Abstract:
The present invention provides for a shroud plate for headgear comprising a shell, an insert, a lock and a release mechanism wherein the shell extends around at least a portion of the insert has a smooth surface with rounded edges and corners and is shaped to match the contour of the headgear. Further, the insert is adapted to receive a lock plate, the lock is adapted to secure the lock plate to the insert, and the release mechanism allows for removal of the lock plate from the insert.

Description:
FIELD OF THE INVENTION 
     This invention relates to helmet attachment mechanisms used with mounting assemblies for night vision devices, and more particularly to a shroud plate which may act as an interface between a helmet and the helmet mount for a night vision device. 
     BACKGROUND OF THE INVENTION 
     Night vision devices are commonly used by military personnel for conducting operations in low light or night conditions. The night vision devices used by the military typically include image intensifier tubes and associated optics that convert infrared and near infrared light into viewable images. A common night vision device currently being used in the U.S. Army is the PVS7 night vision goggle, manufactured by ITT Corporation of Roanoke, Va. 
     Assemblies for mounting night vision devices to a helmet are well-known in the art. These mounting assemblies allow a user&#39;s hands to remain free while viewing a scene through the night vision device. It is also desirable for these mounting assemblies to be removable from the helmet so that they do not interfere with a user&#39;s actions when they are not needed, such as during the daytime or when a user parachutes from an airplane. 
     A night vision device may be attached to a helmet through a helmet attachment mechanism which acts as an interface between a helmet mount and the helmet. In previous designs, helmet attachment mechanisms have been attached to a helmet by a strap secured around the helmet. See, for example, U.S. Pat. No. 6,472,776 to Soto et al. However, in such mechanisms, the strap and helmet attachment mechanism is not permanently attached to the helmet, and may be susceptible to being lost during a maneuver or simply being misplaced. Alternatively, fasteners have been used to secure attachment mechanisms directly to the helmet. Yet, previous helmet attachment mechanisms have comprised sharp edges and/or hooked shaped portions which may interfere with or even seriously injure a user. For instance, a hook portion may catch the shroud line of an opening parachute, cutting the line or violently jerking the user&#39;s head and neck. In order to prevent a shroud line from snagging on a helmet attachment mechanism, paratroopers have placed tape or a similar material over the mechanism before jumping and engaging their parachute. However, this is not desirable because it then requires removal of the tape before the night vision mount can be attached and a new piece of protection is required for each use of the helmet mount. Moreover, a suitable material may not always be available. 
     These and other problems exist with the helmet attachment mechanisms for night vision devices disclosed in the prior art. Consequently a need exists for an improved helmet attachment mechanism. 
     SUMMARY 
     The present invention, therefore, provides for a shroud plate to act as an interface between a helmet mount and a helmet. More particularly, the shroud plate of the present invention allows a helmet mount for a night vision device to be easily attached and removed from a helmet. Further, when the night vision device is not attached to the helmet, the shroud plate has no sharp edges or hook portions or any other type of crevice or opening on which an opening parachute shroud line may snag. 
     The present invention provides for a shroud plate for headgear comprising a shell, an insert, a lock and a release mechanism wherein the shell extends around at least a portion of the insert has a smooth surface with rounded edges and corners and is shaped to match the contour of the headgear. Further, the insert is adapted to receive a lock plate, the lock is adapted to secure the lock plate to the insert, and the release mechanism allows for removal of the lock plate from the insert. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a shroud plate attached to a helmet. 
     FIG. 2 is a perspective view of a shroud plate. 
     FIG. 3 is a front view of the shroud plate. 
     FIG. 4 is a back view of the shroud plate. 
     FIG. 5 is a back view showing an alternate embodiment of the shroud plate. 
     FIG. 6 is a bottom view of a lock. 
     FIG. 7 is a side view of the lock. 
     FIG. 8 is a side view of a flanged insert. 
     FIG. 9 is a perspective view of a lock plate. 
     FIG. 10 is a side view of the lock plate. 
