Patent Publication Number: US-9428872-B2

Title: Anti-ram vehicle barrier system

Description:
RELATED APPLICATIONS 
     This application is a non-provisional patent application of Ser. No. 61/234,118, filed on Aug. 14, 2009. 
     This application is a continuation-in-part of Ser. No. 12/813,457, filed on Jun. 10, 2010, which is a non-provisional patent application of Ser. No. 61/185,930, filed on Jun. 10, 2009. 
     This application is a continuation-in-part of Ser. No. 12/057,181, filed on Mar. 3, 2008, now U.S. Pat. No. 8,083,433, which is a non-provisional patent application of Ser. No. 60/908,391, filed Mar. 27, 2007, all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates in general to barriers to vehicular traffic and more specifically to an above grade, barrier to arrest a vehicle that attempts to breach the barrier by ramming the vehicle into the barrier. 
     BACKGROUND 
     This section provides background information to facilitate a better understanding of the various aspects of the present invention. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art. 
     Vehicle barrier systems are utilized to guard against access to protected areas. In particular, the systems are provided to stop motor vehicles, such as trucks, from being intentionally driven into certain areas for nefarious purposes. At least one agency of the United States Government has provided standards to certify barriers for use. Heretofore, it has commonly been believed that vehicle systems must be so called mass-to-mass systems, wherein the barrier comprises structures of great mass to counteract the mass and kinetic energy of the impacting vehicle. 
     SUMMARY 
     According to one or more aspects of the invention an anti-ram vehicle barrier system for arresting an impacting vehicle of substantial mass within a selected distance of the barrier comprises a pair of terminal posts positioned in and secured to the ground in a spaced apart relationship; at least three cables, each cable having opposing terminal ends connected respectively to each of the terminal posts, the at least three cables held in tension a distance above a grade of the ground and vertically spaced apart from one another in relation to the grade; and a line post secured in the ground and positioned between the pair of terminal posts, the line post holding a portion of each of the cables. 
     According to one or more aspects the anti-ram vehicle barrier system includes a gate for arresting an impacting vehicle of substantial mass within a selected distance of the barrier. According to one or more aspects of the invention the gate comprises a cable extending across a panel, the panel movable between a closed position blocking an entry port and an open position; a first post secured in the ground on a first side of the entry port, wherein a first end of the panel is connected to the first post; and a second post secured in the ground on a second side of the entry port, wherein the second end of the panel is connected to the second post. According to at least one embodiment, the panel is moved laterally relative to the ground to open and close the gate. According to some embodiments, the panel is moved vertically relative to the ground to open and close the entry point. In some embodiments, the panel is moved to a position below the ground level when the entry port is opened. 
     A method according to one or more aspects of the invention of arresting a vehicle of substantial mass from penetrating into a protected area comprises providing a barrier fence, the barrier fence comprising a pair of terminal posts positioned in and secured to the ground in a spaced apart relationship and a cable having opposing terminal ends connected respectively to each of the terminal posts, the cable held in tension a distance above a grade of the ground between the pair of terminal posts and a gate; impacting a motor vehicle having a substantial mass and moving at a rate of speed into the barrier fence; and stopping penetration of an identified portion of the vehicle from extending a selected distance beyond the cable. 
     The foregoing has outlined some of the features and technical advantages of the invention in order that the detailed description of specific embodiments of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion. 
         FIG. 1  is an elevation view of an embodiment of a vehicle barrier fence according to one or more aspects of the present disclosure. 
         FIG. 2  is a plan view of an embodiment of the vehicle barrier fence of  FIG. 1 . 
         FIG. 3  is a plan view of an embodiment of a terminal post according to one or more aspects of the present disclosure. 
         FIG. 4  is an elevation view of an embodiment of a portion of a terminal post according to one or more aspects of the present disclosure. 
         FIG. 5  is a view of a terminal post along the line I-I of  FIG. 3 . 
         FIG. 6  is a plan view of an embodiment of a corner type terminal post according to one or more aspects of the present disclosure. 
