Patent Publication Number: US-9414681-B2

Title: Flexible seating surface

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to seating surfaces, and more particularly to flexible seating surfaces. 
     Seating surfaces have experienced many advances over the years. For example, the materials used in the seating surface, the manufacturing methods used to create the seating surface, and the visual appearance of the seating surface have all been improved over time. 
     Another area of advancement in seating surfaces involves the contouring of the seat. Much time and effort have been spent designing contoured seats that closely match the shape of a user&#39;s body. Although some prior art surfaces are closely contoured to a user&#39;s body, some of these surfaces still create high pressure areas in certain zones. This results in discomfort for the user, and possibly injury over an extended period of sitting. 
     Some prior art seating surface configurations include slotted configurations. However, in many of these slotted configurations, the slots appear to be randomly spaced across the entire seating surface. Some of these configurations therefore fail to recognize or address the specific high pressure areas present in certain zones of the seat. 
     Further, many prior art seating surfaces are designed for a narrow range of user weights. Many of these surfaces may work well for users within a narrow range of weights, but are less than desirable for users having a weight outside of the intended narrow weight range. 
     Although much advancement has been made in the field of seating surfaces, there remains room for improvement in this technology area. 
     SUMMARY OF THE INVENTION 
     The present invention provides a seat with slots specifically designed and positioned to provide desired support characteristics and relieve pressure for a user while sitting on the seat. The slots may allow cantilevering of various seat portions, which contours the seat based on a user&#39;s weight. This configuration may have beneficial support characteristics similar to a foam seat. 
     In one embodiment, the seat includes a first ischial region, a second ischial region, a tailbone region and a thigh transitional region. Each of these regions includes at least one slot for providing desired support characteristics. A longitudinal axis extends from a front of the seat to a rear of the seat and generally divides the seat into two halves. A center of the seat is located between the first ischial region, the second ischial region, the tailbone region and the thigh transitional region. A plurality of first ischial slots are defined within the seat in the first ischial region and generally open outwardly, away from the center of the seat. A plurality of second ischial slots are defined within the seat in the second ischial region and generally open outwardly, away from the center of the seat. A tailbone slot is defined within the seat in the tailbone region and generally opens outwardly, away from the center of the seat. A thigh transitional slot is defined within the seat in the thigh transitional region and generally opens outwardly, away from the center of the seat. 
     In another embodiment, at least a portion of each of the first ischial slots and the second ischial slots may extend substantially parallel to the longitudinal axis. At least a portion of each of the tailbone slot and the thigh transitional slot may extend at an angle relative to the longitudinal axis. 
     In another embodiment, each slot may include an elongated central portion, a first distal portion and a second distal portion. An end portion may be defined adjacent each distal portion. The central and distal portions may be substantially linear, and the distal portions may extend from each corresponding central portion at an angle. The angles between each distal portion and the corresponding central portion may be substantially equal. 
     In another embodiment, the slots in the seat may have a specific configuration with respect to each other to provide desired support characteristics. The tailbone slot central portion and the thigh transitional slot central portion may be substantially parallel to each other and may be substantially perpendicular to the longitudinal axis. The first ischial slot central portions and the second ischial slot central portions may be substantially parallel to each other and may be substantially parallel to the longitudinal axis. The first ischial slot first distal portions, the second ischial slot second distal portions, the tailbone slot first distal portion and the thigh transitional slot first distal portion may be substantially parallel to each other. The first ischial slot second distal portions, the second ischial slot first distal portions, the tailbone slot second distal portion and the thigh transitional slot second distal portion may be substantially parallel to each other. 
     In another embodiment, the slots in the seat may have a further specific configuration with respect to the longitudinal axis to provide desired support characteristics. The longitudinal axis may separate the first ischial slots and the second ischial slots. The longitudinal axis may intersect the tailbone slot and thigh transitional slot, and may bisect the central portion of each of these slots. 
     In another embodiment, the slots may generally be curved or open outward, away from a center of the seat. The outwardly opening configuration may allow portions of the seat positioned adjacent and outward of each slot to deflect downward relative to the seat surface and outward relative to the center of the seat. 
