US 3749094 A
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Description (OCR text may contain errors)
United States Patent 1 1 Duncan 1451 July 31,1973
 Inventor: Robert C. Duncan, Wyoming, Ohio  Assignee: The Proctor & Gamble Company, Cincinnati, Ohio 221 Filed: Aug. 18, 1971 21 App1.No.: 172,789
Bailey .1 128/285 X 2,884,925 5/1959 Meynier, Jr 128/270 3,054,403 9/1962 Baker 128/285 X 3,559,646 2/1971 Mullan.... 128/270 Primary Examiner-Lucie H. Laudeglgger H 7 Attorney-Richard C. Witte, John V. Gorman et a1.
[ 5 7 ABSTRACT A tampon prepared for use and used so that the narrow end of a tampon, which is wide at one end and narrow at the other end when subjected to intravaginal pressures, is the last point of attachment for the withdrawal string and that narrow end is located deepest in the vagina. After being placed, the string extends from the narrow end, along the side of the tampon, and through the introitus to the outside of the vagina. A pull on the withdrawal string will reverse the tampon during removal so that the narrow end is the first portion of the tampon to exit the vagina.
8 Claims, 6 Drawing Figures PATENIEDJULQI ms SHEEI 1 BF 2 Fig. 3
INVENTOR. Robert C. Duncan l V r e C Vagina PATENIED 1 I915 3.749 .094
SHEET. 2 0F 2 Uterus INVENTOR. Robert C. Duncan BYQIF TAMPON WI'II-I STRING ATTACHED TO ITS PROXIMAL END FIELD OF THE INVENTION DESCRIPTION OF THE PRIOR ART Anatomy references teach that the vaginal passage is a pocket irregular in shape, rather than a cylindrical tube. It is shorter on its anterior wall and longer on the posterior wall. It is collapsed to form a slit crosswise of the body, i.e., being wide but with little height. Distended, it forms a gourd shaped or pear shaped balloon, wider at the top, and possibly lopsided because of the greater size of one lateral pocket or fornix.
The anterior wall generally is more than about 3 inches long and the posterior wall generally is more than about 4 inches long. These lengths are measured from the hymen to the rearmost wall of the vagina. The distended width at the rearmost or upper end ranges from about 1% inches to 3 inches and the circumference at that point is about 8 inches.
The vagina is most distensible at its upper end and has its maximum potential cross sectional area in that region. The vagina is least distensible near the introitus (entrance) and has its minimum potential cross sectional area in that region. The introital region contains more nerve endings and is more sensitive to outwardly directed pressures than the remainder of the vagina, therefore a tampon should be positioned for use within the vagina beyond the introital region.
Catamenial tampons are subject to four distinct kinds of failure: bypass, partitioning, compression, and exceeding saturation capacity. Bypass failure occurs when the menses travels the length of the vagina without contacting the tampon, i.e., the tampon fails to intercept the flowing menses. This generally occurs because the tampon does not till the cross section of the vagina. Partitioning failure occurs when the menses flow rate past a particular area of the tampon is greater than the absorption rate into the tampon in that area. Thus, although some of the menses is absorbed, that flow which is greater than the absorption rate into the tampon proceeds past the tampon and out the introitus. This partitioning occurs many times because the tampon surface is blocked by mucus secretions, clotted blood, or endometrial debris. Compressive failure occurs when the user inadvertently brings pressure to bear on a tampon which has absorbed menses, and this pressure is great enough to squeeze the menses from the tampon. Exceeding the saturated capacity occurs when the tampon has absorbed all the fluid it can, and for every drop added thereafter, another drop must leave the tampon.
The ideal tampon is one which will have a continuous line of contact with the wall of the vagina around the entire inside periphery of the vagina. This continuous line of contact intercepts menses and other secretions as they flow down the vaginal walls. A conical tampon is advantageous because it has a wide skirt to establish a continuous line of contact with the vaginal wall, it is relatively thin at the skirt which provides deformability of the tampon so that it can better adapt to the shape of the vagina, and it has a varying cross section to provide a wedge" action for moving through orifices. Hollow tampons having one end closed and the opposite end open provide a tampon with less resistance than a solid tampon to lateral deformation, thereby permitting the tampon to more closely approximate the cross sectional shape imposed by the vagina.
OBJECTS OF THE INVENTION It is an object of this invention to provide a catamenial device wherein the tampon is placed in the vagina in one. orientation and turned end for end during removal of the tampon from the vagina.
Another object of this invention is to provide a method of placing a tampon within the vagina so that its orientation upon removal is 180 from its orientation as it was placed within the vagina.
A further object of this invention is to provide a catamenial device which allows easy and comfortable removal of the tampon from the vagina.
SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there isprovided a catamenial device comprising a flexible resilient tampon, a flexible withdrawal string,
.and an inserter. The inserter has a proximal end adapted to be the leading end during insertion into a vagina. The tampon is flexible and absorbent, having a proximal end and a distal end, and it is within the inserter such that the proximal end of the tampon is located adjacent the proximal end of the inserter. The flexible withdrawal string is attached to the tampon and depends therefrom at a last point of attachment which is on the exterior of the proximal end of the tampon. Thus, upon placement of the tampon in a vagina, a pull on the string turns the tampon end for end and permits removal of the tampon with its proximal end leading.
In accordance with another aspect of the present invention, there is provided a method of inserting a tampon comprising placing a tampon in the vaginal cavity with the removal string attachment end thereof oriented in a position adjacent the cervix and with the removal string extending downward therefrom through the introitus.
BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as forming the present invention, it is believed that the invention will be better understood from the following description taken in connection with the accompanying drawings, in which the thickness of some of the materials is exaggerated for clarity and in which:
FIG. 1 is a fragmentary perspective view of a tampon adapted to be used in connection with this invention;
FIG. 2 is a cross sectional view of the tampon of FIG. 1 in a tubular inserter, the tampon being resiliently compressed by and enclosed by the inserter;
FIG. 3 is a perspective view of the uterus and vagina of a human female wherein the vagina is fragmented to show the tampon of FIG. 1 in place;
FIG. 4 is a perspective view of the uterus and vagina of a human female wherein the vagina is fragmented to show the tampon of FIG. 1 at one stage of its removal from the vagina wherein it is rotated about its vertical axis;
FIG. 5 is a perspective view of the uterus and vagina of a human female wherein the vagina is fragmented to show the tampon of FIG. 1 at one stage of an alternate removal path wherein it is doubling back on itself; and
FIG. 6 is a perspective view of the uterus and vagina of a human female wherein the vagina is fragmented to show the tampon of FIG. 1 exiting the vagina with its apex, closed end, first.
DETAILED DESCRIPTION OF THE INVENTION The preferred embodiment of this invention concerns a conical, hollow absorptive tampon 20, such as is shown in FIG. 1. Tampon has a removal or withdrawal string 12 attached to its proximal end 19, which is the closed end, or apex, and is enclosed within an inserter 22 by resiliently compressing it therewithin, such as is shown in FIG. 2. As used herein, resiliently com pressed" is intended to mean compressed to a degree where permanent set, i.e., cold flow to or a bonding in the compressed configuration, has not occurred. A resiliently compressed tampon may return to its approximate free state after being released through the mere passage of time or by moderate flexing of the compressed tampon. Thus inserter 22 acts as a restraining means for a resilient tampon. Tampon 20 is oriented within the inserter 22 such that the last point of attachment 25 of withdrawal string 12, located at the proximal end 19 of the tampon, is adjacent the proximal end 24 of the catamenial device 26. The proximal end of the catamenial device 26, i.e., the inserter 22 and the tampon 20, is that end which is intended to breach the introitus, lead the way through the vagina, and probe deepest into the vagina.
The unattached portion of the withdrawal string 12, i.e., that portion depending from the last point of attachment 25,'can be enclosed within inserter 22 along with tampon 20 so it extends beyond the distal end, base 18, of the tampon 20 and the inserter 22 as shown in FIG. 2. It can also be left outside the inserter 22 when tampon 20 is enclosed therewithin and it will hang free until the catamenial device 26 is inserted into a vagina. At that time the withdrawal string 12 will be forced along the side of inserter 22 by the insertion process, and the end of string 12 will remain outside the vagina.
Tampon 20 is prepared and used so that its proximal end 19 is the last point of attachment 25 for the withdrawal string 12. When the tampon 20 is ejected from the inserter 22 in the vagina, the withdrawal string 12 extends downwardly along the exterior surface 11 of tampon 20 as shown in FIG. 3. A pull on the withdrawal string 12 to affect removal of the tampon from the vagina reverses the tampon 20, 180 along its longitudinal axis, i.e., turns the tampon 20 end for end, so that the proximal end 19 which was located near the cervix, FIG. 3, becomes located near the introitus, FIG. 6, whereby the proximal end 19 of the tampon exits the vagina first and the base 18, the distal end of the tampon, exits the vagina last. 1
The tampon used in this invention is placed to reverse upon withdrawal because there are advantages to inserting it and operating it with the closed end deepest in the vagina and there are advantages in withdrawing it with the closed end leading the way out of the vagina.
The principal advantages experienced with the preferred embodiment of the tampon 20 of this invention are (I) it is easier to insert; (2) it is easier to remove;
and (3) it leaves the vaginal surface cleaner after removal.