         FIG. 7  is a plan view of an embodiment of a line post according to one or more aspects of the present disclosure. 
         FIG. 8  is an elevation view of a portion of the line post of  FIG. 7 . 
         FIG. 9  is an elevation view of an embodiment of a cable spacer mechanism according to one or more aspects of the present disclosure. 
         FIG. 10  is a plan view of an embodiment of a gate according to one or more aspects of the present disclosure. 
         FIG. 11  is an elevation view of an embodiment of a gate according to one or more aspects of the present disclosure. 
         FIG. 12A  is a schematic elevation view of a latch post according to one or more aspects of the present disclosure depicting terminals ends of cables secured to a latch post. 
         FIG. 12B  is a schematic elevation view of a latch post according to one or more aspects of the present disclosure depicting terminals ends of cables disconnected from the latch post. 
         FIGS. 13A, 13B  are schematic side and plan views of a post device according to one or more aspects of the present disclosure. 
         FIGS. 14A, 14B  are schematic views of cable spacing according to one or more aspects of the present disclosure. 
         FIG. 15  is an elevation view of an illustrative embodiment of a pop-up gate according to one or more aspects of the present disclosure. 
         FIG. 16A  is an exploded view of another embodiment of a terminal post according to one or more aspects of the present disclosure. 
         FIG. 16B  is a cut-away view of the terminal post depicted in  FIG. 16A . 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. 
       FIG. 1  is an elevation view of an embodiment of a vehicle barrier of the present invention generally denoted by the numeral  10 .  FIG. 2  is a plan view of barrier fence  10  depicted in  FIG. 1 .  FIG. 2  further illustrates a motor vehicle  6 , depicted as a truck having a bed  6 , moving in the direction of the arrow toward barrier fence  10 . The hatched line  7  represents a distance L1 of 36 inches from barrier fence  10 . In the depicted embodiment, vehicle  5  has a mass of 15,000 pounds. 
     The depicted embodiment is of a longitudinal barrier fence  10 , or a portion of a barrier fence. The depicted and described embodiments are for a “K12” rated vehicle barrier. K12 refers to a certification class for the United States Department of State. A K12 rating, or certification, requires that the barrier must prevent the bed of a 15,000 pound (6810 kg) truck, traveling at the speed of 50 miles per hour (80 kilometers per hour) from penetrating the barrier more than 36 inches (55 cm) indicated as “L1” in  FIG. 2 . Barrier fence  10  is also adapted for stopping vehicle  5  within the limits of L1 when traveling 30 miles per hour (48 kph) and 40 mph (65 kph) for obtaining a K4 and a K8 certification respectively. Unexpectedly, a barrier fence corresponding to an embodiment of the present disclosure has been shown to meet the criteria for a K12 certification. Barrier fence  10  is not a mass to mass type barrier that is commonly utilized to achieve the standards necessary for a United States Department of State certification. 
     Referring to the embodiments of  FIGS. 1 and 2 , barrier fence  10  includes cables  12 , terminal posts  14 , and line posts  16 . Barrier fence  10  may further include one or more cable spacing members  18  and/or a security fencing generally denoted by the numeral  20 . In  FIG. 1 , fencing  20  is depicted as chain link, although other fencing materials including without limitation barb wire, razor wire, wood fencing, and iron. Fencing  10  may be provided to limit or prevent passage of pedestrians, provide an aesthetic covering, or to conceal the vehicle barrier system. 
     For purposes of brevity and clarity, barrier fence  10  is described herein with reference to a fence or section of fence extending between opposing terminal posts  14 . “Terminal” is utilized herein in designating posts to which the terminal end of a cable  14  is connected. Terminal posts  14 , as described further below, may be positioned along a longitudinal section or portion of barrier fence  10  or be a corner post. Corner terminal posts are generally utilized for changes of direction in the section of fence. For example, it may be desired to utilize a corner terminal post for a change in direction of cable  12  of greater than about 15 degrees. As will be readily understood, a terminal post  16  may be an “in-line” post wherein the terminal end of a first cable  12  extending a first direction is connected and the terminal end of a second cable  12  that extends a different direction from the first direction (for example 180 degrees) is connected. 
