Abstract:
Provided is a sanitary panty including a front part, a back part, a crotch part located between the front part and the back part, a waist portion formed by an upper edge portion of the front part and an upper edge portion of the back part, a pair of leg openings defined below joining portions of both side edges of the front part and both side edges of the back part, a suspending member extending over the front part, the crotch part and the back part in a longitudinal direction, and an extension cloth extending from both sides of the suspending member located at least in the crotch part and the back part. The suspending member is gradually reduced a width from the waist portion to the crotch part in the back part. The suspending member has greater elastic modulus in a longitudinal direction than that in a lateral direction.

Description:
An entire disclosure and claims in the commonly owned U.S. patent application Ser. No. 09/799,421 entitled “SANITARY PANTY”, filed on Mar. 5, 2001, is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sanitary panty with superior wear ability and wearing comfort. 
     2. Description of the Related Art 
     A sanitary panty typically has a structure, in which a water-proof sheet is sewn on inner side of crotch cloth portion of a general panty for preventing leakage and external extruding of menstrual blood. Since the sanitary panty is required to prevent side leakage or so forth due to motion of body or variation of attitude in sporting and sleeping, various measures have been taken in sewing position and dimension of the water-proof sheet. Various measures have also been taken for overall structure of the sanitary panty for providing superior wear ability and wearing comfort of a sanitary napkin. 
     Japanese Registered Utility Model No. 2554676 discloses a sanitary panty taken a measure set forth above. FIGS. 5A and 5B are a front elevation and a back elevation of a sanitary panty of the type disclosed in the above-identified publication. 
     The sanitary panty illustrated in FIGS. 5A and 5B is formed with a cloth  1   a  forming a front part and a crotch part, cloth  1   b  forming a center portion of a back part, and cloths  2  forming both side portions of the front part and the back part. The cloths  1   a ,  1   b  and  2  have smaller tensile strength in a longitudinal direction than that in a lateral direction. On the other hand, the tensile strength in the longitudinal direction of the cloths  1   a  and  1   b  is greater than that of the cloths  2 . 
     The conventional sanitary panty is designed so that the overall panty may be tightly fitted on a wearer&#39;s body by differentiating tensile strength between the cloths  1   a  and  1   b  located at laterally center portion and the cloths  2  located at laterally side portions. While the shown panty is designed to be tightly fitted on the wearer&#39;s body as a whole, a measure has not be taken for penetrating the crotch part along the wearer&#39;s body. Namely, in the crotch part, a lateral stretching force acts on the panty to make it impossible to apply a force urging the center portion of a sanitary napkin toward the wearer&#39;s body. Therefore, the conventional sanitary panty cannot achieve a function for tightly fitting the panty onto the wearer&#39;s body with deforming the sanitary napkin in convex form (i.e., generally reverse V-shaped cross-section) adapting to the shape of the body. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide a sanitary panty which can be well fitted on a wearer&#39;s body without causing disposition of a sanitary napkin. 
     Another object of the present invention is to provide a sanitary panty which can permit tight fititing of the sanitary napkin onto a wearer&#39;s body in convex shape. 
     According to the first aspect of the present invention, a sanitary panty comprises: 
     a front part; 
     a back part; 
     a crotch part located between the front part and the back part; 
     a waist portion formed by an upper edge portion of the front part and an upper edge portion of the back part; 
     a pair of leg openings defined below joining portions of both side edges of the front part and both side edges of the back part; 
     a suspending member extending over the front part, the crotch part and the back part in a longitudinal direction; 
     an extension cloth extending from both sides of the suspending member located at least in the crotch part and the back part, 
     the suspending member being gradually reduced a width from the waist portion to the crotch part in the back part, and 
     the suspending member having greater elastic modulus in a longitudinal direction than that in a lateral direction. 
     The sanitary panty may further comprise an elastic member mounted on the waist portion, and the suspending member has an elastic modulus in the longitudinal direction at least in the vicinity of a center line smaller than that in a circumferential direction of the elastic member. The extension cloth may be formed with a non-stretchable material or a stretchable material having smaller elastic modulus in the longitudinal and lateral directions in comparison with the suspending member. The extension cloth may be provided on both sides of the suspending member over the front part, the crotch part and the back part, and the leg openings are formed with the material of the extension cloth. 
