US3766921A

US3766921A - Proximal apex tampon

Info

Publication number: US3766921A
Application number: US00172792A
Authority: US
Inventors: B Dulle
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1971-08-18
Filing date: 1971-08-18
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23
Also published as: CA990002A

Abstract

A catamenial device wherein a flexible, resilient, dryexpanding, elastic absorbent tampon, which when subjected to intravaginal pressures becomes wider at one end, is resiliently compressed and oriented in the inserter so that the end opposite the intravaginal wider end will be located deepest within the vagina when the tampon is ejected into the vagina.

Description

United States Patent 1191 Dulle Oct. 23, 1973 PROXIMAL APEX TAMPON 2,330,257 9 1943 Bailey 128/285 x [75] Inventor: Bernard A Dune Montgomery, 1,884,089 10/1932 Mlllner l28/285 Ohio FOREIGN PATENTS OR APPLICATIONS [73] Assignee: The Proctor & Gamble Company, 1,592,445 5/1970 France Cincinnati, Ohio Primary ExaminerLucie H. Laudenslager [22] Flled: 1971 Att0meyRichard C. Witte et al. [21] Appl, No.: 172,792

[57] ABSTRACT 128/263 ia ig gg A catamenial device wherein a flexible, resilient, dry- [58] Field of Search 128/285, 270, 263 f eIaSWFbWbem tampm ected to lntravagmal pressures becomes wider at one [56] References Cited end, 1s resiliently compressed and. orlented 1n the 1nserter so that the end opposlte the mtravagmal wider UNITED STATES PATENTS end will be located deepest within the vagina when the 3,628,533 12/1971 Loyer 128/263 tampon is ejected into the vagina. 3,054,403 9 1962 Baker l2s 2 s5 x 2,884,925 5/l959 ,Meynier,Jr "128/270 14 Claims, 5 Drawing Figures l9 v v l /4 A, i I

I I I L PAIENTEIJ B81 23 W3 INVENTOR. Bernard A. Dulle PROXIMAL APEX TAMPON 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 about 3 to 4 inches long, shorter on its anterior wall and longer on the posterior wall. ltis collapsed to form a slit crosswise of the body, i.e., being wide but with little height. Distended, it forms a gourd-shape or pear-shape balloon, wider at the top, and possibly lopsided because of the greater size of one lateral pocket or fornix.

The anterior wall generally is greater than about 3 inches long and the posterior wall generally is greater than about 4 inches long. These lengths are measured from the hymen to the rearmost wall of the vagina. The 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.

Menstrual fluid enters the vagina through the cervix which is located where the vagina is most distensible and therefore has its maximum potential cross section area. The vagina is least distensible near the introitus and therefore the potential cross section is reduced. The introital region of the vagina is more sensitive to outwardly directed pressures than the remainder of the vagina. Methods of collecting the recurring menses which flow periodically from females during their child bearingyears are many and varied and are generally wellknown to those skilled in the art. Most methods proposed fall into one of the following two general classifications: retentive and absorptive means. Retentive means are those which form an impervious dam across an internal canal; these are generally in the form of a rubber cap or diaphragm which prevents flow from passing them, thereby damming up the menses using an internal organ as a reservoir. Retentive means generally fall into two main classes: devices which are intended to cover or contact the cervix and devices which are intended to lie in the vaginal canal below the position of the cervix.

Absorptive devices can also be placed into two broad categories, i.e., interior and exterior devices. Exterior devices are generally in the form of pads and probably are the most commonly used type of menstrual sanitary device, but they are unsatisfactory for a variety of reasons.

Internal absorptive devices generally in use are fibrous assemblies which are highly compressed into 1% 2 inches long cylinders approximately one-half inch in diameter. These products do not expand in a cross sectional direction until contacted with body fluids. Prior art insertion techniques are designed to achieve placement of the tampon deep (2% inches 2% inches) in the vagina near the point of fluid entrance, i.e., near the cervix, and thereby avoid placement near the introitus to avoid wearing discomfort. Deep insertion to a position where the collapsed vaginal vault contains many folds and convolutions coupled with the small cross sectional area of the compressed tampon frequently results in bypass failures, i.e., the menses discharged from the cervix travels the length of the vagina without contacting the tampon and thereby escapes through the introitus without being absorbed. Bypass failures occur because the deeply inserted, compressed tampon cannot block the many folds and convolutions of the vagina in that deep region, but the menses can and does flow down through these folds and convolutions and ultimately through the introitus to soil the womans clothing.