     In another embodiment, the seat may include a plurality of grooves positioned at a front of the seat to facilitate curling of the front of the seat. The grooves may be substantially linear and may extend substantially parallel to each other and substantially perpendicular to the longitudinal axis. 
     These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiments and the drawings. 
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and may be practiced or may be carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a seat according to one embodiment of the present invention. 
         FIG. 2  is a top view of the seat from  FIG. 1 . 
         FIG. 3  is an enlarged top view of the seat from  FIG. 1 . 
         FIG. 4  is a front view of the seat from  FIG. 1 . 
         FIG. 5  is a side view of the seat from  FIG. 1 . 
         FIG. 6  is an enlarged perspective view of a seat according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE CURRENT EMBODIMENT 
     I. Overview 
     A seat assembly  10  is shown in  FIG. 1  and includes a seat  20  constructed in accordance with one embodiment of the present invention. Although  FIG. 1  illustrates the seat  20  as part of a complete seat assembly  10  with a seat back  14  and support structure  16 , this is only exemplary. The seat  20  may be generally used in connection with any structure intended to provide seated support. 
     As shown in  FIG. 2 , the seat  20  generally includes a longitudinal axis  12  drawn from a front of the seat  20  to a rear of the seat  20  and generally dividing the seat  20  into two equal halves. As shown in  FIG. 2 , the seat  20  includes multiple high pressure regions. A first ischial region  30  is generally positioned below the right ischial (hip) bone of a user and is located on a first side of the longitudinal axis  12 . A second ischial region  60  is generally positioned below the left ischial bone of a user and is located on a second side of the longitudinal axis  12 . A tailbone region  90  is generally positioned below the tailbone of a user and is located rearward of the first and second ischial regions  30 ,  60 . A thigh transitional region  110  is generally positioned between the upper thighs of a user and is located forward of the first and second ischial regions  30 ,  60 . A center of the seat is located between the first ischial region  30 , the second ischial region  60 , the tailbone region  90 , and the thigh transitional region  110 . The first ischial region  30 , second ischial region  60 , tailbone region  90 , and thigh transitional region  110  each include at least one slot specifically designed to provide a desired amount of deflection of the corresponding region of the seat  20  when a user sits on the seat  20 . The slots may generally open outwardly, away from the center of the seat, and may be designed to allow a cantilevering of the areas adjacent to the slots to contour the seat based on a user&#39;s weight. The cantilevering effect and slot configuration was found to provide a substantially consistent support profile over a wide range of user weights. The slot configuration may also allow the seat to achieve the same or a similar magnitude and profile of flexing as is created by some foam materials. 
     II. Structure 
     As shown in  FIG. 3 , the first ischial region  30  includes a plurality of first ischial slots  32 - 38  defined in the seat  20 . The first ischial slots  32 - 38  may be defined partially or completely through the seat  20 . As illustrated, the seat  20  may have four first ischial slots  32 - 38 , although a greater or fewer number of slots may be used depending on the support desired. As illustrated in connection with first ischial slot  32 , each of the first ischial slots  32 - 38  may include a central portion  40 , a first distal portion  42  adjacent a first end of the central portion  40 , and a second distal portion  44  adjacent a second end of the central portion  40 . The central portion  40 , first distal portion  42  and second distal portion  44  may be any suitable shape, including curved and substantially linear. An end portion  46 ,  48  may be defined adjacent and connect with the respective distal portions  42 ,  44 . The end portion  46 ,  48  may be designed to relieve stress in the seat material surrounding the end portions  46 ,  48 . Although illustrated as substantially circular, the end portions  46 ,  48  may have any suitable rounded shape, including an oval or an elongated oval. The distal portions  42 ,  44  may each form an angle  50 ,  52  relative to the central portion  40 . The angles  50 ,  52  may be any suitable angle, and may be unequal or substantially equal. The distal portions  42 ,  44  may have any desired orientation with respect to one another, including being at an angle to one another and being substantially perpendicular to one another. The central portion  40  may extend at an angle to or substantially parallel to the longitudinal axis  12 , and the distal portions  42 ,  44  may extend at an angle to or substantially parallel to the longitudinal axis  12 . The central portions  40  and distal portions  42 ,  44  of each of the first ischial slots  32 - 38  may have any suitable configuration with respect to the other central portions  40  and distal portions  42 ,  44 , including being substantially parallel to or at an angle to the central portions  40  and distal portions  42 ,  44  of each of the other first ischial slots  32 - 38 . The relative sizes of the central portions  40  of the first ischial slots  32 - 38  may vary as desired. As illustrated, the central portion  40  of the first ischial slot  36  may be the longest, followed by the central portion  40  of the first ischial slot  34 , the central portion  40  of the first ischial slot  32 , and the central portion  40  of the first ischial slot  38 . The relative sizes of the distal portions  42 ,  44  of the first ischial slots  32 - 38  may vary as desired. The distal portions  42 ,  44  may be substantially equal in length, or may have unequal lengths. As shown in  FIG. 3 , the central portions  40  may have a greater length than each of the distal portions  42 ,  44 . 
     As shown in  FIG. 3 , the second ischial region  60  includes a plurality of second ischial slots  62 - 68  defined in the seat  20 . The seat  20  may have four second ischial slots  62 - 68 , although a greater or fewer number of slots may be used depending on the support desired. As illustrated in connection with the second ischial slot  62 , each of the second ischial slots  62 - 68  may include a central portion  70 , a first distal portion  72  adjacent a first end of the central portion  70 , and a second distal portion  74  adjacent a second end of the central portion  70 . The second ischial slots  62 - 68  may generally have the same configurations as described above in connection with the first ischial slots  32 , and those configurations will not be redescribed here. The second ischial slots  62 - 68  may have any suitable configuration, including generally being a mirror image of the first ischial slots  32 - 38 . The central portions  70  of each of the second ischial slots  62 - 68  may be oriented substantially parallel to or at an angle to the central portions  40  of each of the first ischial slots  32 - 38 . The first distal portions  72  of the second ischial slots  62 - 68  may be oriented substantially parallel to or at an angle to the second distal portions  44  of the first ischial slots  32 - 38 , and the second distal portions  74  of the second ischial slots  62 - 68  may be oriented substantially parallel to or at an angle to the first distal portions  42  of the first ischial slots  32 - 38 . 
     A tailbone slot  92  may be defined within the seat  20  in the tailbone region  90 . The tailbone slot  92  may be defined partially or completely through the seat  20 . As illustrated, the seat  20  may have one tailbone slot  92 , although a greater or fewer number of slots may be used depending on the support desired. The tailbone slot  92  may include a central portion  94 , a first distal portion  96  adjacent a first end of the central portion  94 , and a second distal portion  98  adjacent a second end of the central portion  94 . The central portion  94 , first distal portion  96  and second distal portion  98  may be any suitable shape, including curved and substantially linear. An end portion  100 ,  102  may be defined adjacent and connect with the respective distal portions  96 ,  98 . The end portion  100 ,  102  may be designed to relieve stress in the seat material surrounding the end portions  100 ,  102 . Although illustrated as substantially circular, the end portions  100 ,  102  may have any suitable rounded shape, including an oval or an elongated oval. The distal portions  96 ,  98  may each form an angle  104 ,  106  relative to the central portion  94 . The angles  104 ,  106  may be any suitable angle, and may be unequal or substantially equal. Optionally, the angles  104 ,  106  may be unequal to or substantially equal to one or more of the angles  50 ,  52 ,  80 ,  82  formed by the first ischial slots  32 - 38  and the second ischial slots  62 - 68 . Further optionally, the angles  104 ,  106  may be unequal to or substantially equal to all of the angles  50 ,  52 ,  80 ,  82  formed by the first ischial slots  32 - 38  and the second ischial slots  62 - 68 . The distal portions  96 ,  98  may have any desired orientation with respect to one another, including being at an angle to one another and being substantially perpendicular to one another. The distal portions  96 ,  98  may be substantially equal in length, or may have unequal lengths. Further, the distal portions  96 ,  98  may have a length unequal to or substantially equal to one or more of the first ischial distal portions  42 ,  44  and second ischial distal portions  72 ,  74 . Optionally, the distal portions  96 ,  98  may have a length unequal to or substantially equal to all of the first ischial distal portions  42 ,  44  and second ischial distal portions  72 ,  74 . The central portion  94  may extend in any suitable direction, including at an angle to or substantially perpendicular to the longitudinal axis  12 . The central portion  94  may be any suitable length, and may have a greater length than each of the distal portions  96 ,  98 . Optionally, the longitudinal axis  12  may intersect the central portion  94 , and further optionally, the longitudinal axis  12  may bisect the central portion  94 . The distal portions  96 ,  98  may extend at an angle to or substantially parallel to the longitudinal axis  12 . 
