Patent Publication Number: US-2020299996-A1

Title: Attack-resistant and weather-resistant lock

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to U.S. Provisional Application No. 62/821,123, filed Mar. 20, 2019, entitled ATTACK-RESISTANT AND WEATHER-RESISTANT LOCK, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     This disclosure relates to locks with enhanced resistance to torque attacks and weather. 
     DESCRIPTION OF THE RELATED TECHNOLOGY 
     Doors, item receptacles, mailboxes, and various other enclosures have long been secured with locks. Due to the potential for valuable items to be present within lock-secured locations, locks are frequently the target of attacks such as picking, snapping, or the like. Pin tumbler locks are often susceptible to torque attacks in which a forceful rotational motion is applied at the keyway to dislodge the lock plug or cylinder, allowing the lock to be removed. Pin tumbler locks may also be susceptible to weather conditions such as rain, freezing rain, sleet, slush, ice storms, wintry mix, or the like, as liquid precipitation may enter the lock cylinder and/or plug and subsequently freeze within the lock, thereby preventing its intended operation. 
     SUMMARY 
     The systems and methods of this disclosure each have several innovative aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope as expressed by the claims that follow, its more prominent features will now be discussed briefly. 
     In one embodiment, a securable receptacle is described. The securable receptacle comprises a wall at least partially surrounding an inner volume of the receptacle, a hinged door coupled to the receptacle, and a lock coupled to and extending through the wall or the hinged door. The lock comprises a locking mechanism at least partially disposed within the inner volume of the receptacle, the locking mechanism configured to be actuated by a key; an external keyway disposed external to the inner volume and aligned with a keyway of the locking mechanism; and a sacrificial link at least partially coupling the external keyway to the locking mechanism, the sacrificial link configured to fail when a threshold torque is applied at the external keyway. 
     In some embodiments, the threshold torque is smaller than a torque required to break or dislodge the locking mechanism. In some embodiments, the sacrificial link comprises a plastic coupling rotationally fixing the external keyway to the locking mechanism. In some embodiments, the securable receptacle further comprises a drain in fluid communication with the external keyway, the drain configured to accommodate gravity-assisted drainage of fluid from the external keyway. In some embodiments, the securable receptacle further comprises an external housing at least partially surrounding the external keyway and the sacrificial link. In some embodiments, the locking mechanism remains operable and accessible via the external keyway when the sacrificial link has failed. In some embodiments, the locking mechanism comprises a pin tumbler lock. In some embodiments, the securable receptacle is a cluster mailbox. 
     In another embodiment, an attack-resistant lock is described. The attack-resistant lock comprises a housing comprising an internal section and an external section; a locking mechanism disposed at least partially within the internal section of the housing, the locking mechanism comprising a keyway configured to receive a key blade for actuating the locking mechanism; and an external keyway structure disposed within the external section of the housing. The external keyway structure comprises a scalp covering an externally facing side of the locking mechanism; an opening sized and shaped to receive the key blade, the opening aligned with the keyway such that a key blade can be inserted into the keyway through the opening; and a sacrificial fixing structure configured to prevent rotation of the external keyway relative to the locking mechanism. The sacrificial fixing structure is further configured to separate from the external keyway structure when a threshold torque is applied at the opening, and wherein the threshold torque is insufficient to dislodge the locking mechanism from the housing. 
     In some embodiments, the sacrificial fixing structure comprises one or more tabs integrally formed with at least a portion of the external keyway structure, the one or more tabs disposed within tab openings of the locking mechanism configured to retain the one or more tabs such that the tabs break away from the external keyway structure when the threshold torque is applied at the opening. In some embodiments, the one or more tabs and the portion of the external keyway structure comprise plastic, and wherein the locking mechanism comprises a metal. In some embodiments, separation of the sacrificial structure from the external keyway structure allows the external keyway structure to be rotatable relative to the locking mechanism while being retained within the housing. In some embodiments, the attack-resistant lock remains functional after separation of the sacrificial structure. In some embodiments, the attack-resistant lock further comprises a drain. In some embodiments, the drain comprises a first drain opening extending through a bottom portion of the housing and a second drain opening extending through a bottom portion of the external keyway structure, the first drain opening and the second drain opening substantially aligned to accommodate drainage of liquid matter from the external keyway structure and the housing. In some embodiments, the housing comprises an outer scalp coupled to the external section of the housing, and wherein the outer scalp retains the external keyway structure within the housing. In some embodiments, the housing prevents external access to the keyway other than through the external keyway structure. 