More particularly, placing a conical and/or hollow tampon, the preferred embodiment, within the vagina such that the apex, or proximal end, which is closed, of the tampon is near the cervix, i.e., toward the rear of the vagina, is advantageous in that the smooth closed end, which leads into the vagina, provides a better surface for spreading the vaginal walls during placement of the tampon. It is also desirable to place the closed end of a hollow tampon deepest in the vagina because this orientation promotes the most efficient wicking and wetting of a tampon considering that the origin of the fluid to be collected is deep in the vagina. Therefore, the most probable point of first wetting on this tampon is at the closed end and wicking from the closed end can propagate in the most direct line to any other part of the tampon. An advantage of orienting a tampon, having a wider distal end than its proximal end, with its proximal end near the cervix, is that the widest part is then located nearer the introitus in a narrower portion of the vagina where the probability of a continuous line of contact between the vaginal wall and the tampon is increased, therefore, bypass control is enhanced. A still further advantage gained by orienting a wide base tampon, like a cone, as stated above is that it faces a larger tampon surface, i.e., the entire exterior surface 1 1, upstream. See FIG. 3. Thus, a larger surface is exposed to the natural secretion of the vagina, i.e., menses, mucus, and clottable whole blood, which otherwise could block a smaller surface more easily and prevent further menses absorption. Also, it must be realized that because the proximal end is located near the origin of the menses, i.e., the cervix, the menses will be concentrated more heavily in the proximal end than in other areas of the tampon.
Furthermore, there are advantages associated with proximal apex orientation of a conical tampon in an inserter, such as, (1) because of reduced mass at the tampon proximal end, spreading of the flexible sectorshaped flaps, such as those of FIG. 2, is not promoted prematurely; (2) the flexible flaps of such inserters are supported by the tampon proximal end 19 during insertion; and (3) the narrow proximal end promotes products usability in an open-ended, blunt-nosed, inserter. The flaps on an inserter such as in FIG. 2 will tend to collapse due to the pressure exerted on them during insertion if these flaps are not supported. The shape of the proximal end of the conical tampon as it is compressed within the inserter is close enough in shape to the interior of the flaps at the proximal end 24 to support them during insertion without spreading them.
Although the above suggested placement is best for collection of the menses with the preferred embodiment, the reverse orientation is best for withdrawal through the introitus. Withdrawing the apex of the cone first presents the introitus with a small cross section which is gradually increased. This allows the tampon to act as a dilative wedge, gradually urging the introitus larger and larger, rather than presenting the introitus with a large blunt cross section which would demand a rapid dilation. The wedge action of the cone urges the introitus, which is encompassed by a muscle, to a wider opening. This type of removal is easier and more comfortable than the removal of a large blunt cross section which forces the introitus open in one step. Another advantage associated with removing the proximal end first is that the distal end is relatively free of menses and can absorb any menses squeezed from the proximal end by the constriction at the introitus, thus preventing squeeze out and providing more complete removal of the menses. In addition to the advantages accompanying removal of the proximal end first, there are at least two advantages associated with the turning of the tampon end for end within the vagina, i.e., the vaginal rugae are swept by the tampon to help remove clots and debris from the vaginal walls and the vaginal rugae are swept last by the relatively dry distal end, leaving the vaginal wall cleaner. Thus, the present invention provides each of the desirable features mentioned above inasmuch as the proximal end 19 is located adjacent the cervix during use and is located adjacent the introitus for removal.
The inserter 22 and the ejector 23 used to eject the tampon 20 from the inserter 22 after the inserter is positioned within the vagina can be any inserter known to those skilled in the art, e.g., the telescoping tube type inserters, such as are described in detail in the following patents which are incorporated herein by reference: U.S. Pat. No. 2,754,822, Emelock, patented July 17, 1956; U.S. Pat. No. 2,178,840, Lorenian, patented Nov. 7, 1939; U.S. Pat. No. 1,538,678, Blinn, patented May 19, 1925; and an allowed design patent application entitled OUTER TUBE FOR A TAMPON IN- SERTER, by Alfred R. Thomas, et al., allowed Apr. 9, 1971, Ser. No. D-21,492; U.S. Pat. No. 3,320,956, Steiger, patented May 23, 1967; U.S. Pat. No. 3,138,159, Schmidt, patented June 23, 1.964; U.S. Pat. No. 2,998,010, Griswold et al., patented Aug. 29, 1961; U.S. Pat. No. 2,879,769, Gordon et al., patented Mar. 31, 1959.
The inserter 22 and the ejector 23 can be made of any of the acceptable materials, e.g., cardboard or molded polyethylene. The inserter can be sized similarly to those presently commercially used and can, for example, be approximately 2% inches long, has an inside diameter in its main part of about inches, and has an outside diameter in its main part of about at inches.
