Abstract:
A battery pack according to an exemplary aspect of the present disclosure includes, among other things, an enclosure that houses at least one battery cell and a vent device comprised of a polymeric material and adapted to discharge battery vent byproducts vented by the battery cell to a location external to the enclosure while preventing ingress of environmental fluids into the enclosure.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to a battery pack of an electrified vehicle. A vent device of the battery pack establishes a flow path for discharging battery vent byproducts during battery cell venting events. 
       BACKGROUND 
       [0002]    The desire to reduce automotive fuel consumption and emissions is well documented. Therefore, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle currently being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles because they are selectively driven by one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to propel the vehicle. 
         [0003]    A high voltage battery pack typically powers the electric machines and other electrical loads of the electrified vehicle. The battery pack includes a plurality of interconnected battery cells that store energy for powering these electrical loads. Battery vent byproducts may be expelled from the battery cells during certain conditions. The battery vent byproducts may need purged from the battery pack when a venting event occurs. 
       SUMMARY 
       [0004]    A battery pack according to an exemplary aspect of the present disclosure includes, among other things, an enclosure that houses at least one battery cell and a vent device comprised of a polymeric material and adapted to discharge battery vent byproducts vented by the battery cell to a location external to the enclosure while preventing ingress of environmental fluids into the enclosure. 
         [0005]    In a further non-limiting embodiment of the foregoing battery pack, the vent device includes a vent tube and a removable cap received over the vent tube. 
         [0006]    In a further non-limiting embodiment of either of the foregoing battery packs, the vent tube includes a barb received within a groove of the removable cap. 
         [0007]    In a further non-limiting embodiment of any of the foregoing battery packs, the vent device includes a flap movable between a first position in which an outlet of the vent device is closed and a second position in which the outlet is open. 
         [0008]    In a further non-limiting embodiment of any of the foregoing battery packs, the flap is part of a grommet of the vent device. 
         [0009]    In a further non-limiting embodiment of any of the foregoing battery packs, the flap is part of a vent tube of the vent device. 
         [0010]    In a further non-limiting embodiment of any of the foregoing battery packs, the vent device includes a predefined failure area configured to plastically deform in response to pressure build-up inside the vent device. 
         [0011]    In a further non-limiting embodiment of any of the foregoing battery packs, the predefined failure area includes a notch formed in an outer surface of a vent tube. 
         [0012]    In a further non-limiting embodiment of any of the foregoing battery packs, the vent device includes a vent tube having a closed end, a predefined failure area formed near the closed end, and an enlarged section disposed between the predefined failure area and the closed end. 
         [0013]    In a further non-limiting embodiment of any of the foregoing battery packs, the vent device includes a vent tube, a bulb formed on an end of the vent tube, and a stress notch formed in the bulb. 
         [0014]    In a further non-limiting embodiment of any of the foregoing battery packs, the vent device is mounted externally of the enclosure. 
         [0015]    In a further non-limiting embodiment of any of the foregoing battery packs, the vent device is at least partially mounted inside the enclosure. 
         [0016]    A battery pack according to another exemplary aspect of the present disclosure includes, among other things, a vent device including a flap this is movable between a first position and a second position to expose an outlet of the vent device if a pressure inside the vent device exceeds a threshold pressure. 
         [0017]    In a further non-limiting embodiment of the foregoing battery pack, the flap is part of a grommet of the vent device. 
         [0018]    In a further non-limiting embodiment of either of the foregoing battery packs, the flap is part of a vent tube of the vent device. 
         [0019]    In a further non-limiting embodiment of any of the foregoing battery packs, the flap is connected to a base of the vent device by a hinge. 
         [0020]    In a further non-limiting embodiment of any of the foregoing battery packs, battery vent byproducts are discharged from the vent device if the flap is in the second position and environmental elements are block from ingress into the vent device if the flap is in the first position. 
         [0021]    A battery pack according to another exemplary aspect of the present disclosure includes, among other things, a vent device configured to plastically deform at a predefined failure area to expose an outlet of the vent device if a pressure inside the vent device exceeds a threshold pressure. 
