Abstract:
A flame resistant, lightweight tent liner is disclosed. The tent liner is made from flame resistant polyester fibers. In one embodiment, the tent liner is opaque and white in appearance in order to provide maximum lighting inside a tent while at the same time preventing bystanders on the outside of the tent from looking into the tent.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a tent, such as the type used by military personnel as a modular command post. More particularly, the present invention is directed to a tent having a flame resistant inner lining. In particular, a tent liner made according to the present invention has proven to be lightweight, white/opaque, and flame resistant. 
     BACKGROUND OF THE INVENTION 
     Military operations generally require a central location from which they can be effectively commanded. For mobile operations, the military defines such a central location as a Modular Command Post. Modular Command Posts generally contain a single tent or a network of tents from which commanders can direct various military operations. 
     Conventional tents used for Modular Command Posts are generally constructed with a number of discrete sections. Typically, a tent will include a plain wall, a window wall, an entrance way wall, and a roof cap. The sections are generally made from a lightweight, flame resistant fabric. In addition to the primary sections, conventional tents also include a plain wall liner and an entrance way/window wall liner. 
     The tent liner provides enhanced flame resistant qualities, as well as insulation qualities that allow the liner to be used as an outside wall during warm weather and daylight. Moreover, the tent liner aids in light diffusion to allow increased visibility for persons within the tent, while preventing visibility into the tent by an outside observer. 
     In the past, tent liners were made from a lightweight, pajama check weave cloth constructed from aramid fibers. One example of a fabric currently used as a tent liner in Modular Command Posts is made from NOMEX fibers marketed by DUPONT. 
     One difficulty encountered by current manufacturers of military tents is the high cost associated with producing an aramid fiber tent liner that is capable of complying with military specifications, which require that the liner be white/opaque, lightweight, and flame resistant. 
     As such, a need currently exists for a less expensive and/or improved tent and tent liner fabric. In particular, a need exists for a tent liner fabric that is white/opaque, lightweight, and flame resistant. 
     SUMMARY OF THE INVENTION 
     The present invention recognizes and addresses the foregoing disadvantages, and others of prior art constructions and methods. 
     Accordingly, an object of the present invention is to provide an inexpensive, improved tent suitable for use by military personnel. 
     It is another object of the present invention to provide an inexpensive tent for military personnel that is lightweight and flame resistant. 
     Still another object of the present invention is to provide an inexpensive tent liner for use in military tents that is lightweight, white/opaque, and flame resistant. 
     These and other objects of the present invention are achieved by providing a flame resistant tent liner for constructing a tent suitable for use by military personnel. The tent liner can be attached to an outer wall enclosure, which includes wall sections that comprise the primary structural components of the tent. 
     In accordance with the present invention, polyester fibers can be used to form the tent liner fabric. The tent liner fabric can have a weight of from about 1.5 ounces per square yard to about 12 ounces per square yard. Further, the polyester fibers can also have a combined denier from about 70 to about 1200 in the warp and fill directions. 
     In one embodiment of the present invention, the tent liner fabric can be made from AVORA FR polyester fibers marketed by Kosa. A tent liner comprising AVORA FR fibers and produced according to the present invention is generally flame resistant. Under vertical flammability testing, i.e. NFPA 701 and Fed. Test Method Standard No. 191A, Method 5903, a tent liner of the present invention was found to have a char length less than 6.5 inches (average of 5.5 inches for 10 samples) and an after flame time of less than 2.0 seconds. 
     A tent liner of the present invention can also be opaque and white in color. The opaqueness of the tent liner can prevent observation into the tent or into a segmented section of the tent by persons located outside the tent. Moreover, the white color of the tent liner can aid in light diffusion within the tent, allowing increased visibility by persons located inside the tent. 
     These and other objects of the present invention are also achieved by providing a flame resistant tent liner that can be attached to an outer wall enclosure. The outer wall enclosure can include a rear wall, side walls, and an entrance way wall. In particular, one embodiment of the present invention includes an outer wall enclosure having a plain (rear) wall, two side walls, and an entrance way wall. The walls can be interconnected by fasteners and supported by a frame assembly. Furthermore, a roof cap supported by cable assemblies can be used to cover the outer wall enclosure. The covered outer wall enclosure can be lined by a flame resistant tent liner of the present invention. Similar to the wall sections, the tent liner can be attached to the interconnected walls by fasteners. 
     Other objects, features and aspects of the present invention are discussed in greater detail below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which: 
     FIG. 1 is a perspective view of one embodiment of a tent made according to the present invention; 
     FIG. 2 is a cross-sectional view of the plain wall of the embodiment illustrated in FIG. 1; 
     FIG. 3 is a cross-sectional view of a window wall of the embodiment illustrated in FIG. 1; and 
     FIG. 4 is a cross-sectional view of the entrance way wall of the embodiment illustrated in FIG.  1 . 
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary construction. 
