US 3794033 A
A contoured disposable diaper is formed from a generally rectangular flat pad wherein a pair of slits are positioned in the sides and the resulting flaps are folded over and bonded to form a constricted center portion. By appropriately positioning the slits, the overall asymmetrical shape of the diaper can be determined based on anatomical size while at the same time placing more absorbent material in the critical areas of severe wetting.
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United States Patent 1 1 3,794,033 Ryan Feb. 26, 1974 DISPOSABLE DIAPER WITH CENTER 2,788,003 4/1957 Morin 128/284 C S CT 2,866,460 12/ 1958 Tomlinson....
3,461,871 8/1969 Foote  Inventor: Arthur Sensor y Kelso, Wash- 3,176,688 4/1965 Tschappat 128/284  Assignee: Weyerhaeuser Company, Tacoma,
Wash. Primary ExaminerCharleS F. Rosenbaum  Filed: Mar. 1, 1972 21 Appl. No.2 230,571  ABSTRACT A contoured disposable diaper is formed from a generally rectangular flat pad wherein a pair of slits are CCll. positioned in the sides and the resulting flaps are  Fieid s /28 4 287 folded over and bonded to form a constricted center portion. By appropriately positioning the slits, the I 56] References Cited overall asymmetrical shape of the diaper can be determined based on anatomical size while at the same time UNITED STATES PATENTS placing more absorbent material in the critical areas 1,490,303 4/1924 Woody 128/284 of severe wetting, 1,694,161 12/1928 Budwig et al.... 128/284 2,122,417 7/1938 Fridolph 128/284 2 Claims, 4 Drawing Figures DISPOSABLE DIAPER WITH CENTER CONSTRICTION BACKGROUND OF THE INVENTION This invention relates generally to a disposable diaper and, more particularly, to an improved disposable diaper having a construction with increased absorbent material in the central crotch area.
One of the big problems with disposable diapers is with the fitting, especially where anatomical boy/girl differences shift the point of maximum wetting. All diaper designs must also be reconciled with the relative ease of making flat pads. The ideal disposable diaper constructed from a generally rectangular flat pad is one that offers efficient absorbing characteristics, that is, maximum absorbent material is positioned at critical areas, together with a contoured form for ease of fitting about the infant. It is also important to realize that with high production methods, since the consumer market for disposable diapers is extremely high, relatively simple and inexpensive manufacturing techniques must necessarily be established to form the disposable diaper having the above noted characteristics.
The prior art recognizes the above two noted characteristics, but does not offer a simple disposable diaper formed from a single rectangular flat pad with a builtup crotch area that is easy to fit about the infant. Examples of prior art patents showing a built-up crotch area are those issued to R. .l. Woody U.S. Pat. No. 1,190,303, M. Budwig et al U.S. Pat. No. 1,694,161, A. Vogt U.S. Pat. No. 3,368,562, T. H. Foote U.S. Pat. No. 3,461,87l, and others. The patents just mentioned show a symmetrical pattern for forming the built-up crotch area and most would not offer the most efficient placement of absorbent material, recognizing the fact that the majority of the absorbent material should be placed toward the front of the diaper, while at the same time recognizing that the buttocks portion of the diaper should be larger in area than the front. While a symmetrically folded diaper may be esthetically pleasing, it bears little resemblance to how the body is built.
Accordingly, from the foregoing, one object of the present invention is to offer a disposable diaper with additional absorbent material positioned at the point of maximum wetting.
Another object of the present invention is to construct a contoured diaper with the additional absorbent material that recognizes the fact that the buttocks area of the diaper should be larger than the front portion of the diaper.
Yet another object is to provide a diaper with the built-up crotch portion that allows easy fitting about the infant.
Still a further object is to provide the built up crotch area and contoured diaper in a manner that lends itself to simple and economical manufacturing techniques.
These and other objects of the invention will become apparent upon reading the following specification in conjunction with the attached drawing.
