Patent Application
20080100521
The present disclosure generally relates to antenna assemblies mountable to mobile platforms, such as automobile or vehicle roofs, hoods, or trunk lids.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Various antenna types are used in the automotive industry, including aerial AM/FM antennas, patch antennas, etc. Antennas for automotive use are commonly positioned on the vehicle's roof, hood, or trunk lid to help ensure that the antenna has an unobstructed view overhead or towards the zenith. By way of example, some antenna assemblies include a die cast or stamped metal base that operates as the main load-bearing structure for the antenna assembly when mounted to a vehicle. These die cast or stamped metallic bases can be fairly costly due to the material and manufacturing costs associated therewith, especially when compared to the manufacturing costs associated with the other antenna elements.
An antenna assembly according to one embodiment generally includes a load-bearing composite antenna base. The antenna assembly is configured such that, when the antenna assembly is fixedly mounted to a vehicle body wall, the load-bearing composite antenna base is operable as a primary load-bearing structure transferring loads associated with the antenna assembly to the vehicle body wall.
In another embodiment, an antenna assembly generally includes a composite antenna base integrally defining mounting means for a printed circuit board. The antenna assembly may also include a printed circuit board having at least one antenna element. The printed circuit board may be mounted to the mounting means integrally defined by the composite antenna base without mechanical fasteners.
In a further embodiment, an antenna assembly is configured to be installed and fixedly mounted to a vehicle body wall after being inserted into a mounting hole in the vehicle body wall from an external side of the vehicle and nipped from the interior compartment side. In this exemplary embodiment, the antenna assembly generally includes a composite antenna base integrally defining one or more resiliently flexible retention members. The resiliently flexible members are configured to be inserted through the mounting hole and disposed on the interior compartment side of the vehicle body wall to thereby help retain the relative position of the composite antenna base to the vehicle body wall before the antenna assembly is fixedly mounted to the vehicle body wall.
Further aspects and features of the present disclosure will become apparent from the detailed description provided hereinafter. In addition, any one or more aspects of the present disclosure may be implemented individually or in any combination with any one or more of the other aspects of the present disclosure. It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the present disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is in no way intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Accordingly, aspects of the present disclosure relate to antenna assemblies having composite antenna bases. In yet other aspects, the present disclosure provides composite antenna bases having integrally formed snap retention features, integrally formed PCB mounting features, and/or that are configured as a primary load bearing structure for the antenna assembly. Further aspects relate to methods of assembling and/or installing antenna assemblies having composite antenna bases.
Some embodiments include the combination of a composite antenna base, an EMI shield, and an electrically-conductive insert for retaining a fastener element. Advantageously, these exemplary embodiments may allow for reduced costs, as compared to antenna assemblies having relatively expensive die cast or stamped metal antenna bases.
In some embodiments, a composite antenna base is provided that is operable as the primary load bearing structure for the antenna assembly. For example, the composite antenna base may support (and bear the loads and weight associated with) other components of the antenna assembly, such as the printed circuit board, EMI shield, grounding element, thread provider or insert, radome, environmental cover, heat stake posts, ferrule, antenna mast, etc. In these embodiments, the composite antenna base may transfer loads from the antenna assembly to external supporting structure, such as a vehicle rooftop, hood, trunk lid, or other supporting structure to which the antenna assembly is mounted.
Aspects of the present disclosure also relate to antenna assemblies having composite antenna bases formed from lower-cost materials and/or manufacturing methods, as compared to the antenna bases formed from die cast or stamped metals. The use of composite materials for the antenna base can also allow for reduced part counts through part consolidation or integration. For example, some embodiments include a composite antenna base having integrally formed snap retention features, where the composite antenna base and snap retention features are monolithically formed (e.g., injection molded, etc.) as a single component structure.
During the antenna installation process, the snap retention features may be used for temporarily holding the antenna assembly in place within a mounting hole by virtue of the snap retention features being snapped or disposed under the interior compartment side of the vehicle roof, while the other portion of the antenna base is on the external side of the vehicle roof.
Using a composite antenna base may also provide improved functionality for automotive (and other suitable antenna) environments. For example, composite antenna bases tend to be more corrosion resistant to the environment, weather, and the elements, as compared to antenna bases formed from die cast or stamped metal.
Composite antenna bases may also provide significantly lower cost antenna solutions, improved assembly (e.g., composite antenna base with integrated snap retention features, etc.), and large volume production capability (e.g., injection molding, etc.).
Some embodiments include EMI shielding for one or more electrical components of a printed circuit board of the antenna assembly. For example, this EMI shielding may be provided by using an EMI shield can, which, in turn, may be soldered, press fit, or molded to the printed circuit board. Additionally, or alternatively, a suitable material may be applied to or coated on one or more components of the antenna assembly to thereby provide EMI shielding.
Some embodiments may include one or more sealing members (e.g., an O-ring, a resiliently compressible elastomeric or foam gasket, caulk, adhesives, other suitable packing or sealing members, etc.) for substantially sealing the mounting hole. For example, a sealing member may be at least partially seated within a groove defined along an underside of the composite antenna base. In which case, the sealing helps to inhibit the ingress or penetration of water, moisture, dust or other contaminants through the mounting hole into the interior of the vehicle body. Additionally, or alternatively, a sealing member may also be provided generally between the composite antenna base and the radome. In other embodiments, sealing may be achieved by one or more integral sealing features rather than with a separate sealing mechanism.
Using composite materials for antenna bases also allow for different assembly methods to be used for coupling or attaching the various antenna components to one another. For example, various embodiments include a radome sonically welded to the composite antenna base. In such embodiments, the ultrasonic welding may provide a sufficiently robust seal, such that there is no need for a separate sealing member thereby reducing part count. In other embodiments, a separate sealing member may be provided for sealing the interface generally between the radome and the composite antenna base, to thereby inhibit the ingress or penetration of water, moisture, dust or other contaminants into the interior of the radome.
Additional embodiments may include a radome having reinforcement walls or other features to provide structural reinforcement to the antenna base. In such embodiments, the structural reinforcement provided to the antenna base by the radome may allow for reductions in the amount of material needed for the antenna base.
Some embodiments may include electrically-conductive inserts (e.g., metal thread providers, etc.) to retain a fastening mechanism, such as a threaded bolt, clip, etc. Some embodiments may include one or more heat staked bosses that help retain the relative position of the printed circuit board within the radome. Some embodiments may include a welded perimeter rib or ridge generally between the radome and composite antenna base.
With reference now to
The printed circuit board 118 includes one or more antenna elements. The antenna elements themselves may vary depending, at least in part, on the intended purpose for the antenna assembly 100. In this particular embodiment, the printed circuit board 118 and antenna elements carried thereby are configured for receiving satellite signals, such as Satellite Digital Audio Radio Services (SDARS). Alternative embodiments, however, may be configured for receiving AM/FM radio signals, GPS signals, cellular signals, etc. In this regard, two exemplary antenna assemblies 200 and 300 configured for receiving AM/FM radio signals are described below and respectively shown in
Referring back to
As noted above, the antenna assembly 100 is configured for receiving satellite signals. Given the relatively high frequencies typically associated with satellite signals, the antenna assembly 100 preferably includes EMI shielding. While this EMI shielding can be accomplished in various ways, the illustrated antenna assembly 100 includes an EMI shield can 108. When the antenna assembly 100 is fully assembled, this EMI shield can 108 is sandwiched or disposed generally between the antenna body 104 and the printed circuit board 118. In which case, the EMI shield can 108 is thus operable for shielding the PCB's electronic circuits and/or antenna elements, for example, from electromagnetic interference (EMI) generated by other devices proximal to the antenna assembly 100. Or, for example, the EMI shield can 108 may also help localize the EMI generated by the antenna assembly 100 to thereby help insulate other devices proximal to the antenna assembly 100 from being affected therefrom.
In the illustrated embodiment, the EMI shielding can 108 comprises stamped metal (e.g., steel, tin, etc.) that is preferably soldered to the printed circuit board 118. Alternatively, the antenna assembly 100 may include an EMI shielding component formed from other materials, manufacturing methods, and/or secured via other means. Some embodiments may include an EMI shielding component that is not fixedly attached directly to another antenna component. Instead, the relative positioning of the EMI shielding component may be maintained by virtue of the EMI shielding component being compressively sandwiched between the antenna base and printed circuit board. Additionally, or alternatively, some embodiments include a suitable EMI shielding material applied or coated onto the antenna base and/or other antenna components.
As used herein, the term “EMI” should be considered to generally include and refer to EMI emissions and RFI emissions, and the term “electromagnetic” should be considered to generally include and refer to electromagnetic and radio frequency from external sources and internal sources. Accordingly, the term shielding (as used herein) generally includes and refers to EMI shielding and RFI shielding, for example, to prevent (or at least reduce) ingress and egress of EMI and RFI relative to an electrical component.
Regarding the antenna base 104, a wide range of composite materials may be used for the antenna base 104. Exemplary composite materials include polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some preferred embodiments, the antenna base 104 is injection molded from polymer. Alternative embodiments include antenna bases formed using other materials and/or other manufacturing processes.
As shown in
With further reference to
As shown in
In the illustrated embodiment, the fastener member 128 comprises a threaded bolt having a hexagonal head 130. Accordingly, an installer may use a socket wrench or other suitable tool to grip the fastener's hexagonal head 130 and then rotate the fastener 128. Alternatively, other embodiments may include different driving elements, fasteners, bolts having differently-shaped or non-hexagonal heads, etc.
When rotated, the threaded bolt is threaded into the corresponding threaded portion associated with the insert 116, which, in turn, is configured to be engagingly received (e.g., friction or interference fit, etc.) within corresponding openings 132 and 134 of the EMI shielding can 108 and antenna base 104, respectively. Alternatively, threads may be integrally defined or formed by the antenna base 104 and EMI shielding can 108.
When the fastener member 128 is threaded into the insert 116, the fastener member 128 captures the retaining component 112 against the antenna base 104. This facilitates antenna installation since the retaining component 112 and fastener member 128 will not fall or drop out as the antenna assembly 100 is being installed. Capturing the components in this exemplary manner also allows the installer (from outside the vehicle) to position the antenna assembly 100 (and components 104, 108, 112, 116, 128 thereof as a single unit into an opening or mounting hole of a vehicle roof.
Also shown in
As noted above, the insert 116 provides structure (e.g., threads, etc.) for engaging the fastener member 128. The insert 116 is configured to be engagingly received within corresponding openings 132 and 134 of the EMI shield can 108 and antenna base 104, respectively. In some preferred embodiments, the insert 116 is configured (e.g., sized, shaped, etc.) so as to form a friction or interference fit with the EMI shield can 108 and antenna base 104. Additionally, or alternatively, the insert 116 may also be attached to the EMI shield can 108 and/or antenna base 104 via other means (e.g., adhesives, welding, etc.).
The insert 116 is preferably electrically-conductive so as to form at least a portion of a grounding or electric transmission path from the printed circuit board 118 to the vehicle roof. In such preferred embodiments, at least a portion of the insert 116 may electrically contact at least one electrically-conductive surface of the printed circuit board 118, such as a grounding trace or a board-mounted electrical component. In addition, the insert 116 may be formed from a wide range of materials (e.g., metals, materials rendered electrically conductive, etc.) and manufacturing methods (e.g., die casting, etc.).
A housing or radome may be also provided for enclosing components of the antenna assembly 100. The housing may be seated generally upon the antenna base 104. The housing may be formed from a wide range of materials, such as polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some embodiments, the radome and antenna base 104 are formed from compatible composite materials such that the radome may be attached to the composite antenna base 104 via ultrasonic welding. Alternatively, the radome may be attached to the antenna base 104 via other suitable means, such as interference or snap fit, solvent welding, heat staking, latching, bayonet connections, hook connections, integrated fastening features, mechanical fasteners, combinations thereof, etc.
One or more sealing members (e.g., O-rings, resiliently compressible elastomeric or foam gaskets, etc.) may also be provided for the antenna assembly 100. For example, a sealing member may be provided to substantially seal the mounting hole in which the antenna assembly 100 is mounted, to thereby inhibit the ingress or penetration of water, moisture, dust or other contaminants through the mounting hole into the interior of the vehicle body. As another example, a sealing member may also be provided generally between the antenna base 104 and the radome. Alternatively, or additionally, sealing may be achieved by one or more sealing features integrally formed or defined by the antenna base 104.
With further reference to
The antenna assembly 100 may then be positioned (from outside the vehicle) as a single unit into a mounting hole of the vehicle roof. As the antenna assembly 100 is moved downwardly relative to the vehicle roof, the snap retention features (integrally defined by the antenna base 104) will be temporarily deformed or distorted inward. In this stage of the process, the antenna assembly 100 is temporarily held in place by virtue of the interaction of the snap retention features, vehicle roof, and antenna base 104. That is, the snap retention features are disposed under the interior compartment side of the vehicle roof, while the upper remaining portion of the base 104 is disposed on the exterior side of the vehicle roof.
The installer may then enter the vehicle and use a socket wrench or other tool to grip the hexagonal head 130, and rotate the fastener member 128. This rotation drives the fastener member 128 for moving the retaining component 112, such that the legs 124 are deformed and expanded generally outwardly relative to the vehicle roof. In this exemplary manner, the antenna assembly 100 may thus be secured to the vehicle roof in a final installed position.
With further reference to
The heat stake posts 254 are engagingly received within openings of the antenna base 104, and pass through holes in the printed circuit board 218. In this exemplary manner, the heat stake posts 254 help retain the relative positioning of the printed circuit board 218 within the antenna radome 258. The relative positioning of the printed circuit board 218 may also be at least partially retained by a retaining wall or rib member 262 integrally defined or formed by the antenna base 204. That is, the printed circuit board 218 may be at least partially positioned within the opening defined by the wall 262. In which case, contact between the sides of the printed circuit board 218 and the retaining wall 262 will inhibit movement of the printed circuit board 218. Alternatively, the printed circuit board 218 may be secured using other suitable means, such as screws, other mechanical fasteners, etc. For example, other embodiments may include one or more grounding elements configured for securing a printed circuit board to an insert without any such heat posts. To this end,
With reference back to
The antenna base 204 integrally includes or defines a reinforcement/retaining wall or rib member 262. The antenna base 204 may also integrally include or define a lower protruding portion, which, in turn, integrally includes or defines snap retention features. See, for example, the snap retention features 370 shown in
In some embodiments, the antenna assembly 200 may be mounted to a vehicle roof in a substantially similar manner as that described above for the antenna assembly 100 shown in
As shown in
The insert 216 is preferably electrically-conductive so as define at least a portion of a grounding or electric transmission path from the printed circuit board 218 to the vehicle roof. In such preferred embodiments, at least a portion of the insert 216 may electrically contact at least one electrically-conductive surface of the printed circuit board 218, such as a grounding trace or a board-mounted electrical component. In addition, the insert 216 may be formed from a wide range of materials (e.g., metals, materials rendered electrically conductive, etc.) and by a wide range of manufacturing methods (e.g., die casting, etc.).
The housing or radome 258 may also be formed from a wide range of materials, such as polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some embodiments, the housing 258 and antenna base 204 are formed from compatible composite materials that allow the housing 258 to be attached to the composite antenna base 204 via ultrasonic welding (as generally represented by the welded perimeter rib 260). Alternatively, the housing 258 may be attached to the antenna base 204 via other suitable means, such as interference or snap fit, solvent welding, heat staking, latching, bayonet connections, hook connections, integrated fastening features, mechanical fasteners, combinations thereof, etc.
The antenna assembly 300 also includes heat stake posts 354 and grounding elements 356 disposed between corresponding pairs of the heat stake posts 354. The grounding elements 356 may be formed from a wide range of electrically-conductive materials (e.g., metals, materials rendered electrically conductive, etc.) and by a wide range manufacturing methods (e.g., stamping, etc.).
The heat stake posts 354 are engagingly received within openings of the antenna base 304, and pass through holes in the printed circuit board 318. In this exemplary manner, the heat stake posts 354 help retain the relative positioning of the printed circuit board 318 within the housing 358. The relative positioning of the printed circuit board 318 may also be at least partially retained by a wall or rib member 362 integrally defined or formed by the antenna base 204. Alternatively, the printed circuit board 318 may be secured using other suitable means, such as screws, other mechanical fasteners, etc.
The antenna base 304 may be formed from a wide range of composite materials, such as polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some preferred embodiments, the antenna base 304 is injection molded from polymer. Alternative embodiments include antenna bases formed using other materials and/or other manufacturing processes.
As shown in
In the illustrated embodiment, the fastener member 328 comprises a threaded bolt having a hexagonal head 330. Accordingly, an installer may use a socket wrench or other suitable tool to grip the fastener's hexagonal head 330 and then rotate the fastener 328. Alternative embodiments may include other suitable driving elements, fasteners, bolts having differently-shaped or non-hexagonal heads, etc.
As shown in
The retaining component 312 shown in
With further reference to
The insert 316 is preferably electrically-conductive so as define at least a portion of a grounding or electric transmission path from the printed circuit board 318 to the vehicle roof. In such preferred embodiments, at least a portion of the insert 316 may electrically contact at least one electrically-conductive surface of the printed circuit board 318, such as a grounding trace or a board-mounted electrical component. In addition, the insert 316 may be formed from a wide range of materials (e.g., metals, materials rendered electrically conductive, etc.) and by a wide range of manufacturing methods (e.g., die casting, etc.).
The radome 358 may be formed from a wide range of materials, such as polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some embodiments, the radome 358 and antenna base 304 are formed from compatible composite materials that allow the radome 358 to be attached to the composite antenna base 304 via ultrasonic welding (as generally represented by the weld area 360). Alternatively, the radome 358 may be attached to the antenna base 304 via other suitable means, such as interference or snap fit, solvent welding, heat staking, latching, bayonet connections, hook connections, integrated fastening features, mechanical fasteners, combinations thereof, etc.
A sealing member 364 (e.g., a foam gasket, etc.) is provided for substantially sealing the interface between the underside of the antenna base 304 and the external side of the vehicle roof. As shown in
This particular antenna assembly 400 is configured for receiving cellular signals and GPS signals. To this end,
Because this particular antenna assembly 400 is configured for receiving satellite signals at relatively high frequencies, this embodiment preferably includes at least some EMI shielding. As shown in
Regarding the antenna base 404, a wide range of composite materials may be used for the antenna base 404. Exemplary composite materials include Exemplary composite materials include polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some preferred embodiments, the antenna base 404 is injection molded from polymer. Alternative embodiments include antenna bases formed using other materials and/or other manufacturing processes.
The antenna base 404 may integrally include or define a lower protruding portion, which, in turn, integrally includes or defines snap retention features. See, for example, the snap retention features 370 shown in
In some embodiments, the antenna assembly 400 may be mounted to a vehicle roof in a substantially similar manner as that described above for the antenna assembly 100 shown in
With further reference to
The antenna base 404 also integrally defines a ridge or shoulder 476. The shoulder 476 extends generally around the perimeter of the antenna base 404. Accordingly, an O-ring or other suitable sealing member may be seated against the shoulder 476 to substantially seal an interface between the antenna base 404 and a housing or radome. The O-ring prevents (or at least inhibits) the ingress or penetration of water, moisture, dust, or other contaminants through the interface into the interior of the housing.
The antenna base 404 also includes a weld area 460 sufficiently sized so as to permit ultrasonically welding of a composite housing or radome to the antenna base 404. Therefore, the housing may be formed from a wide range of materials, such as polymers, urethanes, plastic materials (e.g., polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, thermoplastic materials (e.g., GE Plastics Geloy® XP4034 Resin, etc.), among other suitable materials. In some embodiments, the housing and antenna base 404 are formed from compatible composite materials that allow the housing to be attached to the composite antenna base 404 via ultrasonic welding. Alternatively, the housing may be attached to the antenna base 404 via other suitable means, such as interference or snap fit, heat staking, solvent welding, latching, bayonet connections, hook connections, integrated fastening features, mechanical fasteners, combinations thereof, etc.
As shown in
The insert 416 is preferably electrically-conductive so as define at least a portion of a grounding or electric transmission path from the printed circuit board 418 to the vehicle roof. In such preferred embodiments, at least a portion of the insert 416 may electrically contact at least one electrically-conductive surface of the printed circuit board 418, such as a grounding trace or a board-mounted electrical component. In addition, the insert 416 may be formed from a wide range of materials (e.g., metals, materials rendered electrically conductive, etc.) and manufacturing methods (e.g., die casting, etc.).
A sealing member may be provided between the underside of the antenna base 404 and the external side of the vehicle roof for substantially sealing the mounting hole. Alternatively, or additionally, sealing may be achieved by one or more sealing features integrally formed or defined by the antenna base 404.
The antenna assembly 400 may also include a stamped metal grounding element 456. In this embodiment, a grounding path may thus be formed from the printed circuit board 418 to the vehicle roof by way of the grounding element 456, insert 416, fastener member, and retaining component.
An exemplary grounding element 456 is shown in
It should be noted that embodiments and aspects of the present disclosure can be used in a wide range of antenna applications, such as patch antennas, telematics antennas, antennas configured for receiving satellite signals (e.g., Satellite Digital Audio Radio Services (SDARS), Global Positioning System (GPS), cellular signals, etc.), antennas configured for receiving RF energy or radio transmissions (e.g., AM/FM radio signals, etc.), combinations thereof, among other applications in which wireless signals are communicated between antennas. Accordingly, the scope of the present disclosure should not be limited to only one specific form/type of antenna assembly.
In addition, various antenna assemblies and components disclosed herein can be mounted to a wide range of supporting structures, including stationary platforms and mobile platforms. For example, an antenna assembly disclosed herein could be mounted to supporting structure of a bus, train, aircraft, among other mobile platforms. Accordingly, the specific references to automobiles or vehicles herein should not be construed as limiting the scope of the present disclosure to any specific type of supporting structure or environment.
Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.
When introducing elements or features and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.