         [0022]    In a further non-limiting embodiment of the foregoing battery pack, the predefined failure area is a notch formed in an external surface of a tube. 
         [0023]    In a further non-limiting embodiment of either of the foregoing battery packs, the predefined failure area is a stress notch formed in a bulb of the vent device. 
         [0024]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  schematically illustrates a powertrain of an electrified vehicle. 
           [0027]      FIG. 2  illustrates a battery pack of an electrified vehicle. 
           [0028]      FIG. 3  illustrates a cross-sectional view of the battery pack of  FIG. 2 . 
           [0029]      FIG. 4  illustrates another exemplary battery pack. 
           [0030]      FIGS. 5A and 5B  illustrate a vent device according to a first embodiment of this disclosure. 
           [0031]      FIGS. 6A, 6B, and 6C  illustrate a vent device according to additional embodiments of this disclosure. 
           [0032]      FIGS. 7A and 7B  illustrate a vent device according to a third embodiment of this disclosure. 
           [0033]      FIGS. 8A and 8B  illustrate a vent device according to a fourth embodiment of this disclosure. 
           [0034]      FIG. 9  illustrates a vent device according to another embodiment of this disclosure. 
           [0035]      FIG. 10  illustrates a vent device according to another embodiment of this disclosure. 
           [0036]      FIG. 11  illustrates a vent device according to yet another embodiment of this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    This disclosure describes a battery pack for an electrified vehicle. The battery pack includes an enclosure and a vent device. The enclosure houses battery cells that may occasionally release battery vent byproducts. The vent device is configured to discharge the battery vent byproducts from the battery pack while blocking ingress of environmental elements, such as air, moisture and/or insects, into the battery pack. The vent device may include a cap, flap or other feature that seals against the external environment normally but opens as a function of internal pressures to release the battery vent byproducts. These and other features are discussed in greater detail in the following paragraphs of this detailed description. 
         [0038]      FIG. 1  schematically illustrates a powertrain  10  for an electrified vehicle  12 . Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEV&#39;s and could extend to other electrified vehicles, including, but not limited to, plug-in hybrid electric vehicles (PHEV&#39;s), battery electric vehicles (BEV&#39;s) and fuel cell vehicles. 
         [0039]    In one non-limiting embodiment, the powertrain  10  is a power-split powertrain system that employs a first drive system and a second drive system. The first drive system includes a combination of an engine  14  and a generator  18  (i.e., a first electric machine). The second drive system includes at least a motor  22  (i.e., a second electric machine), the generator  18 , and a battery pack  24 . In this example, the second drive system is considered an electric drive system of the powertrain  10 . The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels  28  of the electrified vehicle  12 . Although a power-split configuration is depicted in  FIG. 1 , this disclosure extends to any hybrid or electric vehicle including full hybrids, parallel hybrids, series hybrids, mild hybrids or micro hybrids. 
         [0040]    The engine  14 , which in one embodiment is an internal combustion engine, and the generator  18  may be connected through a power transfer unit  30 , such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine  14  to the generator  18 . In one non-limiting embodiment, the power transfer unit  30  is a planetary gear set that includes a ring gear  32 , a sun gear  34 , and a carrier assembly  36 . 
         [0041]    The generator  18  can be driven by the engine  14  through the power transfer unit  30  to convert kinetic energy to electrical energy. The generator  18  can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft  38  connected to the power transfer unit  30 . Because the generator  18  is operatively connected to the engine  14 , the speed of the engine  14  can be controlled by the generator  18 . 
         [0042]    The ring gear  32  of the power transfer unit  30  may be connected to a shaft  40 , which is connected to vehicle drive wheels  28  through a second power transfer unit  44 . The second power transfer unit  44  may include a gear set having a plurality of gears  46 . Other power transfer units may also be suitable. The gears  46  transfer torque from the engine  14  to a differential  48  to ultimately provide traction to the vehicle drive wheels  28 . The differential  48  may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels  28 . In one embodiment, the second power transfer unit  44  is mechanically coupled to an axle  50  through the differential  48  to distribute torque to the vehicle drive wheels  28 . 
