Apparel – Guard or protector – Body cover
Reexamination Certificate
2000-07-27
2002-01-29
Calvert, John J. (Department: 3741)
Apparel
Guard or protector
Body cover
C002S081000, C002S097000, C002S272000
Reexamination Certificate
active
06341384
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a new thermally protective liner which can be used as an inner, outer or intermediate liner in protective garments designed to protect the wearer from hazardous environmental conditions. More particularly, the present invention relates to a new thermally protective liner which (i) is extremely thin, perspiration permeable, and breathable; (ii) provides the wearer with the best protection possible from high external heat by supplying a significantly higher Thermal Protective Performance value in a thinner format; and (iii) provides the suit designer with the ability to design specify the water vapor ventilation, the thermal protective performance (TPP), the thickness, and the weight, thereby rendering protective garments lighter, thinner and more efficacious than those currently available.
BACKGROUND OF THE INVENTION
Protective garments are designed to shield the wearer from a variety of environmental hazards such as heat and fire. Fire fighter garments as well as garments worn by individuals working on high voltage power lines, are representative of such garments.
Fire, in particular, is a very dangerous element. It moves and spreads quickly, putting lives and property in danger in a very short period of time; including the very lives of those fighting the fire. Consequently, fire fighters must themselves be properly protected, while at the same time be provided with tools and garments that allow them to move with tremendous speed and alacrity, while simultaneously allowing them to maintain their strength and stamina.
Accordingly, the qualities most desirable in fire fighters' garments as well as other thermal control garments are minimum weight, maximum flexibility, high thermal protection, vapor ventilation, tensile strength and minimum water absorption.
Thermally protective garments and more particularly, fire fighters' garments basically comprise three layers: (a) an outer shell, (b) an inner liner, including a moisture barrier, and (c) a thermally protective liner; traditionally insulation.
The outer shell basically consists of a fabric of aramid fibers such as NOMEX®, KEVLAR® (both registered trademarks of E. I. DuPont) or a NOMEX®/KEVLAR® blend which provides resistance to abrasion, some thermal resistance, and structural integrity.
The moisture barrier, which usually is located right next to the outer shell, basically consists of a membrane of GORETEX® (a registered trademark of W. L. Gore & Associates, Inc.) material. The GORETEX® material has micropores, which permit the transport of moisture vapor, thereby allowing the perspiration moisture vapor of the wearer to escape outwardly; but which are sufficiently small to prevent liquid moisture from passing through to the wearer from the outside.
Finally, the thermally protective liner comprises an insulation layer of spun carbon, NOMEX, KEVLAR fibers, or a batting of any combination of such fibers, often quilted to a lightweight NOMEX face cloth. The batting of the thermal barrier traps air and possesses sufficient loft to provide the necessary thermal resistance, while the face cloth provides resistance to abrasion of the thermal liner by the wearer, and provides structural integrity and tensile strength to the insulation layer.
The prior art has many disadvantage and drawbacks. Specifically, in order to increase the Thermal Protective Performance (TPP) value of the prior art, one would have to use a thicker layer of insulation. In so doing, the wearer of the prior art would experience an increased weight, increased “hobbling” effect, a decreased mobility and a decreased drapeability and a diminished flexibility. Furthermore, as a result to the increased thickness of the insulation, there will be an increase in the capillary action, which in turn will result in the absorption of water vapor. This absorption of water vapor will make the suit heavier and less wearable; increase fatigue; and under certain circumstances or rare high heat, the excess water trapped in the insulation could adversely affect the insulation's Thermal Protective Performance value.
In summary therefore, the additional bulk and loft provided by the fabric thermal liner of the prior art inhibits the freedom of movement of the wearer, producing a “hobbling effect”, thereby increasing the stress imposed on the wearer in a situation requiring high activity and accelerating the onset of the wearer's fatigue. This “hobbling effect” becomes particularly pronounced when the fabric thermal liners are excessively thick.
The replacement of this thermal liner, as described above with an Aldridge et. al. U.S. Pat. No. 5,136,723 open mesh insulation thermal barrier will still impede the transport of moisture vapor. Nor will the replacement of this thermal liner with the Aldridge U.S. Pat. No. 5,697,101 apertured closed cell foam material, will resolve the above referenced disadvantages and drawbacks.
First, closed-cell foam is stiff. Accordingly, even at minimum thicknesses a closed-cell foam thermal liner will be bulky, and unmanageable. Thus, the use of a closed-cell foam thermal liner in thermal protective garments, such as fire fighters' garments will continue to produce the “hobbling effect” produced by bulkier materials, and to contribute to the stress and fatigue of the wearer.
Second, in order for perspiration to escape to the outside, the closed-cell foam thermal liner must be perforated by as much as 45% of the total surface area of the liner. When 45% of the area is perforated, it leaves only 55% of effective closed-cell foam insulation for the liner. This means that as a function of the loss of 45% insulation, the TPP of said thermal liner drops dramatically. As the TPP drops, it limits the thinness of the closed-cell foam thermal liner and mandates the formation of a thicker closed-cell foam thermal liner to compensate for the loss of TPP.
Since, the closed-cell foam thermal liner will have to be made thicker to compensate for the loss of TPP, it will be bulkier and less flexible if it is to be used for protection from extreme heat exposure. Accordingly, it will have minimum use in situations where the wearer still needs flexible drapeable garments but more than adequate protection from extreme heat. Furthermore, it will fail miserably in reducing the “hobbling effect” usually associated with thermal protective garments.
It is, therefore, an object of the present invention to provide a flexible, drapeable thermally protective liner capable of significantly reducing the “hobbling effect” produced by bulkier thermal liner materials, thereby diminishing the stress and fatigue on the wearer.
It is another object of the present invention to provide a very thin thermally protective liner capable of meeting and exceeding the National Fire Protection Association's (hereinafter “N.F.P.A.”) requirements for sufficient thermal insulation and protection, in extreme high heat conditions.
It is another object of the present invention to provide a very thin thermally protective, endothermic liner capable of both protecting the wearer and remaining stable and effective under extreme environmental situations.
It is another object of the present invention to provide an endothermic flexible material suitable for apparel and clothing having the ability to absorb high amounts of heat and protecting the wearer of such clothing when exposed to extreme environments of heat.
It is another object of the present invention to provide an endothermic material for applications requiring a material to be thin, flexible, drapeable, conformable, breathable, lightweight and comfortable, while simultaneously protecting and insulating against high heat environments.
It is another object of the invention to provide a thermally protective liner and/or endothermic flexible material/fabric which can be appropriately and easily modified to meet design specifications as determined by specific applications.
SUMMARY OF THE INVENTION
According to the present invention there is provided a thinner, lighter, fle
Bauer & Schaeffer, LLP
Calvert John J.
Muromoto Jr. Robert H.
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