Bullet Resistant Panel Member
A bullet resistant panel member for protecting an object, for example a vehicle, from a projectile comprises inner and outer skin layers receiving a plurality of intermediate layers of woven aramid fibres therebetween. The inner and outer skin layers comprises rigid sheets of material arranged to conform to a shape of the object to be protected. Fastening members span under tension between the outer skin layer and the inner skin layer such that the intermediate layers are compressed under pressure between the outer skin layer and the inner skin layer.
This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 61/025,370, filed Feb. 1, 2008.
FIELD OF THE INVENTIONThe present invention relates to a panel member for protecting an object from projectiles in the form of bullets and shrapnel and the like, and more particularly the present invention relates to a bullet resistant panel member which is suited for protecting various objects, for example for mounting onto a vehicle to protect occupants of the vehicle from bullets and/or shrapnel, for mounting onto walls and surfaces of a mobile or fixed building or shelter and the like.
BACKGROUNDThe desirability of protecting persons and objects from bullets and shrapnel from an explosion are well-known. The following US patents disclose various examples of devices offering protection against bullets and the like. U.S. Pat. No. 4,566,237 belonging to Turner; U.S. Pat. No. 4,716,810 belonging to DeGuvera; U.S. Pat. No. 4,326,445 belonging to Bemiss; U.S. Pat. No. 4,323,000 belonging to Dennis et al.; U.S. Pat. No. 4,529,640 belonging to Brown et al.; U.S. Pat. No. 5,905,225 belonging to Joynt; U.S. Pat. No. 5,533,781 belonging to Williams; U.S. Pat. No. 4,404,889 belonging to Miguel; U.S. Pat. No. 4,111,097 belonging to Lasker; U.S. Pat. No. 4,131,053 belonging to Feguson; U.S. Pat. No. 4,186,648 belonging to Clausen et al.; U.S. Pat. No. 5,851,932 belonging to Dickson et al.; U.S. Pat. No. 6,389,594 belonging to Yavin; U.S. Pat. No. 4,079,464 belonging to Roggin; U.S. Pat. No. 5,179,244 belonging to Zufle; U.S. Pat. No. 3,601,935 belonging to Cadwell; U.S. Pat. No. 5,531,500 belonging to Podvin; and U.S. Pat. No. 5,413,026 belonging to Medden, Jr.
None of the prior art is well suited for ease of manufacturing to produce a member of sufficient strength within a small enough and lightweight enough panel-like structure as would be desired for use in vehicles and the like to protect the occupants of the vehicle from roadside bombs and the like without greatly interfering with use of the vehicle.
SUMMARY OF THE INVENTIONAccording to one aspect of the invention there is provided a bullet resistant panel member for protecting an object from a projectile, the panel member comprising:
an outer skin layer comprising a rigid sheet of material arranged for facing outwardly away from the object;
an inner skin layer comprising a rigid sheet of material arranged for facing inwardly towards the object;
a plurality of intermediate layers between the outer skin layer and the inner skin layer, each intermediate layer spanning generally in a direction of the outer skin layer and the inner skin layer, and each intermediate layer comprising a woven material of aramid fibres;
a plurality of fastening members spanning under tension between the outer skin layer and the inner skin layer such that the intermediate layers are compressed under pressure between the outer skin layer and the inner skin layer.
Use of low weight material such as aramid fibres which are maintained under pressure results in a panel which occupies little space while remaining relatively lightweight despite considerable strength and resistance to bullets and the like. Use of fastening members, for example bolts and the like, permits the panel member to be readily constructed with low skill and at a reasonable cost. In particular embodiments of the present invention, the outer skin may comprise rigid metal which is shaped to a vehicle or other object to be protected so as to provide minimal interference to the object being protected. Various types of fastening members can be used to achieve considerable compression of the woven material of aramid fibres for optimal resistance against projectiles. The fasteners can be further provided in an evenly spaced array following a grid pattern to ensure that even compression is applied to the intermediate layers between the inner and outer skin layers across the length and width thereof.
Preferably each intermediate layer comprises a sheet of Kevlar™ material.
The fastening members may maintain the intermediate layers under a pressure of at least 500 psi to 1000 psi, and preferably greater than 2500 psi.