An intervaginal device, for proper function per se, must satisfy mutually contradictory criteria, as indicated by the following anatomical facts: (1) The entrance (introitus) to the vagina is provided with a functional sphincter comprised of several muscles which form the main closure of the vagina. These muscles resist distension of the vaginal vestibule, hence, resist entry to and exit from the vaginal proper. Consequently, the diameter of any intervaginal device should be small for easy, comfortable, and safe insertion and withdrawal. (2) Beyond this sphincter, the vagina per se is a flaccid organ, the walls of which are normally collapsed, touching one another to give a cross section of roughly H-shape capable of relatively great radial distension without appreciable resistance. Consequently, an intervaginal occlusive device must be of relatively large diameter and small mass.

Therefore a catamenial tampon should be (1) sniall enough in diameter or compressible enough to faciliate insertion into, and removal from the vaginal cavity; (2) large enough in diameter to permit the tampon to substantially fill the. cross section of. the vagina; and (3) great enough in absorptive capacity to permit the tampon to be worn for an extended period of time during which it will accumulate the menses released and hold them without leakage. These contradictory requirements are difficult to reconcile.

Catamenial tampons are subject to four distinct kinds of failure: bypass,'partitioning, compression, andexceeding saturation capacity. Bypass failure occurs when the menses travels the lengthof the vagina without contacting the tampon, i.e., the tampon fails to intercept the flowing menses. This generally occurs because the tampon does not fill 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 ressure is reat enou h to ueeze the menses from P 8 8 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 prior art shows solid and hollowed out conical and cylindrical tampons made from polyurethane foams such as those shown in US. Pat. No. 2,884,925 issued to Meynier, Jr. on May 5, 1959 and U.S. Pat. No. 3,559,646 issued to Mullan on Feb. 2, 1971. The device taught by the Meynier, Jr. patent is a truncated conical shaped plug which can be hollowed out to some extent, has microscopic pores, and which is made of a deformable, expansive material, preferably regenerated cellulose, but the polyurethane foam will suffice. It has a removal string attached to the narrow closed end and is compressed within an inserter to ease insertion. Meynier, Jr. shown tampon insertion with the wide portion, the base, of the tampon oriented upwardly and it also shows the tampon in the inserter with the base of the tampon adjacent that end of the inserter which normally is intended to be inserted first so that upon placement in the vagina, the base of the tampon will be positioned deepest in the vagina. This places the base of the tampon deep in the vagina where the vagina is broadest which reduces the probability of intercepting fluid flow. The Mullan patent teaches a tampon having a body of compressibly spongy absorptive material which is hollow, closed at one end, and tapered inwardly toward the closed end. It has a withdrawal string attached at the closed end and is enclosed in an inserter such that the open end, not the closed end, is adjacent the end of the inserter intended to be inserted first. This patent hasthe same shortcomings as the Meynier, Jr. patent in that it teaches placing a varying cross sectioned tampon in the vagina with the smallest cross section nearest the introitus, teaches placing a hollowed out tampon inthe vagina with the hollow pointed inwardly so that it will act as a cup to catch any flowing fluid, and it teaches placing the maximum periphery of a varying cross section tampon in the widest region of the vagina and thereby reduces the probability of intercepting fluid flow.

OBJECTS OF THE INVENTION It is an object of this invention to provide a tampon which is easy and comfortable to insert.

Another object of this invention is to provide a tampon which effectively provides bypass control.

A more specific object of this invention is to orient a tampon upon placement to improve its absorption and wicking characteristics.

Another object of this invention is to place a tampon such that it will more completely block the vaginal canal.

SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there is provided a catamenial device comprising an inserter, a tampon, and a tampon ejection means. The inserter is adapted to resiliently compress an elastomeric tampon and has a proximal end adapted to be the leading end during insertion into a vagina. The tampon has a dry-expanding elastomeric absorbent body and the body has a proximal end and a distal end. The distal end has a diameter larger than that of the proximal end when the tampon is subjected to intravaginal pressures. The body of the tampon is resiliently compressed within the inserter and the proximal end of the tampon is located adjacent the proximal end of the inserter, whereby the proximal end is the leading end of the tampon during insertion. The tampon eject means is adapted to eject the tampon through the proximal end of the inserter. Then, following ejection, the tampon is positioned within a vagina so that the proximal end of the tampon is closer to the cervix than is the distal end of the tampon.

In accordance with another aspect of this invention, there is provided a method of inserting a tampon into a vagina. The tampon has a dry-expanding, elastomeric absorbent body which has a proximal end and a distal end. The distal end has a diameter larger than that of the proximal end when the tampon is subjected to intravaginal pressures. The method comprises placing the tampon in the vaginal cavity with the proximal end of the tampon oriented in a position deeper within the vagina than the position of the distal end.

BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing 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 descriptions taken in connection with the accompanying drawings, in which the thickness of some of the materials are exaggerated for clarity and in which:

FIG. I is a fragmentary perspective view of a tampon used in 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 cross sectional view of the tampon of FIG. 1 in an alternate tubular inserter;

FIG. 4 is a perspective view of the uterus and vagina whereby the vagina is fragmented to show the tampon of FIG. 1 in place; and

FIG. 5 is a front elevation view of an alternate tampon of this invention, said tampon having distally directed lips.

DETAILED DESCRIPTION OF THE INVENTION The practice of this invention will provide better performance by showing fewer failures before the absorptive capacity of the tampon is reached and a more efficient wicking within the absorbent body. The improved performance will result for any tampon having a dryexpanding, elastomeric, absorbent body which, when in use and subjected to intravaginal pressures may deform to have one end which is narrow and the opposite end wider than the narrow end. Dry-expanding as used herein means a spreading from a compacted configuration, e.g., as when 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. This structure encompasses solid tampons having a cross section which varies from one end to the other such as a conical one and tampons which have an internal discontinuity in the absorbent body whereby the portion including the internal discontinuity distends under pressure. The internal discontinuity may be in the form of a slit or a hollow cavity within the tampon.

A preferred embodiment of a tampon for this invention is a closed end, hollow, absorptive tampon such as tampon 20 shown in FIG. 1, and which is disclosed in detail in the concurrently filed, copending, commonly assigned applications, Compliant Conformable Tampon, By Bernard A. Dulle, Ser. No. 172,694, Hollow Foam Tampons From Flat Blanks and Method of Making Same," by Bernard A. Dulle, Ser. No. 172790, and Tampon With String Attached to its Proximal End, By Robert C. Duncan, Ser. No. 172789, said applications being incorporated herein by reference. Cylindrical, conical, parabolical, and eliptical tampons which are hollow and open at the distal end will also perform well. The tampon is positioned in the vagina with its closed or narrow end near the cervix and its open or wider end remote from the cervix as shown in FIG. 4. To accomplish this placement within the vagina, the tampon is positioned within an inserter such that the closed end 19 will be oriented proximally, that is, inwardly in the vaginal canal, to become the proximal end of the tampon 20. This requires that the tampon be enclosed in the inserter 22 as shown in FIG. 2, i.e., with its closed end 19 toward the proximal end 24 of the inserter. Thus, when the inserter is placed in the vagina, with its proximal end 24 entering first, and the tampon 20 is ejected from the inserter 22, the tampon 20 is positioned with its closed end 19 near the cervix.

If the tampon 20 is placed as shown in FIG. 4, the usual collapsed state of the vaginal canal will make it likely that draining menses will first contact the tampon near the closed end. If this point of first contact be tween the fluid and the tampon is near the closed end, the fluids have a shorter, unobstructed absorptive path to the rest of the tampon and a maximum effectiveness is obtained from the absorptive material of the tampon. The absorptive path from the probable point of first fluid contact with a tampon placed as shown in the prior art, i.e., the open end near the cervix and the closed end remote from the cervix, is longer and obstructed in that the fluid must wick around the periphery of the tampon to get to its top side whereas when a tampon is oriented as in this invention, i.e., with the closed end proximally disposed, the fluids can wick in a substantailly straight line to all parts of the tampon. Tampon 20, oriented in a vagina with its closed end proximally, also promotes a mode of absorption which tends to insure that the tampon open end periphery, being distally located and having the largest potential cross sectional area in the tampon, is the last portion wetted and thus can more effectively serve to control failures at a higher average level of tampon saturation than can be obtained with other designs and orientation, particularly all hollow tampons which have their closed ends oriented for use in a distal position. Keeping the skirt, or open end, of the tampon unsoiled as late in use as possible serves also to promote a cleaning action in that the vaginal walls are wiped upon removal of the tampon. This cleaning action reduces the possibilities of leaving menses along the wall which could be missed by the next tampon if a sleeved inserter is used. Theunwiped residual menses could contribute to spotting of the users clothing before the tampon has absorbed to its capacity, which would be interpreted as bypass failure.