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment of the present invention is shown in FIG.  1 . The shroud plate  10  is shown attached to a standard U.S. Army Kevlar composite helmet  12 . The helmet is based on U.S. Design Pat. No. 449,411 to Largeot and is manufactured by CGF Helmets, Inc. of Akron, Ohio. In an exemplary embodiment, the shroud plate  10  may be attached to the helmet  12  by stainless steel screws  14  inserted into openings in the helmet  12  and shell  13 . Flanged threaded inserts  15  may be driven into holes machined into shell  13 . Threaded inserts  15  may also comprise a knurled outer surface in order to more securely attach them to the shell  13  when they are inserted into the machined hole. The threaded portion of the insert may also comprise two opposite halves attached to a flange at one end of the insert with a small gap separating the halves on their longitudinal axis. This separation allows the inserts to expand slightly when screws are threaded into them, tightly securing them to the shell  13 . However, the shroud plate  10  may also be attached to the helmet  12  in any manner sufficient to secure a helmet attachment mechanism to the helmet  12  and support the accompanying helmet mount and night vision device. In the present invention, a shroud plate  10  may be retrofitted to any suitable helmet or other headgear, and it will be understood by those skilled in the art that the invention is not restricted to the helmet shown. 
     FIG. 2 shows a front side view of an exemplary embodiment of the present invention. The shroud plate  10  comprises a shell  13  which may be manufactured to fit the contour of a helmet. In one exemplary embodiment, the shell  13  may be machined from a block of nylon 6/6. However, the shell  13  may be manufactured from any suitable material sufficient to sustain the forces subjected to it during operation. The shell  13  may alternatively be injection molded from nylon 6/6 or a suitable polymer. When the shell  13  is injection molded, its walls are about {fraction (80/1000)} inch on all sides and the back side of the shell may comprise indented sections separated by support ridges. The indented sections allow the shell  13  to be a minimum weight while still providing a suitably sturdy base for the shroud plate  10 . In addition to fitting the shell  13  to the contour of the helmet  12 , the top surface of the shell  13  may be smooth with rounded edges and corners. Fitting the shell  13  to the shape of the helmet  12  and having a smooth surface with rounded edges and corners on the shell  13  ensures that there are no unnecessary edges on which another object, such as a shroud line of a parachute or a dangling tree branch in heavy foliage, may catch. The screws  14  which secure the plate  10  to the helmet  12  may be inserted from the inside of the helmet so that the heads of the screws are not exposed on the external surface. The length of the screws is such that the bodies of the screws  14  do not protrude beyond the external surface of the shell  13 . The screws  14 , however, should be long enough to securely attach the shell  13  to the helmet  12 . 
     An exemplary embodiment of the present invention further comprises an aluminum insert or receiving plate  16 . The insert  16  could also be made of titanium or other suitable materials. The insert  16  is designed as a bay for a lock plate or adapter plate  17  (see FIG. 9) and functions as the interface between a helmet mount and a helmet  12 . The shroud plate  10  may comprise an insert  16  that is integral with a shell  13  essentially making the plate one piece. The shroud plate  10  may comprise two integrally related pieces, the shell  13  and the insert  16 , to optimize weight and durability. A lightweight shell minimizes the weight a user must bear while a durable lock plate ensures a sturdy interface between a helmet mount and a helmet. However, it is also possible that the shroud plate  10  may be one piece made from one material, for example all nylon or all aluminum. 
     In order to secure the lock plate  17 , the base of the insert  16  may be indented from the top surface of the plate. Further, the insert  16  may comprise a hollowed indentation  19  on a side wall to fit a corresponding edge of the lock plate  17 . The insert  16  may also comprise an opening in a side wall designed to accommodate a lock  18  which is slidably coupled to the insert  16 . 
