to be processed
into blanks. Such pads will have, for example, a density ranging
from about 0.04 to about 0.07 grams/cc. On the other hand where
materials are in powdered form, they may be combined with fibers to
form a pad or may be held together by means of binders or the like.
One possibility, for example, is to form a nonwoven fabric from a
combination of fibers and powders and use the fabric as an
absorbent. It will be understood that a pad rolled into a spiral
blank is not the only form of a starting blank useable in
connection with the teachings of this invention. For example,
absorbent material can be enveloped by a generally cylindrical
shaped sack of fluid pervious nonwoven fabric and may be used in
this form as well. Additionally, the blank may be provided with a
cover of an apertured film or of woven or non-woven fibers such as
polyester, polyethylene, polypropylene, rayon, or the like.
[0024] Irrespective of the materials of construction or the methods
for providing the blank, the blank has a length in excess of the
desired length for the finished tampon and a diameter in excess of
the desired diameter of the finished tampon. Preferably, it is
first radially compressed. Several methods for such radial
compression are known in the art. For example, U.S. Pat. Nos.
2,798,260; 3,422,496; 3,845,520; and 4,081,884 all illustrate
radial compression. FIGS. 4a-4c schematically illustrate a radial
compression scheme employable in connection with this invention. As
viewed in these Figures, the rolled blank 24 is shown in
cross-sectional end view. In FIG. 4a, the blank has been inserted
into the radial compression chamber 26 of a tampon apparatus 27.
The chamber 26 has a length (out of the plane of the drawing) of at
least that of the longitudinal length of the blank 24. In the open
position illustrated in FIG. 4a, the chamber comprises an immovable
flat side wall 28 and an immovable concave inwardly shaped end wall
30, a pivotal flat side wall 32 and a reciprocating concave
inwardly shaped end wall 34. As illustrated in FIG. 4b, upon
insertion of the blank 24 into the chamber 26, the pivotal flat
side wall 32 is pivoted against the blank to be parallel to the
opposed immovable flat side wall 26 and to impart a first radial
compression to the blank. Then, as illustrated in FIG. 4c, the
reciprocating concave inwardly shaped end wall 34 is reciprocated
toward the immovable concave inwardly shaped end wall 30 to further
radially compress the blank therebetween and impart thereto a
cylindrical shape.
[0025] The now radially compressed blank 36 is next transferred to
an axial compression chamber. As aforementioned, axial compression
and apparatus for carrying out such compression are known in the
art and are illustrated, for example, in U.S. Pat. Nos. 3,738,364
and 4,081,884. FIGS. 5a-c, schematically represent such prior art
methods and devices. Referring to FIG. 5a, the prior art axial
compression chamber 38 is illustrated as having a cylindrical
chamber formed of immovable side walls 40, a reciprocating
insertion end wall 42 and a reciprocating withdrawal end wall 44.
The inwardly facing surface of insertion end wall 42 is provided
with a spherically shaped recess to provide the dome tip of the
insertion end of the tampon. Generally, the radially compressed
blank 36 may be transferred from the radial compression chamber 26
and into the axial compression chamber by axially aligning the two
chambers and pushing the radially compressed blank 36 out of the
radial compression chamber and into the axial compression chamber.
This pushing may be accomplished, for example, by use of the
reciprocating withdrawal end wall 44 which can be used to urge the
blank out through the radial compression chamber and into the axial
compression chamber. Alternatively, other pushing means (not shown)
may be employed and, in fact, an intermediate transfer or carrying
chamber may be employed in transferring or carrying the radially
compressed blank to the axial compression chamber.
[0026] Irrespective of the means of transfer, FIG. 5a illustrates
the radially compressed blank 36 residing within the prior art
axial compression chamber prior to any axial compression. Referring
to FIG. 5b, the axial compression is accomplished by urging the
reciprocating end walls towards each other thereby compressing the
blank 36 therebetween and imparting a hemispherical dome shape to
the insertion end of the blank. The compression may be accomplished
by moving both reciprocating ends, or instead, by fixing one end,
e.g., the insertion end, and moving the other end toward the fixed
end. Upon completion of the compression, the insertion wall is
reciprocated to eject the finished tampon.