The fastening members may be arranged to compress the intermediate layers to a combined thickness which is near half a thickness of the intermediate layers between the inner and outer skin layers before compression.
The compressed intermediate layers preferably have a thickness between the inner and outer skin layers which is generally within a range of one to two inches.
There may be provided near 200 or greater intermediate layers.
Preferably the inner and outer skin layers comprise a rigid metal.
The outer skin layer may be formed of a softer metal than the inner skin layer.
The fastening members may comprise mechanical fasteners, for example threaded fasteners which arranged in a spaced apart grid pattern relative to one another.
The fastening members may be arranged in pairs which extend from the outer skin layer to the inner skin layer angularly offset in diametrically opposed directions from an axis extending perpendicularly between the outer and inner skin layers. The fastening members are preferably received through preformed apertures formed in the intermediate layers.
The inner and outer skin layers may be shaped so as to be arranged to conform to a shape of the object to be protected such that the inner and outer skin layers are evenly spaced apart from one another along a width and a length thereof. More particularly, the inner and outer skin layers may be shaped to conform to a portion of a body of a vehicle, for example a panel of the vehicle, a door of the vehicle, or an under body of the vehicle.
Preferably the inner and outer skin layers are arranged to be continuous across a length and a width of the vehicle.
Some of the intermediate layers adjacent the inner skin layer may have more slack in a direction the inner skin layer extends than other ones of the intermediate layers nearer to the outer skin layer.
Furthermore, some of the intermediate layers adjacent the inner skin layer may have greater dimension in a direction the inner skin layer extends than other ones of the intermediate layers nearer to the outer skin layer such that each intermediate layer is progressively larger in dimension in a direction that the skin layers span than a previous one of the intermediate layers from the outer skin layer to the inner skin layer.
Some embodiments of the invention will now be described in conjunction with the accompanying drawings in which:
In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTIONReferring to the accompanying figures there is illustrated a bullet resistant panel member generally indicated by reference numeral 10. The panel member 10 is particularly suited for use with a vehicle 12 for mounting against various panels of the vehicle including panels of the door 14 or the undercarriage of the vehicle. In each instance the panel member is shaped to have a mating profile and contour in three-dimensions which conforms to the shape of the object being protected. In further embodiments the panel member 10 can be shaped to protect various other configurations of objects or persons by suitably shaping the panel member for mating configuration therewith.
Although various embodiments of the present invention are shown and described in the following, the common features will first be described herein.
In each instance the panel member comprises an outer skin layer 20 which forms an outer side of the panel member 10 which is arranged for facing outwardly away from the object to be protected to confront the projectile at the leading side of the panel relative to an oncoming projectile. The outer skin layer 20 is a rigid metal sheet which is shaped to conform to the object being protected so as to retain the shape thereof.
The panel member also includes an inner skin layer 22 which spans the inner side of the panel member to face the object being protected and to be located at the trailing side of the panel member relative to an oncoming projectile. The inner skin layer 22 is also comprised of rigid metal and is shaped similarly to the outer skin layer 20 so that the inner and outer skin layers are generally parallel and evenly spaced relative to one another along the length and width thereof.
The panel member further comprises a plurality of intermediate layers 24 which are stacked between the inner and outer skin layers. Each intermediate layer comprises a woven fabric material formed of aramid fibres in the form of Kevlar™ or other like materials. The intermediate layers 24 are each formed into a sheet which spans generally in the direction of the inner and outer skin to remain parallel thereto along length and width thereof. Up to 200 or more intermediate layers 24 may be provided.
A plurality of fastening members 26 are provided which span under tension between the inner and outer skin layers so as to be arranged to maintain all of the intermediate layers 24 under compression between the inner and outer skin layers. The inner and outer skin layers are joined by the fastening members in a manner such that the intermediate layers 24 are compressed to approximately half of their original uncompressed thickness between the inner and outer skin layers so that an overall thickness of the assembled panel member is typically between one to two inches in thickness when using 200 intermediate layers. The fastening members 26 serve to maintain the intermediate layers 24 under compression which may be greater than 500 psi and preferably greater than 1000 psi. Pressures of up to 2500 psi are known to be desirable and yet greater pressures may increase the effectiveness of the resistance to bullets of the panel member 10. The fastening members 26 comprise a plurality of individual members at evenly spaced positions relative to one another in laterally and longitudinally spaced directions perpendicular to one another to define an evenly spaced array following a perpendicular grid pattern which ensures even compression of the intermediate layers along the length and width thereof. The fastening members 26 are received through preformed holes in the intermediate layers 24.
