Abstract:
A docking module for use in a modular locking system includes a locking daughter board configured to selectively operate a locking mechanism into locking and unlocking positions. The docking module further includes an ID daughter board configured to interact with an identifier incorporated into a latching body of a tangible item in order to generate identification information regarding the tangible item. The ID daughter board is configured to transmit the identification information to a remote computer. The locking daughter board is configured to receive instructions from the remote computer regarding whether to selectively move the locking mechanism into the locking and unlocking positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 14/044,714, filed Oct. 2, 2013, now U.S. Pat. No. 9,361,601, which claims priority to U.S. Provisional Application No. 61/708,913, filed on Oct. 2, 2012. The contents of the above applications are incorporated herein by reference for all purposes. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relate generally to systems and methods for facilitating automated transactions. In particular, embodiments of the present invention relate to a system employing a series of docking modules that control access to goods or services. 
     BACKGROUND 
     Traditional transactions involve a customer directly interacting with an employee, such as a cashier. In many traditional transactions, for example, renting a product, employees are required to repeatedly intake and record data regarding the rental when the customer receives the product and when the customer returns the product. Requiring on-site personnel increases costs and limits locations for transactions. 
     SUMMARY 
     According to some embodiments, a modular system includes a system computer in communication with one or more Primary Lock Control Boards. Each Primary Lock Control Board communicates with multiple Lock Control Boards, which in turn communicate with a plurality of Daughter Boards. A Primary Lock Control Board, either alone or in combination with the system computer, authorizes a transaction and records data pertinent to that transaction. The Primary Lock Control Board transmits a signal to a Lock Control Board, which instructs its Daughter Boards to release an item to a customer. 
     While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a modular system for facilitating automated transactions, according to embodiments of the present invention. 
         FIG. 2  illustrates the modular system of  FIG. 1  with additional components, such as a kiosk computer. 
         FIG. 3  illustrates a second modular system for facilitating automated transactions, according to embodiments of the present invention. 
         FIG. 4  illustrates a third modular system for facilitating automated transactions, according to embodiments of the present invention. 
         FIG. 5  illustrates a perspective view of a docking module and a latching body, according to embodiments of the present invention. 
         FIG. 6  illustrates a side view of the docking module and latching body of  FIG. 5 . 
         FIG. 7  illustrates a cut-away lateral side view of the docking module and latching body of  FIG. 5 . 
         FIG. 8  illustrates a perspective view of a docking module and a second latching body, according to embodiments of the present invention. 
         FIG. 9  illustrates a perspective view of some components of a second docking module, according to embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention relate generally to a modular system for facilitating automated transactions. Specifically, in some embodiments a modular system includes a plurality of lock modules that are controlled by one or more primary lock control boards. The lock modules control access to products or services. The modular system enables customers to access the products or services, for example, to check out and return a tool, without requiring the customer to fill out forms and without requiring an employee to intake and process customer information. 
     Exemplary System Architectures 
     As shown in  FIG. 1 , a modular system  100  includes a system server  102  and a system computer  104 . As described below in more detail, in some embodiments the system server  102  and/or the system computer  104  are used to maintain the modular system  100  (e.g., verify that other modular components are properly functioning) and/or oversee automated transactions (e.g., verify customer access information and update databases). The system server  102  may be any standard data server and the system computer  104  may be a PC, laptop, etc. In some embodiments, the system server  102  and/or system computer  104  may form part of a kiosk for customer interaction or may host a website for receiving customer input. 
     In  FIG. 1 , the system server  102  communicates with a Primary Lock Control Board (PLCB)  106  through a network  108 , such as the Internet. In some embodiments, the system computer  104  communicates with the PLCB  106  through the network  108 . The network  108  may be any communications network, such as a cellular network, an intranet, a publically-switched telephone network, etc. While only one PLCB  106  is shown in  FIG. 1 , it is intended that a plurality of PLCBs  106  may be employed. In some embodiments, the PLCB  106  has the ability to read ambient temperature, to switch between multiple power sources, and/or to switch power on and off at any one of a plurality of connections (e.g., voltage inputs of various magnitudes). In those embodiments, the PLCB  106  may report voltage and/or amperage readings for power sources. The PLCB  106  may also include one or more input/output ports that can initiate or terminate power transmittal to external devices. For example, the PLCB  106  could initiate and/or terminate power for LCD displays, wife or cellular cards, GPS transceivers, external lighting, etc., to conserve power or to restrict usage. 