         [0043]    The motor  22  can also be employed to drive the vehicle drive wheels  28  by outputting torque to a shaft  52  that is also connected to the second power transfer unit  44 . In one embodiment, the motor  22  and the generator  18  cooperate as part of a regenerative braking system in which both the motor  22  and the generator  18  can be employed as motors to output torque. For example, the motor  22  and the generator  18  can each output electrical power to the battery pack  24 . 
         [0044]    The battery pack  24  is an exemplary electrified vehicle battery. The battery pack  24  may be a high voltage traction battery pack that includes a plurality of battery assemblies  25  (i.e., battery arrays or groupings of battery cells) capable of outputting electrical power to operate the motor  22 , the generator  18  and/or other electrical loads of the electrified vehicle  12 . Other types of energy storage devices and/or output devices could also be used to electrically power the electrified vehicle  12 . 
         [0045]    In one non-limiting embodiment, the electrified vehicle  12  has two basic operating modes. The electrified vehicle  12  may operate in an Electric Vehicle (EV) mode where the motor  22  is used (generally without assistance from the engine  14 ) for vehicle propulsion, thereby depleting the battery pack  24  state of charge up to its maximum allowable discharging rate under certain driving patterns/cycles. The EV mode is an example of a charge depleting mode of operation for the electrified vehicle  12 . During EV mode, the state of charge of the battery pack  24  may increase in some circumstances, for example due to a period of regenerative braking. The engine  14  is generally OFF under a default EV mode but could be operated as necessary based on a vehicle system state or as permitted by the operator. 
         [0046]    The electrified vehicle  12  may additionally operate in a Hybrid (HEV) mode in which the engine  14  and the motor  22  are both used for vehicle propulsion. The HEV mode is an example of a charge sustaining mode of operation for the electrified vehicle  12 . During the HEV mode, the electrified vehicle  12  may reduce the motor  22  propulsion usage in order to maintain the state of charge of the battery pack  24  at a constant or approximately constant level by increasing the engine  14  propulsion. The electrified vehicle  12  may be operated in other operating modes in addition to the EV and HEV modes within the scope of this disclosure. 
         [0047]      FIGS. 2 and 3  illustrate a battery pack  24  that can be employed within an electrified vehicle. For example, the battery pack  24  could be part of the electrified vehicle  12  of  FIG. 1 . The battery pack  24  includes a plurality of battery cells  56  that store electrical power for powering various electrical loads of the electrified vehicle  12 . Although a specific number of battery cells  56  are depicted in  FIG. 2 , the battery pack  24  could employ a greater or fewer number of battery cells within the scope of this disclosure. In other words, this disclosure is not limited to the specific configuration shown in  FIGS. 2 and 3 . 
         [0048]    The battery cells  56  may be stacked side-by-side along a longitudinal axis or on top of one another to construct groupings of battery cells  56 , sometimes referred to as “cell stacks.” The battery pack  24  can include one or more separate groupings of battery cells  56 . 
         [0049]    In one non-limiting embodiment, the battery cells  56  are prismatic, lithium-ion cells. However, battery cells having other geometries (cylindrical, pouch, etc.), other chemistries (nickel-metal hydride, lead-acid, etc.), or both, could alternatively be utilized within the scope of this disclosure. 
         [0050]    The battery cells  56 , along with any other support structures (e.g., spacers, rails, walls, plates, etc.), may be collectively referred to as a battery assembly  25 . Two battery assemblies  25  are shown in  FIG. 3 ; however, the battery pack  24  could include a greater or fewer number of battery assemblies within the scope of this disclosure. 
         [0051]    An enclosure  60  generally surrounds each battery assembly  25  of the battery pack  24 . In one non-limiting embodiment, the enclosure  60  includes a tray  62  and a cover  64 . A portion of the cover  64  is shown removed in  FIG. 2  to better illustrate the interior features of the battery pack  24 . The cover  64  is attachable to the tray  62  in order to cover the battery assemblies  25 . The tray  62  and cover  64  together establish the enclosure  60 , which houses the various hardware and electronics of the battery pack  24 , including but not limited to the battery assemblies  25 . The cover  64  may be attached to the tray  62  in any known manner In one non-limiting embodiment, the cover  64  is mechanically fastened to the tray  62  using one or more fasteners. 
