Wetness indicating diaper

• US 5,389,093 A
• Filed: 03/29/1993
• Issued: 02/14/1995
• Est. Priority Date: 04/01/1992
• Status: Expired due to Fees

• Current Assignee: Wesley A. Howell
• Original Assignee: Wesley A. Howell
• Inventors: Howell, Wesley A.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): JONES, MARYBETH O
• Application Number:
  US08/039,804
• Time in Patent Office: 687 Days
• Field of Search: 604/358, 604/361, 604/385.1
• US Class Current: 604/361
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 13/49004 with fastening means
• CPC Class Codes: A61F 13/49011 the elastic means is located at the waist region
• CPC Class Codes: A61F 13/491 specially adapted for gender distinct urine discharge pattern
• CPC Class Codes: A61F 13/511 Topsheet, i.e. the permeable cover or layer facing the skin
• CPC Class Codes: A61F 13/537 characterised by a layer facilitating or inhibiting flow in one direction or plane, e.g. a wicking layer A61F13/538 takes precedence
• CPC Class Codes: A61F 13/62 Mechanical fastening means, A61F13/5611, A61F13/5616, A61F13/581, A61F13/66 take precedence; Fabric strip fastener elements, e.g. hook and loop
• CPC Class Codes: A61F 2013/429 Thermochromic materials, e.g. ink or dye
• CPC Class Codes: A61F 2013/8452 being contained in microcapsules
• CPC Class Codes: A61L 15/56 Wetness-indicators or colourants

Abstract

The present invention is a reusable wetness indicating cloth diaper which uses a thermally sensitive indicator to indicate that the diaper has become soiled. The diaper of the present invention includes material which at least partially thermally insulates the outer surface from said inner surface and an indicator on the outer surface which provides a visual indication when the outer surface has a temperature above a given threshold. The temperature threshold is chosen such that the visual indication will generally not be present when a baby wearing said diaper is dry, but will generally be present when the baby secretes waste material into the diaper. A thermochromic ink indicates a temperature change in the diaper. A plurality of discrete indicators are distributed over substantially the entire outer surface of the diaper with the indicators forming a repeating pattern. Desirably, the indicators cover a significant portion of the outer shell of the diaper so that the wetness condition can be easily detected from most viewing angles of the diaper in an aesthetically pleasing manner.

Claims

1. A diaper system for indicating wetness, comprising an outer shell having a front portion, a back portion and a connecting portion extending between said front and back portions, said outer shell defining an outer surface;

an insulation layer positioned between a wearer and said outer shell which, when dry is insufficiently thermally conductive for a normal body temperature to raise said outer surface above a given threshold, but being sufficiently thermally conductive when wet to raise said outer surface temperature above a given threshold, at least partially thermally insulates said outer surface from said inner surface;

a thermal indicator on said outer surface which provides a visual indication when said outer surface has a temperature above a given threshold; and

said threshold being chosen such that said visual indication will generally not be present when said wearer is dry, but will generally be present when said wearer secretes waste material which is absorbed by said insulation layer.

2. The diaper system of claim 1, wherein said material wicks moisture secreted from said wearer toward said outer layer.

3. The diaper system of claim 1, wherein said threshold is above 80 degrees Fahrenheit.

4. The diaper system of claim 1, wherein said threshold is above 87 degrees Fahrenheit.

5. The diaper system of claims 1, wherein said indicator is no longer visible when said outer shell has a temperature which falls below said threshold.

6. The diaper system of claim 2, wherein said indicator comprises thermochromic ink.

7. The diaper system of claim 5, wherein said indicator comprises a mixture of thermochromic inks, one of which becomes colorless above said threshold.

8. A method of detecting when a wearer has excreted moisture between its legs, comprising:

providing an outer shell having a front portion, a back portion and a connecting portion extending between said front and back portions, said outer shell defining an outer surface on which is positioned a thermal indicator;

positioning said outer shell on said wearer such that said connecting portion fits between the legs of said wearer;

at least partially thermally insulating;

wicking moisture excreted from said wearer from said wearer towards said outer surface to bring said moisture into thermal contact with said thermal indicator; and

,

providing a visual indication when said thermal indicator is exposed to a temperature above a given threshold.

9. The method of claim 8, wherein said visual indication is provided by means of a change in color.