     The tailbone slot  92  may have any suitable positioning relationship relative to the first ischial slots  32 - 38  and the second ischial slots  62 - 68  to provide desired support characteristics. The tailbone slot central portion  94  may be oriented at any suitable angle, including being substantially perpendicular to one or more of the central portions  40  of the first ischial slots  32 - 38  and the central portions  70  of the second ischial slots  62 - 68 . Optionally, the tailbone slot central portion  94  may be substantially perpendicular to all of the central portions  40  of the first ischial slots  32 - 38  and the central portions  70  of the second ischial slots  62 - 68 . The tailbone slot first distal portion  96  may be at an angle to or substantially parallel to one or more of the first distal portions  42  of the first ischial slots  32 - 38  and the second distal portions  74  of the second ischial slots  62 - 68 . Optionally, the tailbone slot first distal portion  96  may be at an angle to or substantially parallel to all of the first distal portions  42  of the first ischial slots  32 - 38  and the second distal portions  74  of the second ischial slots  62 - 68 . The tailbone slot second distal portion  98  may be at an angle to or substantially parallel to one or more of the second distal portions  44  of the first ischial slots  32 - 38  and the first distal portions  72  of the second ischial slots  62 - 68 . Optionally, the tailbone slot second distal portion  98  may be at an angle to or substantially parallel to all of the second distal portions  44  of the first ischial slots  32 - 38  and the first distal portions  72  of the second ischial slots  62 - 68 . 
     A thigh transitional slot  112  may be defined within the seat  20  in the thigh transitional region  110 . The thigh transitional slot  112  may be defined partially or completely through the seat  20 . As illustrated, the seat  20  may have one thigh transitional slot  112 , although a greater or fewer number of slots may be used depending on the support desired. The thigh transitional slot  112  may include a central portion  114 , a first distal portion  116  adjacent a first end of the central portion  114 , and a second distal portion  118  adjacent a second end of the central portion  114 . The central portion  114 , first distal portion  116  and second distal portion  118  may be any suitable shape, including curved and substantially linear. An end portion  120 ,  122  may be defined adjacent and connect with the respective distal portions  116 ,  118 . The end portion  120 ,  122  may be designed to relieve stress in the seat material surrounding the end portions  120 ,  122 . Although illustrated as substantially circular, the end portions  120 ,  122  may have any suitable rounded shape, including an oval or an elongated oval. The distal portions  116 ,  118  may each form an angle  124 ,  126  relative to the central portion  114 . The angles  124 ,  126  may be any suitable angle, and may be unequal or substantially equal. Optionally, the angles  124 ,  126  may be unequal to or substantially equal to one or more of the angles  50 ,  52 ,  80 ,  82 ,  104 ,  106  formed by the first ischial slots  32 - 38 , the second ischial slots  62 - 68  and the tailbone slot  92 . Further optionally, the angles  124 ,  126  may be unequal to or substantially equal to all of the angles  50 ,  52 ,  80 ,  82 ,  104 ,  106  formed by the first ischial slots  32 - 38 , the second ischial slots  62 - 68  and the tailbone slot  92 . The distal portions  116 ,  118  may have any desired orientation with respect to one another, including being at an angle to one another and being substantially perpendicular to one another. The distal portions  116 ,  118  may be substantially equal in length, or may have unequal lengths. Further, the distal portions  116 ,  118  may have a length unequal to or substantially equal to one or more of the first ischial distal portions  42 ,  44 , the second ischial distal portions  72 ,  74 , and the tailbone slot distal portions  96 ,  98 . Optionally, the distal portions  116 ,  118  may have a length unequal to or substantially equal to all of the first ischial distal portions  42 ,  44 , the second ischial distal portions  72 ,  74 , and the tailbone slot distal portions  96 ,  98 . The central portion  114  may extend in any suitable direction, including at an angle to or substantially perpendicular to the longitudinal axis  12 , as illustrated. The central portion  114  may be any suitable length, and may have a greater length than each of the distal portions  116 ,  118 . Optionally, the longitudinal axis  12  may intersect the central portion  114 , and further optionally, the longitudinal axis  12  may bisect the central portion  114 . The distal portions  116 ,  118  may extend at an angle to or substantially parallel to the longitudinal axis  12 . 