[0027] The above described axial compression methods and apparatus
have been quite satisfactory in providing domed tampons when, as is
employed in the methods of U.S. Pat. No. 4,081,884, only relatively
moderately compression is applied. For example, in the
aforementioned patent, the compression is sufficient to compress
the tampon blank to a length of about 90-98% of the final desired
length of the tampon. To prevent "growth" and to stabilize the
tampons length, when employing such moderate compression it is
necessary to also apply a heat set and such a method has proved to
be commercially impractical.
[0028] In accordance with the teachings of this invention, the
axial compression is employed to provide a stable finished tampon
length without the need for a heat setting step. This is
accomplished, as taught herein, by a far more severe axial
compression than has been proposed heretofore. Specifically, the
blank is pressed from its original length to a length ranging from
about 15-30% of its original length. By this means, growth is
limited to about 65% of the blank's original length. The length of
the original blank is of course chosen so as to reach the desired
length after this extreme compression and regrowth process. For
example, to produce a tampon of 45 mm in length, the axial
compression is carried out on a blank of 70 mm in length axially
compressed to 16 mm (23% of the original blank length) and then
allowed to "grow" to 45 mm (64% of the original blank length).
[0029] The prior art methods and apparatus as described in FIGS. 5a
and 5b have proven to be inappropriate for the methods of this
invention. Specifically, referring to FIGS. 5a and 5b it should be
noted that in order to reciprocate the end walls 42 and 44, it is
necessary to provide a gap or tolerance fit (shown as dimension T)
between the side walls 40 and the end walls 42 and 44. When axially
compressing the blank under moderate conditions, this has not
proven to be an adverse factor in the process. On the other hand,
when employing the teachings of this invention and compressing
under the severe conditions set out herein, we have found that the
prior art methods and apparatus produce disastrous results. Under
the severe compressing conditions, fibers from the blank are forced
into the gap producing the product illustrated in FIG. 5c. In
contrast to the desired smooth surface, a circular ridge 46 is
formed about the domed end of the finished tampon 48, clearly an
intolerable result.
[0030] Referring now to FIGS. 6a-6d, illustrated therein is a
method and apparatus for employing the teachings of this invention
and avoiding the aforementioned drawbacks of the prior art.
Illustrated in FIGS. 6a is the radially compressed blank 36, in
longitudinal cross-section as it resides in the radial compression
chamber 26 just after end wall 34 has been reciprocated (in the
direction of the arrow) to complete the radial compression.
Immediately adjacent radial compression chamber 26 and axially
aligned therewith, is axial compression chamber 50. Axial
compression chamber 50 is comprised of cylindrical side walls 52
and an immovable insertion end wall 54. As best seen in FIG. 6b,
insertion end wall 54 is machined or otherwise fabricated to have
an inwardly facing concave hemispherical shape so as to impart a
hemispherical dome to the insertion end of the finished tampon. A
bore 56 is provided through end wall 54 and is coaxial with the
axial compression chamber 50 but is of a smaller diameter than the
chamber 50. Fitted into the bore 56 is a reciprocating ejection ram
58 having a ram head 60. The inwardly facing surface 62 of the ram
head 60 is machined or otherwise fabricated to present, together
with the insertion end wall 54, a smooth inwardly facing concave
hemispherical surface for doming the tampon blank 36. The ram head
is tightly fitted in the bore at the periphery of the bore 56 at
the insertion end 54.