     According to the second aspect of the present invention, a sanitary panty comprises: 
     a front part; 
     a back part; 
     a crotch part located between the front part and the back part; 
     a waist portion formed by an upper edge portion of the front part and an upper edge portion of the back part; 
     a pair of leg openings defined below joining portions of both side edges of the front part and both side edges of the back part; 
     a suspending member extending over the front part, the crotch part and the back part in a longitudinal direction; 
     an extension cloth extending from both sides of the suspending member located at least in the crotch part and the back part, 
     the suspending member being gradually reduced a width from the waist portion to the crotch part in the back part, and 
     the suspending member having greater contraction stress in a longitudinal direction than that in a lateral direction, in the worn condition or in a three-dimensional shape approximated with the worn condition. 
     The sanitary panty may further comprise an elastic member mounted on the waist portion, and the suspending member has a contraction stress in the longitudinal direction at least in the vicinity of a center line smaller than that in a circumferential direction of the elastic member. The extension cloth may be formed with a non-stretchable material, or a stretchable material having smaller contraction stress in the longitudinal and lateral directions in comparison with the suspending member. The extension cloth may be provided on both sides of the suspending member over the front part, the crotch part and the back part, and the leg openings are formed with the material of the extension cloth. 
     As set forth above, the suspending member is provided the greater elastic modulus in the longitudinal direction than that in the lateral direction. On the other aspect of the invention, the suspending member is provided greater contraction stress in the longitudinal direction than that in the lateral direction. In either case, according to the present invention, the center portion of the crotch part is pulled up to deform the sanitary napkin in upwardly projecting convex shape to permit firm fitting with the wearer&#39;s body to successfully prevent side leakage of menstrual blood. Also, since the elastic modulus and the contraction stress of the elastic member on the waist portion are greater than those of the suspending member in the longitudinal direction, the sanitary panty will never cause slacking down as worn. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only. 
     In the drawings: 
     FIGS. 1A and 1B are front elevation and back elevation of the first embodiment of a sanitary panty according to the present invention; 
     FIG. 2 is a development elevation of the sanitary panty of FIGS. 1A and 1B; 
     FIGS. 3A and 3B are front elevation and back elevation of the second embodiment of a sanitary panty according to the present invention; 
     FIG. 4 is a development elevation of the sanitary panty of FIGS. 3A and 3B; and 
     FIGS. 5A and 5B are front elevation and back elevation of the conventional sanitary panty. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, well-known structure are not shown in detail in order to avoid unnecessary obscurity of the present invention. 
     Incorporation by Reference 
     An entire disclosure and claims in the commonly owned co-pending U.S. Patent Application Serial No. (not yet known), entitled “SANITARY PANTY”, filed with claiming convention priority based on Japanese Patent Application No. 2000-60267, filed on Mar. 6, 2000, is herein incorporated by reference. 
     FIGS. 1A,  1 B and  2  show the first embodiment of a sanitary panty according to the present invention, in which FIG. 1A is a front elevation and FIG. 1B is a back elevation, and FIG. 2 is a development elevation thereof. 
     The sanitary panty shown in FIGS. 1A,  1 B and  2  is generally formed with a front part  11 , a back part  12  and a crotch part  13 . 
     In FIGS. 1A,  1 B and  2 , Y direction along which the front part  11 , the crotch part  13  and the back part  12  are formed in series is referred to as a longitudinal direction, and X direction transverse to the Y direction is referred to as a lateral direction. A centerline extending in the longitudinal direction at a center in the lateral direction is taken as O-O. 
     As shown in FIG. 2, a side edge  11   a  of the front part  11  and a side edge  12   a  of the back part  12  are sewn and a side edge  11   b  of the front part  11  and a side edge  12   b  of the back part  12  are sewn to form a sanitary panty having a waist portion  14  and leg openings  15 . 
     In a laterally center region of the panty, a stretchable suspending member  16  extending in the longitudinal direction along a center line O-O. In the back part  12 , the suspending member  16  is shaped to gradually reduce the width from the waist portion  14  to the crotch part  13 . Similarly, in the front part  11 , the suspending member  16  is shaped to gradually reduce the width from the waist portion  14  to the crotch part  13 . 
     On both sides of the suspending member  16 , extension cloths  17  are provided. The suspending member  16  and the extension cloths  17  are formed with different cloths. The extension cloths  17  and the suspending member  16  may be sewn at the boundaries thereof. In the alternative, the entire panty may be formed with the cloth of the extension cloth  17  and the suspending member  16  may be sewn at the center portion thereof overlapping with the corresponding portion formed with the cloth forming the entire panty. 