     The thigh transitional slot  112  may have any suitable positioning relationship relative to the first ischial slots  32 - 38 , the second ischial slots  62 - 68  and the tailbone slot  92  to provide desired support characteristics. The thigh transitional slot central portion  114  may be oriented at any suitable angle, including being substantially perpendicular to one or more of the central portions  40  of the first ischial slots  32 - 38  and the central portions  70  of the second ischial slots  62 - 68 . Optionally, the thigh transitional slot central portion  114  may be substantially perpendicular to all of the central portions  40  of the first ischial slots  32 - 38  and the central portions  70  of the second ischial slots  62 - 68 . The thigh transitional slot central portion  114  may be at an angle to or substantially parallel to the tailbone slot central portion  94 . The thigh transitional slot first distal portion  116  may be at an angle to or substantially parallel to one or more of the first distal portions  42  of the first ischial slots  32 - 38 , the second distal portions  74  of the second ischial slots  62 - 68 , and the tailbone slot first distal portion  96 . Optionally, the thigh transitional slot first distal portion  116  may be at an angle to or substantially parallel to all of the first distal portions  42  of the first ischial slots  32 - 38 , the second distal portions  74  of the second ischial slots  62 - 68 , and the tailbone slot first distal portion  96 . The thigh transitional slot second distal portion  118  may be at an angle to or substantially parallel to one or more of the second distal portions  44  of the first ischial slots  32 - 38 , the first distal portions  72  of the second ischial slots  62 - 68 , and the tailbone slot second distal portion  98 . Optionally, the thigh transitional slot second distal portion  118  may be at an angle to or substantially parallel to all of the second distal portions  44  of the first ischial slots  32 - 38 , the first distal portions  72  of the second ischial slots  62 - 68 , and the tailbone slot second distal portion  98 . 
     In use, the slots  32 - 38 ,  62 - 68 ,  92 ,  112  may be designed to allow a cantilevering of the areas adjacent to the slots  32 - 38 ,  62 - 68 ,  92 ,  112  to contour the seat based on a user&#39;s weight. The slot configuration may approximate the support magnitude and profile provided by some foam constructions. As illustrated, the slots may generally be curved or open outward relative to a center of the seat, which may allow portions of the seat positioned adjacent and outward of each slot to cantilever and deflect downward relative to the seat surface and outward relative to the center of the seat. In this manner, the areas of seat  20  adjacent the slots  32 - 38 ,  62 - 68 ,  92 ,  112  may dynamically flex to support a user while accommodating the dynamic movements of the user. The degree or magnitude of flex may be based on the weight of the user. The seat  20  may relieve the high pressure otherwise present in the first ischial region  30 , the second ischial region  60 , the tailbone region  90  and the thigh transitional region  110 . 