     In another embodiment, a weather-resistant lock is described. The weather-resistant lock comprises a locking mechanism comprising a keyway configured to receive a key blade for actuating the locking mechanism, and a housing at least partially surrounding the locking mechanism. The housing comprises an internal section retaining the locking mechanism and configured to be disposed in an interior volume of a receptacle when the weather-resistant lock is in an installed configuration, and an external section configured to be disposed outside the interior volume, the external section comprising a drain opening. In the installed configuration, the drain opening is disposed at a lower height relative to the locking mechanism to facilitate drainage of liquid matter from the housing. 
     In some embodiments, the weather-resistant lock further comprises an external keyway structure retained within the external section of the housing, the external keyway structure comprising an external keyway drain opening aligned with the drain opening of the external section to facilitate drainage of liquid matter from the external keyway structure. In some embodiments, the weather-resistant lock further comprises a keyway flap pivotable between an open position and a closed position blocking ingress of foreign matter into the keyway, wherein the keyway flap is biased in the closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features of the disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
         FIG. 1A  is a perspective view of an example embodiment of a lock with attack-resistant and weather resistant features. 
         FIG. 1B  is a perspective view of the lock of  FIG. 1A  as installed on a receptacle door. 
         FIG. 1C  is an exploded perspective view of the lock of  FIGS. 1A and 1B  illustrating the components thereof. 
         FIG. 2  schematically illustrates components of an example torque-resistant lock. 
         FIGS. 3A-3D  depict the operation of attack-resistant features of the lock of  FIGS. 1A-1C  during a torque attack. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Thus, in some embodiments, part numbers may be used for similar components in multiple figures, or part numbers may vary from figure to figure. The illustrative embodiments described herein are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations by a person of ordinary skill in the art, all of which are made part of this disclosure. 
     Reference in the specification to “one embodiment,” “an embodiment”, or “in some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Moreover, the appearance of these or similar phrases throughout the specification does not necessarily mean that these phrases all refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive. Various features are described herein which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but may not be requirements for other embodiments. 
     The present disclosure provides locking systems and devices that provide enhanced resistance to tampering and/or weather. Some of the locks described herein include one or more anti-tampering features to prevent or mitigate damage to the locks in the event of torque attacks. In some embodiments, an attack-resistant lock includes a cylinder lock coupled to one or more external components by one or more sacrificial links such that a torque attack results in breakage of the sacrificial links but does not damage or dislodge the lock plug or cylinder. Some embodiments of the present disclosure incorporate weather-resistant features, such as one or more drain holes within external components of a lock that facilitate drainage of liquids and prevent liquids from entering internal components of the lock. 
     As used herein, the term “receptacle” may include any enclosed or partially enclosed space. Non-limiting examples of receptacles may include mailboxes, lockers such as parcel lockers, letter or package drop boxes, collection boxes, postal relay boxes, safe deposit boxes, or any other lockable volume. In some examples, a receptacle may be a cluster mailbox having a plurality of individually lockable receptacles accessible through a plurality of individual doors on a first side (e.g., a front side) for access by recipients, and through one or more universal doors on the first side or a second side (e.g., a rear side) for access by a mail carrier, property manager, or other authorized user. 
       FIG. 1A  is a bottom right front perspective view of a lock  100  incorporating attack-resistant and weather-resistant features.  FIG. 1B  is a perspective view depicting the lock  100  installed on a door  55  of a receptacle  50 .  FIG. 1C  is an exploded view of the lock  100  illustrating internal and external components thereof. Any of the various components of the lock  100  may comprise one or more suitable materials such as metals (e.g., aluminum, steel, copper, or the like), plastics or other polymeric materials (e.g., rigid plastics, etc.), or other suitably rigid materials. In some embodiments, components of the lock  100  that will be exposed to the exterior when installed may be formed from metals such as aluminum or steel for enhanced durability and/or resistance to forces applied thereto. 
     The lock  100  includes a cylinder  110  having an internal section  112  and an external section  116 , and a plug  130  at least partially disposed within an internal volume  114  of the internal section  112  of the cylinder  110 . A well  118  in the external section  116  of the cylinder  110  contains an intermediate faceplate  140 , a plug scalp  150 , and a cylinder seal  160 . A cylinder scalp  170  is secured about the external section  116  of the cylinder  110  to form an external housing of outward-facing components of the lock  100 . 
     The plug  130  may be any suitable type of locking mechanism configured to be opened by a key. For example, the plug  130  may comprise a pin tumbler lock or other tumbler lock. In the case of a pin tumbler lock, a plurality of tumblers  136  and corresponding springs  138  are retained within the cylinder  110  by a tumbler retainer  124 . In some embodiments, a retaining pin  137  is included to retain the plug  130  within the cylinder  110  prior to installation (e.g., during shipping, delivery, handling, etc.). A keyway  132  is sized and shaped to accommodate the blade of a corresponding key to actuate the plug  130  to lock or unlock the lock  100 . 