     In general, the present invention is directed to an improved tent for military personnel that is more cost-effective than prior tents. In particular, the present invention is directed to a tent having a rear wall, two side walls, an entrance way wall, a roof, and a liner. In one embodiment, a tent of the present invention includes a plain wall (rear), two window walls (side), an entrance way wall, a roof, and a tent liner. In comparison to prior art constructions, a tent of the present invention includes a white/opaque, flame resistant, and lightweight tent liner that is significantly less expensive than conventionally produced tent liners. In particular, it has been discovered that by using AVORA FR fibers in accordance with the present invention, the cost of a tent liner made according to the present invention is approximately one third the cost of tent liners used in prior constructions. 
     Referring to FIG. 1, one embodiment of an improved tent generally  10  constructed in accordance with the present invention is illustrated. It should be understood, however, that other embodiments are also anticipated and are intended to be covered by this invention. 
     As shown in FIG. 1, tent  10  includes window wall  20 , entrance wall  30 , roof cap  40 , and plain wall  60 . In the embodiment shown as FIG. 1, only one window wall  20  is shown. However, it should be understood that a second window wall exists opposite window wall  20  that is essentially identical to window wall  20 , and is thus not shown in FIG. 1, nor specifically described herein. 
     In one embodiment of the present invention, plain wall  60 , window wall  20 , entrance wall  30 , and roof cap  40  can be constructed of mildew and flame resistant polyester duck cloth. The dimensions of the tent can vary significantly based upon the particular application. In one embodiment, plain wall  60 , window wall  20 , and entrance wall  30  are approximately 12′6″ wide×8′ high. In the illustrated embodiment, plain wall  60  is located adjacent to window wall  20  and opposite of entrance wall  30 . However, due to the inherently similar size and shape of each wall section, it should be further understood that other embodiments of tent  10  can be easily constructed by simply manipulating the positioning of the wall sections. 
     Generally, any means suitable for connecting two or more sections of fabric or cloth can be used to connect the wall sections of the tent. In one embodiment, quick release fasteners can be provided for securing the wall sections of the tent together. 
     As shown in FIG. 1, window wall  20  contains a window  22  that, in one embodiment, can include a nylon webbing screen  26  and a window flap  28 . In one embodiment of the present invention, window  22  can be sewn into the bottom seam of a window opening  29  in wall  20 , and further attached along window opening  29  by quick release fasteners. Moreover, a window flap  28  can be sewn to the top seam window opening  29 . In addition to window  22 , the tent can also include a fireproof port  22  located on roof cap  40  for use with internally-fired stoves. 
     In the embodiment of the present invention depicted in FIG. 1, entrance way wall  30  includes an entrance way door  50  to cover entrance way opening  52 . Entrance way door  50  is generally constructed from the same material as the wall sections of tent  10  and is attached to entrance way wall  30  and entrance way opening  52  by quick release fasteners similar to the manner in which the wall sections are attached as described above. 
     The wall sections can generally be supported by a basic frame assembly, which in one embodiment, is constructed from aluminum alloy tubing that is assembled with a series of fittings and joints. Two end frame assemblies connect to a center frame assembly with eave and ridge purlins that snap together. Moreover, cable assemblies can allow the frame to support roof loads by connecting the sides of tent  10  together. The assembly is designed such that one side can be raised at a time, thus allowing tent  10  to be located on a sloping terrain. 
     As shown in FIGS. 2-4, tent  10  is also equipped with a liner material located along the plain wall, window walls, and entrance way wall. In general, liners  64  and  24  can be made from the same fabric. In accordance with the present invention, the fabric that comprises the tent liners can be formed from polyester fibers that are white/opaque and flame resistant. More particularly, a preferred embodiment of the present invention contains tent liners  64  and  24  which are formed from a polyester filament produced by Kosa known as AVORA FR Type 692 FR Fiber. AVORA FR fibers are made from a flame resistant polyester that contains an organic phosphorus compound in the polyethylene terephthalate chain. 
     To produce a tent liner in accordance with the present invention, first, the yarn is generally unified. In particular, two strands of yarn made from continuous filaments are unified by false twist texturizing. Generally, each strand can have a denier between about 70 and about 1200. For instance, in one embodiment of the present invention, each yarn made from AVORA FR fibers has a denier of about 150, resulting in a combined yarn having a denier of about 300. 
     False twist texturizing first requires twisting the feeder yarn in the clockwise direction and subsequently twisting the feeder yarn in the counterclockwise direction. Furthermore, heat is applied to the feeder yarn during each twisting step to provide the yarn with memory, to heat-set the yarn, to draw the yarn, and to properly orient the molecular structure of the yarn. Generally, the amount of heat applied to the feeder yarn depends on the type of fiber used. Normally, it is preferred that the temperature of the yarn not exceed its melting point. In one embodiment of the present invention, the feeder yarn made from AVORA FR fibers can be heated to a temperature less than about 482° F., the melting point of the fibers. 
     Once the yarn is formed, the yarn is then woven or knitted into a fabric for use in accordance with the present invention. In general, the fabric formed from the yarn can have any suitable type of woven or knitted structure. Further, the fabric can be made with various weights in order to optimize the properties of the fabric for any particular application. 