         [0052]    Each battery cell  56  may include one or more vents  58 . The vents  58  expel battery vent byproducts  66 , such as gases or other byproducts, from the battery cells  56  during certain battery cell venting events. For example, battery venting events may occur during over-temperature or over-charging conditions of the battery cells  56 , or during other cell conditions. 
         [0053]    The battery vent byproducts  66  vent into vent chambers  68  arranged inside the battery pack  24 . The vent chambers  68  could simply be open spaces established between the battery assemblies  25  and the walls of the enclosure  60 . A venting system  70  of the battery pack  24  is adapted to discharge the battery vent byproducts  66  from the interior of the battery pack  24  to a location external to the battery pack  24  while preventing environmental elements (e.g., air, moisture, insects, etc.) from entering the battery pack  24  through the venting system  70 . 
         [0054]    In one non-limiting embodiment, the venting system  70  includes one or more vent chambers  68  and a vent device  72 . The venting system  70  establishes a venting path VP (shown in dashed lines) through the vent device  72  for expelling the battery vent byproducts  66  when a battery cell venting event occurs. For example, the battery vent byproducts  66  may flow, under their own motive pressure, through the vent chamber  68  and then through the vent device  72  prior to being expelled outside of the battery pack  24 , such as to atmosphere  78  (i.e., outside the vehicle). The vent device  72  may include one or more vent tubes, grommets, ports, seals, or any combination of such components. 
         [0055]    In one non-limiting embodiment, best shown in  FIG. 2 , the vent device  72  is mounted outside the enclosure  60 . For example, portions of the vent device  72  may be mounted to a wall  74  of the battery pack  24 . The wall  74  could be part of either the tray  62  or the cover  64  of the enclosure  60 . The vent device  72  is mounted such that it is fluidly connected to the vent chamber(s)  68 . The vent device  72  may include one or more branches  76  for connecting to multiple vent chambers  68 . In another non-limiting embodiment, each branch  76  connects to a different vent chamber  68 . 
         [0056]    The vent device  72  permits the battery vent byproducts  66  to flow along the venting path VP out of the battery pack  24  to atmosphere  78 . The vent device  72  may also block environmental elements from being communicated along a reverse path from atmosphere  78  into the vent chamber  68 . Moisture/humidity of the atmospheric air, insects and other elements associated with the atmosphere  78  are undesirable inside the battery pack  24  and are therefore blocked from ingress by the vent device  72 . 
         [0057]    In the non-limiting embodiment of  FIG. 2 , a vehicle interface structure  80  extends from a portion of the enclosure  60  of the battery pack  24 . The vehicle interface structure  80  may be part of the tray  62  or the cover  64 , or could be a separate structure, such as a bracket, that is mounted to the tray  62  or the cover  64 . The battery pack  24  is mounted to a vehicle structure  86  using the vehicle interface structure  80 . In one non-limiting embodiment, the vehicle structure  86  is a floor pan having an aperture  82  that opens to the atmosphere  78 , or to a location external to the electrified vehicle. Other structures may alternatively be employed as the vehicle structure  86 . 
         [0058]    A distal portion  84  (e.g., a tube outlet or grommet) of the vent device  72  is mounted to the vehicle interface structure  80 . A vent aperture  85  is formed through the vehicle interface structure  80  and can accept a portion of the distal portion  84  of the vent device  72 . Once the battery pack  24  is mounted, an outlet of the distal portion  84  of the vent device  72 , the vent aperture  85  of the vehicle interface structure  80 , and the aperture  82  of the vehicle structure  86  substantially align to further establish the venting path VP for discharging the battery vent byproducts  66  to the atmosphere  78 . 