     The intermediate faceplate  140  includes an inner keyway opening  142  oriented to align with the keyway  132  of the plug  130 . Similarly, the plug scalp  150  includes an outer keyway opening  152  oriented to align with the keyway  132  of the plug  130 . In some embodiments, the inner keyway opening  142  and the outer keyway opening  152  can be sized larger than the cross-sectional profile of the corresponding key in order to allow the key to access the keyway  132  of the plug  130  through the inner keyway opening  142  and the outer keyway opening  152 . The inner keyway opening  142  and the outer keyway opening  152  form an external keyway opening through which a key or other object must pass to reach the keyway  132 . Components such as the intermediate faceplate  140 , the plug scalp  150 , and/or any other components disposed along a key entry path external to the plug  130  (e.g., any components contained within the well  118  of the external section  116  of the cylinder  110 ) are collectively referred to herein as an external keyway or as external keyway components. 
     The intermediate faceplate  140  includes tabs  144  sized and shaped to fit within tab openings  134  at the periphery of the plug  130 . When disposed within the tab openings  134 , the tabs  144  prevent rotation of the intermediate faceplate  140  to retain the intermediate faceplate  140  in a desired orientation such that the inner keyway opening  140  and the outer keyway opening  152  remain aligned with the keyway  132  of the plug  130 . As will be described in greater detail with reference to  FIGS. 3A-3D , the tabs  144  may also serve as a sacrificial link during torque attacks by breaking away from the intermediate faceplate  140  when a relatively large torque is applied at the inner keyway opening  142 . Accordingly, the intermediate faceplate  140  and the tabs  144  may be integrally formed from a plastic having a suitable strength such that the tabs  144  can break away from the intermediate faceplate  140  under a torque small enough to be exerted by a human using a tool such as a screwdriver. 
     A keyway flap  154  may be disposed between the inner keyway opening  142  and the outer keyway opening  152 . The keyway flap  154  may advantageously act as a shutter or barrier to keep unwanted matter out of the keyway  132 . For example, the keyway flap  154  may prevent the ingress of dust, dirt, water, snow, or other materials that may clog the keyway  132 . In the example embodiment of  FIGS. 1A -IC, the keyway flap  154  is sized and shaped to fit within the inner keyway opening  142  of the intermediate faceplate  140 . The keyway flap  154  is biased in a closed position by a biasing member  158  such as a spring housed within a spring housing  146  of the intermediate faceplate  140 . When a key is inserted into the lock  100 , the keyway flap  154  may pivot about extensions  156 , which are retained by the intermediate faceplate  140 , to allow the key to enter the keyway  132 . 
     The cylinder seal  160  is sized and shaped to cover the portion of the well  118  surrounding the plug  130 , intermediate faceplate  140 , and plug scalp  150 . One or more alignment features such as alignment protrusions  164  of the cylinder seal  160  are configured to engage with alignment features such as alignment indentations  120  within the well  118  of the cylinder  110 , to retain the cylinder seal  160  in a desired orientation relative to the cylinder  110 . A cylinder seal opening  162  is substantially the same size as the exterior face of the plug scalp  150  and allows access to the outer keyway opening  152  therethrough. 
     The cylinder scalp  170  is sized and shaped to fit around the external section  116  of the cylinder  110  and serves as an exterior housing for the lock  100 . A cylinder scalp opening  172  in the face of the cylinder scalp  170  is substantially the same size as the cylinder seal opening  162  and allows access to the outer keyway opening  152  therethrough. The cylinder scalp  170  may be secured to the external section  116  of the cylinder  110  by any suitable securing means, for example, by an adhesive, by one or more mechanical fasteners, by any known welding technique, or the like. In some embodiments, the cylinder scalp  170  may advantageously retain all of the lock components within the lock  100  when secured to the external section  116  of the cylinder  110 , such that the lock  100  remains assembled during transport and prior to installation. In such embodiments, the retaining pin  137 , which conventionally served this component retaining function, may be omitted. In some embodiments, the space typically occupied by the retaining pin  137  may be used to include an additional tumbler  136  in order to provide an additional degree of security and making the lock  100  more difficult to attack by picking. 
     The lock  100  further includes weather resistance features that may advantageously prevent failure or inoperability of the lock  100  under adverse weather conditions such as rain, freezing rain, snow, ice, or the like. In the example embodiment illustrated in  FIGS. 1A -IC, various components of the lock  100  include drainage features. Specifically, the cylinder  110  includes a cylinder drainage opening  122 , the plug scalp  150  includes a plug scalp drainage opening  153 , the cylinder seal  160  includes a cylinder seal drainage opening  166 , and the cylinder scalp  170  includes a cylinder scalp drainage opening  174 . The drainage openings  122 ,  153 ,  166 ,  174  are located along the circumference of their respective lock components such that they are substantially aligned with each other and are disposed at the bottom of the lock  100  when the lock  100  is in an installed configuration. Any foreign matter such as rain, snow, or freezing rain that enters the well  118  and/or the interior of the plug scalp  150 , cylinder seal  160 , and/or cylinder scalp  170  can pass out of the lock  100  due to gravity through the aligned drainage openings  122 ,  153 ,  166 ,  174 . Thus, liquids such as rainwater may drain out to the exterior of the lock  100  rather than entering the plug  130  or the internal section  112  of the cylinder  110  where liquids may cause damage such as by oxidation or corrosion of internal components. In addition, in freezing conditions, cold or supercooled water may drain out to the exterior lock  100  before it can freeze within the lock. In some embodiments, at least some of the drainage openings  122 ,  153 ,  166 ,  174  are disposed lower than the plug  130  when the lock  100  is installed, such that liquid matter entering the external section  116  of the cylinder  110  drains out of the lock  100  rather than entering the internal section  112  and/or the plug  130 . 
       FIG. 2  schematically illustrates components of a locking receptacle  200  with tamper-resistant and weather-resistant features. The receptacle  200  is securable by a locking mechanism  205  such as a tumbler lock or the like. A sacrificial link  210  is disposed between the locking mechanism  205  and an external keyway  215 . An external housing  220  is disposed adjacent to the exterior of the receptacle  200  and prevents access to the locking mechanism  205  other than through the external keyway  215  and the sacrificial link  210 . A drain  225  allows foreign matter to pass out of the external keyway  215  and out of the external housing  220  without entering the locking mechanism  205 . 
     The configuration illustrated in  FIG. 2  may be implemented in a variety of physical embodiments, of which the lock  100  of  FIGS. 1A -IC is a single non-limiting example. For example, the locking mechanism  205  may correspond to the plug  130  and/or cylinder  110  of the lock  100 , or other locking mechanism. The sacrificial link  210  may correspond to the tabs  134  and tab openings  144  of the lock  100 , or other sacrificial link structures configured to fail during intrusion attempts. The external keyway  215  may correspond to components such as the inner keyway opening  142 , outer keyway opening  152 , and keyway flap  154  of the lock  100 , and/or other components disposed along an outward-facing access path to the sacrificial link  210  and locking mechanism  205 . The external housing  220  may correspond to the cylinder scalp  170 , the cylinder seal  160 , and/or the external section  116  of the cylinder  110  of the lock  100 , or one or more similar components in other embodiments. The drain  225  may corresponding to any suitable opening in fluid communication with the external keyway, for example, the drainage openings  122 ,  153 ,  166 ,  174  of the lock  100 . 
     Although the locks of  FIGS. 1A-1C  and  FIG. 2  each include both weather-resistant features and attack-resistant features, it will be understood that various embodiments of the locks described herein may be constructed without weather-resistant features or without attack-resistant features, without departing from the spirit or scope of the present disclosure. Some locks may include a drained external keyway but not a sacrificial link, or may include a sacrificial link and not a drained external keyway, depending on one or more aspects of the intended installation location. For example, a lock to be installed in an enclosed space that is open to the public, but where weather exposure is unlikely, may have a sacrificial link  210  to prevent torque attacks, but may not include a drain  225 . In another example, a lock to be installed in a secure or limited-access outdoor location may have a drain  225  to prevent weather damage, but may not include a sacrificial link  210 . 
     Referring now to  FIGS. 3A-3D , attack-resistant features of the lock  100  of  FIGS. 1A-1C  will now be described. Throughout  FIGS. 3A-3D , the cylinder seal  160  and the cylinder scalp  170  of the lock  100  are omitted so that the internal components of the lock  100  can be seen. It will be understood that the cylinder seal  160  and the cylinder scalp  170  would be present in an installed configuration. 
       FIG. 3A  is an exploded view of the lock  100  prior to a torque attack. The exterior keyway components, including the plug scalp  150  and the intermediate faceplate  140 , are contained within the well of the cylinder  110  such that the tabs  144  are disposed within the tab openings  134 . The plug  130  is rotationally fixed within the interior of the cylinder  110 , and the exterior keyway components are rotationally fixed, relative to the plug  130 , by the tabs  144  within the tab openings  134 . In the initial configuration of  FIG. 3A , the keyway openings of the intermediate faceplate  140  and the plug scalp  150  are aligned with the keyway  132  of the plug  130 . 
       FIG. 3B  illustrates an initial stage of a torque attack on the lock  100 . In a typical method of attacking cylinder locks such as the lock  100 , a blade  305  of a tool  300  is inserted along a longitudinal direction  310  into the external keyway opening, such as the outer keyway opening  152 . Although the tool  300  is illustrated in  FIGS. 3B-3D  as a flat-head screwdriver, various other flat-bladed tools may frequently be used to attack cylinder locks. In the example lock  100 , the blade  305  may be inserted until the tip of the blade  305  abuts the plug  130  and/or partially enters the keyway  132 . Because flat-bladed tools used for torque attacks are generally larger than the keys corresponding to the lock  100 , the blade  305  typically will not extend substantially into the keyway  132  within the plug  130 . 
       FIG. 3C  illustrates a second stage of a torque attack on the lock  100 . In a typical method of attacking cylinder locks such as the lock  100 , the tool  300  is rotated forcefully about the longitudinal axis, along a rotational direction  315 . In conventional cylinder locks, the forceful rotation of the blade  305  within the external keyway causes the entire lock, or a substantial portion thereof, to rotate with the blade  305 , either breaking the lock or dislodging it entirely such that the lock can be opened or removed and the attacker can access the interior of the locked receptacle. However, in the attack-resistant lock  100 , the sacrificial link components within the lock  100  mitigate the damage to the lock  100  caused by the torque attack. 
       FIG. 3D  is an exploded view of the aftermath of a torque attack on the attack-resistant lock  100 . When the tool  300  is rotated in an attempt to break or dislodge the lock, as shown in  FIG. 3C , a torque is applied to the cylinder scalp  150  and/or intermediate faceplate  140 . The only structures rotationally fixing the intermediate faceplate  140  and the cylinder scalp  150  to the plug  130  are the tabs  144 , which may be integrally formed with the intermediate faceplate  140  from a plastic or other polymeric material. The force required to cause the intermediate faceplate  140  material to break or snap can be substantially less than the force that would be required to dislodge the plug  130  from the cylinder  110  and/or to dislodge the cylinder  110  from its mounting within the wall of the receptacle. Accordingly, the tabs  144  are retained within the tab openings  134  and break free of the intermediate faceplate  140  before the tool  300  can apply sufficient torque to dislodge the plug  130  or cylinder  110 . The separated tabs  144  may be retained within the tab openings  134 , may be retained within the cylinder  110 , and/or may fall out of the lock  100  through a drain opening in the cylinder  110 . 
     In the configuration of  FIG. 3D  following the torque attack of  FIGS. 3B and 3C , the receptacle or other volume secured by the lock  100  remains secured. The intermediate faceplate  140  and the plug scalp  150  are no longer rotationally fixed to the plug  130 , and in some cases may be freely rotatable about the longitudinal axis. Advantageously, all or substantially all components of the lock may still be retained by the cylinder scalp  170  (not shown in  FIGS. 3A-3D ). Due to the relatively small size of the internal keyway  132  of the plug  130 , the plug  130  is still protected from subsequent attacks with a similarly sized blade  305 . The attacker may be discouraged from further attempts at attacking the lock because the initial attack causes breakage of certain lock components but does not cause the lock to open. Moreover, the lock  100  remains operable despite the attack, as the newly rotatable intermediate faceplate  140  and plug scalp  150  may be rotated back into alignment with the keyway  132  to allow a key to be inserted into the plug  130  and open the lock  100 . 
     The foregoing description details certain embodiments of the systems, devices, and methods disclosed herein. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the systems, devices, and methods can be practiced in many ways. It should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the technology with which that terminology is associated. 
     It will be appreciated by those skilled in the art that various modifications and changes may be made without departing from the scope of the described technology. Such modifications and changes are intended to fall within the scope of the embodiments. It will also be appreciated by those of skill in the art that parts included in one embodiment are interchangeable with other embodiments; one or more parts from a depicted embodiment can be included with other depicted embodiments in any combination. For example, any of the various components described herein and/or depicted in the Figures may be combined, interchanged or excluded from other embodiments. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     All references cited herein are incorporated herein by reference in their entirety. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material. 
     The term “comprising” as used herein is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. 
     It is noted that some examples above may be described as a process, which is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel, or concurrently, and the process can be repeated. In addition, the order of the operations may be rearranged. A process is terminated when its operations are completed. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a software function, its termination corresponds to a return of the function to the calling function or the main function. 
     The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims.