Patent Publication Number: US-2023142702-A1

Title: Thermal dampening devices for window systems

Description:
BACKGROUND 
     Windows are commonly used in residential and commercial buildings, e.g., in storefronts and in curtain walls used on the façade of high-rise buildings. Aesthetic considerations play an important part in architectural design of buildings, including the design of its window systems. Another important factor in architectural design, however, is the overall energy efficiency of a building, including energy transfer characteristics of its window systems. There is a continued demand for building features and methods of construction that improve energy efficiency. 
     Some windows and window systems utilize frames made of metal, such as aluminum or an aluminum alloy, and such metal frames can reduce the thermal efficiency of the building by serving as conductors of thermal energy between the exterior and the interior of a building. Improved and/or alternative structures and methods for controlling the heat transfer characteristics of windows and window structures, while simultaneously achieving or maintaining aesthetic design objectives, remain desirable. 
     SUMMARY OF THE DISCLOSURE 
     Embodiments disclosed herein include a window system that includes a frame, a glazing assembly held within the frame and including a glass stop attachable to the frame, wherein attaching the glass stop to the frame defines an air pocket between the glass stop and the frame, and a thermal dampening device positioned within the air pocket and defining one or more discrete cavities. In a further embodiment, the frame includes a head, a sill, and opposing left and right vertical jambs extending between the head and the sill, and wherein the glass stop is attachable to any one of the head, the sill, and the opposing left and right vertical jambs. In another further embodiment, the thermal dampening device provides a base and one or more fins that extend from the base, the one or more fins defining the one or more discrete cavities. In another further embodiment, the base is removably attached to the glass stop. In another further embodiment, the one or more fins extend to and engage the frame. In another further embodiment, further comprising a thermal break mounted to the frame, wherein at least one of the one or more fins contacts the thermal break. In another further embodiment, wherein the base and the one or more fins are made of a thermoplastic polymer. In another further embodiment, the base is made of a rigid material and the one or more fins are made of flexible material different from the rigid material. In another further embodiment, the base and the one or more fins are co-extruded. In another further embodiment, the thermal dampening device extends between and contacts the glass stop and the frame. In another further embodiment, the thermal dampening device provides multiple structural members that cooperatively define the one or more discrete cavities. In another further embodiment, at least a portion of the thermal dampening device is made of an elastomer to seal an interface between the frame and the thermal dampening device. 
     Embodiments disclosed herein may further include a method of reducing thermal transmission through a window system, the method including the steps of positioning a thermal dampening device within an air pocket defined between a glass stop of a glazing assembly and a frame of the window assembly, wherein the thermal dampening device defines one or more discrete cavities, and reducing thermal transmission through the air pocket with the thermal dampening device. In a further embodiment, the method further includes educing convective heat transfer through the air pocket with the one or more discrete cavities. In another further embodiment, the thermal dampening device extends between and contacts the glass stop and the frame, the method further comprising reinforcing the glass stop with the thermal dampening device. In another further embodiment, at least a portion of the thermal dampening device is made of an elastomer, the method further comprising sealing an interface between the frame and the thermal dampening device with the thermal dampening device. 
     Embodiments disclosed herein may further include a method of retrofitting a window system, the method including the steps of removing a glass stop from a glazing assembly held within a frame of the window assembly, arranging a thermal dampening device such that it is positioned within an air pocket defined between the glass stop and the frame when the glass stop is attached to the frame, and reattaching the glass stop to the frame, wherein the thermal dampening device defines one or more discrete cavities. In a further embodiment, the thermal dampening device extends between and contacts the glass stop and the frame, the method further comprising reinforcing the glass stop with the thermal dampening device. In another further embodiment, arranging the thermal dampening device comprises removably attaching the thermal dampening device to the glass stop. In another further embodiment, at least a portion of the thermal dampening device is made of an elastomer, the method further comprising sealing an interface between the frame and the thermal dampening device with the thermal dampening device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure. 