     Still referring to the embodiments in  FIG. 1 , a Lock Control Board (LCB)  110  communicates with the PLCB  106  and with Daughter Boards  112 ,  114 . While only one LCB and two Daughter Boards are shown in  FIG. 1 , it is intended that a plurality of LCBs may be used with each PLCB and a plurality of Daughter Boards may be employed with each LCB. For example, in some embodiments, an LCB includes four Daughter Boards. As described below in more detail, the LCB  110  and/or Daughter Boards  112 ,  114  may be incorporated into a docking module and the Daughter Boards  112 ,  114  may control various functions of the docking module. The LCB  110  instructs Daughter Boards  112 ,  114  to perform particular functions and reports data from the Daughter Boards  112 ,  114  to the PLCB  106 . For example, Daughter Board  112  may operate a locking mechanism and Daughter Board  114  may operate a data reader or identification sensor, such as an RFID reader. Each Daughter Board  112 ,  114  transmits data back to the LCB  110  (e.g., indicating the lock was successfully released and transmitting data read from an RFID chip) which transmits the data to the PLCB  106 . As also described below in more detail, the PLCB  106  may use that data for local operations (e.g., updating a user interface) and/or may transmit the data to the system server  102 . 
     As shown in  FIG. 2 , the modular system  100  may include a kiosk computer  113 , which operates locally to facilitate communications between PLCB  106 , PLCB  122 , and the system server  102 . The kiosk computer  113  may also be a server and/or may operate one or more user input devices, such as a touch screen, keyboard, mouse, RFID reader, etc. In some embodiments, the kiosk computer  113  is integrated into a kiosk or other device for user interaction. 
     In some embodiments, PLCB  106  performs similar or identical functions with respect to its LCB  110  as PLCB  122  performs with respect to its LCBs  124 ,  126 . In other embodiments, each PLCBs  106 ,  122  perform different functions than another PLCB with respect to its LCBs, which allows the modular system  100  to offer a variety of goods and services under a variety of conditions. Exemplary functions that may be performed by the PLCBs are described below in more detail. 
     Still referring to  FIG. 2 , the LCBs  110 ,  124 ,  126  each communicate with their respective Daughter Boards  112 ,  114 ,  130 ,  132 ,  134 ,  136 . In some embodiments, each LCB performs similar or identical functions with respect to (or in conjunction with) its Daughter Boards than another LCB with respect to (or in conjunction with) its Daughter Boards. In other embodiments, each LCB performs different functions with respect to (or in conjunction with) its Daughter Boards than another LCB with respect to (or in conjunction with) its Daughter Boards, which allows the modular system  100  to offer a variety of goods and services under a variety of conditions. Exemplary functions that may be performed by the LCBs and Daughter Boards are described below in more detail. 
       FIGS. 3 and 4  illustrate embodiments that use particular protocols to communicate between components of a modular system. Nevertheless, it is intended that other protocols could be used, such as ATM, RS-232, or any other known communications protocol. In other words, the communication protocols provided herein are merely examples and are not intended to be limiting. 
     Referring to  FIG. 3 , a modular system  200  includes a PLCB  206  that communicates with a computer  204  using a USB HID (Universal Serial Bus Human Interface Device) connection. In some embodiments, the computer  204  could be a server (e.g., system server  102  in  FIG. 1 ) or a kiosk computer (e.g., kiosk computer  113  in  FIG. 2 ). The computer  204  communicates with a switch (e.g., Ethernet switch  240 ) using TCP protocols. The Ethernet switch  240  communicates with the LCB  210  using TCP protocols. The LCB  210  communicates with four Daughter Boards,  230 ,  232 ,  234 ,  236 , which may be incorporated into a docking module. 
