Disposable training pants having a suspended crotch covering sheet

A disposable training pants include a basic structure wet telling means provided inside the basic structure. The basic structure include a pair of elastically stretchable/contractile suspender sheets extending circumferentially of front and rear waist regions of the basic structure, respectively, and an elastically stretchable/contractile crotch covering sheet secured at its longitudinally opposite ends to the respective suspender sheets at their middle portions so as to extend between the front and rear waist regions and serving to make a baby aware of wetness.

BACKGROUND OF THE INVENTION 
 This invention relates to disposable training pants and more particularly 
 to such pants useful to be put on a baby who should be trained so that the
 baby can smoothly proceed to a stage of life requiring no diaper. 
 Training pants of this type are well known, for example, from Japanese 
 Utility Model Application Disclosure No. Hei7-33916, in which a wetness 
 holding sheet is bonded along its longitudinally opposite ends to an inner
 surface of a pants laminate panel in its crotch region. 
 In the above-mentioned training pants, the wetness holding sheet does not 
 extend longitudinally beyond the crotch region. A dimension of the wetness
 holding sheet as measured between its two fulcra at which the wetness 
 holding sheet is bonded to the laminate panel is correspondingly small. 
 Consequently, a degree of freedom for a relative movement between the 
 wetness holding sheet and the laminate panel is too limited to stabilize 
 the wetness holding sheet properly and satisfactorily in close contact 
 with the baby's crotch and thereby to reliably make the baby aware of 
 wetness. 
 SUMMARY OF THE INVENTION 
 In view of the above problem, it is an object of the invention to provide 
 disposable training pants provided with wetness telling means adapted to 
 satisfy requirements such that the degree of freedom is sufficiently high 
 to stabilize the wetness telling means properly and satisfactorily in 
 close contact with the baby's crotch and thereby to improve a wetness 
 telling effect thereof. 
 According to the invention is provided an improvement in disposable 
 training pants comprising a laminate panel composed of a liquid-permeable 
 topsheet, a liquid-impermeable backsheet and a liquid-absorbent core 
 disposed between these two sheets so as to define front and rear waist 
 regions, a crotch region, a waist-opening and a pair of leg-openings, the 
 openings being respectively provided with elastic members adapted to be 
 stretchable/contractile circumferentially of the respective openings; and 
 wetness telling means provided inside the laminate panel. 
 The improvement is characterized in that the wetness telling means comprise
 a pair of elastically stretchable/contractile suspender sheets 
 respectively provided on an upper surface of the topsheet in the front and
 rear waist regions so as to extend circumferentially of the front and rear
 waist regions, each of the suspender sheets having upper and lower ends 
 parallelly extending circumferentially of the associated one of the waist 
 regions and transversely opposite side edges connecting these upper and 
 lower ends to each other, and a crotch covering sheet secured at 
 longitudinally opposite ends to the paired suspender sheets in the 
 proximity of their middle portions; the wetness telling means are attached
 to the laminate panel by securing the upper ends of the paired suspender 
 sheets to the laminate panel in the proximity of the front and rear upper 
 ends of the waist-opening and securing the transversely opposite side 
 edges of the paired suspender sheets to the laminate panel in the 
 proximity of the transversely opposite side edges of the front and rear 
 waist regions; and the crotch covering sheet has its transverse dimension 
 insufficient to extend outward beyond the elastically 
 stretchable/contractile members provided in association with the 
 leg-openings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
 Specific modes in which the invention may be implemented will be described 
 in details in reference with the accompanying drawings. 
 Referring to FIGS. 1-3, disposable pants according to the invention 
 includes a laminate panel 1 and wetness telling means 2. The laminate 
 panel 1 includes a liquid-permeable topsheet 3, a liquid-impermeable 
 backsheet 4 and an hourglass-shaped liquid-absorbent core 5 disposed 
 between the two sheets 3, 4. The laminate panel 1 assembled from these 
 components defines a front waist region 6, a rear waist region 7 and a 
 crotch region 8 extending between the front and rear waist regions 6, 7. 
 The topsheet 3 and the backsheet 4 extend outward beyond peripheral edges 
 of the core 5 longitudinally as well as transversely to define respective 
 extensions and their transversely opposite side edges in the crotch region
 8 describe concavely curved lines 9, 9. Longitudinally opposite extensions
 of the topsheet 3 and the backsheet 4 contain therebetween elastically 
 stretchable/contractile members 10, 10 circumferentially acting upon the 
 front and rear waist regions 6, 7 in a circumferential direction. 
 Transversely opposite extensions of the topsheet 3 and the backsheet 4 
 contain therebetween elastically stretchable/contractile members 11, 11 
 acting thereupon along the concavely curved lines 9, 9, respectively. The 
 elastically stretchable/contractile members 10, 10, 11, 11 are secured to 
 the respective extensions under appropriate tension longitudinally of 
 these members 10, 10, 11, 11. The laminate panel 1 is folded in two along 
 a transverse center line extending across the crotch region 8 with the 
 topsheet 3 lying inside the laminate panel 1. The front and rear waist 
 regions 6, 7 are then intermittently bonded together along transversely 
 opposite side edges 12, 12 of these front and rear waist regions 6, 7 by 
 means of heat-sealing so as to define a waist-opening 13 and a pair of 
 leg-openings 14, 14. 