A further advantage of orienting a tamponwith its narrow end proximally oriented is that a flexible tampon having one or more distinct lips; such as the outer periphery of

tampon base

18 or 30 in FIG. 5, in a plane or planes perpendicular to the longitudinal axis of the tampon and slanted outwardly or away. from the narrow end, said lipsfacing to the outside of the tampon; will creep or move in a direction away from the edges and toward the narrow end when the tampon is restricted on its lateral edges within a flexible channel such as a vagina and pulsating pressure or forces are exerted on the channel. The lips are at a location distal from the proximal end of the tampon. The lips on such a tampon will promote travel within the vagina due to the flexing and frequent movement of the rugous vagina. In a conical shaped tampon, the lips 30 preferably face away from the apex and the travel is in the direction of the apex. This creeping effect can be created or enhanced by any projections which point away from the proximal end, toward the distal end, and have some resistance to bending toward the proximal end. Multiple slanted rings, projections, and slanted nap will all enhance the creeping effect. Proximal apex orientation as in this invention tends to prevent such a tampon from unintended expulsion and in fact tends to move it deeper into the vaginal vault. Such creeping action serves to move the tampon to a deeper, more comfortable, and more effective position where accumulation of menses may have occurred or nearer to the cervix, the source of the menses. There the tampon will soak up accumulated menses and prevent reaccumulation.

Another advantage of orienting a tampon with its narrow end proximally, i.e., closest to the back of the vagina, is that the skirt or wide portion of the tampon, such as the periphery of the base 18 of tampon 20, is positioned lower in the vagina where it can be more effective at preventing bypass. The tampon skirt is more effective in the lower position, whereat proximal apex orientation locates it, because the vaginal perimeter is less in the lower portion of the vagina. Therefore, the skirt will contact a greater portion, if not all, of the vaginal wall periphery than it will if located deep in the vagina.

An additional advantage of orienting a tampon so its narrow endis closest to the cervix, i.e., proximally, is that a greater percentage of the tampon area facing upstream, with respect to the menses flow, has improved wicking associated with the localized capillary gradient hereinafter described. The lateral edges of the deformed tampon, i.e., those edges near the lateral edges of the vaginal vault as seen in FIG. 4, have the localized capillary gradient hereinafter described. When a tampon is oriented with its narrow end proximally, almost the entire leading surface of the tampon has improved wicking properties and the area available for first menses contact is increased because two sides of the tampon, i.e., those sides along the lateral edges 14 and 15, face upstream as shown in FIG. 4. Also, in a proximally oriented tampon, its improved wicking areas extend along the lateral edges of the vaginawhere contact pressure between the tampon and the vaginal walls is probably the least, partitioning is most likely to occur, and the best absorbency and wicking properties are desired. The capillary gradient within the lateral edges of the tampon have these properties. A distally oriented tampon presents very little improved wicking area and not as much total area facing upstream and any menses which bypasses or partitions past the lateral edge of the wider end, which is near the cervix in this orientation, will probably not contact another surface of the tampon and thus would show up as a failure.

FIG. 2 shows the catamenial device of this invention wherein tampon 20 of FIG. I is resiliently compressed, i.e., tampon 20 will undergo dry-expansion upon being enclosed within and ejected from inserter 22, and enclosed in the tubular inserter 22 which acts as a restraining means for the resiliently compressed tampon. As used herein, resiliently compressed is intended to mean compressed to a degree where permanent set, i.e., cold flow to or a bonding in the compressed config uration, 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. Other restraining means include gelatins, dissolvable by intravaginal fluids or body heat, formed about a resiliently compressed tampon and tools similar to forceps which can resiliently compress a tampon just prior to insertion. The ejecter 23 is operatively associated with the inserter 22 to eject the tampon 20 from the inserter 22 through the proximal end 24 of the inserter 22. The proximal end 24 of the inserter is that end which leads the way into the vagina during insertion and is intended to be the leading end during insertion. The other end of the inserter is herein referred to' as the distal end.

The inserter and ejecter can be any of those known to men of ordinary skill in the art as a telescoping tube type inserter. The proximal end of the inserter may be of the tapered tip type wherein a plurality of curved, flexible, sector-shaped flaps combine to substantially enclose the tampon, as shown in FIG. 2, or of the open, blunt kind such as shown in FIG. 3. Detailed disclosures of telescoping tube type inserters having flexible sector-shaped flaps at the proximal end of the inserter can be found in U.S. Pat. No. 2,754,822, Emclock, patented on July 17, 1956; U.S. Pat. No. 2,178,840, Lorenian, patented on Nov. 7, 1939; U.S. Pat. No. 1,538,678, Blinn, patented on May 19, 1925; and an allowed design patent entitled, Outer Tube For A Tampon Inserter, by Alfred R. Thomas, et al., allowed Apr. 9, 1971, Ser. No. D-21,492, all of which are incorporated herein by reference. Telescoping tube type inserters having an open or blunt proximal end are disclosed in detail in the following patents, all of which are incorporated herein by reference. US. Pat. No. 2,879,769, issued to Gordon et al. on Mar. 31, 1959; U.S. Pat. No. 2,998,010, issued to Griswold et al. on Aug. 29, 1961; U.S. Pat. No. 3,138,159, issued to Schmidt on June 23, 1964; and U.S. Pat. No. 3,320,956, issued to Steiger on May 23, 1967.