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In preferred embodiments both the inner and outer skin layers comprise a rigid metal having a relatively high strength. In some embodiments it may be desirable to have the outer skin layer 20 comprise a tougher and more ductile metal such as aluminium relative to the inner layer which may comprise a more rigid and harder metal, for example certain types of steel. In further embodiments both the inner and outer skin layers may comprise a similar steel alloy.
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Evidence of the effectiveness of compression of intermediate layers of woven aramid fibres between rigid skin layers can be found in the following experimental results.
In a first experiment, a target was placed at 5 meters distance. A Glenfield model 30a firearm manufactured by Marlin Firearms Co. North Haven, Conn. was used with Winchester Super X 150 gr. Power point, (soft point) projectiles with a muzzle velocity of 2390 ft/sec. The purpose was to determine the limitations of compressed Kevlar™ within a skin of soft steel, and in turn apply this knowledge to creating a bullet and bomb resistant barrier for “light duty” vehicles used by allied military and domestic police forces.
A target block comprised common hot rolled soft steel, ⅛″ thick including a square tube 4″×4″×2″ deep and two flat end plates 3¾″×3¾″. The intermediate layers comprise Kevlar™ manufactured by Canadian body armor ltd. rated at level 2. This material was cut to fit within the square tube to form 120 layers. Each layer was packaged with packing tape into bundles of 10 layers. This would later assist in counting the number of layers penetrated to the nearest 10th layer.
Assembly involved welding the front faceplate onto the rearward surface, flush with the outside edge of the square tube. A hydraulic press then compacted the 120 layers of Kevlar™ between both end plates to approximately 2500 lbs/square inch. The total depth of this material, including both steel plates was measured at 1.5 inches. This resulted in a void inside the rear of the 4″×4″ square tube of ½ inch. This void was created to prevent any extra support or backing for the rear plate once it was fired upon. We need to determine the strength of this material, and the rear plate on its own. Under the hydraulic pressure the rear plate was then welded in place. The press was then retracted and the pressurized area is maintained between the front and rear plates.
Three projectiles were fired counter-clockwise at the target block and all three entered near the centre approximately 1 inch apart. Prior to the test, minor outward swelling was observed by the faceplates, most likely the result of the pressure within. All projectiles were contained and disintegrated by the 40th layer. The estimated depth of penetration was ¾ of an inch into the target block. After the test, outward swelling of the rear plate in line with each projectile was apparent. No fracturing occurred on this plate, but the deformity was estimated at ⅜ of an inch. In this experiment the projectiles penetrated up to the 40th layer. In the next example Kevlar™ was reduced to 50 layers to see if the same depth of penetration was seen.
In a second experiment, a similar target was positioned at a 5 meter distance from the same firearm as the previous example with the only difference being the use of 50 layers of Kevlar™ compressed between the end plates instead of 120 layers. Four projectiles were fired in a counter clockwise sequence as follows: Bullet #1 was at top dead centre, ½ inch from the edge of the target; Bullet #2 was at the 11:00 position within ½ inch of Bullet #1; Bullet #3 was at the 9:00 position within ⅛ inch from Bullet #2; and Bullet #4 was at the 4:00 position just over 1 inch away from Bullets #1 & 3. All four projectiles were contained by the 40th layer of Kevlar™, however, a severe impression was apparent in the 50th layer. Bullet #'s 2 and 3 struck within ⅛ inch of one another, and it appears that #3 followed some of #2's internal path. This resulted in the most damage to this target block. Bullet #4 landed further from the first three and left a shock wave imbedded in the 50th layer that measured approximately 2¼ inches wide by ½ inch deep. The rubber backing that was installed behind the Kevlar™ appeared to have no benefits. This material was intended to relieve the swelling of the rear faceplate caused by the projectile, however the internal pressure applied appeared to have limited cushion effect desired.