SUMMARY OF THE INVENTION Briefly, this invention is practiced in one form by constructing a disposable diaper froma generally rectangular flat pad. A pair of opposed slits are made along both sides of the flat pad and extend inwardly from the respective edges of the pad a distance of from oneeighth to one-third the width dimension of the flat pad. The looseflaps thus created by making the slits are then folded over the inner surface of the flat pad, one atop the other, and bonded together. This positions additional absorbent material at the critical wetting area. By selecting the appropriate dimensioning for making the slits, it is apparent that the contoured outline of the finished diaper can be varied for different size infants.
BRIEF DESCRIPTION OF THE DRAWING FIG. l is a plan view showing the inner surface of a generally rectangular flat absorbent pad having a pair of opposed slits therein.
FIG. 2 is a similar plan view showing the first overfold for the flaps that are created by the inclined slits.
FIG. 3 is a similar plan view showing both overfolds made in the absorbent flat pad such that the contoured disposable diaper having a constricted-crotch portion is thereby formed.
FIG. 4 is yet a similar plan view showing the slits positioned in a different arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT The finished disposable diapers that are constructed according to the present invention are generally manufactured from a rectangular flat pad having an inner absorbent layer normally comprised of cellulosic pulp, an outer moisture impermeable layer normally comprised of a polyethylene film, and an inner pcrvious tissue layer extending over the inner absorbent layer. This construction for a disposable diaper is, of course, well known in the art and is depicted in many issued patents and, for this reason, the present drawing does not specifically show the layered construction. The functions of each of the layers is also well known but will be briefly mentioned here for clarification of the present invention. The moisture impermeable layer, of course, operates to contain the fluid within the bounds of the absorbent pad. The inner absorbent layer operates to generally hold the majority of the fluid while the pervious tissue layer acts to contain the inner absorbent layer within its intended bounds and also to allow better distribution of the liquid over a larger area of the absorbent inner layer.
In forming a disposable diaper according to the present invention, the first step is to establish the generally rectangular flat pad 1 such that its inner surface 2, that is, the surface which will be adjacent the infants skin, can be divided into appropriate forming lines. For purposes of this description, the reference to the flat pad 1 will be taken to mean the absorbent layer. The construction of the contoured diaper of this invention is first applied to the flat pad I and after forming the contoured shape, the other layers can then be applied to finish the construction. In the discussion contained under the heading BACKGROUND OF THE INVEN- TION, it was stated that a purpose of the present invention was to provide a constricted crotch area having more absorbent material at the critical wetting areas, while at the same time establishing a contoured disposable diaper that recognized the fltting requirements and anatomical differences between the front and back of an infant.
ln manufacturing the disposable diaper of the present invention from a generally rectangular flat pad 1, a pair of opposed slits 3 and 4 are cut inwardly from the sides of the flat pad 1. These slits 3 and 4 are preferably cut at an inclined angle and sized according to a geometric determination that will ultimately determine the plan outline of the final contoured disposable diaper.
In determining the relative positions for the slits 3 and 4, there are two primary considerations. The first consideration is the desired final plan outline with respect to the shape of the infant who will be utilizing the disposable diaper. The second consideration is that in order to avoid waste and enhance the fitting characteristics of the diaper, the two folds made in the flat pad ideally will not extend beyond the boundary lines of the flat pad.