Tampon 20 is comprised of a body 10 of flexible, resilient, elastic, absorbent material and it has a with drawal string 12 attached thereto. The body 10 has a transverse periphery which is defined as the maximum periphery existing in a plane perpendicular to its longitudinal axis. In the preferred embodiment, the transverse periphery is the periphery around the base of the cone, the longitudinal axis is that axis which passes through the apex and the center of the base of the cone, and the proximal end of the tampon is the apex of the cone. The transverse periphery forms the primary seal between the absorbent body 10 and the vaginal walls; therefore, it is desirable to contact the vaginal wall on all sides.
In the preferred embodiment, the interior of the absorbent body 10 is hollow so it has an internal discontinuity whereby a wider skirt can be formed at its base without making the tampontoo bulky for insertion or removal.
The cavity can be of almost any shape such as spherical, cylindrical or rectangular, but the shape which seems to promote the best deformability and distensibility is a shape coaxial with and similar to the exterior surface 11, which in this case is generally conical. Therefore,. tampon 20 has an absorbent body 10 wherein the exterior surface 11 and the interior surface 13 are generally conical.
The absorbent body 10 can be made from any materials having acceptable absorbency and modulus of elasticity properties. if a foam is used as the absorbent body of this tampon, it can be a flexible resilient polyurethane foam. The preparation of flexible resilient polyurethane foams is disclosed in general and in detail in the next entitled, polyurethanes: Chemistry and Technology, of the series entitled High Polymers, by .l. H. Saunders and K. C. Frisch, copyrighted in 1962 and published by lnterscience Publishers, said work being incorporated herein by reference. A similar disclosure of polyurethane technology can be found in Polyurethane Technology, edited by Paul F. Bruins, copyrighted in 1969 and published by Interscience Publishers, this work also being incorporated herein by reference.
The absorbent body 110 of this invention should be mensesphilic, i.e., having surface characteristics such that the menstrual fluid tends to spread readily or spontaneously on the surface and in the capillaries. Since the menstrual fluid is primarily an aqueous solution, materials onto and into which it spreads readily could be loosely described as hydrophilic. But the state of the art respecting wetting of materials allows a more precise description in terms of contact angles and surface tensions of the fluids and solids involved. This description is disclosed in detail in the American Chemical Society publication entitled Contact Angle, Wettability and Adhesion, edited by Robert F. Gould, and copyrighted in 1964; said publication being incorporated herein by reference.
The contact angle between a fluid and a solid, and consequently the philicity or phobicity of the solid for the liquid, is related to the ratio between the surface tension of the fluid and the solid. In practice, the method for determining surface tension of the solid is to compare contact characteristics of the solid against various liquids. This method is more completely described in p. 12 et seq. of the above mentioned American Chemical Society publication. The value derived from this method is usually called the critical surface tension of the solid. If the ratio is greater than 1:1, i.e., the surface tension of the fluid is greater, the solid is -phobic. if the ratio is less than 1:1, i.e., the surface tension of the solid is greater, the solid is -philic. As the ratio becomes smaller, the solid is more and more -philic.
Menstrual fluid has a surface tension range of about 35 to 60 dynes per centimeter. It will have a contact angle of less than and will tend to spread spontaneously on a solid which has a critical surface tension value greater than its surface tension.
Water has a high surface tension which is about 72 dynes per centimeter and would be apt to spreadspontaneously only on solids with critical surface tensions higher than 72 dynes per centimeter unless the solids surface had changed through an interaction with the water. Therefore, hydrophilicity is not a precise definition with respect to the affinity of a solid for menstrual fluid. The contact angle between menstrual fluid and a solid or the ratio between the surface tension of the menstrual fluid and the critical surface tension of the solid is definitive of their mutual amnity and tendency toward spontaneous wetting. Since the surface tension of water is higher than that of menstrual fluid, any solid which is hydrophilic is also usually mensesphilic.
Although flexible polyurethane foams in general can be used, there are drastic differences in tampon performance between tampons prepared from conventional mensesphobic flexible polyurethane foams and mensesphilic flexible polyurethane foams. The differences are sufficiently great that mensesphilic polyurethane foams are highly preferred.