 Construction of the laminate panel is well known and materials for the 
 respective components are also well known. Fundamentally, it is essential 
 for the laminate panel 1 assembled with the wetness telling means only to 
 have the construction as has been described hereinabove. Additional 
 arrangements and/or components are not important for the invention. 
 The wetness telling means 2 include a pair of suspender sheets 15, 15 and a
 crotch covering sheet 16. Each of the suspender sheets 15, 15 has upper 
 and lower ends 15a, 15b extending circumferentially around the waist 
 regions and transversely opposite side edges 15c, 15d connecting the upper
 and lower ends 15a, 15b to each other. The respective suspender sheets 15,
 15 are provided in the form of rectangular strips narrower than the front 
 and rear waist regions 6, 7, respectively. These paired suspender sheets 
 15, 15 are secured to the front and rear waist regions 6, 7 with their 
 upper ends 15a, 15a to upper ends of the waist-opening 13 defined on the 
 sides of the front and rear waist regions 6, 7, respectively and with 
 their transversely opposite side edges 15c, 15d to the transversely 
 opposite side edges of the front and rear waist regions 6, 7, 
 respectively. The respective lower ends 15b, 15b are left free. There are 
 provided a plurality of elastically stretchable/contractile members 17 in 
 the proximity of the respective lower free ends 15b, 15b so that these 
 members 17 may act upon the suspender sheets 15, 15 circumferentially of 
 the waist regions, respectively. The crotch covering sheet 16 has a width 
 smaller than a dimension by which the elastically stretchable members 11, 
 11 associated with the respective leg-openings 14, 14 are spaced from each
 other. The crotch covering member 16 extends between the paired suspender 
 sheets 15, 15 and are secured to middle portions of the respective 
 suspender sheets 15, 15 in the proximity of their lower free ends 15b, 
 15b. The crotch covering member 16 is provided along its transversely 
 opposite side edges with elastically stretchable/contractile members 18, 
 18 adapted to act thereupon along these side edges. 
 The crotch covering member 16 may be made of a sheet which can absorb and 
 hold a quantity of urine discharged thereon, for example, a hydrophilic 
 fibrous sheet or a foamed plastic sheet having open cells. Inversely, it 
 is also possible to form the crotch covering sheet 16 using a hydrophobic 
 fibrous sheet or a foamed plastic sheet having closed cells which are 
 urine-unabsorbent but substantially urine-impermeable. In fact, it is not 
 important whether the crotch covering sheet 16 should be made of 
 hydrophilic material or hydrophobic material so far as an adequate 
 quantity of urine stays on the crotch covering sheet 16 in contact with 
 the baby's skin make the baby aware of wetness. Such material will be 
 easily prepared by those skilled in the art. 
 In the disposable training pants according to the invention, a dimension of
 the crotch covering sheet extending between front and rear fulcra as 
 measured longitudinally of the laminate panel is relatively large. This is
 achieved by the unique arrangement as follows: The suspender sheets as the
 components of the wetness telling means are secured in the proximity of 
 their upper ends and transversely opposite side edges to the laminate 
 panel in the proximity of the upper ends and the transversely opposite 
 side edges of the front and rear waist regions. The crotch covering sheet 
 forming the most important component of the wetness telling means is 
 suspended from the lower free ends of the paired suspender sheets along 
 which the crotch covering sheet is secured to the respective suspender 
 sheets. In contrast with the conventional training pants in which the 
 front and rear fulcra for the crotch covering sheet lie in the crotch 
 region, a higher degree of freedom is ensured for a relative movement 
 between the crotch covering sheet and the laminate panel. This means that 
 the crotch covering sheet is properly and satisfactorily stabilized in 
 close contact with the baby's crotch while the crotch covering sheet is, 
 at least principally, suspended in midair. Accordingly, even if any 
 external force moves the laminate panel relatively to the baby's body, the
 crotch covering sheet can be maintained in the close contact and reliably 
 make the baby aware of wetness without being affected by the movement of 
 the laminate panel. 
 The paired suspender sheets secured to the laminate panel in the proximity 
 of the waist-opening have the elastically stretchable members provided 
 independently of the elastically stretchable members associated with the 
 laminate panel. These elastically stretchable members of the suspender 
 sheets allow the suspender sheets to suspend the crotch covering sheet so 
 as to be elastically kept in close contact with lower portions of the 
 baby's trunk. In this manner, the paired suspender sheets are very 
 effective to stabilize the crotch covering sheet relatively to the baby's 
 crotch and thereby to prevent the crotch covering sheet from being easily 
 displaced from its proper position.