     In the first embodiment shown in FIGS. 1A,  1 B and  2 , the extension cloths  17  are extended laterally on both sides of the suspending member  16  in the front part  11 , the back part  12  and the crotch part  13 . In a form of panty, the extension cloths  17  define leg openings  15 . On the other hand, in the waist portion  14 , the suspending member  16  of the front part  11  and the suspending member  16  of the back part  12  are jointed to form the entire waist portion with the stretchable material of the suspending member  16 . However, it is not essential to form the entire waist portion with the stretchable material of the suspending member  16 . In the alternative, it is possible to extend the extension cloth  17  even in the waist portion so that the extension cloths  17  in the waist portion  14  are joined to form the waist portion. 
     In the waist portion  14 , one or more strip or string form elastic members  21  are mounted along the waist portion to form an elastic waist holding portion. Even on the leg openings  15 , one or more strip or string form elastic members  22  are mounted along the leg openings  15  to form elastic leg holding portions. 
     The entire suspending member  16  is formed with a woven fabric fabricated with stretchable yarn or fiber, or a woven fabric sewn elastic stretchable material such as rubber in the longitudinal direction (Y direction) and the lateral direction (X direction). The suspending member  16  has greater elastic modulus in the longitudinal direction than that in the lateral direction. Namely, contraction stress at the time when the stretchable material forming the suspending member  16  is cut into a predetermined lateral width and is applied a predetermined distortion in the longitudinal direction, is greater than the contraction stress at the time when the stretchable material forming the suspending member  16  is cut into the same longitudinal width (i.e., the length) and is applied a predetermined distortion in the lateral direction thereof. 
     Accordingly, when the sanitary panty is worn on the wearer&#39;s body or is formed into a three-dimensional shape approximated with the worn condition (when comparable expansion as that applied in worn condition is applied to the panty in both longitudinal and lateral directions), the contraction stress (the tension force per a predetermined width) in longitudinal direction of the suspending member  16  becomes greater than the contraction stress in the lateral direction thereof. 
     The suspending member  16  is continuous in the front part  11 , the back part  12  and the crotch part  13  in the longitudinal direction. Also, the suspending member  16  is shaped to have a narrow width in the lowermost end portion Oy of the crotch part  13 . Accordingly, when the sanitary panty is worn on the wearer&#39;s body, in the suspending member  16  mating with the crotch part  13 , the contraction stress in the longitudinal direction becomes greater than that in the lateral direction, for example, in the extent greater than or equal to about 1.5 times and smaller than or equal to about 8 times. Accordingly, when the sanitary napkin is fitted on inside of the sanitary panty in the crotch part  13 , a large urging force is applied at the center line O-O of the sanitary napkin. 
     On the other hand, as shown in FIG. 1B, in the three-dimensional shape of the sanitary panty, the suspending member  16  in the back part  12  is provided the same or substantially the same width as that in the crotch part  13  from the lowermost end Oy to a height H 1 . This portion having a narrow width may penetrate into a gluteal cleft so that the suspending member  16  may be tightly fitted onto the crotch part  13 . Accordingly, the sanitary napkin fitted in the crotch part is tightly fitted on the wearer&#39;s body. Furthermore, since a tension force is applied along the center line O-O of the sanitary panty, the lateral center portion of the sanitary napkin is deformed into convex shape penetrating into the crotch part of the wearer. Accordingly, the sanitary napkin can be firmly fitted on the crotch part of the wearer&#39;s body. Therefore, side leakage of the menstrual blood is hardly caused and disposition of the sanitary napkin is hardly caused. 
     On the other hand, when the sanitary panty is worn on the wearer&#39;s body, even if the suspending member  16  is stretched laterally, due to difference of the elastic modulus, large contraction stress can be caused in the longitudinal direction to permit creation of tension force along the center line O-O as set forth above. Namely, even if the expansion is applied in the lateral direction upon wearing of the sanitary panty, the suspending member  16  may be stretched relatively freely in the lateral direction and may constantly apply large contracting force in the longitudinal direction. Therefore, the sanitary napkin fitted on the crotch part is upwardly urged by large tension force along the center line O-O for firmly fitting on the wearer&#39;s body. 
     On the other hand, the elastic member  21  forming the waist holding portion is mounted on the waist portion  14 . The elastic modulus in the longitudinal direction at least in the vicinity of the center line O-O is preferably smaller than the elastic modulus in the waist direction of the elastic member  21  (“the waist direction” is also referred to as a circumferential direction). On the other hand, in the worn condition or in the three-dimensional shape approximated with the worn condition as shown in FIGS. 1A and 1B, contraction stress of the suspending member  16  in the longitudinal direction around the center line O-O is preferably smaller than the contraction stress of the elastic member  21 . 