Another desirable quality of tampon 20 is low compression set when radially compressed within an inserter since dry expansion after insertion provides better bypass control. It is, of course, desirable to use foams having a minimum content of extraneous soluble materials since the product may be retained in the body for a considerable period of time retained soluble extraneous materials could cause a safety hazard if they are toxic, irritants, or sensitizers.
in general, the flexible polyurethane foams used in the preferred embodiment of this invention will be prepared from a reaction mix comprising a polyhydroxy compound which will be, at least in part, a polyether but which may be also, in part, a polyester, and mixtures of polyester and polyether compounds. The following patents, all of which are incorporated herein by reference, disclose mensesphilic polyurethane foams which are especially desirable. Joerg Sambeth, et al, U.S. Pat. No. 3,586,648, patented June 22, 1971; Alexis Archipoff, et al, U.S. Pat. No. 3,573,234, patented Mar. 30, 1971; Joerg Sambeth, et al, U.S. Pat. No. 3,560,416, patented Feb. 2, 1971; Charles H. l-lofrichter, et al, U.S. Pat. No. 3,463,745, patented Aug. 26, 1969; Stanley I. Cohen, et al, U.S. Pat. No. 3,457,203, patented July 22, 1969; Joerg Sambeth, et al, U.S. Pat. No. 3,451,954, patented June 24, 1969; Joerg Sambeth, et al, U.S. Pat. No. 3,451,953, patented June 24, 1969; Joerg Sambeth, et al, U.S. Pat. No. 3,432,448, patented Mar. 1 1, 1969; Rudolf Merten, et a1, U.S. Pat. No. 3,388,081, patented June 11, 1968; Bernard Rabussier, U.S. Pat. No. 3,385,803, patented May 28, 1968; James A. Calamari, U.S. Pat. No. 3,164,565, patented Jan. 5, 1965; Morris V. Shelanski, et al, U.S. Pat. No. 3,098,048, patented July 16, 1963; Carl V. Strandskov, U.S. Pat. No. 3,042,631, patented July 3, 1962; Fritz Schmidt, et al, U.S. Pat. No. 3,007,883, patented Nov. 7, 1961; Harold L. Elkin, U.S. Pat. No. 2,965,584, patented Dec. 20, 1960; Erwin Windemuth, et al, U.S. Pat. No. 2,948,691, patented Aug. 9, 1960; Elekal, British Pat. No. 1,180,316, patented Feb. 4, 1970; Vereinigt Papierwerke Schickedanz & Co., French Pat. No. 1,350,709, patented Dec. 23, 1963.
Other mensesphilic polyurethane foams can also be used, including the foams disclosed in the following patents which are also incorporated herein by reference. George Shkapenko, et al, U.S. Pat. No. 3,535,143, pa-- tented Oct. 20, 1970; John G. Simon, et al, U.S. Pat. No. 3,508,953, patented Apr. 28, 1970; Whitney R. Adams, et al, U.S. Pat. No. 3,458,338, patented July 29, 1969; John R. Caldwell, et al, U.S. Pat. No. 3,418,066, patented Dec. 24, 1968; Joerg Sambeth et al, U.S. Pat. No. 3,413,245, patented Nov. 26, 1968; Lyle W. Colburn, U.S. Pat. No. 3,404,095, patented Oct. 1, 1968; Fred W. Meisel, et al, U.S. Pat. No. 3,382,090, patented May 7, 1968; Yvan Landler, et al, U.S. Pat. No. 3,326,823, patented June 20, 1967; Ming Chih Chen, U.S. Pat. No. 3,249,465, patented May 3,
1966; Sotirios S. Beicos, U.S. llat. No. 3,149,000, patented Sept. 15, 1964; John Bugosh, et al, U.S. Pat. No. 3,094,433, patented June 18, 1963; Karl Goldann, U.S. Pat. No. 2,998,295, patented Aug. 29, 1961; Marvin J. l-lurwitz, et al, U.S. Pat. No. 2,990,378, patented June 27, 1961; John Bugosh, U.S. Pat. No. 2,920,983, patented Jan. 12, 1960; and William R. Powers, et al, U.S. Pat. No. 2,900,278, patented Aug. 18, 1959.
in general, it is preferred to have mensesphilic foam which is at least partially mensesphilic by virtue of the reactants; but it is also desirable in many instances to add additional mensesphilic materials to the foam to increase either the mensesphilicity of the foam or the ability of the foam to hold liquid and resist compressive failure, i.e., squeeze out. A mensesphilic, polyurethane foam used should have a critical surface tension of at least about 60 dynes per centimeter and preferably greater than about 72 dynes per centimeter.
If a foam absorbent material is used, its density should range between about 1.0 pound per cubic foot and about 3.0 pounds per cubic foot in an unstressed state, preferably about 2.0 cubic feet per square foot of foam. Also, foams are more porous in the direction of their rise during formation than in a direction transverse the rise. The cells within the foam are elongated somewhat in the direction of rise. It is preferable to orieat the foam when making the tampon such that the direction of highest porosity is approximately in the direction of preferred wicking. It has been found advantageous to have the wicking direction transverse the longitudinal axis of the tampon to affect greater efficiency in transporting fluids from exterior surface 11 to interior surface 13.