A blunt nose inserter like 25 in FIG. 3 which has been effectively used was made from cardboard tube having an inside diameter of 0.640 inch and an outside diameter of 0.700 inch available from Stone 1ndustrialCorp., Washington, DC, as paper tubes of the following specifications: No. 154 White Outer Ply No. 953, White Kromekote, Outer Seam Close Butt. Tampon 20 of the preferred size hereinafter described was radially compressed to approximately 0.600 inch diameter and put into the inserter through the distal end. An ejector 23 comprising a smaller diameter tube was then placed behind tampon 20 in the distal end of the inserter.

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 tale 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 tam'pon 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 talc 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 coefficient 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.

The tampon 20 has a conically shaped body 10 of flexible, resilient, absorbent material having a removal string 12 attached to its apex 19. The removal string 12 can also be attached to areas other than the apex or proximal end of the tampon, e.g., anywhere along the base 18 of tampon 20, at several points on base 18 of tampon 20, along the side on the exterior surface 11, or on the inside surface 13. The removal string 12 can be attached by any of well known means, e.g., gluing, tying and sewing.

In a preferred embodiment, the interior of the absorbent body 10 is relieved so it has an internal discontinuity whereby diametrically opposed walls of the tampon have no interconnection across the diameter, thus little or no diametrical tensile strength remains to resist lateral spread when a force transverse the tampons longitudinal axis is exerted on the tampon. As used herein, the word diameter is intended to have the broader meaning of the length of a straight line through the center of an object. The internal discontinuity allows the compressive forces generated within the absorbent body during deformation of the tampon to force the lateral edges 14 and 15, FIG. 4, outwardly toward the sides of the vagina. Without the internal discontinuity, the outward movement (distension) is retarded by the internal tensile strength of the absorbent body 10 associated with a continuous or solid interior. The internal discontinuity is instrumental in reducing the shrinkage of the transverse periphery which occurs when the tampon is deformed to its collapsed state as shown in FIG. I

4. The lateral edges distend because the vertical force exerted by the vagina is transmitted through the walls as compression forces which push outwardly on the lateral edges 14 and 15. With no diametrical tensile forces to restrain them, the lateral edges 14 and 15 move outwardly.

The internal discontinuity of a tampon, if it exists, can take various forms, one of which is a single slit extending from the base 18 of the tampon 20 up through the interior passing through its longitudinal axis or close thereto. If a single slit is used, it must be realized the tampon probably will have to be oriented during placement because of the directionality inherent to a unidirectional internal discontinuity. A plurality of slits, either parallel or radially dispersed, can also be used to relieve the tampon. The preferred form for an internal discontinuity is a hollow or cavity, as shown in FIG. 1, which creates interior surface 13. A cavity as compared to a slit in addition to promoting greater lateral spread or distension, yields a tampon having a lower shape modulus of compression hereinafter described. Any internal discontinuity to be effective should extend from the base at least 50 percent of the length of the longitudinal axis of the tampon.

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, and thus the greatest perimeter maintenance, is a shape essentially coaxial with and similar to the exterior surface 11 of the tampon, which in this case is generally conical. Also, a larger cavity will promote greater deformability, distensibility, and perimeter maintenance. When the tampon 20 is in its free state, the diameter of the cavity is about 61 percent of the transverse diameter in a preferred embodiment and it should be at least about 50 percent to be effective in permitting deformation of the tampon and reduction in total tampon mass.

The absorbent body of tampon 20 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 text entitled, Polyurethanes: Chemistry and Technology, Vol., XVI (in two parts) of the series entitled, High Polymers, by J. 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 lnterscience Publishers, this work also being incorporated herein by reference.

Other disclosures of polyurethane foams can be found in the following patents, all of which are incorporated herein by reference. William J. Considine, et al., U.S. Pat. No. 3,391,091, patented July 2, 1968; William E. Erner, U.S. Pat. No. 3,376,236, patented Apr. 2, 1968; George T. Gmitter, et al., U.S. Pat. No. 3,341,482, patented Sept. 12, 1967; Robert A. Volz, U.S. Pat. No. 3,171,820, patented Mar. 2, 1965; Harlan B. Freyermuth, U.S. Pat. No. 3,148,163, patented Sept. 8, 1964; Robert P. Kane, U.S. Pat. No. 2,955,091, patented Oct. 4, 1960; Rudolf Bick, et al., U.S. Pat. No. 2,938,005, patented May 24, 1960; Newell R. Bender, et al., U.S. Pat. No. 2,888,409, patented May 26, 1959; and Andrew Mitchell 111, U.S. Pat. No. 2,850,464, patented Sept. 2, 1958.