     With such construction, the waist portion  14  may not be pulled downwardly in significant magnitude by the contracting force of the suspending member  16  to hardly cause slacking of the sanitary panty upon wearing of the sanitary panty. It should be noted that the elastic modulus becomes a total value of the elastic modulus of one or more elastic members  16 , when the elastic member  21  is one or more. On the other hand, the contraction stress represents a difference between a contracting tension force created when a predetermined distortion is applied to all of one or more elastic members  21  having a predetermined width and a contracting tension force created when the same distortion is applied to the suspending member  16  in the same width as the one or more elastic members  21 , in the longitudinal direction. 
     Next, it is preferred that the extension cloth  17  may not apply large lateral tension force to the suspending member  16  at the crotch part  13 . When large lateral tension force is applied to the suspending member  16  in the crotch part  13 , the longitudinal tension force applied along the center line O-O urging the center portion of the sanitary napkin toward the wearer&#39;s body can be reduced to cause difficulty in deforming the sanitary napkin in convex shape and in tight fitting of the sanitary napkin onto the wearer&#39;s body. 
     Furthermore, the extension cloth  17  is preferably not created large contracting force in the longitudinal direction in comparison with the suspending member  16 . If large contracting force is created in the longitudinal direction in the extension cloth  17  during wearing, both side portions of the waist portion  14 , namely portion contacting with hip born, is pulled downwardly to easily cause slacking of the sanitary panty. 
     As set forth above, it is preferred that the extension cloth  17  is formed with a non-stretchable material or a material having smaller elongation amount (maximum distortion) than that of the suspending member  16 . Namely, expansion upon wearing is mainly provided by the suspending member  16 , and the extension cloth  17  has little expansion. Difference of stresses in the longitudinal direction and the lateral direction is preferably caused only by the suspending member  16 . In the alternative, when the extension cloth  17  is formed with a stretchable material, the stretchable material should be stretched quite easily and thus have smaller elastic modulus in longitudinal direction and lateral direction in comparison with the suspending member  16 . In this case, upon wearing to the body, the extending cloth  17  may also cause expansion. The stress caused by expansion is smaller so as not to prevent large contraction stress of the suspending member  16  in the longitudinal direction. 
     FIGS. 3A,  3 B and  4  show the second embodiment of the sanitary panty according to the present invention, in which FIG. 3A is a front elevation of the second embodiment of the sanitary panty according to the present invention, FIG. 3B is a back elevation thereof and FIG. 4 is development elevation thereof. 
     In the sanitary panty shown in FIGS. 3A,  3 B and  4 , the suspending member  16  of substantially the same shape shown in FIGS. 1A,  1 B and  2  are provided. Elastic modulus and contraction stress in the longitudinal direction and the lateral direction of the suspending member  16  are the same as the first embodiment. 
     In the embodiment shown in FIGS. 3A,  3 B and  4 , extension cloths  27  formed with the same material as the extension cloth  17  of FIGS. 1A and 1B are provided. The extension cloths  27  are extended from both side portions of the suspending member  16 . In the embodiment shown in FIGS. 3A,  3 B and  4 , the extension cloths  27  are provided only on both sides from the portion close to the boundary between the front part  11  and the crotch part  13  to the suspending member  16  of the back part  12 . No extension cloth  27  is provided in the front part  11 . 
     In the sanitary panty formed as illustrated in FIGS. 3A and 3B, both lateral edge portions of the suspending member  16  in the front part  11  and both lateral edge portions of the suspending member  16  in the back part  12  are joined to form the waist portion  14 . Thus, the entire length of the waist portion  14  is formed with the material of the suspending member  16 . 
     Similarly to the former embodiment, the elastic members  21  and  22  are provided on the waist portion  14  and the leg openings  15 . 
     The suspending member  16 , the waist member  14  and the extension cloths  27  in the second embodiment of the sanitary panty shown in FIGS. 3A,  3 B and  4  are formed with stretchable materials having the same or similar property as those of the first embodiment of the sanitary panty of FIGS. 1A,  1 B and  2 . Therefore, the sanitary napkin fitted to the crotch part  13  can be firmly fitted on the wearer&#39;s body. 
     As set forth above, by forming the sanitary panty formed with the materials set forth above, the center portion of the sanitary napkin can be deformed in convex shape to be firmly fitted on the wearer&#39;s body. 
     The sanitary napkin thus firmly fitted will hardly cause disposition in lateral direction, hardly cause side leakage of menstrual blood from the sanitary napkin, and hardly cause side leakage of menstrual blood from the sanitary panty. 
     Although the present invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omission and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodied within a scope encompassed and equivalent thereof with respect to the feature set out in the appended claims.