BACKGROUND The present disclosure relates generally to body armor and more particularly to ballistic panel assemblies used in body armor.
BRIEF SUMMARY Many improvements have been made in body armor resulting in relatively comfortable body vests and the like. Modem lightweight body armor often includes flexible, ballistic resistant panels formed from any number of polymeric materials such as Kevlar® ballistic grade fibers/fabrics and other materials formed from para-aramid or polyethylene synthetic fibers. Metal or ceramic plates can also be used either by themselves or in conjunction with flexible ballistic resistant panels and while metal or ceramic plates offer additional protection that soft body armor, when used alone, cannot offer, metal or ceramic plates have the drawback of being rigid and accordingly less comfortable to wear for extended periods of time.
Although significant developments have been made in flexible, ballistic resistant body armor, it does have its shortcomings Specifically, it is known that the performance of flexible body armor can be compromised if the flexible body armor is exposed to liquids.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a ballistic vest assembly 10 which incorporates front vest panel 12 and rear vest panel 14;
FIG. 2 is the rear vest panel 14 taken from the ballistic vest 10 of FIG. 1;
FIG. 3 is a ballistic panel assembly portion 22 of the rear vest panel 14 of
FIG. 2;
FIG. 4 is a partial cross sectional view taken through lines 4-4 of FIG. 3 showing a tape embodiment;
FIG. 5A is a partial cross sectional view taken through lines 5-5 of FIG. 3 showing a double-sided tape embodiment;
FIG. 5B is a partial cross sectional view taken substantially through lines 5-5 of FIG. 3 showing an adhesive embodiment;
FIG. 5C is a partial cross sectional view taken substantially through lines 5-5 of FIG. 3 showing a heat sealing method;
FIG. 5D is a partial cross sectional view taken substantially through lines 5-5 of FIG. 3 showing an ultrasonic welding method;
FIG. 6 is another embodiment of the ballistic panel assembly;
FIG. 7 is a partial cross sectional view taken substantially through lines 7-7 of FIG. 6;
FIG. 8A-8D are yet additional embodiments showing a cap member which is not comprised of tape;
FIG. 9A-9C show yet another embodiment which does not depend on a cap member for sealing liquids from entering between the plies.
DETAILED DESCRIPTION Ballistic panels can be incorporated into any number of vestments worn by soldiers, police officers, and the like. One common type of ballistic vestment is a ballistic vest 10 shown in FIG. 1. Ballistic vest 10 is typically an assembly and may be comprised of one or more vest panels (such as front vest panel 12 and rear vest panel 14). Front panel 12 and rear panel 14 can be selectively joined to one another by using any number of joining techniques including using shoulder straps 16 and side torso straps 20. Straps 16 and 20 can be made operational by way of any common type of joining system such as belts, zippers, hook and loop fasteners and the like. Both front 12 and rear 14 panels may include an outer carrier 11 which may be the visible portion of the ballistic vest and which carries therein a ballistic panel assembly 22. Carrier 11 may completely encase assembly 22 or may encase portions thereof.
Now referring to FIGS. 1, 2, 3 and 4, ballistic panel assembly 22 (also known as ballistic package 22) can be comprised of two or more layers or plies 24. Each ply may be formed from flexible polymeric material or fibers such as para-aramid or polyethylene synthetic fibers, or the like.
Two or more plies 24 may be sandwiched between a first face 25 and a second face 26 of first and second plies respectively. In the embodiment of FIG. 4, the peripheral edge along the entire ballistic panel assembly 22 is sealed using a peripheral treatment which forms and anti-liquid ingress system 26. In the embodiment of FIG. 4, the anti-liquid ingress system 31 is formed using tape 27. Tape 27 is formulated to be comprised of a back face and an adhesive face 30. Collectively tape back face 29 and tape adhesive face 30 form a cap member 28 which extends across a portion of first face 25, along the edges of all of the plies 24 and along a portion of second face 26 (see FIG. 4). By extending cap 28 along the entire periphery of ballistic panel assembly 22, a protective continuous cap is formed impeding the ability of one or more liquid types (e.g. oil based liquids and water based liquids) to penetrate (wick) between or within plies 24. By preventing liquids from wicking into the interstices between adjacent plies 24, or between the warps and wefts of each within each ply, the integrity of the ballistic panel assembly 22 to perform to its highest standard is maintained possible. Tape back face 29 can be comprised of any number of materials which are impervious to water based and oil based liquids. For example, polymer, fiberglass, or carbon based fibrous materials can be used to fabricate tape back face 29. Also combinations of two or more of these fibrous materials can also be used to fabricate tape back face 29. Also, metal foil materials can be used to comprise tape back face 29. The adhesives deposited on and carried by tape adhesive face 30 can be any number of compositions which are both impervious to water based liquids and petroleum based liquids. Such adhesives include elastomers, thermoplastics, emulsions or thermosets, rubber, polychloroprene, acrylic, urethanes, polymides, epoxies, polyvinyl acetate (PVAC), heat/ultrasonic seals. Other types of materials that can be used for tape back face 29 include vinyl, polyester, polyamide, polyethylene, polypropylene, PTFE tape. The term “tape” as it is used herein is used to describe a material that is prefabricated having a back face 29 and an adhesive face 30, wherein the adhesive face 30 is joined to the back face 29 prior to any assembly steps disclosed herein.