     Referring now to the embodiment depicted in  FIGS. 1 and 2 , three cables  12  extend between opposing terminal posts  14   a ,  14   b . Cables  12  are vertically spaced apart from one another relative to the grade  22  of ground  24 . For example, in  FIG. 1  each of the cables  12  are spaced approximately 6 inches (9 cm) from one another and the lowest cable  12  is spaced about 20 inches (30.8 cm) from grade  22 . 
     Each cable  12  has opposing terminal ends, generally denoted by the numeral  26 , and identified separately as ends  26   a ,  26   b . Each terminal end  26  is connected to terminal post  14 . As will be further described below, terminal end  26  is hingedly connected to terminal post  14  in the embodiments of  FIGS. 1 and 2 . In the depicted embodiment, terminal posts  14   a  and  14   b  are spaced apart a distance D1. D1 corresponds to the length of cable  12  when it is pulled taught and in position for arresting an impacting motor vehicle. For example, a wire cable  12 , having tensile strength of approximately 40,000 pounds (88,000 kg) may span distance D1 when tensioned to about 500 pounds (1,100 kg). In the depicted embodiment, D1 is no greater than about 2,000 feet (609 m). 
     Terminal posts  14  are secured into ground  24  by securing means  28 . In the depicted embodiments, securing means  28  is reinforced concrete. Terminal post  14  may further be secured and stabilized by an anchor mechanism  30 . Anchor mechanism  30  may include a cross-member  32  secured between terminal post  14  and an anchor  34  positioned in ground  24 . In the depicted embodiment, anchor  34  is spaced approximately eight feet from terminal post  14  and secured in ground  24  by reinforced concrete. Cross-member  32  is a metal tube. 
     Positioned between terminal posts  14  are one or more line posts  16  which are spaced apart a distance D2. One or more line posts  16 , described further with reference to  FIGS. 7 and 8 , are positioned between terminal posts  14 . Line posts  16  are positioned and secured in ground  24  by a securing means  24 . Line post  16  is operationally connected to cables  12  in a manner to absorb energy from an impacting vehicle and reduce the force that must be absorbed by terminal posts  14  and the cable to terminal post connections. In the depicted embodiments, line posts  16  are spaced from one another no more than about 20 feet (6 m). As will be described further below, cable  12  does not terminate at line posts  16  but is in operational connection to line posts  16 . 
     Cable spacing members  18  are depicted in  FIG. 2  connected to cables  12  and along the span of cables  12 . Spacing members  18  tend to maintain cables  12  in a spaced apart relationship when impacted by a vehicle, and therefore maintain contact with the vehicle. Various mechanisms may be utilized to space cables  12  vertically apart, such as but not limited to the embodiment depicted in  FIG. 9 . Spacing mechanisms  18  may be independently connected to cables  12  or interconnect cables  12  and a post member. 
     For example, with reference to  FIG. 1 , spacers  18  may be connected to intermediate posts  36 . Intermediate posts  36  are, in this embodiment, tubular posts that are positioned into ground  24 . Posts  36  are not necessarily secured in ground  24 . In the depicted embodiments, posts  36  are provided for erecting fencing  20  and provide an additional structure to cooperate with spacing members  18 . Spacing members  18  and intermediate posts may be evenly spaced from one another, for example, by the distance D3 which is approximately 10 feet (3 m) in these embodiments. Cables  12  may be spaced apart, for example, by securing each cable to posts  36  in a spaced apart relationship by a U-bolt or other suitable connector. It is envisioned that a spacing mechanism  18 , such as depicted in  FIG. 9 , that is solely connected to cables  12  may facilitate the maintenance of the desired spacing during impact by a vehicle. 
     Refer now to  FIG. 3 , wherein an embodiment of a terminal post-cable connection, generally denoted by the numeral  38 , is shown. First, terminal post  14  is a tubular member having an internal cavity  40  and a face portion  42 . Face portion  42  is a portion of the wall of tubular post  14  that is facing the direction in which a cable  12  extends, or the portion through which cable  12  extends. In the depicted embodiments, post  14  is depicted as a square or rectangular member, although other geometric shapes may be utilized. For example, terminal post  14  may be circular or triangular as well. 