         FIG.  1    is a schematic diagram of an example window system  100  that may incorporate the principles of the present disclosure. 
         FIG.  2    is a schematic section view of the window assembly of  FIG.  1   , as taken along the corresponding section lines indicated in  FIG.  1   , according to one or more embodiments. 
         FIG.  3    is another schematic section view of the window assembly of  FIG.  1   , as taken along the corresponding section lines indicated in  FIG.  1   , according to one or more embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is related to window systems and, more particularly, to thermal dampening devices deployed into glass retention devices or “glass stops” for the purpose of reducing thermal transmission (radiant, convective, etc.) through a large air pocket defined, at least partially, by the glass retention device. 
     Window systems often include large air cavities commonly formed by deep and/or tall glass retention devices, alternatively referred to as “glass stops”. These air cavities facilitate a high rate of thermal transmission from the exterior to the interior of a building, and vice versa. The window system embodiments presented herein incorporate the use of a thermal dampening device, which can be located in the large air cavity of a glass stop for the purpose of mitigating or reducing thermal transmission through the window system. Example thermal dampening devices can be made of low emissivity thermoplastic polymers or other low emissivity materials. Moreover, the thermal dampening devices described herein can include structural features that effectively break up the air pocket into smaller air cavities, which helps to break up and slow thermal waves into smaller interrupted waves, and thereby mitigates or interrupts thermal transmission through the air pocket. Portions of the thermal dampening devices described herein can also be made of flexible materials, which allows the thermal dampening device to conform to various designs and configurations of the glass stop. 
       FIG.  1    is a schematic diagram of an example window system  100  that may incorporate the principles of the present disclosure. As illustrated, the window system  100  includes a frame  102 , and upper and lower glazing assemblies  104   a  and  104   b  (alternately referred to as “lite assemblies”) are held within the frame  102 . The frame  102  includes a horizontally mounted head  106  and a horizontally mounted sill  108  vertically opposite the head  106 . Opposing left and right vertical jambs  110   a  and  110   b  extend vertically between the head  106  and the sill  108  to complete the sides of the frame  102 . 
     In the illustrated embodiment, the upper and lower glazing assemblies  104   a , b  are separated by an integral horizontal rail  112 , alternately referred to as a “meeting” rail, that extends horizontally between the vertical jambs  110   a ,b. In other embodiments, however, the horizontal rail  112  is omitted and the upper and lower glazing assemblies  104   a , b  could be combined into a single, monolithic glazing assembly, without departing from the scope of the present disclosure. 
     The upper glazing assembly  104   a  includes a first glazing or infill  114   a  held in place, at least partially, with an upper glazing adapter  116   a  that coincides with the head  106  and the left and right vertical jambs  110   a , b . More specifically, the upper glazing adapter  116   a  includes opposing left and right vertical glazing adapters  118   a  and  118   b , and an upper horizontal glazing adapter  120   a  extending horizontally between the vertical glazing adapters  118   a , b . Similarly, the lower glazing assembly  104   b  includes a second infill  114   b  held in place, at least partially, with a lower glazing adapter  116   b  that coincides with the sill  108  and the left and right vertical jambs  110   a , b . The lower glazing adapter  116   b  includes opposing left and right vertical adapters  122   a  and  122   b , and a lower horizontal glazing adapter  120   b  extending horizontally between the vertical glazing adapters  122   a , b . 
     The infills  114   a , b  may comprise, for example, panes of window glass, polycarbonates, or other clear, translucent, tinted, or opaque panels. 
       FIG.  2    is a schematic section view of the window assembly  100 , as taken along the corresponding section lines indicated in  FIG.  1   , according to one or more embodiments. More specifically,  FIG.  2    depicts a section view of the top portion of the frame  102  (i.e., the head  106 ), to which the upper horizontal glazing adapter  120   a  of the upper glazing assembly  104   a  is coupled. While the discussion below is directed to a section of the frame  102  located at the head  106 , the principles described herein are equally applicable to other sections or locations of the frame  102 , such as at the bottom portion of the frame  102  (i.e., the sill  108  of  FIG.  1   ) or at either of the vertical jambs  110   a , b , without departing from the scope of the disclosure. 