Now referring to FIGS. 5A-5D, in another embodiment, ballistic assembly 22 does not include the tape cap 28 edge treatment 26 as shown in FIG. 1, but rather includes a peripheral edge treatment 26 which utilizes folding over at least one of the first ply 25′ or the second ply 26′ onto the remaining face. For example, FIG. 5A shows the second ply 26′ of two or more plies 24 cut larger than the remaining plies in order to provide sufficient material to cover the stacked edges of plies 24 and also to fold upon and overlap a portion 27 of first face 25 of first ply 25′. By cutting second ply 26′ large enough so that it provides surplus material 23 and 27, in effect, the excess material 23, 27 forms the anti-liquid ingress system 31. Of course, the overlap (i.e. seam) 27 between second ply 26′ and first face 25 of first ply 25′ must be liquid tight in order to prevent the ingress of liquids between plies 24 along their peripheral edges. One such method of sealing the seam between overlapping portions of second ply 26′ and first ply 25′ is to introduce double-sided tape 38 between the adjoining surfaces of second ply 26′ and first ply 25′.
Another method for sealing the overlap between first ply 25′ and second ply 26′ is to introduce an adhesive 40 between the overlapping portions of first ply 25′ and second ply 26′ (see FIG. 5B). Adhesive 40 may be comprised of any number of adhesives which are impervious to water based liquids and petroleum based liquids. Such adhesive might include silicone based adhesives, epoxy based adhesives, or any of the adhesives mentioned herein.
Now referring to FIG. 5C, still yet another means of sealing the overlapping portions of first ply 25′ and second ply 26′ are to use heat sealing methods to seal the overlapping plies 25′, 26′. For example, FIG. 5C shows heat source 42 which is operatively coupled to an upper pinch arm 44 and a lower pinch arm 46. Manipulating means 48 can be used to manipulate 50, 52 pinch arms 44, 46 away from or towards plies 24. Manipulating means 48 can include any number of hydraulic, electromechanical, or other motors which are capable of manipulating arms 44, 46 into and out of a pinch position. Once manipulating means 48 manipulate arms 44, 46 into a pinch (i.e. compressed) position (pinch position shown in FIG. 5C), heat source 42 activates a heat generating device (such as an electric heat source) which, in turn, heats pinch arms 44, 46 and directs heat via thermal conduction into the plies 24. Plies 44 can be comprised of, or coated with, any number of thermo-plastic type materials which will liquefy when heated and then resolidify when cooled. This heating process can cause the plies to “melt” together forming a liquid tight barrier.
Now referring to FIG. 5D, still in another embodiment, ultrasonic welding techniques (using an ultrasonic welder 42′) can be used (similarly to the heat techniques shown and discussed in FIG. 5C), to create an elevated temperature between plies 24. This elevated temperature will act in the same way it did in conjunction with the embodiment of FIG. 5C to solidify plies 24 together thereby forming a liquid impervious barrier.
Now referring to FIG. 6, ballistic panel assembly 22′ can be composed of two or more plies which are sandwiched between a first ply 25′ having a first face 25 and second ply 26′ having a second face 26. At least one of the first ply 25′ or second ply 26′ includes extended portions which extend across the ply edge portions 23 and partially across 27 the first face 25 of the first ply 25′. In this embodiment, the anti-liquid ingress system 26 is at least partially formed by a liquid impermeable member 39 which is adhered to both first face 25 and second face 26 and which spans across the seam 54 which is formed at the interface of second ply 26′ and the first face 25 of first ply 25′. Liquid impermeable member 39 of FIG. 7 can be comprised of tape (as it has been defined herein) or it can also be comprised of any of the systems set forth in FIGS. 5A-5D used for creating a liquid-proof ingress.
Now referring to FIGS. 8A-8D, another embodiment may include a cap 28′ which is not comprised from tape. Rather, cap 28′ is comprised of a water impervious material such as foil, vinyl, polyester, polyimide, polyethylene, polypropylene, PTFE, fiberglass mating, water impervious coated fabrics (such as coated cotton fabrics), or the like. In the embodiment set forth in FIGS. 8A-8D, because cap 28′ is not a tape (i.e. it does not carry a pre-adhesive face 30) various methods are employed for creating a water tight seal between the first and second faces 25, 26 respectively.
For example, in the embodiment of FIG. 8A, cap 28′ is fabricated from liquid impervious material. Prior to placing cap 28′ onto plies 24, a continuous piece of double-sided tape 38 is laid along the entire outer perimeter of ballistic panel 22. Double-sided tape 38 should be wide enough so that it not only continuously spans the end portions 38 of two or more plies 24 but that it also covers a portion of first face 27 and second face 27′. The system of FIG. 8A allows a cap 28′ to be used of any suitable material and a double-sided tape 38 to be used therewith having suitable adhesives that resist water or petroleum based liquids. Thus, divorcing the cap material 28′ from the adhesives gives the designer great flexibility in matching the performance characteristics of cap 28′ and double-sided tape 38 to the ballistic panel application at hand.
Now referring to FIG. 8B, cap 28′ can be adhered to first face 25 and second face 26 by use of adhesives 40. The types of adhesives under consideration here are the same adhesives that are mentioned in the embodiment of FIG. 5B and which have already been discussed.
Now referring to FIG. 8C, cap 28′ can be joined to plies 24 by using the same heat apparatus and method as described for use in FIG. 5C.
Now referring to FIG. 8D, describes the use of cap 28 and joining it with the first and second faces of plies 24. The same ultrasonic apparatus and techniques disclose in conjunction with FIG. 5D can also be used in securing the cap 28′ shown in the embodiment of FIG. 8D.
Now referring to FIGS. 9A-9C, in another embodiment, the ballistic panel assembly 22 may employ an anti-liquid ingress system 26 which does not use a cap 28, 28′ nor does it use a fold over of first ply or second ply. Specifically, the embodiment set forth in FIGS. 9A-9C includes a peripheral treatment system 26 which joins plies 24 together directly without the need of cap 28, 28′ or overlapping portions of first or second plies 25′, 26′ respectively. Specifically, FIG. 9A depicts an embodiment wherein each ply face is adhesively joined to the face of its adjoining ply. Specifically, in the method of FIG. 9A, an adhesive is placed in a continuous bead around the outer periphery of each ply face. Once the adhesive layers 40 have been deposited continuously along the ply faces, a compressive force 50, 52 is exerted onto the first face 25 and the second face 26 wherein the adhesive is compressed therebetween. Once the adhesive has had a chance to solidify, the compressive forces exerted 50, 52 can be removed and the plies 24 will have a liquid impervious outer perimeter which prevents water from ingressing from the ply edges into the interstices between the plies.
Now referring to FIG. 9B, shows a heat source being used to compress the plies 24 along a continuous peripheral edge portion. The heat source is used similar to that which has been discussed in conjunction with FIGS. 5C and FIG. 8C such that the heat source liquefies or melts portions of the plies thereby causing the plies to generally melt together with one another forming a liquid impervious outer peripheral around ballistic panel assembly 22. In cases where the polymeric material used to comprise plies 24 does not generally react favorably to being bound together via heat and/or heat and pressure, and intermediate medium 41 can be added between plies 24 which is reactive to heat and when heated will interact with the fibers and fabric of ballistic panel assemblies to create a water impervious bond between plies 24.
Now referring to FIG. 9C, the same materials as disclosed in FIG. 9B can be used with the method of FIG. 9C but instead of using a traditional heat source which is used to thermally conduct heat along pinch arms 44, 46, an ultrasonic welding device can be used to compress plies 24 and then ultrasonically vibrate so that the frictional rubbing between plies will result in a heat buildup which effectively bonds plies 24 forming a liquid impervious path. Optionally, a medium 41 can be inserted between plies if the plies are comprised of material such that they do not bind and adhere satisfactorily using ultrasonic vibrational welding techniques alone.
Although the present embodiments have been described in detail in connection with the above disclosure, it should be understood that such detail is illustrative and not restrictive and that those skilled in the art can make various variations without departing from the spirit of the disclosure. The scope of protection afforded herein is indicated by the following claims rather than the foregoing description. All changes and variations that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