     Daughter Board  230  is a Sensory Daughter Board  230  that includes lights  240 ,  242 ,  244 ,  246  and a speaker  248 . As described below in more detail, these lights and speaker may be used to direct a user&#39;s attention to a particular docking module. While  FIG. 3  illustrates four lights and one speaker, other communicative mechanisms are contemplated and more or less than five communicative mechanisms may be used. In some embodiments, the light/lights of a Sensory Daughter Board may be incorporated into a screen to visually communicate information to a user. In some embodiments, the Sensory Daughter Board  230  controls multiple LEDs and the Sensory Daughter Board has the ability to turn individual LEDs on and off and/or blink individual LEDs at a specific interval. In some embodiments, the Sensory Daughter Board  230  controls any number of LEDs with each LED directly connected to the Sensory Daughter Board  230 . In other embodiments, the LEDs and/or speaker are pluggable through an IDC connection for remote installation. The speaker  248 , in some embodiments, has the ability to sound a buzzer for a specified interval or emit other predetermined sounds or music for a predetermined period of time. The speaker  248  may be directly connected to the Sensory Daughter Board  230 . 
     Daughter Board  232  is a Lock Daughter Board  232  and operates a locking mechanism in a docking module. For example, the Lock Daughter Board  232  may supply power to engage or disengage a locking mechanism in the docking module. In some embodiments, the Lock Daughter Board  232  also maintains and reports the state of the lock (e.g., transmits data indicating whether a locking mechanism is currently engaged in a locked or unlocked configuration). Daughter Boards  234 ,  236  are ID daughter boards  234 ,  236  that receive input, for example, by reading an RFID chip. ID Daughter Boards  234 ,  236  may use one of any number of wireless identification technologies, such as RFID, NFC, etc. 
     Still referring to  FIG. 3 , the Ethernet switch  240  communicates with a wireless bridge  250 , which in turn communicates with a network  208 , such as the Internet. A second wireless bridge  252  communicates with the network  208  and with a second switch (e.g., Ethernet switch  254 ), which communicates with LCB  222 . LCB  222 , like LCB  210 , includes several Daughter Boards, such as a Sensory Daughter Board  256  (operating lights  264 - 270  and speaker  272 ), Lock Daughter Board  258 , and ID Daughter Boards  260 ,  262 . 
     Referring now to  FIG. 4 , a modular system  300  includes a computer  304  in communication with a PLCB  306  using a USB HID connection. In some embodiments, the computer  304  could be a server (e.g., system server  102  in  FIG. 1 ) or a kiosk computer (e.g., kiosk computer  113  in  FIG. 2 ). The PLCB  306  communicates with one or more LCBs (e.g., LCB  310  and LCB  322 ) using a connection based on RS-485. Each LCB includes connections to multiple Daughter Boards (i.e., LCB  310  is connected to Daughter Boards  330 - 336  and LCB  322  is connected to Daughter Boards  356 - 362 ). In this manner, various components of the modular system  300  may communicate in a “daisy-chain” like configuration. In  FIG. 4 , the LCBs  310 ,  322  and Daughter Boards  330 - 336  and  358 - 362  are similar to the LCBs  210 ,  222  and Daughter Boards  230 - 236  and  258 - 268  in  FIG. 3 . However, the Sensory Daughter Board  356  is different than Sensory Daughter Board  256  in that the lights  364 - 370  and sensor  372  are not incorporated into the Sensory Daughter Board  356 . Instead, those communicative mechanisms are external to the Sensory Daughter Board  356 . For example, the communicative mechanisms may be located on external surfaces of a docking module to facilitate user interaction. 
     In some embodiments, each board (PLCB, LCB, Daughter Boards) has connections that are uniquely configured while in other embodiments groups of connections are key-based, for example, with groups of connections with the same functionality having the same configuration or key. 
     In some embodiments, the fuses in the modular system (e.g., modular system  100 ) are field-replaceable or self-healing. The components of the modular system may be arranged so that there is ample space around each connection for easy removal. In some embodiments, the connectors support IDC connection technology. In some embodiments, the data cables and power cables in a modular system are separate, for example, with data cables using RJ-45 connections and running over CAT 6 cabling and with power cables using two wires (e.g., 12 AWG) with a power cable header of 1-350942-0. 
     Exemplary Component Operations 
     As discussed above, in various embodiments each component of a modular system (e.g., modular system  100 ) may perform certain functions or execute particular operations. While reference is primarily made to components illustrated in  FIGS. 1 and 2  (i.e., modular system  100 ), it is intended that the exemplary operations described below could be performed, either alone or in combination, by various components in various embodiments of the modular system. 
     In some embodiments, the modular system  100  is used to facilitate automated rentals. Specifically, in those embodiments the modular system  100  interfaces with a user, releases an item into the user&#39;s possession, and/or receives an item when the user is finished. For example, some embodiments the modular system is used to rent goods (e.g., tools, though other goods such as equipment, vehicles, etc. may also be used in a system, either alone or in combination). In those embodiments, LCB  110  and/or Daughter Boards  112 ,  114  are incorporated into a docking module (e.g., docking module  500  in  FIG. 5 ). Specific examples of the docking module and how the LCB  110  and daughter boards  112 ,  114  operate with respect to the docking module are discussed below in more detail. 
     The docking module includes a locking mechanism that secures (e.g., locks) a particular tool (e.g., a drill) to the docking module. The docking module is secured at the site, for example, using a security cable (e.g., a hardened steel cable) to attach the docking module to a building or to another secure structure. In some embodiments, the docking module may be free hanging with the security cable and a data cable coupling the docking module to the secure structure. If the cable is cut or disconnected from the docking module, an alarm may sound. In other embodiments, the docking modules are integrated into the secure structure (e.g., mounted into a wall of a building). The modular system  100  may include any number of docking modules to offer a variety of goods. 
     The PLCB  106  is incorporated into a kiosk or is in communication with a kiosk. That kiosk includes one or more user input mechanisms, such as touch screens, keyboards, RFID readers, etc, as well as a kiosk computer  113  and/or a system computer  104 . The kiosk may operate in a power-down or sleep mode until user input (e.g., contacting a touch screen or pressing a button) transmits a signal to “wake-up” the kiosk. 
     The customer begins the transaction by interfacing with the kiosk (e.g., using a touch screen). The customer enters personal information (name, email, billing information, etc.) and selects a desired good, for example, a drill. The PLCB  106  receives a signal conveying the customer&#39;s selection and identifies a docking module holding a drill. In some embodiments, the PLCB  106  identifies the docking module using a database maintained at the kiosk. In other embodiments, the PLCB  106  may look to a database maintained external to the kiosk (e.g., by the server  102 ). In yet other embodiments, the PLCB  106  may poll the LCBs to identify docking modules with a drill. Once the PLCB  106  has identified an appropriate docking module, it transmits a signal to the LCB  110  of the docking module. 
     In some embodiments, the LCB  110  receives the signal from the PLCB  106 , processes that signal, and transmits particular messages to its daughter boards  112 ,  114  based on the signal from the PLCB  106 . For example, the LCB  110  may instruct a Sensory Daughter Board (e.g., Sensory Daughter Board  330  in  FIG. 4 ) to activate communicative mechanisms on the docking module, such as lights or speakers, to help the customer locate the correct docking module. The LCB  110  may instruct a Lock Daughter Board (e.g., Lock Daughter Board  332  in  FIG. 4 ) to disengage a locking mechanism securing the drill to the docking module. The user is then able to remove the drill from the docking mechanism. 
     In some embodiments, when the user has finished using the drill, the user may simply reinsert the drill (or a component attached to the drill) into a docking module. As described below in more detail, in some embodiments the docking module (e.g., via one or more Daughter Boards) detects the return of the drill and engages a locking mechanism to secure the drill and may identify the particular drill using, for example, RFID technology. The LCB  110  receives data regarding the return of the drill and transmits that data to the PLCB  106 , which may forward the data to a kiosk computer  113 , system computer  104  and/or system server  102 . 
     In some embodiments, the modular system  100  maintains a database of customer transactions. For example, when the user selects the good (e.g., the drill), the PLCB  106 , computer  112 , system server  102 , and/or system computer  104  creates an entry in a database containing, e.g., a user identification, an identifier for the drill, a time stamp for when the tool was removed, billing information for the user, and/or other information pertinent to the transaction. When the drill is returned, the PLCB  106  (in conjunction with its Daughter Boards) generates data indicating that the drill was returned and when the drill was returned. The database is then updated with that information. The rental entry may then be processed (e.g., by the system server  102 ) for billing. The database may also be used to identify the locations of particular goods (i.e., the docking modules currently securing those particular goods). 
     In some embodiments, the modular system  100  is used to facilitate automated sale of goods in, e.g., a vending-locker system. In those embodiments, an identifier, for example an RFID chip, is located on an item (e.g., within a vase containing flowers) placed in a locker in the vending-locker system. A Daughter Board (e.g., ID Daughter Board  334 ) reads the RFID chip and transmits the identifier to the LCB  110 , which forwards the information to the PLCB  106 . The PLCB  106 , either alone or in combination with a kiosk computer  113 , system computer  104 , and/or system server  102 , matches the identifier to an entry in a database to determine what product is located in that locker. Correctly identifying the product allows the system  100  to convey the correct information (e.g., price) to a user seeking to purchase that item. Once the item is purchased (e.g., using the kiosk or through an Internet website), the PLCB  106  transmits a signal to the corresponding LCB  110 , which will disengage the locking mechanism on the locker door using a Lock Daughter Board. 
     In some embodiments, the modular system  100  is used to facilitate automated rental of services, such as, for example, renting a ski locker. In those embodiments, the LCB  110 , using a Lock Daughter Board, controls a locking mechanism on the locker door. A user interacts with a kiosk, which may include the PLCB  106 , to rent the ski locker. Once the rental is approved, the kiosk records the user identifier and a locker identifier in a database. When the user wishes to access the locker, he or she enters her user identifier into the system. For example, an ID Daughter Board equipped to read RFID chips is placed adjacent to the locker door. The user places his or her RFID chip near the ID Daughter Board. The ID Daughter Board transmits the user identifier read from the RFID chip to the LCB  110 , which passes the data to the PLCB  106 . The PLCB  106  verifies the user identifier and locker number against the database. If the entries match, the PLCB  106  instructs the LCB  100  to open the locker. The Lock Daughter Board  112  is then used to engage/disengage the locking mechanism and to record time entries indicating when the locker was locked or unlocked. 
     In some embodiments, the user submits identifying information, billing information, or other required information to the system server  102  over the Internet. For example, the user may transmit information using a smart-phone or computer. The system server  102  authorizes the sale/rental, identifies an appropriate docking module for that user, and/or transmits a signal to the PLCB  106  for that docking module. The PLCB  106  receives that signal and instructs the LCB  110  to allow the user to access the goods/services that he or she has purchased. 
     In some embodiments, the kiosk is configured to receive a user identifier using RFID technology, Near-field communications, laser/barcode technology, or any other data entry mechanism. The kiosk may access user records, for example, in a database maintained at the kiosk or at a remote location, to identify a customer associated with that user identifier. In other embodiments, the modular system does not employ a kiosk. Instead, the PLCB  106  uses an ID Daughter Board to receive a user identifier and initiate the transaction. Those embodiments are useful when the goods are identical, such that the user does not need to select a particular good from a variety of sources and so no additional user input is required. 
     Exemplary Docking Modules 
     In some embodiments, the modular system  100  includes one or more docking modules, which may incorporate components such as the LCB  110  and/or the Daughter Boards  112 ,  114 . In the embodiments shown in  FIGS. 5-7 , a docking module  500  includes a cable  510  that secures the docking module  500 , for example, by coupling the docking module to a building. The cable  510 , in some embodiments, carries power to the docking module  500  and/or data to and from the docking module  500 . The cable  510  could include both a security cable and a data cable that are independent cables. As mentioned above, in some embodiments the modular system  100  triggers an alarm if the cable  510  is severed. 
     In some embodiments, the docking module  500  receives a latching body  520  and selective secures the latching body  520  within the docking module  500 . As shown in  FIG. 5 , the latching body  520  includes a latch base  522 , a latch neck  524 , and a latch head  526 . The latch head  526  includes an upper head surface  528 , a side head surface  530 , and a lower head surface  532 . The upper head surface  528  is generally parallel to the lower head surface  532 . The side head surface  530  is sloped with respect to the upper head surface  528  and the lower head surface  532  to facilitate a locking engagement with the docking module. The latch base  522  is secured to the item to be sold or rented (e.g., the drill). For example, the latch base  522  in  FIG. 5  includes three screw holes  534  that can be used to secure the latch base  522  to the item. Other attachment mechanisms, such as adhesive, welding, etc., may also be used. While the latch base  522  in  FIG. 5  is a flat disc, other shapes and sizes are envisioned. For example, the latch base  522  may be shaped to match a corresponding surface on the item to which it is attached. The latching body  520  may be coupled to the item either through a rigid attachment or through a floating attachment. 
     Still referring to  FIG. 5 , the docking module  500  includes an outer casing  536  that may be formed of a hard plastic, metal, fiberglass-filled nylon, or other similar materials. The outer casing  536  may include some metal components as long as that metal does not interfere with any identification sensors. The outer casing  536  defines a rectangular prism with an aperture  538  in a bottom section  540  of the outer casing  536  through which the latch head  526  may pass. In other embodiments, the outer casing  536  forms other shapes according to the particular spatial requirements of the modular system  100  and/or its surroundings. 
     Within the outer casing  536  is a left jaw  542  and a right jaw  544 , which pivot about a left jaw midpoint  546  and a right jaw midpoint  548 , respectively. The left jaw  542  (specifically a lower head portion  543  of the left jaw  542 ) and the right jaw  544  (specifically a lower head portion  545  of the right jaw  544 ) form a jaw latch that, when in a locked position (see  FIG. 6 ), engages the lower head surface  532  of the latching body  520  and secures the latching body  520 . To move the jaw latch between a locked and unlocked position, the docking module  500  includes a motor or solenoid  552 . In some embodiments, the jaw latch is in the locked position when the solenoid  552  is unpowered and moves into the unlocked position only when the solenoid  552  receives power (e.g., from a Lock Daughter Board). In other embodiments, the jaw latch is in the unlocked position when the solenoid  552  is unpowered and moves into the locked position only when the solenoid  552  receives power (e.g., from a Lock Daughter Board). In other embodiments, the latching body  520  includes a ring and the locking mechanism within the docking module is a trunk lock. A variety of locking configurations may be used to secure the latching body  520  to the docking module. 
     The docking module  500  also includes a plug seated sensor  560 . In some embodiments, and as best shown in  FIG. 7 , the plug seated sensor  560  includes a sensor arm  562  pivotally coupled to the seat  564 . When the latching body  520  enters the docking module  500 , the upper head surface  528  contacts the sensor arm  562  and moves it toward the seat  564 . The plug seated sensor  560  detects the sensor arm movement and sends a signal to a Daughter Board, for example, an ID Daughter Board. The ID Daughter Board then activates an identifier sensor  570 , such as an RFID sensor, that reads an RFID chip  572  embedded within the latching body  522 . By activating the identifier sensor  570  only when the latching body  522  is within the docking module  500 , the modular system  100  conserves power. In addition, the ID Daughter Board may be configured to activate the identifier sensor  570  only once each time a latching body  522  is removed from and/or returned to the docking module  500 . Specifically, the ID Daughter Board will turn on the identifier sensor  570 , which then searches for an identifier (e.g., via an RFID chip). When the identifier sensor  570  senses a return signal, it transmits that signal to the ID Daughter Board, which forwards the signal to its LCB. The LCB may verify the signal itself, or it may forward the signal to the PLCB or other system components for verification. Once the signal is verified as a user identification, the ID Daughter Board turns the identifier sensor  570  off. Thus, the ID Daughter Board is configured to operate the identifier sensor  570  until a received user identifier is verified, at which point it turns off the identifier sensor  570  to conserve power. 
     In the embodiments shown in  FIG. 8 , the latching body  522  is coupled to a latching cord  580 . The latching cord  580  secures the latching body  522  to an item, for example, by looping the latching cord  580  around the item (or part of the item) and closing the loop (e.g., with a crimp). 
       FIG. 9  illustrates a cut-away view of a docking module  600  in which the latching head  626  passes through an aperture  638  in a side section  640  of the docking module  600 . Specifically, the docking module  600  forms a rectangular prism and the aperture  638  is in the middle of a side section  641  of the docking module  600 . Also in  FIG. 9 , the left jaw  642  and the right jaw  644  pivot at different points. Specifically, the left jaw  642  pivots about a midpoint  646  while the right jaw  644  pivots at an upper point  680 . 
     Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features.