     As illustrated, the frame  102  (i.e., the head  106 ) may include a first or “exterior” portion  202   a  and a second or “interior” portion  202   b . The exterior portion  202   a  is generally exposed to the exterior of a building, while the interior portion  202   b  is generally exposed to the interior of the building. To improve thermal performance of the window assembly  100 , the frame  102  may include a thermal break  204 , which operates to interconnect the exterior and interior portions  202   a , b  while simultaneously preventing conductive thermal energy loss between the exterior and interior portions  202   a , b . The thermal break  204  may be made of one or more materials having a thermal conductivity that is less than the thermal conductivity of the frame  102 , such as a polyurethane foam, a polymer, or the like. 
     As depicted in  FIG.  2   , the first infill  114   a  is secured between the upper horizontal glazing adapter  120   a  and a glass stop  206 . Both the upper horizontal glazing adapter  120   a  and the glass stop  206  are coupled to the frame  102  (i.e., the head  106 ). An exterior gasket  208   a  interposes the first infill  114   a  and the upper horizontal glazing adapter  120   a , and an interior gasket  208   b  interposes the first infill  114   a  and the glass stop  206 . The gaskets  208   a ,b may be made of a variety of materials capable of generating a sealed interface at their respective locations. In the illustrated embodiment, the interior gasket  208   b  comprises a bulb gasket, but could alternatively comprise a wedge gasket or another type of gasket, without departing from the scope of the disclosure. 
     The glass stop  206 , alternately referred to as a “glass retention device,” a “glass bead,” or a “glazing bead,” provides or otherwise defines a base  210  that extends laterally from the first infill  114   a  and into the interior. As illustrated, the interior gasket  208   b  is arranged to provide a sealed interface between the base  210  and an inner surface of the first infill  114   a . 
     The glass stop  206  may also include one or more legs  212  that extend from the base  210  to secure the glass stop  206  to the head  106 . In some embodiments, the legs  212  may be configured to removably attach the glass stop  206  to the head  106 . More specifically, one or both of the legs  212  may include an attachment mechanism  214 , which may comprise any type of structural or mechanical attachment means capable of removably coupling the glass stop  206  to the frame  102  (i.e., the head  106 ). In the illustrated embodiment, the attachment mechanism  214  is provided on each leg  212  in the form of hook features configured to locate and engage corresponding structural features provided by the frame  102 . In such embodiments, the attachment mechanism  214  allows the glass stop  206  to form a snap-fit attachment to the frame  102 . 
     In some embodiments, the legs  212  may extend perpendicularly from the base  210 , but could alternatively extend at an angle offset from perpendicular. Moreover, while two legs  212  are depicted in  FIG.  2   , the glass stop  206  could include more or less than two, without departing from the scope of the disclosure. 
     When the glass stop  206  is secured to the frame  102  (i.e., the head  106 ), an air pocket  216  is defined between the glass stop  206  and the frame  102 . During installed use of the window assembly  100 , heat may tend to transfer from the exterior to the interior by passing (at least partially) through the air pocket  216 . According to embodiments of the present disclosure, such heat transfer may be reduced (mitigated) by positioning a thermal dampening device  218  within the air pocket  216 . 
     In the illustrated embodiment, the thermal dampening device  218  provides a base  220  and one or more fins  222  (three shown) that extend from the base  220 . The base  220  may provide a substantially planar substrate, and the fins  222  can extend from the base  220  in a variety of directions or angles. In some embodiments, for example, one or more of the fins  222  may extend perpendicularly from the base  220 . In other embodiments, however, one or more of the fins  222  may extend from the base  220  at an angle offset from perpendicular to the base  220 . 