     As shown in FIG. 6, the sides  20  of the lock  18  may be tapered into a dovetail shape in order to secure the lock  18  to the insert  16  at the opening in the side wall, which opening has a mating dovetail shape. In a preferred embodiment, as shown in FIG. 7, the top surface  22  of the lock  18  is contoured to match that of the shell  13  in order to ensure a smooth surface. Also, in a further preferred embodiment, the rear of the lock  18  may comprise a tapered overhanging ledge  24  which serves to further secure the lock plate  17  when it is introduced into the insert  16 . With further reference to FIG. 7, a protrusion  34  may extend from the bottom surface of the lock  18 . Protrusion  34  allows for the lock  18  to be connected to release button  26  by a link plate  28  as shown in FIG.  4 . Protrusion  34  may be attached to lock  18  by a threaded insert or by any other suitable means. Lock  18  may be connected to link plate  28  by a rivet, bolt, screw or any other appropriate means for attachment. In a preferred embodiment, the lock  18  may be machined from titanium. However, the lock  18  may also be manufactured from any other suitable material. 
     FIG. 4 shows a back side view of an exemplary embodiment of the present invention. Release button  26  may be attached to link plate  28  by a rivet, a bolt or a screw  30 , or by any other means sufficient to secure them together. Release button  26  and link plate  28  may be machined from aluminum and titanium respectively in a preferred embodiment or any other suitable material. Link plate  28  may have drilled openings at either end to accommodate means for attaching release button  26  and lock  18  to it. The back surface of insert  16  may be contoured to the shape of the helmet  12 , but may also contain a flat center channel which houses the link plate  28  and allows it to slide on a smooth surface. In a presently preferred embodiment, two springs  33  may be placed between the release button  26  and the rear of the insert  16  on opposite sides of the link plate  28 . Springs  33  bias lock  18  to secure the lock plate  17  until release button  26  is pressed, thereby counteracting the bias of the springs  33 , moving the lock  18  out of the way and allowing the night vision device to be removed. In an alternate embodiment, as shown in FIG. 5, a spring  32  may be placed between protrusion  34  on the lock  18  and a wall formed by the shell  13  where it meets the insert  16 . 
     In operation, a user may attach a night vision device to the shroud plate  10  by fitting one edge of the lock plate  17  into the hollowed indentation  19  of the insert  16 . In order to introduce the lock plate  17  to the insert  16 , the user may press the lock plate  17  against the lock  18 , forcing the lock  18  to displace enough to allow the lock plate  17  to become flush with the insert  16 , a snap-lock action. A rounded front edge on the ledge  24  allows the lock plate  17  to displace the lock  18  upon insertion by a user. Tapered sides interface between the insert  16  and the lock plate  17  and also between the lock plate  17  and the lock  18 . These tapered sides create a secure fit between the components. Further, the tapered top surface of the lock plate  17  matching the tapered ledge  24  should provide for automatic adjustment to normal wear between the mating surfaces. The user also may depress and hold the release button  26  which will move the overhanging ledge  24  of the lock  18  to allow insertion of the lock plate  17 . Once the lock plate  17  is flush with the insert  16 , the user may let go of the release button  26 . Springs  33  will then cause the lock  18  and release button  26  to return to their original position, with the ledge  24  of the lock  18  securing the lock plate  17  to the insert  16 . The tapered interface of ledge  24  prevents casual separation of the lock plate  17  from the insert  16  without displacement of the lock  18 . 
     In order to release the night vision device from the insert  16 , the user may depress and hold the release button  26 . The ledge  24  of the lock  18  will again slide upward, allowing removal of the lock plate  17 . 
     As shown in FIG. 3, the release button  26  is centrally located at the bottom of the shell  13 , which allows the user to reach up in a natural motion and have their thumb in position to depress the release button  26  and thereby disengage the night vision device from the insert  16 . Having a centrally located release button  26  further allows a right-handed or left-handed person the same ease of release. The release button  26  may also have rounded edges and a bottom edge contoured to match the rounded bottom edge of the shell  13 . The lock  18  and release button  26  may be positioned opposite one another at different sides of the insert  16 . Further, alternate arrangements of the lock  18  and release button  26  are possible. For instance, the release button  26  may be located adjacent to the lock  18 . 
     While various embodiments of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concept herein. It is, therefore, to be understood that within the scope of the appended claims, this invention may be practiced otherwise than as specifically described.