[0031] Reciprocating withdrawal end ram 64 is provided coaxial to
both compression chambers 36 and 50. In operation, reciprocating
withdrawal end ram 64 is reciprocated against the withdrawal end of
radially compressed blank 36 to urge blank 36 coaxially out of
radial compression chamber 26 and into axial compression chamber
50. As illustrated in FIG. 6c, ram 64 is then further or
continuously reciprocated towards insertion end 54 of chamber 50 to
axially compress blank 36. The hemispherical dome shape desired is
imparted on the insertion end of the blank by the concave inwardly
hemispherical shaped surface comprising the inwardly facing
surfaces of the insertion end 54 and the face 62 of the ejection
ram head 60. Because there is essentially no gap between the face
62 and the periphery of the bore 56 at the end wall 54, no fibers
of the blank can be trapped to create the undesirable ridge found
in the prior art; this is so notwithstanding the extreme
compression applied to the blank in accordance with the teachings
herein.
[0032] As illustrated in FIG. 6d, notwithstanding the lack of a
gap, the ejection ram can now be reciprocated smoothly towards the
withdrawal end of the axial chamber to eject the now axially
compressed tampon. The need for the gap at the end wall has been
primarily avoided in that the ram head and of course the main shaft
of the ram is of a substantially smaller diameter then the axial
compression chamber and hence experiences no frictional resistance
as the ram freely reciprocates through the axial compression
chamber and, in the example illustrated, through the radial
compression chamber. Smooth passage of the tight fitting ram head
is further facilitated by providing the bore 56 and the ram 60 with
a taper i.e., with a diameter which decreases in a direction
axially away from the insertion in wall 54. In this manner, the ram
makes essentially only line contact with the end wall at the
periphery of the bore just prior to reciprocating the ejection ram
58. Thereafter, no frictional contact exists, thus essentially
obviating the need for a gap. An additional advantage of the taper
is that the ram will thus be better supported to resist the forces
of the extreme compression step of this invention. By virtue of the
taper, force components are created against the side walls of the
bore, adding to the resistance of the ram. The taper should be such
as to provide an included angle (angle A in FIG. 6d) of at least
ten degrees.
[0033] The diameter of the face 62 of the ram head 60 is
substantially smaller than that of the chamber 50 and need only be
large enough to ensure stable ejection of the axially compressed
blank without damage thereto. Preferably such diameter is from
about 40% to about 95% of the chamber diameter and still more
preferably from about 70% to about 90%. If the diameter is too
large, in addition to creating friction, the tapered ram head will
from the geometry of the design, be required to be too sharp and,
in the extreme create a weakened knife edge at the periphery. If
the diameter is too small, the head will be unstable and may also
damage the tampon.
[0034] Referring now to FIG. 7, illustrated there in schematic,
fragmented, cross-sectional view, is an axially compressed blank
70. In accordance with the teachings of the invention, the axially
compressed blank 70 has been compressed to a degree that circular
pleats 72 have been formed on the cylindrical surface of the
compressed blank. These pleats are formed by the action of friction
between the constraining walls 76 and the blank when walls 76
represent the walls of the compression chamber. Moreover, the axial
compression is applied to the extent that the pleats 72 fold over
toward the adjacent portion 74 of the cylindrical wall of the blank
in the direction toward the withdrawal end of the blank. It is
believed that this configuration provides axial direction
stability. It is suggested that this comes about when such a
compressed pleated tampon is placed within the constraining walls
of packaging materials or a tampon applicator. For the purposes of
describing this suggestion, the walls 76 in FIG. 7 may be taken as
such constraining walls. It seems then, that for the tampon to
"grow" axially, it is necessary for the pleats to unfold and hence
for the pleats 78 to rise, in a radial direction away from the
cylindrical wall portions 74 of the tampon. It also appears that
with little constraining force, the constraining walls 76 preclude
this rising of the pleats and hence the axial growth of the tampon
is precluded.
[0035] The specification above are presented to aid in the complete
and non-limiting understanding of the invention disclosed herein.
Since many variations and embodiments of the invention can be made
without departing from its spirit and scope, the invention resides
in the claims hereinafter appended.
* * * * *