The absorbent body 10 of this invention should be mensesphilic, i.e., have surface characteristics such that the menstrual fluid tends to spread readily or spontaneously on the surface and in the capillaries. Menstrual fluid has a surface tension range of about 35 to 60 dynes per centimeter. It 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 spread spontaneously only on solids with critical surface tensions higher than 72 dyne per centimeter. 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 sufliciently great that mensesphilic polyurethane foams are highly preferred.

In general, the flexible polyurethane foams used in the tampon 20 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 a1, 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. Hofrichter, etaL, U.S. Pat. No. 3,463,745, patented Aug. 26, 1969; Stanley 1. 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. 11, 1969; Rudolf Merten, et al., 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, pa-

tented 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 alsobe 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, patented 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. 3,3 82,090, 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, US. Pat. 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. Hurwitz, et al., U.S. Pat. No. 2,990,378, patented June 27, 1961; John Bugosh, us. 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 desirablein 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.

The foam used as the absorbent body should have a dry modulus of compressibility as defined in ASTM Test Dl,564, Compression Load Deflection Test (Suffix D), of from about 0.2 pound per square inch to about 0.6 pound per square inch, preferably about 0.4 pound 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 ATSM 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.

The density of a foam used as absorbent body can preferably be about 2.0 pounds per cubic foot. Also, foams are more porous in the direction of their rise during formation than in a direction transverse the rise and thus wick better in the direction of the rise. The cells within the foam are elongated somewhat in the direction of rise. Thus the foam should be oriented when making the tampon such that the direction of highest porosity is in the preferred direction. One of several advantageous orientations is to have the direction of the rise approximately transverse the longitudinal axis of the tampon and to effect greater efficiency in transporting fluids from exterior surface 11 to interior surface 13.

Tampon thus can be a conical, mensesphilic, polyurethane, foam tampon 2.0 inches high, having a 2.1 inch base diameter and hollowed out to achieve a wall thickness of about 0.40 inch, having a critical surface tension of greater than about 72 dynes per centimeter, having a shape modulus of compression of approximately 0.2 to 0.4 pounds and a material dry modulus of compression of approximately 0.4 pounds per square inch, and made from Scott I-Iydro Foam, a mensesphilic, wet swellable, polyurethane foam, available from Scott Paper Company, Foam Division, Eddystone, Pa.

In a preferred embodiment of tampon 20, it should have a shape modulus of compression, i.e., the unidirectional pounds force required to deform the tampon to its collapsed state, i.e., it is 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. 4, ranging from about 0.05

pound to about 1.00 pounds, preferably about 0.20 to mance 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 7 of the vaginal wall is in contact with 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 the tampon 20 is deformed, the exterior surface.

11 and the interior surface 13 at the lateral edges 14 and 15 are respectively placed in tension and compression, creating a localized capillary gradient along the lateral edges; and the exterior surface 11 and the interior surface 13 of the top and

bottom walls

16 and 17, FIG. 4, are respectively put in compression and tension. The tension on the exterior surface tends to increase the diameter of the capillaries and the compression on the interior surface tends to reduce the diameter of the capillaries, thereby forming a capillary gradient.

The tampon 20 can be formed by cutting a hollow cone from a solid block of foam or by joining two superimposed coextensive triangular or trapezoidal blanks along their lateral edges. These blanks should 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 iong 'b as e of317 inchs ja short base ofTOE' inches, and a thickness of 0.40 inch. The superposed blanks are sewed together and the tampon is 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 tampon s longitudinal axis. This bending moment creates an overall capillary gradient in that the cells on the exterior surface are placed in tension and the cells on the interior surface are placed in compression whereby'there is a gradient in the average diameter of the capillaries through the tampon walls and the gradient is substantially linear. The average cell diameter on the exterior surface 11 of a tampon 20 formd by joining and turning inside out superposed flat blanks is approximately 62 percent larger than the average cell diameter on the interior surface 13. This advantageous overall capillary gradient is also present in both a cone cut from a block of foam or a foam cone cast after they have been turned inside out.