     The thermal dampening device  218  may be removably attached to the glass stop  206 . For example, in at least one embodiment, the base  220  may include one or more attachment features  224  configured to locate and form a snap-fit engagement with corresponding attachment features provided by the glass stop  206 . In other embodiments, however, the thermal dampening device  218  may be secured to the glass stop  206  via an interference fit or using one or more mechanical fasteners (e.g., screws). In yet other embodiments, the thermal dampening device  218  may be merely placed in contact with the glass stop  206 , such as being inserted lengthwise into the air pocket  216  (e.g., slid into the air pocket  216 ). 
     While  FIG.  2    shows the thermal dampening device  218  being removably attached to the glass stop  206 , it is contemplated herein that the thermal dampening device  218  may alternatively be removably attached to the frame  102  (e.g., the head  106 ), without departing from the scope of the disclosure. 
     The base  220  may be made of a rigid material, such as a (low emissivity) thermoplastic polymer. This allows the base  220  to be capable of snapping into engagement with the glass stop  206 , while simultaneously holding its shape during wind loads and other external forces. The fins  222  may also be made of a (low emissivity) thermoplastic polymer, but may be made of a more flexible material than the base  220  and otherwise exhibit a lower durometer as compared to the base  220 . In at least one embodiment, the fins  222  may be co-extruded with the base  220 , but may alternatively be attached thereto via a variety of other means, such as laser welding, an interference fit, a snap-fit engagement, mechanical fasteners, or any combination thereof. 
     The flexibility of the fins  222  may prove advantageous in allowing the fins  222  to dynamically conform to the shape of the air pocket  216  when installed, and otherwise be compliant when coming into contact with the thermal break  204  or portions of the frame  102  (e.g., the head  106 ). As a result, the thermal dampening device  218  may be incorporated into a variety of design configurations for the frame  102 , since the fins  222  are capable of adapting to varying shapes and sizes of the thermal break  204  and the frame  102 . 
     The thermal dampening device  218  may also prove advantageous in helping to reinforce the glass stop  206  during heavy wind loads or installation. More specifically, as illustrated, one or more of the fins  222  may extend to engage (contact) one or both of the frame  102  (e.g., the head  106 ) or the thermal break  204 . By extending to the frame  102  or the thermal break  204 , the thermal dampening device  218  may be able to transfer loading from the glass stop  206  to the frame  102 . Without the thermal dampening device  218 , however, the glass stop  206  may tend to bend, flex, and even buckle during heavy wind loads or installation. 
     In the illustrated embodiment, the thermal dampening device  218  includes three fins  222  that extend from the base  220  and thereby define one or more discrete cavities  226  separated by laterally adjacent fins  222 . The fins  222  and the resulting cavities  226  break up the air pocket  216  into smaller air cavities, which mitigates convective heat transfer and thereby helps reduce or interrupt thermal transmission through the air pocket  216 . This results in reduced thermal flow and higher thermal performance of an entire glazing system. 
     In some embodiments, the thermal dampening device  218  may be part of a retrofit for older glazing units (e.g., windows and window systems). In such embodiments, the glass stop  206  may be detached from the head  106  and the thermal dampening device  218  may be arranged such that it resides within the air pocket  216  when the glass stop  206  is reattached to the head  106 . In at least some embodiments, this may require a new or updated design for the glass stop  206 , and otherwise a glass stop that is designed to receive and seat the thermal dampening device  218 . Upon reattaching the glass stop  206  to the head  106 , the thermal dampening device  218  will effectively divide the air pocket  216  into the plurality of discrete cavities  226  separated by laterally adjacent fins  222 , as generally described above, and thereby provide a more thermally efficient and robust window. 
       FIG.  3    is another schematic section view of the window assembly  100 , as taken along the corresponding section lines indicated in  FIG.  1   , according to one or more embodiments. More specifically,  FIG.  3    depicts a section view of the bottom portion of the frame  102  at the sill  108 , which is coupled to the lower glazing assembly  104   b . While  FIG.  3    depicts a section of the window assembly  100  at the sill  108 , the principles described below are equally applicable to other sections of the frame  102 , such as at the top portion of the frame  102  (i.e., the head  106  of  FIG.  1   ) or at either of the vertical jambs  110   a , b , without departing from the scope of the disclosure. 