The foam used as the absorbent body 10 should have a dry modulus of compressibility as defined in ASTM Test D1564, Compression Load Deflection Test (Suffix D), of from about 0.2 pounds per square inch to about 0.6 pounds per square inch, preferably about 0.4 pounds per square inch, and a wet modulus of compressibility to attain 75 percent of the original dry thickness ranging from about 0.1 to 0.3 psi, preferably about 0.2 psi. The ASTM Compression Load Deflection Test consists of measuring the load necessary to produce a 25 percent compression over the entire top area of the foam specimen.
A flexible, resilient, elastic, dry-expanding, absorbent material which has been found to perform well as the absorbent material for the tampon incorporated in this invention is Scott Hydro-Foam available from Scott Paper Company, Foam Division, Eddystone, Pennsylvania. Dry-expanding" as used herein means a spreading from a compacted configuration, e.g., as when resiliently compressed within an inserter, without relying on the actions of fluids to release compression set which may have taken place within the absorbent body while it was compacted.
The tampon 20 should have a shape modulus of compression, i.e., the unidirectional pounds force required to deform the tampon to its collapsed state, i.e., collapsed so any interior cavity is substantially eliminated and the interior surface is reduced to line contact between opposing points such as is shown in FIG. 3, ranging from about 0.05 pounds to about 1.00 pounds, preferably about 0.20 to 0.40 pounds. The shape modulus should be greater than about 0.05 pounds so the tampon has some tendency to maintain its shape when compressed. For example, a tampon as limp as a wet dishrag" would not work well because it has essentially no shape modulus. The shape modulus should not be greater than about 1.0 pound because then the tampon becomes too difficult to deform and retains its round cross section which is not as good for tampon performance because the vaginal walls do have some strength and do not drape perfectly; therefore, if the vagina is not fully distended by a tampon, a greater percentage of the vaginal wall is in contact wtih a collapsed, i.e., flattened tampon than is in contact with an uncollapsed, i.e., round tampon. The shape modulus is dependent upon the density and elasticity of the material and the shape of the tampon.
As a flexible, resilient, hollow tampon is deformed, the exterior surface lll is placed in tension and the interior surface 13 is placed in compression at the lateral edges 14 and 15, the exterior surface l1 and the interior surface 13 of the top and bottom walls 16 and 17 are respectively put in compression and tension.
Tampon 20 can be formed by cutting a hollow cone from a solid block of foam, a cut cone, or by joining two superposed coextensive triangular or trapezoidal blanks along all edges except the long base, a formed cone. These blanks should preferably be cut transverse the direction of foam rise so that any elongation of the foam cells associated with foam rise is parallel to the thickness of the blanks. Trapezoidal blanks which have worked well have an altitude of 2.25 inches, a long base of 3.75 inches, a short base of 1.06 inches, and a thickness of 0.40 inch. The superposed blanks were sewed together and the tampon was turned inside out to acquire a tampon having a generally conical shape or more specifically, a bell shape having the approximate dimensions as follows: altitude of 2.0 inches, exterior base diameter of 2.1 inches, interior base diameter of 1.2 inches. Turning the sewed blanks inside out imparts a bending moment to the blanks such that the tampon formed has a generally circular periphery in a plane transverse to the tampons longitudinal axis. Also, this bending moment places the cells on the exterior surface in tension and the cells on the interior surface in compression whereby there is a gradient, between the exterior and interior surfaces 11 and 13, in the average diameter of the capillaries through the tampon walls and the gradient is substantially linear.
in conjunction with the transverse periphery, a removal comfort modulus must also be considered. There is a maximum compressed cross sectional area which can be comfortably removed from the vagina through the introitus. This removal comfort modulus is dependent upon (I) the cross sectional area of the material in the absorbent body in a section through the transverse periphery and (2) the material modulus of compressibility at the time of removal. Thus for a larger transverse periphery, the tampon wall be thinner or have a lower material modulus of compressibility or both. Thus for removal confort, the tampon when wetted should be compressible normal to the longitudinal axis by an encompassing compressive force to a maximum cross section perpendicular to the longitudinal axis of less than about 1 inch in diameter and preferably less than about 0.75 inch in diameter. The preferred embodiment of tampon 20 is compressible, either wet or dry, to a diameter of 0.75 inch by a 0.50 inch wideteflon band which encircles the tampon and .is subjected to a tensile force of less than 600 grams and in the range of 350 to 600 grams, i.e., a tenthickness must sile force is put on both ends of the encircling band and the tensile load imposed on the band is less than 600 grams.