It was observed that 50 layers of Kevlar™ appear to be enough to safely contain these projectiles at 5 meters, even when one bullet partially followed a pre-damaged path. All bullets were contained by the 40th layer. The final two layers of ½ inch rubber seemed to have allowed a more even swelling of the rear plate. However, the internal pressure applied to this material seems to have limited the cushion effect desired. The shock wave in the 50th layer caused by the 4th bullet was possibly partly due to the rubber matting which influenced the outward re-direction of the impact energy. This material seems to have only a small benefit in relation to the space it would occupy. A ratio shared between the Kevlar™, a layer of internal added steel, along with another a support layer of rubber has been considered to further justify the rubber as an ingredient.
In a third embodiment, the target was again placed at a 5 meter distance with the same firearm and projectiles as the previous embodiment. The intermediate layers from the front end plate to the rear end plate in this instance comprise 30 layers of Kevlar™, followed by an interior steel plate ⅛ inch thick, followed by a ½ inch rubber layer. These layers were assembled similar to the previous embodiments under pressure of approximately 2500 lbs/square inch.
Four projectiles were fired in a counter clockwise sequence comprising: Bullet #1 at a 2:00 position 1½ inch from the right edge of the target; Bullet #2 at a 10:00 position ½ inch from left edge of the target; Bullet #3 at the 8:00 position ½ inch from a bottom left corner of the target; and Bullet #4 at the 6:00 position ¾ inch from the bottom centre of the target. All four projectiles were contained, and each were spaced far enough from one another that one did not affect the path of the other. It appears that all four bullets penetrated through all the layers except for the rear plate. No fractures in this plate are apparent, but a definite imprint was visible. 30 layers of Kevlar™ appears to be inadequate to contain these projectiles. The single layer of ⅛th metal did not supply enough backing to allow the ½ in rubber to disperse the blunt force of the projectile. The ½ inch rubber matting couldn't make up for the lack of endurance of the previous two layers of Kevlar™ and ⅛th metal. From the information gathered from experiment #1 and #2 it appears that it would be reasonable to assume that 50 layers of Kevlar™ under 2500 lbs/sq.in. are adequate to contain the 150 gr 30-30 calibre bullet at 5 meters distance. Further experiments involve more powerful firearms.
In a fourth experiment, a similar target was placed 5 meters from a Ruger m77 mark ii firearm using federal power-shok 175 gr.(soft point) projectiles at a muzzle velocity of 2860 fps/energy=3180 ft-lbs. The same target construction of end plates was used in this instance with 70 intermediate layers of Kevlar™ under 2500 lbs/square inch of pressure. Each layer was packaged with packing tape into bundles of 10 layers. This would later assist in counting the number of layers penetrated to the nearest 10th layer. A single projectile was fired which passed completely through the target block. The 70 layers of Kevlar™ along with the ⅛th thick rear faceplate are believed to be not strong enough to contain a 7 mm bullet.
In the 5th experiment, the same firearm and projectiles were used as the 4th experiment at a distance of 5 meters, however the target block was varied in that 160 intermediate layers of Kevlar™ were instead compressed between both end plates by approximately 2500 lbs/square inch. Four projectiles were fired in a counter clockwise sequence and all four bullets landed within 1.25 inches to the centre of the target block. The four bullets were all successfully stopped, however the energy forced on the target block tore the rear plate mostly off the weld. The 160 layers of Kevlar™ appear to be strong enough to contain a 7 mm bullet. The weld fracture on the rear plate is believed to be due to the poor quality weld. Due to swelling at the rear of the target, a minimum of 1.5 inches between the rear plate and the backstop is recommended to prevent unwanted bracing against any energy coming from the projectiles.
According to a 6th experiment, a similar projectile and firearm as the previous two embodiments was used at a distance of 5 meters from the target. The target was again assembled with 160 intermediate layers of Kevlar™. Each layer was packaged with packing tape into bundles of 10 layers. No compression was used in this experiment however to compare if compressing Kevlar™ has benefit. Accordingly the 160 layers were simply laid inside the target block in this instance. The final depth of Kevlar™ along with the face and rear plates amounted to 2.5 inches. Six projectiles were fired. Bullet one and two were contained with minimal damage, however, bullet #3 landed within a ¼ inch and appears to have followed the path of bullet #2. As a result bullet #3 penetrated the block, however, no evidence was found of it entering the backstop. Also bullet#3 appears to have torn the rear plate off the weld. Projectiles 4, 5, and 6 were then fired, all with minimal damage, these three rounds landed within ½ inch of one another. The 160 layers of uncompressed Kevlar™ appear to be strong enough to contain a 7 mm bullet, however the target was required to be considerably thicker.