         [0059]    In another non-limiting embodiment, shown in  FIG. 4 , the vent device  72  is at least partially mounted inside the enclosure  60  of the battery pack  24 . The vent device  72  of this embodiment is a grommet style device. The vent device  72  could extend through any wall of either the tray  62  or the cover  64  for expelling battery vent byproducts  66  from the battery pack  24 . Because the vent device  72  of  FIG. 4  is mounted inside the battery pack  24 , tubing is not required to expel the battery vent byproducts  66  from the battery pack  24 . An outlet  88  of the vent device  72  may be positioned at any location suitable to communicate the battery vent byproducts  66  to atmosphere  78 . In this embodiment, the outlet  88  is positioned beneath the tray  62  of the battery pack  24 . 
         [0060]    The vent device  72  can embody a variety of designs and configurations. The particular design of the vent device  72  may depend on a specific vehicle application. Non-limiting embodiments of several vent devices are illustrated in  FIGS. 5-11 . In one non-limiting embodiment, each component of the vent devices illustrated in  FIGS. 5-11  is made of plastic or polymeric materials and may be a molded part. Non-limiting examples of suitable plastic or polymeric materials include rubber, polypropylene, polyethylene, and polyamide. 
         [0061]      FIGS. 5A and 5B  illustrate a vent device  72  according to a first non-limiting embodiment. The vent device  72  embodies a two-piece design that includes a vent tube  90  and a cap  92  received over an outlet  94  of the vent tube  90 . Although not shown in  FIG. 5A or 5B , the vent tube  90  would be fluidly connected at one end to a vent chamber of a battery pack and the outlet  94  would open to the atmosphere at a location outside of the battery pack. 
         [0062]    When connected to the vent tube  90 , the cap  92  seals the outlet  94  against the ingress of environmental elements E (see  FIG. 5A ). The cap  92  is removable from the vent tube  90  to allow battery vent byproducts  66  to escape from the vent device  72  (see  FIG. 5B ). For example, in one non-limiting embodiment, the cap  92  is forced, or blown, off of the vent tube  90  as a function of a pressure build-up inside the vent device  72 . The internal pressure build-up may occur during a battery venting event in which battery vent byproducts  66  accumulate near the outlet  94  of the vent tube  90 . 
         [0063]    In yet another non-limiting embodiment, shown in  FIG. 6A , the vent tube  90  may include one or more barbs  96 , or radial projections, that are received in grooves  98  formed in the cap  92 . The barbs  96  increase the amount of pressure that is required to detach the cap  92  from the vent tube  90 . Conversely, if the blow off pressure needs to be lowered, the cap  92  can be sized to have a clearance fit to the vent tube  90  (either outside the vent tube  90  (see  FIG. 6B ) or inside the vent tube  90  (see  FIG. 6C )). A plug  99 , such as a foam plug with an appropriate compressive spring force, can be included in the clearance between the cap  92  and vent tube  90  such that the plug  99  prevents the cap  92  from easily falling away while still holding the cap  92  in place with a lower force than one directly fit onto the vent tube  90 . 
         [0064]      FIGS. 7A and 7B  illustrate another exemplary vent device  72 - 2 . The vent device  72 - 2  is another two-piece design and includes a vent tube  100  and a grommet  102  received over an outlet  104  of the vent tube  100 . A base  106  of the grommet  102  is cut or slit along cut line  105  to form a flap  108 . A portion of the base  106  is uncut to form a hinge  109  that connects the flap  108  to the base  106 . 
         [0065]    Integrally formed flanges  111  may protrude laterally from the grommet  102 . The flanges  111  interface with and seal relative to a first structure  113  of a battery pack and a second structure  115  of a vehicle (see  FIG. 7A ). In one non-limiting embodiment, the first structure  113  is a portion of a battery pack enclosure and the second structure  115  is a floor pan of the vehicle. 