The omnidirectional elastic and compression properties inherent in the foam used in the preferred embodiment, especially in a wetted, wet swellable absorbent foam, help increase removal comfort. When under compression by a band type constriction, the wetted foam tends to migrate from the area of constriction to the limit of its stretch or ultimate strain to relieve the compression. Under tension, as when pulled through a ring, the wetted foam stretches in the direction of pull and necks down to reduce its cross section transverse to the direction of pull. This behavior permits a larger than expected tampon to be removed through the ringlike band of the introitus. The omnidirectional properties are exhibited to a great degree by the material of the preferred embodiment in its wet swollen state.
The omnidirectional properties exhibit their advantage further in that a material having them can adjust to the cross section of a passageway during removal, such as the vaginal introitus, rather than make the passageway conform to the shape of the material. The greatest cross sectional area possible for a given perimeter is attained with a circular shape. If both the tam pon and the wall of the introitus are completely flexible, the passageway will acquire the circular shape as the tampon passes through. if the tampon is not capable of deforming to the circular shape, that tampon having-a given cross sectional area must encounter greater resistance to removal than a tampon of the same cross sectional area which will deform to the circular shape. Even if the introitus does not acquire the circular shape, but is of irregular shape when expanded by the tampon during removal, the omnidirectional properties of the preferred foam tampon allows it to conform to the irregular shape of the introitus and increase removal comfort. The tampon of this inventiom made from a compliant foam of the above specified material modulus of compressibility does adjust or conform to the cross section of the introitus to thereby increase removal comfort.
Tampon 20 is flexible and resilient, and as it is deformed under the pressures exerted by the vagina, it takes the shape as shown in FIG. 3. The tampon is deformed to bring its top wall 16 into contact with the bottom wall l7. As it is deformed as above described, its lateral walls 214 and R5 are distended laterally, i.e., perpendicular to the direction of the force which deformed the tampon. This lateral distension enables the tampon to reach out for the side walls of the vagina to form a seal between the tampon and the vaginal walls against menses flow.
The withdrawal string 12; having a last point of attachment 25 to the tampon 20 should be flexible, waterproof, and strong enough in tension to resist breaking during removal of the product. it can be made of any of the materials used for withdrawal strings and well known to those of ordinary skill in the tampon art. It should belong enough so the unattached portion can extend from said last point of attachment to beyond the distal end of the tampon and out the vaginal introitus when the tampon is properly positioned within the vagina. An unattached length of about 4% inches has been satisfactory for a 2.0 inch long conical tampon. It can be a single string, a tape, or a plurality of strings, all of course having their last point of attachment 25 at the proximal end 19 of the tampon. A material which has worked well as the withdrawal string 12 is a waterproof cotton string having a /3 ply and a 9 pound tensile strength.
Such a string is available from Bibb Manufacturing Company, Macon, Georgia under the name of 5/3 Ply Sno-Spun Bleach 108 Cotton. The waterproofing on the string is to prevent wicking within the string which could lead menses outside the vagina and soil the users clothing.
Another material which could be used for the withdrawal string 12 is a polyester string having approximately the same feel and flexibility as cotton string. The polyester string would probably be stronger, but would also have to be waterproofed to prevent wicking within the string.
The withdrawal string 12 can be incorporated into the tampon made from trapezoidal blanks, as above described, by securing the string in any manner well known to those of ordinary skill in the art so it depends from the tampon at the point of last attachment 25, which is on the exterior surface 1 1 of the proximal end 19 of the tampon 20. One way to attach the string 12 is to locate it within the fastening means used to attach the two trapezoidal blanks together. The string 12 can be positioned along one or more edges of the trapezoidal blanks in the area of attachment and on top or between the superposed trapezoidal blanks. Then a zigzag sewing stitch used to attach the superposed trapezoidal blanks in the area of attachment will simultaneously attach the withdrawal string 12. After the sewed blanks are turned inside out to form a generally conical tampon, the free end, as distinguished from the part affixed to the tampon, of the withdrawal string 12 is pulled through the proximal end of the tampon if the string 12 was laid on top of the superposed blanks. If the string 12 was positioned between the superposed blanks, the free end should already depend from the exterior surface 11 of the tampons proximal end 19. The string 12 can also be attached to the tampon by threading it through a hole, said hole being either parallel or transverse to the longitudinal axis of the tampon or having any other orientation, in the proximal end of the tampon and tying the string so its free end depends from the point of last attachment 25 on the exterior surface 11 of the tampon.
The tampon can reverse, i.e., turn end for end within the vagina, during removal in at least two different ways, as shown in FIGS. 4 and 5, depending upon the position of the withdrawal string 12during placement and the stiffness of the tampon during removal. If the withdrawal string 12 lies somewhat near a lateral edge of the vagina just prior to removal, the tampon will probably reverse during removal as shown in FIG. 4, that is, it will rotate about its vertical axis and the proximal end 19 will proceed downwardly along a lateral edge of the vagina. If the withdrawal string 12 is located away from a lateral wall of the vagina, a tensile force on the string 12 will not provide a rotating moment to the tampon 20 but will make the tampon fold over on itself as is shown in FIG. 5 where the proximal end 19 is folded over the remainder of the tampon 20.