In the following 7th experiment, the same firearm and projectile were used at a distance of 5 meters from the target. The target block was assembled to comprise 160 intermediate layers of Kevlar™ between the inner and outer end plates, compressed to approximately 2500 lbs/square inch. Six projectiles were fired. Bullets 1, 2, and 3 landed in a triangle shape within ½ of an inch of one another. All three were contained. Bullets 4, 5, and 6 were then fired and landed similar to a straight line left to right, with bullet #6 within ⅛th of an inch from bullet #2. As a result #6 penetrated the target block and was embedded well within the wooden backstop. The 160 layers of compressed Kevlar™ appear to be strong enough to contain a 7 mm bullet. The reason projectile #6 penetrated the block appears to have been due to the fact that it found part of the path in the Kevlar™ created by bullet #2. The other 5 projectiles landed within that same region approximately 318th of an inch apart and failed to create their own path clean thru.
The compressed Kevlar™ has created not only a thinner barrier, but also a stiffer barrier than that of the uncompressed version. This effect can be seen along the outside perimeter of the block. This area has collapsed more on the compressed version. Both blocks had 6 projectiles impacted thereon and both blocks were left with a 2 inch void between the rear plate, and the wooden backstop. It should stand to reason that the damage in this area should be very similar. The only change between these two blocks is the pressure applied to one. Upon initial appearance the overall swelling of the rear plate of the compressed version seems to have suffered more inflammation than the non-compressed target which is believed to be a result of the projectiles impacting in closer proximity to one another. Upon observation of the experimental results, it appears that when there is any damage already present from a previous projectile impact causing lines of weakness in the panel member, the compression of the layers results in more resistance against subsequent projectiles following the lines of weakness in the panel member. The panel member is accordingly more resistant to multiple projectile impacts when the layers are compressed.
In the next and 8th experiment, a target block was prepared with 200 layers of Kevlar™ under pressure, but with aluminum forming the surrounding case. The Kevlar™ was also compressed with common grade 5 bolt fasteners. By using the bolts instead of the hydraulic press we can more accurately control the pressure, and furthermore this method allows us to apply and maintain the pressure by hand. A torque wrench can be used to estimate the pressure applied. In addition no welding on the case is done, which in turn prevents the Kevlar™ from being burnt and damaged.
In the 8th experiment, the same projectile and firearm are used as the previous embodiment at a distance of 5 meters from the target. ⅛ inch aluminum plate was used to form the end plates surrounding the intermediate layers therebetween. Four ⅜th inch diameter×3½ inch long grade 5 carriage bolts joined the end plates with the Kevlar™ under compression therebetween. The bolts were installed thru both of plates approximately 1″ in from the each of the four corners. The upper and lower edges of this plate were then bent forward to form the top and bottom sides of this target block.
Three Projectiles Were Fired. Bullet one landed approximately 3″ down and 1″ inch in from the top left corner of this block. It created a swelling on the back plate of approximately 1¼ inch in depth. Along with this swelling this impact pulled the side edge of the rear faceplate away from its original position. The sideward movement was due to the fact that this plate has no support on the edges other than the four bolts. Bullet two landed in the far right corner, striking the top edge of the head of the bolt there. This bolt head interfered with the impact somewhat, and as a result minimal damage was seen on the block in this area. This impact started what seemed to be a previous weak spot along the edge just above the impact point. Bullet three landed approximately 2 inches above bullet 2. The tear in the rear plate from the previous bullet has allowed bullet 3 to continue this same rip to a point where it nearly came thru. This rip went from approximately 1 inch to approximately 4 inches. The 200 layers of compressed Kevlar™ appear to be more than adequate to contain the projectiles. The aluminum was used to lighten the overall weight of the breaker, and due to the fact that it is rust resistant. The swelling caused by the 1st bullet was considerably more than what was seen previously with the steel material. As a result if softer material is used an increase in its thickness to ¼ inch is recommended. The bolts work very well to contain the pressure, and are easy to apply.
The principle design of the present invention as described herein relates primarily to compressing layers of bullet resistant fabric between two outer layers of steel. These skin layers of steel provides structure and strength to contain the pressure of the fabric as well as the added ability to hold various shapes and contours that may allow it to be moulded along with other pre-formed structures, such as a car door.