     As depicted in  FIG.  3   , the second infill  114   b  is secured between the lower horizontal glazing adapter  120   b  and a glass stop  302 . Both the lower horizontal glazing adapter  120   b  and the glass stop  302  are coupled to the frame  102  (i.e., the sill  108 . An exterior gasket  304   a  interposes the second infill  114   b  and the lower horizontal glazing extrusion  120   b , and an interior gasket  304   b  interposes the second infill  114   b  and the glass stop  302 . Similar to the gaskets  208   a , b  of  FIG.  2   , the gaskets  304   a , b  may be made of a variety of materials capable of generating a sealed interface at their respective locations. In the illustrated embodiment, the interior gasket  304   b  comprises a wedge gasket, but could alternatively comprise a bulb gasket or another type of gaskets, without departing from the scope of the disclosure. 
     Similar to the glass stop  206  of  FIG.  2   , the glass stop  302  provides or otherwise defines a base  306  that extends laterally from the second infill  114   b  and into the interior when installed. The interior gasket  304   b  is arranged to provide a sealed interface between the base  306  and an inner surface of the second infill  114   b . 
     The glass stop  302  may also include one or more legs  308  that extend from the base  306  to secure the glass stop  302  to the sill  108 . In some embodiments, the legs  308  may be configured to removably attach the glass stop  302  to the sill  108 . More specifically, at least one of the legs  308  may include an attachment mechanism  310 , which may comprise any type of structural or mechanical attachment means capable of removably coupling the glass stop  302  to the frame  102  (i.e., the sill  108 ). In the illustrated embodiment, the attachment mechanism  310  is provided on both legs  308  in the form of hook features configured to locate and engage corresponding structural features provided by the frame  102 . Accordingly, the attachment mechanism  310  allows the glass stop  302  to form a snap-fit attachment to frame  102 . 
     In some embodiments, the legs  308  may extend perpendicularly from the base  306 , but could alternatively extend at an angle offset from perpendicular. Moreover, while two legs  308  are depicted in  FIG.  3   , the glass stop  302  could include more or less than two, without departing from the scope of the disclosure. 
     When the glass stop  302  is secured to the frame  102  (i.e., the sill  108 ), an air pocket  312  is defined between the glass stop  302  and the frame  102 . During installed use of the window assembly  100 , heat may tend to transfer from the exterior to the interior, or vice versa, by passing (at least partially) through the air pocket  312 . According to embodiments of the present disclosure, such heat transfer may be reduced (mitigated) by positioning a thermal dampening device  314  within the air pocket  312 . 
     In the illustrated embodiment, the thermal dampening device  314  extends between the glass stop  302  and the frame  102  (i.e., the sill  108 ). In at least one embodiment, as illustrated, the thermal dampening device  314  may extend to engage the frame  102  and, more particularly, a thermal break  316  mounted to or otherwise forming part of the sill  108 . 
     In some embodiments, the thermal dampening device  314  may be positioned (e.g., slid into place) before the glass stop  302  is installed. In other embodiments, the thermal dampening device  314  may be removably attached to the glass stop  302 . In at least one embodiment, for example, the glass stop  302  may provide or otherwise define one or more attachment features  318  configured to be received by or within a corresponding attachment feature provided by the glass stop  302 . In such embodiments, the attachment feature  318  may facilitate a snap-fit or mated engagement with the glass stop  302 . In other embodiments, however, the thermal dampening device  314  may be secured to the glass stop  302  via an interference fit or using one or more mechanical fasteners (e.g., screws). In yet other embodiments, the thermal dampening device  314  may be merely placed in contact with the glass stop  302 , such as being inserted lengthwise into the air pocket  312  (e.g., slid into the air pocket  312 ). 
     While  FIG.  3    shows the thermal dampening device  314  being removably attached to the glass stop  302 , it is contemplated herein that the thermal dampening device  314  may alternatively be removably attached to the frame  102  (e.g., the sill  108 ), without departing from the scope of the disclosure. 