     In the embodiment of  FIG. 3 , a terminal post-cable connector  38  includes a spelter socket  44  and plate  46 . In this embodiment, terminal end  26  is connected within spelter socket  44 , for example with zinc or an epoxy resin, and hingedly connected to plate  46  by pin or shaft  48 . Plate  46  is connected to the body of terminal post  14  with cable  12  extending outward from face portion  42 . In the depicted embodiment, spelter socket  44  and terminal end  26  are substantially positioned in cavity  40 . 
     Refer now to  FIG. 4 , wherein a face portion  42  of a terminal post  14  is depicted having a slot  56  for passing cable  12 . Slot  56  is a transverse slot that is substantially parallel with the grade and perpendicular to the vertical extension of the post from the ground. Face portion  42  in the depicted embodiment includes a window  50  formed for each cable  12  and cable to post connector. Window  50  is provided as one manner of positioning connection  38  of  FIG. 3  in cavity  40 . An open leg or slot portion  52  is also formed through face portion  42  for positioning a cable  12 . A cover  54  is provided for connecting over a portion of window  50  while providing an open slot  56  that includes leg  52 . Slot  56 , which is formed through face portion  42 , provides for transverse or longitudinal movement of cable  12  during impact by a vehicle thereby limiting or avoiding impact of the cable along the physical body forming the slot. 
     Refer now to  FIG. 5  wherein the terminal-post connection  38  is shown along the line I-I of  FIG. 3 . The cables  12  are spaced vertically apart from one another, relative to the ground, and interconnected by a shaft  48  in this embodiment. 
       FIG. 6  is a plan view of an embodiment of a corner terminal post  14 . In this embodiment, cable  12   a  is extending a direction substantially at a right angle to the direction of cable  12   b . However, cables  12   a  and  12   b  may extend at varying angles from one another. 
     Refer now to  FIGS. 7 and 8  wherein an embodiment of a line post  16  and a line post-cable connection are depicted. Line post  16  is depicted as a tubular post having an internal cavity  58 . In this embodiment, line post  16  is a rectangular or square member having opposing sidewalls  60   a  and  60   b  and an interconnecting face plate  62 . Face plate  62  includes an interior surface  64  directed into cavity  58 . Positioned on interior surface  64  is a spacer member  66 . Positioned in cavity  58  is a stop  68  that is spaced apart from spacer member  66  to form a trap  70 . Thus, trap  70  is defined between spacer member  66 , stop  68 , and opposing sidewalls  60   a ,  60   b . A slot or track  72  ( FIG. 8 ) is formed through each opposing sidewall  60   a ,  60   b  for passing a corresponding cable  12 . 
     Each cable  12  carries a clamping member  74 . Clamping member  74  is secured to cable  12  and then positioned in trap  70  so as to be substantially held in place with regard to post  16 . It is noted that in this embodiment, face plate  62  is connected between opposing sidewalls  60   a ,  60   b  by a connection means  76  such as welding. Face plate  62  is connected to opposing walls  60   a ,  60   b  after cable  12  and clamps  74  are positioned in cavity  58  and against stop  68 . When face plate  62  is connected, cables  12  are positioned within tracks  72 . Tracks  72 , like terminal post slots  56  ( FIG. 4 ), provide for movement of cable  12  when impacted by a vehicle while mediating damage to cable  12  by contact with the physical structure forming the slots. 
     Refer now to  FIG. 9 , wherein an embodiment of a cable spacing mechanism  18  is shown in isolation. In this embodiment, mechanism  18  is an elongated member formed in symmetrical longitudinal sections  18   a  and  18   b . Each half includes a portion of a cable passage  78 . Sections  18   a  and  18   b  are positioned together such that each passage  78  disposes a cable  12 . Sections  18   a  and  18   b  may then be interconnected by welding or the like. 