The capillary gradients mentioned above are advantageous because they promote good wicking into the tampon from the exterior surface. Either a cut or formed hollow cone takes on an acceptable capillary gradient when deformed to its collapsed state. A cut cone is cut from a solid block of the absorbent material whereas a formed cone is made by joining superposed flat blanks as described above with trapezoidal blanks. In a cut cone as deformed, the radius of curvature at the lateral edges is decreased, thereby imparting the 10- calized capillary gradient to the folded lateral edges. The top and

bottom walls

16 and 17 possibly acquire a reverse gradient, i.e., the cell diameter is narrow at the exterior surface and larger at the interior surface. In a formed cone, i.e., formed from flat blanks of foam, not deformed, the exterior surface is already in tension and thus has larger capillaries and the interior surface is in compression and thus has smaller capillaries. When the formed cone is deformed, the radius of curvature at the lateral edges 14 and 15 is decreased, effecting the localized capillary gradient, and the top and

bottom walls

16 and 17 are returned to a substantially neutral state so there is essentially no capillary gradient therein. A capillary gradient at the lateral edges 14 and 15 of a collapsed tampon is established in either the cut or the formed hollow cone when defonned and is advantageous, but the formed cone embodiment is preferred because it also has the overall capillary gradient which is additive to the localized gradient and thus provides better performance.

The localized capillary gradient is present and effectively works at the lateral edges 14 and 15 where the pressure between the vagina and the tampon is the least and the best fluid transport mechanism is needed to prevent partitioning. A gradient does not exist in the formed cone and is reversed in the cut cone in the top and

bottom walls

16 and 17 and thus the fluid transport mechanism is not enhanced at these points. But, the lack of any gradient or the reversed gradient in the top and bottom walls is not disastrous because the maximum force exerted by the vagina on the tampon is vertical and therefore contact between the vagina and the top and bottom walls of the tampon is good. This good contact will prevent partitioning in those two areas even through the fluid transport mechanism is not enhanced.

Further advantages associated with proximal apex orientation of the tampon in an inserter are (1) because of reduced mass at the tampon apex, spreading of the flexible sector-shaped flaps such as those of FIG. 2 is not promoted prematurely, (2) the flexible flaps of such inserters are supported by the tampon apex 19 during insertion, and (3) the apex promotes product usability in an open ended inserter such as shown in FIG. 3. 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. A domed contour on the tampon apex 19 is close enough in shape to the interior of the flaps at the proximal end 24 to support them during insertion without spreading them. A domed contour taken by the apex 19 of tampon is also beneficial when used with an open end inserter such as in FIG. 3 if the dome is left protruding from the blunt open end 26 of the inserter 25. This protruding apex 19 helps insertion because it provides a gradual change in diameter rather than the abrupt change required of the introitus to insert the blunt end- 26 of inserter 25.

Thus it is apparent that there has been provided, in accordance with the invention, a tampon 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 descriptions. 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: l. A catamenial device, comprising: A. an inserter adapted to resiliently compress an elastomeric tampon and having a proximal end adapted to be the leading end during insertion into a vagina,

B. a tampon having a dry-expanding elastomeric body, said body being a material having a dry mod- 6 proximal end when the tampon is subjected to intravaginal pressures, said body being resiliently compressed within said inserter, said proximal end of the tampon being located adjacent said proximal end of the said inserter, whereby said proximal end is the leading end of the tampon during insertion, and

C. a tampon eject means adapted to eject said tampon through the proximal end of said inserter, whereby following ejection, the tampon is positioned within a vagina so that the proximal end of the tampon is closer to the cervix than is the distal end of the tampon.

2. The device'of claim 1 wherein said tampon has an internal discontinuity extending from its distal end inwardly to a point short of its proximal end, whereby the proximal end is closed and the distal end is open.

3. The device of claim 2 wherein the depth of said internal discontinuity along its longitudinal axis is at least about percent the length of the longitudinal axis of th tampon.

4. The device of claim 2 wherein said internal discontinuity in the tampon is a cavity in the uncompressed tampon, said cavity being substantially coaxial with th longitudinal axis of .the tampon.

5. The device of claim 4 wherein the shape of said cavity is similar to the exterior shape of said tampon.

6. The device of claim 4 wherein said tampon is generally conically shaped.

7. The device of claim 4 wherein the diameter of the distal end of said cavity is at least. about 50 percent of the exterior diameter of the distal end of the tampon when said tampon is in its free state.

8. The device of claim 1 wherein said eject means is slideably associated with said inserter.

9. The device of claim 1 wherein a finely pulverized material is placed between the exterior surface of the tampon and the interior surface of the inserter to provide a dry lubricant which reduces the coefficient of friction between the two surfaces.