         [0066]    The flap  108  of the grommet  102  is moveable to expel battery vent byproducts  66  through an outlet  110  of the grommet  102 . For example, in a first position X, shown in  FIG. 7A , the flap  108  lays flat against a seat  112  of the base  106  to cover the outlet  110 . In the first position X, the flap  108  blocks environmental elements E from entering the vent device  72 - 2 . Therefore, the vent device  72 - 2  prevents ingress of the environmental elements E into a battery pack through the vent tube  100 . In a second position X′, shown in  FIG. 7B , the flap  108  has been moved away from the seat  112  by pressure created from the motive flow of the battery vent byproducts  66 . Flow of the battery vent byproducts  66  displaces the flap  108  away from the seat  112  to expose the outlet  110  to atmosphere and allow the battery vent byproducts  66  to be expelled from a battery pack. The amount of pressure required to displace the flap  108  can be tuned to any specific design need. 
         [0067]      FIGS. 8A and 8B  illustrate a vent device  72 - 3  embodying a single-piece design. The vent device  72 - 3  includes a vent tube  120 . Instead of including a separate grommet, a flap  122  is incorporated into a distal portion  124  of the vent tube  120 . The distal portion  124  is cut or slit along cut line  125  to form the flap  122 . A portion of the distal portion  124  is left uncut to form a hinge  126  that connects the flap  122  to the distal portion  124  of the vent tube  120 . 
         [0068]    The flap  122  of the vent tube  120  is moveable to expel battery vent byproducts  66  through an outlet  128 . For example, in a first position X, shown in  FIG. 8A , the flap  122  lays flat against a seat  129  of the distal portion  124  to cover the outlet  128 . In the first position X, the flap  122  blocks environmental elements E from entering the vent device  72 - 3 . Therefore, the vent device  72 - 3  prevents ingress of the environmental elements E into a battery pack through the vent tube  120 . In a second position X′, shown in  FIG. 8B , the flap  122  is moved away from the seat  129  by pressure created by the motive flow of the battery vent byproducts  66 . Flow of the battery vent byproducts  66  displaces the flap  122  away from the seat  129  to expose the outlet  128  to atmosphere and allow the battery vent byproducts  66  to be expelled from the battery pack. 
         [0069]      FIG. 9  illustrates yet another vent device  72 - 4 . The vent device  72 - 4  includes a vent tube  130  having a closed end  132 . The vent tube  130  includes a predefined failure area  134  near the closed end  132 . The predefined failure area  134  may be formed in an outer surface  136  of the vent tube  130  by scoring or cutting a shallow groove  138  into the outer surface  136 . The predefined failure area  134  creates a weakened point in the vent tube  130 . The vent tube  130  can plastically deform or rupture at the predefined failure area  134  if the pressure inside the vent tube  130  exceeds a threshold pressure. Battery vent byproducts may be discharged through an outlet of the vent tube  130  after plastic deformation occurs at the predefined failure area  134 . 
         [0070]    The vent device  72 - 5  of  FIG. 10  is similar to the vent device  72 - 4  of  FIG. 9 . However, in this embodiment, the vent device  72 - 5  includes a vent tube  140  having a closed end  142 , a predefined failure area  144  formed near the closed end  142 , and an enlarged section  146  disposed between the predefined failure area  144  and the closed end  142 . The enlarged section  146  increases the surface area of the vent tube  140  below the predefined failure area  144 . The increased surface area enhances the resultant force developed on the distal end of the vent tube  140  and thus promotes more or faster plastic deformation at the predefined failure area  144 . 
         [0071]      FIG. 11  illustrates a vent device  72 - 6  according to yet another non-limiting embodiment of this disclosure. The vent device  72 - 6  include a vent tube  150  and a bulb  152  formed on an end of the vent tube  150  to conceal an outlet  154  of the vent tube  150 . In one non-limiting embodiment, the bulb  152  is a partial sphere that is blow molded onto an end of the vent tube  150 . A stress notch  156  (or multiple interesting stress notches in an X or star pattern, for example) may be formed in the bulb  152 . The vent tube  150  can plastically deform or rupture at the stress notch  156  if the pressure inside the vent tube  150  exceeds a threshold pressure, thereby severing the bulb  152  into multiple flaps and thus exposing the outlet  154  to atmosphere. Battery vent byproducts may be discharged from the vent tube  150  through the outlet  154  after plastic deformation occurs at the stress notch  156 . 
         [0072]    Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0073]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0074]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.