       FIG. 10  is a plan view of a gate assembly according to one or more aspects of the present disclosure generally denoted by the numeral  100 . Assembly  100  comprises a gate  110  (e.g., panel) depicted in the closed position in  FIGS. 10 and 11 . Gate  110  comprises one or more elongated cables  112  which extend from a first end  113  to a second end  115 . In the depicted embodiment, first end  113  is adapted to be releasably connected to latch post  114 . Depicted in  FIGS. 10 and 11 , latch post  114  is immovably secured in the ground  99 . Latch post  114  comprises a pin assembly  116  depicted in  FIGS. 12A and 12B  for releasably securing cables  112  to latch post  114  thereby securing gate  110  in the depicted closed position. An actuator  118 , depicted in  FIG. 10 , may be connected with the pin assembly for operating the pin assembly  116  between the closed position ( FIG. 12A ) to the open position ( FIG. 12B ). As will be understood by those skilled in the art with the benefit of the present disclosure, pin assembly  116  may be operated via various mechanical systems and/or manually by an operator. Examples of actuator  118  include, without limitation, fluidic cylinders, electric motors and the like. 
     The second end  115  of cables  112  are connected to an end assembly  120 , see  FIGS. 10, 11, 13A and 13B  for example. Depicted gate  110  further comprises two or more vertical members  122  (e.g., pickets). For example, as depicted in  FIG. 11 , gate  110  comprises a plurality of spaced apart vertically oriented pickets  122  interconnected by at least two horizontally (e.g., laterally) oriented members  124 . A moving mechanism  125  (e.g., motor, actuator) can be connected to gate  110 , for example via chain  126  ( FIG. 11 ) to move gate  110  between the open and closed position. In this embodiment, gate  110  (e.g., panel) is moved laterally or horizontally relative to the ground. In some embodiments, for example as depicted in  FIG. 15 , gate  110  is moved vertically relative to the ground surface  99  (e.g., grade) between the open and closed positions. 
     According to one or more aspects of the present disclosure, end assembly  120  is adapted to engage a post device  128  when gate  110  is in the closed position. Depicted in  FIGS. 10 and 11  post device  128  is depicted secured in ground  99 , for example by concrete  129 . In some embodiments, post device  128  can contain concrete  129 . In the embodiment depicted in  FIGS. 10-11 , post device  128  is stationary and the end assembly  120  is moved laterally away, for example to the right in  FIG. 11 , from post device  128  when gate  110  is moved from the closed position as shown in  FIGS. 10 and 11  to the open position. In one or more embodiments, gate assembly  100  may comprise a pop-up gate  110 , depicted for example in  FIG. 15  and further described below, wherein the panel is moved vertically relative to the posts on opposite ends of the entry port. In combination, post device  128  and end assembly  120 , can be referred to as a post or as a hinge post. 
     In the depicted embodiment, a support  130  is secured in ground  99 , for example by concrete. Support  130  is depicted located between entry port  132  and post device  128  in the embodiment of  FIGS. 10 and 11 . Support  130  is shown located in  FIG. 10  on the interior side of gate  110  such that gate  110  is between support post  130  and a vehicle  5  that is approaching entry port  132  from exterior gated area. Referring to  FIGS. 14A and 14B , elements  134  can extend from support post  130  in a manner to space cables  112  from one another. 
     Refer now to  FIG. 12A  wherein the first ends  113  of cables  112  are shown connected and thus secured to latch post  114  and  FIG. 12B  wherein the first ends  113  of cables  112  are shown disconnected from latch post  114 . In the depicted embodiments, connectors  44  (e.g., spelter sockets, cable clamps, etc.) are connected to ends  113  of cables  112 . Pin assembly  116  is utilized to connect and secure connectors  44  and thus cables  112  to latch post  114 . 