The assembly of this product would be completed by inserting fasteners into a pattern of pre-punched holes through the layers of fabric and steel. These fasteners may include a variety of methods such as rivets, threaded rod, straight rod with bent ends, as well as the metal case being fused by welding. Depending on the use of other concerns, each method holds a valid place in the productions of the bullet resistant member described herein.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
Claims
1. A bullet resistant panel member for protecting an object from a projectile, the panel member comprising:
- an outer skin layer comprising a rigid sheet of material arranged for facing outwardly away from the object;
- an inner skin layer comprising a rigid sheet of material arranged for facing inwardly towards the object;
- a plurality of intermediate layers between the outer skin layer and the inner skin layer, each intermediate layer spanning generally in a direction of the outer skin layer and the inner skin layer, and each intermediate layer comprising a woven material of aramid fibers; and
- a plurality of fastening members connected under tension between the outer skin layer and the inner skin layer such that the intermediate layers are compressed under pressure between the outer skin layer and the inner skin layer.
2. The panel member according to claim 1 wherein each intermediate layer comprises a sheet of Kevlar™ material.
3. The panel member according to claim 1 wherein the fastening members maintain the intermediate layers under a pressure of greater than 500 psi.
4. The panel member according to claim 1 wherein the fastening members maintain the intermediate layers under a pressure greater than 1000 psi.
5. The panel member according to claim 1 wherein the fastening members are arranged to maintain the intermediate layers under a pressure near 2500 psi.
6. The panel member according to claim 1 wherein the fastening members are arranged to compress the intermediate layers to a combined thickness which is near half a thickness of the intermediate layers between the inner and outer skin layers before compression.
7. The panel member according to claim 1 wherein the compressed intermediate layers have a thickness between the inner and outer skin layers which is generally within a range of one to two inches.
8. The panel member according to claim 1 wherein there are provided near 200 or greater intermediate layers.
9. The panel member according to claim 1 wherein the inner and outer skin layers comprise a rigid metal.
10. The panel member according to claim 9 wherein the outer skin layer is formed of a softer metal than the inner skin layer.
11. The panel member according to claim 1 wherein the fastening members comprise threaded mechanical fasteners.
12. The panel member according to claim 1 wherein the fastening members are arranged in a spaced apart grid pattern relative to one another.
13. The panel member according to claim 1 wherein the fastening members are oriented at various inclinations from an axis extending perpendicularly between the outer and inner skin layers such that some of the fastening members are non-parallel to other ones of the fastening members.
14. The panel member according to claim 1 wherein the fastening members are arranged in pairs which extend from the outer skin layer to the inner skin layer angularly offset in diametrically opposed directions from an axis extending perpendicularly between the outer and inner skin layers.
15. The panel member according to claim 1 wherein the fastening members are received through preformed apertures formed in the intermediate layers.
16. The panel member according to claim 1 in combination with an object to be protected having a non-planar surface wherein the inner and outer skin layers are shaped so as to conform to a shape of the non-planar surface of said object to be protected such that the inner and outer skin Layers are evenly spaced apart from one another along a width and a length thereof.
17. The panel member according to claim 16 wherein the object to be protected comprises a vehicle and the non-planar surface is a portion of the body of the vehicle and wherein the inner and outer skin layers are shaped to conform to the non-planar surface forming the portion of the body of the vehicle.
18. The panel member according to claim 17 wherein the inner and outer skin layers are arranged to be continuous across a length and a width of the vehicle.
19. The panel member according to claim 1 wherein some of the intermediate layers adjacent the inner skin layer have greater dimension in a direction the inner skin layer extends than other ones of the intermediate layers nearer to the outer skin layer.
20. The panel member according to claim 1 wherein each intermediate layer is progressively larger in dimension in a direction that the skin layers span than a previous one of the intermediate layers from the outer skin layer to the inner skin layer.
Type: Application
Filed: Jan 30, 2009
Publication Date: Nov 22, 2012
Inventor: Kenneth C. Tatarliov (Minton)
Application Number: 12/362,883
International Classification: F41H 7/00 (20060101); F41H 5/013 (20060101); F41H 5/04 (20060101);