One method for positioning the slits 3 and 4 will be described while referring to FlGS. 1 through 3. In FIG. 1, a pair of diagonal lines AD and BC are established on the flat surface of pad 1. As seen on FIG. 1, the points A, B, C and D are all approximately equidistant from the corners that they are adjacent to. This positioning of the four points is representative and is chosen to satisfy the two basic considerations for the completed diaper. For example, the four points A, B, c and D could extend from the four corners of the flat pad as seen in the embodiment of FIG. 4 and still offer the advantages of the present contoured disposable diaper. the embodiment in FIG. 1, however, has the four points spaced from the corners in order to offer more plan area for the completed diaper and a more traditional final shape. After establishing the diagonal lines AD and BC, the angles formed by the sides of the flat pad and the diagonal lines are bisected. Thus, the angle CAD and the angle CBD are bisected such that the bisecting line will divide that portion of the other diagonal line that passes into the area of the flat pad encompassed by the two adjacent pad sides in half. This procedure is repeated for the other included angle such that two opposing flaps and 6 are formed after the slits 3 and 4 are made along each of the diagonal lines from the edges to a position where the bisecting lines intercept the respective diagonal lines. For further discussion purposes, the intersection points of the bisecting lines with the diagonal lines will be indicated as E and F, respectively, while the point where the two diagonal lines AD and BC intercept each other will be designated as G. The two opposed flaps 5 and 6 which have as their respective fold lines AE and BF are then folded 180 over the inner face 2 of flat pad 1 such that one flap overlaps the other.
ln FIG. 2, flap 5 or the area encompassed between points A, E and C is folded 180 and will have point C on flap 5 generally coextensive with point F on flap 6. At this point, the flap 5 which has been folded over the inner face of the flat pad 1 is appropriately bonded to the inner surface 2 through any suitable bonding means depicted at 7. The opposing flap 6 is then ready to be folded l80 to a position over the inner surface 2 and also over a portion of the flap 5. This folding operation is depicted in FlG. 3 and it will be noted that point D on flap 6 then becomes coextensive with point E on flap 5. Again, suitable bonding means depicted at 8 are provided in order to fix flap 6 to the inner surface 2 of the flat pad.
It will be noted from FIG. 3 that after the folding operation for flaps 5 and 6 is completed, the center constricted portion, generally indicated as 9, will be comprised of several layers of absorbent pad material. The portion of the disposable diaper indicated at 10 is comprised of three layers of pad material, while the disposable diaper portions depicted as 11 and 12 opposing one another will be comprised of two layers of pad material. It will thus be appreciated that at the center constricted crotch portion 9, additional layers of absorbent material will be available for accepting fluids where their concentration is the heaviest.
Likewise, by so constructing a disposable diaper from a generally rectangular flat pad, it will be noted from the plan outline as shown in FIG. 3 that a definite diaper back portion depicted at 13 will be formed as will be a definite front portion depicted as 14. This of course recognizes that the buttocks portion of the diaper should be larger than the front portion. It will be readily apparent to one skilled in the art that to increase the size of either the back or front portions 13 and 14 the relative positions of the four points A, B, C and D can be changed accordingly. This is readily apparent from the embodiment as depicted in FIG. 4.
The embodiment depicted in FIG. 4 is formed in exactly the same manner as previously described, except that the diagonal lines A B and B C are selected in order to vary the shape of the disposable diaper slightly and allow more absorbent material to be positioned toward the center constricted portion 9. It will also be readily apparent to one skilled in the art that the slits 3 and 4 need not be positioned exactly according to the method above described, but that the broad and basic feature of the present invention is that two opposed slits can be positioned in a flat pad such such that the resulting flaps that are formed, when folded over, conform to the desired configuration and result in a contoured diaper having additional absorbent material located toward the central constricted portion.
While specific examples of several embodiments have been described, it will be apparent that many changes and modifications may be made without departing from the spirit of the invention. lt is understood that the appendant claims include within their scope all such changes and modifications.
What is claimed is:
1. A diaper pad of the type constructed from a generally quadrilaterally shaped piece of absorbent material wherein the improvement comprises:
a pair of flaps in said pad having as their respective fold axes lines extending inwardly from two opposed sides of said pad, each axis extending from a point near adjacent corner apices of said pad to a point on a common adjacent side of said pad, said flaps being established by a pair of slits in said pad each slit extending from a point near opposite adjacent corner apices on the two opposed sides to the respective fold axis, and said flaps being folded over the surface of said pad to lie in substantially the same plane thereby defining a diaper shape with front, back and center portions and having at said center portion three overlapping layers of absorbent material. 2. The pad as in claim 1 further comprising means to bond said flaps to said pad after folding thereby forming a fixed center constricted portion.
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