       FIG. 13B  is a plan view of post device  128  depicting the position of end assembly  120  when gate  110  is in the closed position according to one or more aspects of the present disclosure. Referring in particular to  FIGS. 10, 11, 13B and 15 , post device  128  comprises a pair of spaced apart members  128   a ,  128   b  defining a interior passage  136 . Passage  136  is adapted to pass gate  110 . As clearly depicted in  FIG. 13B  end assembly  120  can include members  121  for engaging post device  128 . In the depicted embodiment, terminal end  115  of cable  112  is depicted connected to end assembly  120  via pin  48 . Referring to the schematic elevation view of  FIG. 13A , terminal ends  115  are depicted moveably, for example rotationally or hingedly connected to end assembly  120  and pin  48 . In various embodiments, end assembly  120  is moveable relative to post device  128 , for example, when gate  110  is moved between the open and closed position. For example, in the embodiment depicted in  FIGS. 10 and 11 , end assembly  120  is moved laterally to the right away from post device to open the gate, i.e., move gate  110  out of a position blocking entry port  132 . In the embodiment further described below with reference to  FIG. 15 , end assemblies  120  positioned on opposing sides of entry port  132  and connected to opposing ends of cable  112  (e.g., gate  110 ) are moved vertically relative to post device  128 . 
     Refer now to  FIG. 15 , wherein an illustrative embodiment of a pop-up gate according to one or more aspects of the present disclosure. In the depicted gate assembly  100 , gate  110  is secured between two end assemblies  120 . Similar to the embodiment described above with reference in particular to  FIGS. 10, 11 and 13B , end assembly  120  is moveably disposed with post device  128 . However, in the depicted pop-up embodiment, end assembly  120  is moveable relative to post device  128  vertically relative to ground level  99 . In this embodiment, an actuator  210  (e.g., fluidic cylinder) is provided to move gate  110  between a position above ground  99  as depicted and below ground  99  wherein it is disposed in cavity  212 . In some embodiments, gate  110  is not positioned below ground  99  when in the open positioned but raised above ground  99  a sufficient distance to permit passage through the entry port. 
     Refer now to  FIGS. 16A and 16B , wherein  FIG. 16A  is an exploded view of another embodiment of a terminal post  14  and terminal post-cable connection  38  and  FIG. 16B  is a cut-away schematic of terminal post  14 . Depicted terminal post  14  is a tubular member having an internal cavity  40  and a face portion  42 . Face portion  42  is a portion of the wall of tubular post  14  that is facing the direction in which a cable  12  extends. In the depicted embodiment, terminal post  14  is a square or rectangular member, although other geometric shapes may be utilized. 
     In this embodiment terminal post-cable connector  38  includes a cable clamp  144  ( FIG. 16A ) in which the terminal end of cable  12  is secured. In the depicted embodiment, each cable  12  is secured to a separate cable clamp  144 . Each cable  12 , when attached to terminal post  14 , extends through a respective opening  56 , referred to as a slot herein, formed through face  42 . In the depicted embodiment, opening  56  is continuous with an opening  50 , referred to herein as a window, formed through the side wall  41  adjacent to face  42 . The continuous opening  50 ,  56  provides a passage for disposing and securing cable clamp  144  in cavity  40  of terminal post  14 . A cover  54  can be secured to post  14  to cover and close window  50  when desired. 
     Terminal post-cable connector  38  further includes a frame  200  which secures each cable  12  in the desired position within the cavity  40  of terminal post  14 . As will be understood by those skilled in the art with benefit of the present disclosure, frame  200  can be formed in one or more sections. Frame  200  is described herein with reference to a single cable  12  attachment. Frame  200  comprises a face unit  204  and an opposing back unit  206  which are spaced apart a distance substantially equal to the width  143  of cable clamp  144 . In the depicted embodiment, frame  200  comprises a middle member  208  having a width substantially equal to width  143 . Middle member  208  is disposed between face unit  204  and back unit  206 . Depicted front unit  204  (comprising one or more sections) is disposed in cavity  40  and against the interior of face wall  42  with an opening  55  which is co-axial with opening  56  through face  42 . According to one or more aspects of the present disclosure, front unit  204  spaces the intersection point  145  of cable  12  and clamp  144  away from post face  42 . 
     The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure. The scope of the invention should be determined only by the language of the claims that follow. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open group. The terms “a,” “an” and other singular terms are intended to include the plural forms thereof unless specifically excluded.