Once the tampon 20 has been reversed within the vagina, it proceeds downwardly and outwardly as is shown in FIG. 6 with its narrow end first and acting somewhat like a wedge. The wedge action gently urges the vagina to distend. This urging action is beneficial in the introital region where the sphincter surrounding the vagina acts to keep the vagina closed. The removal comfort is enchanced if the sphincter is gradually distended, rather than suddenly distended, and this gradual distension is accomplished by a wedge shaped tampon because the tampon cross section is gradually increased.
If the inserter is tubular, a finely pulverized dry material 21 such as talc, which is described in the Merck Index, An Encyclopedia of Chemicals And Drugs, can be placed between the tampon 20 and the inserter 22 such as is shown in FIG. 2 to ease ejection of the tampon 20. The talc 21 can be put on the tampon 20 before the tampon 20 is resiliently compressed and placed within the inserter 22, by dusting a fine layer on the tampon 20. Another procedure which has worked well for the preferred embodiment is coating the interior of a funnel with talc, letting the excess fall out the funnel neck. Then the tampon of the preferred embodiment is rolled about inside the funnel to pick up the tale coating until approximately 0.08 grams is deposited on the exterior of the tampon. Flexible polyurethane foam has a high coefficient of friction with a cardboard or polyethylene inserter. The pulverized material 21 is surprisingly effective in providing an interface between the polyurethane tampon and the inserter to reduce the force necessary to eject the tampon. Cut surfaces of polyurethane foam have what can be called a cacti coefficient which results from exposed cellular structure at the surface protruding like needles on a cactus. This cacti coefiicient may be what gives the polyurethane tampon a high coefficient of friction. It is theorized that the pulverized material acts like many tiny ball bearings which roll as the tampon 20 is ejected and thereby reduce the coefficient of friction. The effect of the pulverized material 21 is surprising because it was expected that the lubricant would fall into the exposed recesses of the cut cells and not stay on the resultant high points of the foam, and also because it was expected that the high points would scrape the pulverized material away and bear directly on the interior of the inserter.
Although this invention has been described primarily with reference to a hollow conical tampon, it is apparent that a non-hollow tampon could also be used.
Thus it is apparent that there has been provided in accordance with the invention, a catamenial device that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as follows in the spirit and broad scope of the appended claims.
What is claimed is:
1. A catamenial device comprising:
A. An inserter having a proximal end adapted to be the leading end during insertion into a vagina;
B. A flexible, absorbent tampon having a proximal end and a distal end, said tampon being within said inserter, the proximal end of said tampon being located adjacent the proximal end of said inserter; and
C. A flexible withdrawal string, said string being attached to the tampon and depending therefrom at a last point of attachment, said last point of attachment being at the exterior of the proximal end of the tampon, whereby upon placement of the tampon in a vagina, a pull on the string turns the tampon end for end and permits removal of the tampon with its proximal end leading.
2. The device of claim 1 wherein said tampon is constructed of resilient, elastic material, is generally conically shaped, and wherein said proximal end is the apex of the cone.
3. The device of claim 1 wherein the tampon is constructed of a resilient, elastic material and has a dry ma terial modulus of compressibility for a 25 percent compression deflection ranging from about 0.2 to 0.6 pounds per square inch and a wet material modulus of compressibility to attain 75 percent of the original dry thickness ranging from about 0.1 to 0.3 pounds per square inch.
4. The device of claim 3 wherein the tampon has a cellular foam absorbent body.
5. The device of claim 4 wherein the tampon has a polyurethane mensesphilic absorbent body.
6. The device of claim 1 wherein the tampon is constructed of a resilient, elastic material and has a hollow cavity propagating inwardly from its distal end.
- 7. The device of claim 1 wherein the unattached portion of the string is enclosed in the inserter between the exterior surface of the tampon and the interior surface of the inserter from the last point of attachment to beyond the distal end of the tampon.
b. The device of claim ll wherein said tampon has an open celled, polyurethane, resilient, elastic, mensesphilic absorbent body, said body having a generally conical exterior surface, said body having an interior cavity, said cavity similar to and coaxial'with the exterior of the tampon, the bases of said tampon and said cavity being coplanar, the apex of the tampon being the proximal end, and the absorbent body having a dry material modulus of compressibility for a 25 percent compression deflection ranging from about 0.2 to 0.6 pounds per square inch and a wet material modulus of compressibility to attain percent of the original dry thickness ranging from about 0.1 to 0.3 pounds per