     After forming the fabric, the fabric can then be scoured, although scouring may not be necessary for all applications. Scouring can partially stabilize the fabric by preventing residual shrinkage, as well as clean the fabric by removing water soluble lubricants used in yarn processing and fabric manufacturing that could cause inadequate flame resistance. 
     After scouring, the fabric can also be placed on a tenter frame to be dried and heat-set. Generally, heat-setting determines the finished width of the fabric by providing dimensional stability. Specifically, a fabric produced according to the present invention can be heat-set at a temperature between about 350° F. and about 375° F. for approximately one minute. 
     In general, the tent liner can have a weight between about 1.5 to about 12 ounces per square yard (oz/yd 2 ), and preferably between 3.0 to 4.0 oz/yd 2 . In one embodiment of the present invention, the fabric can have a weight of 3.6 oz/yd 2 . In addition, one preferred fabric of the present invention is produced from a 300 denier yarn with a plain weave, approximately 50 ends/inch×34 picks/inch(length x width), to provide the optimal amount of smoothness. 
     A tent liner produced in accordance with the present invention can have a natural white/opaque color, which may aid in the diffusion of light within tent  10 . By aiding in light diffusion, a white-colored tent liner can enable persons within the tent to have increased visibility. Moreover, a white-colored liner that is also opaque can restrict the ability of persons located outside the tent to see inside tent  10 . 
     Further, a tent liner produced according to the present invention is also flame resistant. As required by military specifications, a flame resistant tent liner, such as one made according to the present invention, must satisfy certain flammability tests. One such type of flammability test is known as a Vertical Flammability Test. Among other parameters, Vertical Flammability Tests measure after-flame time and char length to determine the amount of flame resistance possessed by a given fabric. In general, the after-flame time is defined as the time the specimen continues to flame after the burner flame is shut off. Moreover, the char length is generally defined as the distance from the end of the specimen, which was exposed to the flame, to the end of a tear (made lengthwise) of the specimen through the center of the charred area. 
     A tent liner made according to the present invention has been found to be flame resistant in accordance with two Vertical Flammability Tests, the National Fire Protection Association Small Scale Flame Resistant Criteria (NFPA 701) and Fed. Test Method 5903. After performing the above tests on a tent liner material of the present invention, it was determined that the after-flame time was a maximum of 2.0 seconds. It was further determined that the char length was an average of 5.5 inches for 10 samples, none of which exceeded 6.5 inches. 
     As such, it has been discovered that a tent  10  produced according to the present invention is significantly less expensive than prior constructions. Furthermore, it has been discovered that tent  10  having a tent liner made according to the present invention remains white/opaque in color, lightweight, and also flame resistant. 
     As illustrated in FIGS. 2-4, a tent liner constructed according to the present invention is generally attached to plain wall  60 , window walls  20 , and entrance way wall  30 . 
     Specifically, as shown in FIG. 2, tent liner  64  is attached to the inside of plain wall  60 . In one embodiment of the present invention, plain wall liner  64  can be approximately 12′ wide and 7′ high. Eight quick release male fasteners are located on the inside, approximately 18″ apart along the top edge. Seven buckle assemblies with quick release female fasteners are located approximately 12″ apart and 22″ from the edge along each side, with three more located approximately 5′ apart and 12″ above the bottom edge. In addition, seven side straps with quick release male fasteners are located approximately 12″ apart along the outer edge of each side. On the outside, a 2″ strip of pile fastener is sewn along the upper seam of the liner. It should be understood that the above description is one method of attaching plain wall liner  64  to plain wall  60  and other means for attachment may be equally suitable. 
     Further, as shown in FIGS. 3 &amp; 4, entrance way/window wall liner  24  is attached to window wall  20 , as well as entrance way wall  30 . In a preferred embodiment, entrance way/window wall liner  24  can be constructed similar to plain wall liner  64 , except that it contains an approximately 6′½″ high and 3′ wide door. A quick release male fastener is located on the upper, inside edge of the door and quick disconnect female fastener in corresponding location on liner  24 . A strip of 1″ pile fastener is located along the left side and along the top of the liner  24  door opening. A strip of 1″ hook fastener is sewn to the outer edge and top of the door. In addition, seven quick release female fasteners are located on the outside along the door opening. As such, in the preferred embodiment, liner  24  is attached to the two window walls  20  and the one entrance way wall  30  in an identical manner. However, it should be understood that the above description is only one method of attaching liner  24  to window walls  20  and entrance way wall  30 . Therefore, other means for attachment may be equally suitable. 
     Although the preferred embodiment of the present invention is described as a tent that serves as a Modular Command Post, a tent or tent liner of the present invention can also be utilized in other applications. Moreover, it should be understood that the natural white color of the tent liner of the present invention may be died to provide liners of varying color depending on the application. Generally, most dying methods known to those of ordinary skill in the art can be used to die the fabric. 
     These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.