     In the illustrated embodiment, the thermal dampening device  314  provides or otherwise includes multiple structural members  320  that cooperatively define one or more discrete cavities  322 . More specifically, the structural members  320  can comprise vertical and horizontal members that jointly create the cavities  322 , but could alternatively comprise members that extends in directions offset from vertical and horizontal. The structural members  320  and resulting cavities  322  may prove advantageous by breaking up the air pocket  312  into smaller air cavities, which mitigates convective heat transfer and thereby helps reduce or interrupt thermal transmission through the air pocket  312 . This results in reduced thermal flow and higher thermal performance of an entire glazing system. 
     In some embodiments, the thermal dampening device  314  may be made of a rigid or semi-rigid material, such as a (low thermal conductivity) thermoplastic polymer. In other embodiments, however, some or all of the thermal dampening device  314  may be made of an elastomer, such as ethylene propylene diene monomer (EPDM) or thermoplastic vulcanisate (TPV). In one or more embodiments, the outer surface of the thermal dampening device  314  could have a coating of a low-emissivity material applied thereto. Having the thermal dampening device  314  made of an elastomer may prove advantageous in a few ways. First, this allows the thermal dampening device  314  to be flexible and yet provide structural support (reinforcement) to the glass stop  302 . More specifically, positioning the thermal dampening device  314  in the air pocket  312  helps transfer loading from the glass stop  302 , to the thermal dampening device  314 , which transfers at least a portion of the loading to the frame  102  (i.e., the sill  108 ). 
     Second, having the thermal dampening device  314  at least partially made of an elastomer may allow the thermal dampening device  314  to operate as a type of gasket or seal within the air pocket  312 . More specifically, the thermal dampening device  314  may form a sealed interface at the sill  108  (e.g., at the thermal break  316 ) and thereby help prevent fluids (e.g., water and air) from migrating through the air pocket  312  from the exterior and into the interior. Rather, any fluids that find their way into the air pocket  312  may be stopped by the thermal dampening device  314  and forced toward a fluid weep system (not shown). 
     The thermal dampening device  218  of  FIG.  2    may be useful in a glass stop  206  that is long or otherwise extends deep into the interior of the building. In contrast, the thermal dampening device  314  of  FIG.  3    may be useful and otherwise advantageous for incorporation in a glass stop  302  that is shorter or more compact. Both thermal dampening devices  218 ,  314 , however, may prove advantageous in structurally reinforcing the corresponding glass stop  206 ,  302 . For example, in some applications, the interior gaskets  208   b  and  304   b  of  FIGS.  2  and  3   , respectively, may comprise a wedge gasket that needs to be manually installed, which requires that the wedge gasket be inserted (forced) between the infills  114   a  and  114   b  and the corresponding glass stop  206 ,  302 . During this process, the glass stop  206 ,  302  may be urged to flex and rotate outward, and in some cases this may cause the glass stop  206 ,  302  to detach from the frame  102  at the attachment mechanism  214 ,  310 . Inclusion of the thermal dampening device  218 ,  314 , however, will help resist the flex/rotation and maintain the straightness of the glass stop  206 ,  302  when driving in the interior gasket  208   b ,  304   b . In some embodiments, the thermal dampening device  218 ,  314  may be sufficiently elastic to urge the corresponding glass stop  206 ,  302  to spring back to its natural position once the gasket  208   b ,  304   b  is fully installed. 
     Similar to the thermal dampening device  218  of  FIG.  2   , the thermal dampening device  314  of  FIG.  3    may also be part of a retrofit for older glazing units (e.g., windows). Application of the thermal dampening devices  218 ,  314  in a stock length form to its mating glass stop  206 ,  302 , allows the two members to be cut to length simultaneously, and thereby reduces labor costs. 
     Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted. 
     As used herein, the phrase “at least one of” preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C. 
     The use of directional terms such as above, below, upper, lower, upward, downward, left, right, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure.