U.S. patent number 3,731,689 [Application Number 05/111,188] was granted by the patent office on 1973-05-08 for disposable diaper having an integral container and means for application.
Invention is credited to Charles H. Schaar.
United States Patent |
3,731,689 |
Schaar |
May 8, 1973 |
DISPOSABLE DIAPER HAVING AN INTEGRAL CONTAINER AND MEANS FOR
APPLICATION
Abstract
An improved self-containable disposable diaper wherein a portion
of the disposal pouch is slit so as to form integral, oppositely
extending wings, the wings preferably having means thereon for
completing the attachment of the diaper to an infant. A method is
provided for forming the improved diaper featuring folding,
slitting and refolding the portion thereof which is to define the
pouch and wings.
Inventors: |
Schaar; Charles H. (Lake
Zurich, IL) |
Family
ID: |
22337042 |
Appl.
No.: |
05/111,188 |
Filed: |
February 1, 1971 |
Current U.S.
Class: |
604/370;
604/385.04; 604/385.13; 156/256; 604/371; 604/390; 83/54; 604/369;
604/375 |
Current CPC
Class: |
A61F
13/551 (20130101); A61F 2013/530131 (20130101); Y10T
156/1062 (20150115); Y10T 83/0596 (20150401) |
Current International
Class: |
A41D
13/02 (20060101); A61F 13/15 (20060101); A61f
013/16 () |
Field of
Search: |
;128/287,290 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Rosenbaum; Charles F.
Claims
What is claimed is:
1. In a disposable diaper having a fluid absorbent body and pouch
integrate therewith, said fluid absorbent body having a front side
and a back side, said back side having a fluid impervious surface
and said pouch having a wall portion thereof common with said
impervious surface in at least one waist region of the diaper and
in at least a portion of the remaining region of the diaper, the
remainder of the pouch wall comprising a supple, fluid impervious
sheet attached to said body whereby said impervious surface and
said sheet form opposing wall portions of said pouch, the
improvement comprising
slits in said sheet corresponding generally to a T configuration
with the vertical leg of the T extending from the top edge of said
sheet at the waist region of the diaper to a point downwardly
therefrom in the waist region and the crossarm of the T
intersecting said point and extending across at least part of the
width of said wall portion which is common with said impervious
surface, said slits defining a pair of wings.
2. The disposable diaper as claimed in claim 1 wherein the crossarm
of the T extends the whole width of said wall portion which is
common with said impervious surface.
3. The disposable diaper as claimed in claim 2 wherein said
vertical leg forms an angle of less than 90.degree. with said
crossarm.
4. The disposable diaper as claimed in claim 3 wherein said angle
is about 77.degree..
5. The disposable diaper as claimed in claim 2, and further
including means for attaching said wings to a portion of the diaper
in the waist region thereof.
6. The disposable diaper as claimed in claim 5 wherein said
attachment means comprise pressure sensitive adhesive tabs.
7. The disposable diaper as claimed in claim 2 wherein said
impervious surface and said sheet comprise a collapsible tube of
thermoplastic material sealed at one end thereof.
8. The disposable diaper as claimed in claim 2, further comprising
a fluid pervious cover sheet contiguous to the front side of said
fluid absorbent body.
Description
This invention relates to a disposable diaper having an integral
pouch and integral means for application to a baby, and to a method
therefor.
U.S. Pat. No. 3,369,545 describes a disposable diaper and method of
use which permits a soiled diaper to be contained within an
integral pouch for sanitary disposal. While such a structure is
highly advantageous, particularly in situations where immediate
disposal of the soiled diaper is not feasible, it would be
desirable if the diaper could be provided with integral means for
fastening the diaper without the necessity for pinning it to itself
through the pouch.
Various pinless diapers have been previously described in the
literature. Thus, U.S. Pat. Nos. 2,627,858 and 3,089,494 describe
diapers having extensions provided with adhesive for fastening
without the need for safety pins. Although such structures are
functional, they require the use of additional material in
providing the pinless function.
In accordance with this invention, a disposable diaper of the type
disclosed in the aforesaid U.S. Pat. No. 3,369,545 is provided with
integral attachment means without the use of additional material.
It will be apparent that the addition of function and structure
without the use of additional material is economically
attractive.
More specifically, the aforesaid diaper is improved by providing
slits in the outermost wall of the pouch so as to define a pair of
wings preferably having a combined width substantially equal to the
width of the wall, and operable to form wings integrally extending
from said wall in one of the waist regions of the diaper. According
to the method of this invention, the pouch portion of the diaper is
preferably made by flattening a tubular sheet of fluid impervious
material to provide the two pouch walls and slitting through two
opposing wall portions thereof along a line transverse to the
longitudinal axis of the tube from a longitudinal edge of the
flattened tube partially across the width of said flattened tube,
and cutting a second slit along a line extending longitudinally
from one end of the flattened tube to said transverse slit.
The structure of this diaper and the method therefor, will be
better understood by reference to the following description of the
invention and the accompanying drawings in which:
FIG. 1 is a perspective view of a baby wearing a diaper constructed
in accordance with the invention;
FIG. 2 is a front elevational view of the absorbent side of the
diaper constructed in accordance with the invention;
FIG. 3 is a rear elevational view similar to FIG. 2 except that the
wings are folded outwardly so as to extend away from the
diaper;
FIG. 4 is a sectional view taken along the line IV--IV of FIG.
3;
FIG. 5 is a rear elevational view of the diaper of FIG. 2 with the
wings folded inwardly;
FIG. 6 is a fragmentary perspective view illustrating steps in the
disposal of the diaper of the invention; and
FIG. 7 is a schematic perspective view illustrating several of the
improved steps in the method of making the diaper in accordance
with the invention.
Referring to FIG. 1, the invention relates to a disposable diaper
especially adapted for wear by a baby 10, the diaper being the type
which is thrown away after having been soiled. Referring now to
FIGS. 2-5, the invention particularly concerns the disposable
diaper of the type having a fluid absorbent pad 12 and at least two
layers 14 and 16 of fluid impervious sheet material attached to the
pad 12 in such a manner as to form a pouch 18 (FIG. 4). The pad 12
preferably includes a fluid pervious cover sheet 20 as illustrated
in FIG. 4. The layers 14 and 16 are connected at their edges 22, 24
and 26, these edges also coinciding with three of the edges 27, 28
and 29 respectively, of the pad 12 to define three of the edges of
the diaper.
Various modifications are possible in the construction of the
diaper of this invention, as illustrated in FIGS. 8 and 9 of the
aforementioned U.S. Pat. No. 3,369,545. For example, the
longitudinal edges of the cover sheet may be folded around the
corresponding edges of the fluid absorbent pad, in which case the
width of the back sheet need not be greater than the width of the
fluid absorbent body. In this construction, the longitudinal edges
of the back sheet are joined to the folded around longitudinal
edges of the cover sheet.
Alternately the cover sheet may be larger than the absorbent pad.
In this embodiment, the edges of the back sheet are secured to the
folded around edges of the cover sheet. The diaper may also be
constructed with both cover and back sheets having larger
dimensions than the filler, and secured together in any of the
aforementioned manners. In any of these embodiments, the pouch is
formed by joining the impervious sheet at its longitudinal edges
and one of its edges along the width thereof to the corresponding
adjacent edges of the back sheet, as previously described.
Fluid impervious sheets 14 and 16 are preferably films of
thermoplastic materials, thereby allowing construction of the
diaper by heat sealing techniques. Examples of suitable
thermoplastic films are polyethylene films, polypropylene films,
ethylene-acrylate copolymer films, vinyl chloride polymer and
copolymer films, etc.
Fluid absorbent pad 12 may be one or more plies of cellulosic
sheeting, e.g., paper or non-woven fabric or a mass of loosely
associated fibers such as cotton fibers or comminuted wood pulp
commonly known as "fluff."
Cover sheet 20 can be a wet strength tissue paper, polyurethane
foam, or preferably a non-woven fabric of material such as cotton,
rayon, polypropylene, nylon, etc.
In accordance with one aspect of the invention, the outermost layer
16 is slit near one end 31 of the diaper along a line forming an
edge 30 (FIG. 3) at an angle to edges 22 and 24 and along a
longitudinal center line, to form a pair of integral wings 32 and
34 extending from opposite edges 22 and 24 of the layers 14 and 16
and of the diaper. The wings 32 and 34 are foldably attached to the
bottom layer 14 so that the diaper can be stored (FIG. 5) with the
wings 32 and 34 overlapping bottom layer 14. Because the wings are
formed by slitting the layer 16, it will be readily apparent that
the edges 36 and 38 of the wings are contiguous with the slit edge
30 of the layer 16 when the wings are so overlapped. Also, the
outermost edges 40 and 42 of the wings are contiguous with each
other in that overlapped configuration, the combined width of the
wings being that of the width of the layers 14 and 16 and therefore
of the diaper.
When the diaper is to be placed on the baby, the wings fold
outwardly along the edges 22 and 24 to give the configuration shown
in FIGS. 2 and 3. Although the wings 32 and 34 are disclosed as
having approximate equal length, such is not necessary. Equal
length does provide, however, a more aesthetic appearance.
In order to provide a contour fit of the wings around the baby's
legs when the diaper is attached as shown in FIG. 1, it is
necessary that edges 36 and 38 extend from the layer edges 22 and
24 at an angle less than 90.degree.. Accordingly, the value of the
angle "alpha" (FIG. 3) should be less than 90.degree. and
preferably about 77.degree.. It will be readily appreciated that
because of the angle "alpha" differing from 90.degree., the slit
edge 30 forming the top outside edge of the pouch 18 is angled.
Since, as disclosed, the wings 32 and 34 have approximate equal
width, the location of the angle in the slit edge 30 is
approximately centered in the layer 16. Thus, the wings 32 and 34
increase in their width as they extend outwardly from the edges 22
and 24 to their outermost edges 40 and 42, respectively. The
increased width provides the additional advantage of increasing the
attaching strength of the wings. The wing structure thus provides
stronger attachment than could be had if conventional tape tabs
were applied simply to the absorbent pad 12 or the liquid
impervious sheet 14. If desired, wings 32 and 34 can be further
reinforced by any means suitable for reinforcing impervious
sheeting, such as an additional layer of liquid impervious film,
strand reinforcements, etc., or by folding each wing back upon
itself to provide a double thickness.
The pinless function of this diaper is preferably accomplished by
applying a pressure sensitive adhesive to the zones indicated by
the numeral 50, FIGS. 2, 5 and 6. Any conventional pressure
sensitive adhesive can be used, examples being natural rubber
combined with modified wood rosins and adhesives of the type
disclosed in U.S. Pat. No. 3,299,010. Removable facing strips may
be applied to the adhesive zones 50, so that the wings do not stick
until the diaper is ready for use. Alternately, double-face
pressure sensitive adhesive tabs can be used. The adhesive may be
applied to an area other than zone 50; for example, it may be
placed in a thinner or thicker band or as discrete spots.
The above-described diaper can be manipulated for disposal in a
manner similar to the diaper disclosed in the aforesaid U.S. Pat.
No. 3,369,545. That is, referring to FIG. 6 herein, the slit edge
30 of the layer 16 defines the opening into the pouch 18 which
permits the turning inside out of the diaper. When the diaper is
soiled, one hand is then slipped into the pouch 18 to the edge 26
of the layer 16 where that edge is grasped. At the same time the
other hand pulls on the slit edge 30 of the layer 16, the two hands
crossing over so as to turn the pouch inside out. The resulting
configuration places the inside layer 14 completely exposed on one
side of the folded up diaper with the layer 16 on the other side,
the absorbent pad 12 being thus completely enclosed.
While the impervious sheet forming the wings and pouch need not be
co-extensive with back sheet 16, it must have edges contiguous with
at least one of the edges along the width of the diaper in order
that the wings be in the waist region thereof. Furthermore, the
pouch 14 must be of adequate dimensions so as to contain the entire
soiled diaper surface upon reversal.
In accordance with another aspect of the invention, FIG. 7
illustrates a preferred method of manufacturing this diaper. In
accordance with this method, the two layers 14 and 16 of the
impervious sheet are extruded as a single tubular sheet 60. The
sheet 60 is flattened so as to form fold longitudinal edges 62 and
64. The next step is to slit the flattened sheet through two
opposing wall portions transversely from fold edge 64 along the
slit line 66 only partially across the sheet. Preferably slit 66
extends one-half the width of flattened sheet 60. The line 66 is
inclined to the fold 64 at an angle preferably less than
90.degree., the angle "alpha" for example being on the order of
about 77.degree.. A second slit is then cut along the line
indicated by numeral 68 which coincides with the fold edge 64 and
intersects the slit 66 as well as the leading edge 70 of the
tubular sheet which is to form end 31 of the diaper. The next step
is to unfold the tubular sheet and refold it with a 90.degree.
reorientation, so that the folded edges form edges 22 and 24 of the
pouch, these folded edges being in the preferred embodiment
substantially equidistant from the slit 68. One method of
accomplishing this is to slide the tubular sheet over a refolding
mandrel which comprises two planar surfaces intersecting each other
at approximately 90.degree.; 71 is a schematic view of a segment of
such a refolding mandrel, which is known in the art. Thus, the
reformed edges which also coincide with the fold edges 22 and 24
will be formed along the edges 72 of the mandrel. The next step is
to bring the slit and refolded sheet into position for attachment
to the absorbent pad 12 so that the attachment can be made with the
edges of the sheet and pad properly aligned.
It will be apparent that each individual diaper can be made in
accordance with the previous steps on an intermittent basis.
Preferably, however, the previous steps are accomplished in a
continuous process which proceeds in a manner illustrated in FIG.
7. Specifically, the tubular sheet 60 is rolled off a roll 74
having a length considerably in excess of the length of an
individual diaper, the slitting steps occurring periodically so as
to space the slits along the tubular sheet 60 as it unwinds from
the roll 74. After a portion of the tubular sheet is so slit, that
portion passes over the mandrel so as to be refolded. From the
mandrel, the sheet continues on to a station which is opposite a
long roll 78 of the absorbent pad 12. The roll 78 unwinds at the
same speed as the tubular sheet is traveling, and the sheet and the
pad are brought into superposition and continuously adhered or
otherwise attached to each other by an attaching station (not
shown) using techniques such as heat sealing. Thereafter,
individual diapers are periodically severed from the continuous
length of adhered pad and sheet, the severing being spaced so as to
intercept the slits which were formed along the line 68 at the
point where it terminates at the top end 31 of the diaper. The
final severing not only produces each individual diaper but
completes the cut necessary to release the wings so that they can
be unfolded from the layer 16 when the diaper is ready to be used.
The bottom edge 26 of the layers 14 and 16 is sealed in a
concurrent or subsequent operation. It will be recognized that this
continuous process of making the improved disposable diaper reduces
the cost by speeding up the process.
Although the invention has been described in connection with
certain preferred embodiments, it is not intended that the
invention be limited thereto. For example, the only requirement
with respect to the slits in the pouch is that they assume a
general T configuration. Thus, the longitudinal slit can be
positioned at any point along the width of the diaper, thus
providing wings of unequal width. Also, the wings can be trimmed
after manufacture to smaller dimensions. Furthermore, the two
layers of fluid impervious sheet can be formed separately rather
than as an integral tubular sheet, the two layers then being heat
sealed at their edges. Also, if desired, the pouch can open at both
ends, allowing disposal to be accomplished by inverting the diaper
inside out at either end of the pouch. While "slit" has been
illustrated as a continuous severance, the term is meant to include
such equivalents as a perforated tear line. Thus, it is intended
that the invention cover all alternative arrangements, equivalents,
and embodiments as may be included within the scope of the
following claims.
* * * * *