10. The device of claim 9 wherein said finely pulverized material is talc.

11. A catamenial device, comprising:

A. a tubular inserter having a proximal end adapted to be the leading end during insertion into a vagina, and the other end being the distal end,

B. a tampon having a deformable, soft, mensesphilic,

polyurethane foam, absorbent body, said foam having a dry modulus of compression of from 0.2 psi to 0.6 psi, said body being resiliently compressed within said inserter, said body in its uncompressed state being generally conically shaped andhaving an interior cavity which is generally conically shaped and coaxial with the tampon, the base of said cavity being in the same plane as the base of the tampon, said cavity being at least about 50 percent the height of the tampon, the apex of said tampon being located adjacent the proximal end of said inserter, and r C. a tampon ejector being slideably associated with said inserter through the distal end of said inserter,

whereby, following ejection, said tampon is positioned within a vagina so that its apex is deeper in the vagina and closer to the cervix than is its base.

12. The device of claim 1 including projections on the exterior surface of said tampon, said orojections facing the distal and, whereby the tampon will tend to creep in a direction toward the proximal end when the tampon is restricted on its lateral edges within a flexible channel which experiences pulsating pressures or forces, such as a vagina.

13. The device of claim 1 wherein said inserter has flexible flaps at the proximal end thereof to provide a substantially closed, tapered proximal end and wherein the tampon has a gradually increasing cross sectional mass along its longitudinal axis from its proximal end to its distal end, whereby said flaps are gradually eased due to the capillarity effect of the elongated cells.

* l i t

Claims

1. A catamenial device, comprising: A. an inserter adapted to resiliently compress an elastomeric tampon and having a proximal end adapted to be the leading end during insertion into a vagina, B. a tampon having a dry-expanding elastomeric body, said body being a material having a dry modulus of compression of from 0.2 psi to 0.6 psi, said body having a proximal end and a distal end, the distal end having a diameter larger than that of the proximal end when the tampon is subjected to intravaginal pressures, said body being resiliently compressed within said inserter, said proximal end of the tampon being located adjacent said proximal end of the said inserter, whereby said proximal end is the leading end of the tampon during insertion, and C. a tamPon eject means adapted to eject said tampon through the proximal end of said inserter, whereby following ejection, the tampon is positioned within a vagina so that the proximal end of the tampon is closer to the cervix than is the distal end of the tampon.

2. The device of claim 1 wherein said tampon has an internal discontinuity extending from its distal end inwardly to a point short of its proximal end, whereby the proximal end is closed and the distal end is open.

3. The device of claim 2 wherein the depth of said internal discontinuity along its longitudinal axis is at least about 50 percent the length of the longitudinal axis of the tampon.

4. The device of claim 2 wherein said internal discontinuity in the tampon is a cavity in the uncompressed tampon, said cavity being substantially coaxial with the longitudinal axis of the tampon.

6. The device of claim 4 wherein said tampon is generally conically shaped.

7. The device of claim 4 wherein the diameter of the distal end of said cavity is at least about 50 percent of the exterior diameter of the distal end of the tampon when said tampon is in its free state.

10. The device of claim 9 wherein said finely pulverized material is talc.

11. A catamenial device, comprising: A. a tubular inserter having a proximal end adapted to be the leading end during insertion into a vagina, and the other end being the distal end, B. a tampon having a deformable, soft, mensesphilic, polyurethane foam, absorbent body, said foam having a dry modulus of compression of from 0.2 psi to 0.6 psi, said body being resiliently compressed within said inserter, said body in its uncompressed state being generally conically shaped and having an interior cavity which is generally conically shaped and coaxial with the tampon, the base of said cavity being in the same plane as the base of the tampon, said cavity being at least about 50 percent the height of the tampon, the apex of said tampon being located adjacent the proximal end of said inserter, and C. a tampon ejector being slideably associated with said inserter through the distal end of said inserter, whereby, following ejection, said tampon is positioned within a vagina so that its apex is deeper in the vagina and closer to the cervix than is its base.

12. The device of claim 1 including projections on the exterior surface of said tampon, said projections facing the distal end, whereby the tampon will tend to creep in a direction toward the proximal end when the tampon is restricted on its lateral edges within a flexible channel which experiences pulsating pressures or forces, such as a vagina.

13. The device of claim 1 wherein said inserter has flexible flaps at the proximal end thereof to provide a substantially closed, tapered proximal end and wherein the tampon has a gradually increasing cross sectional mass along its longitudinal axis from its proximal end to its distal end, whereby said flaps are gradually eased open as the tampon is ejected from the inserter.

14. The device of claim 1 wherein the absorbent body has elongated cells therein, the elongated dimension of the cells being approximately transverse the longitudinal axis of the tampon, whereby fluids to be absorbed by the tampon are more efficiently transported from the exterior surface to the interior of the tampon due to the capillarity effect of the elongated cells.