     As shown in  FIG. 2 , a thigh region  140  may be generally positioned at the front of the seat  20  in front of the thigh transitional region  110 . The thigh region  140  may be generally positioned below the lower thighs of a user. As shown in the embodiment of  FIG. 6 , the thigh region  140  may include one or more grooves  142 - 154  to facilitate flexing and curling of the front of seat  20 . The flexing movement of the front of seat  20  can provide a desired amount of support for a user&#39;s thighs while the user is sitting in the seat  20 . For example, while a user remains stationary in a seated position with regard to the first ischial region  30 , second ischial region  60 , tailbone region  90  and thigh transitional region  110 , the thigh region  140  may be extended forward or curled rearward under the seat  20  to provide a desired level of support for the user&#39;s thighs. This may be useful because a user may not be able to move forward and rearward to adjust their thigh support, while at the same time remaining in a proper support position with respect to the slots in seat  20 . The grooves  142 - 154  may be defined partially through the seat  20 . Optionally, the grooves  142 - 154  may be defined completely through the seat at certain distances along the lengths of the grooves  142 - 154 . As shown in  FIG. 6 , each of the grooves  142 - 154  may include a top channel  160  defined in a top surface of the seat  20 , and a corresponding bottom channel  162  defined in a bottom surface of the seat  20 . Each groove  142 - 154  may include a thinned section  164  to connect the portions of the seat  20  adjacent the groove  142 - 154 . The grooves  142 - 154  may be positioned in any location suitable to provide desired support characteristics. As shown in  FIG. 2 , the grooves  142 - 154  may extend from one side of the seat  20  to an opposite side of the seat  20 , and may be oriented substantially parallel to one another. Optionally, the grooves  142 - 154  may be oriented substantially perpendicular to one or more of the longitudinal axis  12 , the central portions  40  of the first ischial slots  32 - 38 , and the central portions  70  of the second ischial slots  62 - 68 . Further optionally, the grooves  142 - 154  may be oriented substantially perpendicular to all of the longitudinal axis  12 , the central portions  40  of the first ischial slots  32 - 38 , and the central portions  70  of the second ischial slots  62 - 68 . Still further optionally, the grooves  142 - 154  may be oriented substantially parallel to the tailbone slot central portion  94  and the thigh transitional slot central portion  114 . A greater or fewer number of grooves  142 - 154  may be used, depending on the desired support characteristics. Optionally, the grooves  142 - 154  may be eliminated, depending on the desired support characteristics. 
     The seat  20  may be supported using any suitable mechanism to provide desired support characteristics. The seat  20  may be supported at an outer edge, to allow the interior portions of the seat  20  to be free to flex in response to a user&#39;s weight. Optionally, the seat may be supported by dynamic systems to vary the pressure and contour of the seat. In some embodiments, the interior portions of the seat may be supported using mechanical, pneumatic or hydraulic systems to flex, or control the amount of flexing of selected areas of the seat  20 . Further optionally, a system may be used to flex, or control the amount of flexing of the flexible thigh region  140 . Each of the above systems may be equipped with sensors for determining the weight magnitude and distribution over the seat  20 , and may include programming to control movement of the seat  20  according to the weight magnitude and distribution. 
     III. Manufacture 
     A seat  20  according to one embodiment of the present invention may be made of any suitable material, included plastics, copolymers and composites such as but not limited to BASF Ultraform and Sabic Innovative Plastics Xenoy IQ. The material may have several beneficial characteristics, such as a high elongation prior to yield (&gt;6%), a high resiliency, a resistance to creep over time and a high toughness (&gt;10,000 psi tensile strength at yield and 100,000-275,000 psi tensile modulus). The seat  20  may be made of one consistent material, or may be made with different regions having different materials to provide desired support characteristics. The seat  20  may be made using any suitable process, including injection molding and compression molding. In embodiments with two or more different materials, a two-stage injection molding process, or any other suitable manufacturing process, may be used. 
     The support frame  16  may be made of any suitable material, including plastics, metals and composites. The support frame  16  may be separately formed and attached to the seat  20  using any suitable fastening means, including a friction fit, adhesives, and fasteners. Optionally, if the support frame  16  is made of plastic, the support frame may be integrally formed with the seat  20 . Further optionally, the support frame  16  and seat  20  may be formed during a single molding process. 
     The seat back  14  may be made of any suitable material, including plastics, metals and composites. The seat back  14  may be separately formed and attached to the seat  20  using the fastening means above, or may be integrally formed with the seat  20  as described above in connection with the support frame  16 . 
     The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Features of various embodiments may be used in combination with features from other embodiments. Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “front,” “rear,” “upper,” “lower,” “inner,” “inwardly,” “outer,” “outwardly,” “forward,” and “rearward” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s). Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.