Abstract:
A method of gaining authorized entry into a secure location is provided. The method includes providing an electronic lock having a dial, the lock operably coupled to a microprocessor having memory for storing a user input code and a valid code. The user rotates the dial to activate power to the lock and a first random character is generated. The user again rotates the dial until a first user input character displays in the display. The first user input character is stored in memory and a second random character is generated. After the user has entered all characters of the access code, the microprocessor compares the user input characters with the valid access code stored in memory if the user inputted code comprises an authorized code an indicia is generated on the display to visually indicate to a user that the lock is capable of moving to the opened position.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. provisional patent application Ser. No. 62/144,563, filed on Apr. 8, 2015, the entirety of which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to locks having electronic input means and methods of inputting lock combinations, primarily for safes and other secure containers. 
         [0004]    2. Description of the Related Art 
         [0005]    Safes and other secure containers have traditionally used combination locks for controlling and authorizing entry. Locks had been mechanical and relied on a person dialing a correct combination on a rotating dial. The rotation positioned mechanical elements within the lock such that dialing the correct combination allowed a locking bolt to release the container door. For example, traditional mechanical locks, such as Gartner, U.S. Pat. No. 3,968,667 (1976), rely on a dial rotating tumblers. Proper dial rotation aligns gates in the tumblers. Once the gates are aligned, a fence on a fence lever can enter the aligned gates. Continued rotation of the dial and tumblers pulls the fence lever and withdraws the bolt. 
         [0006]    Electronics have replaced mechanical structures in many locks. Electronic locks can use electronics rather than aligned tumbler wheels to sense entry of the correct combination. The electronics can sense the rotary position of a combination lock dial, or a keypad can replace the combination dial. Consequently, instead of dialing a number, e.g., “72,” the user would first push the “7” and then the “2” keys for the same result. Uyeda, U.S. Pat. No. 5,134,870 (1992) and Gartner, U.S. Pat. No. 5,136,870 (1992) are examples of a keypad entry system for a safe and door lock, respectively. 
         [0007]    When the lock is used to secure entry to a container, the electronic components are typically mounted on a housing inside the container door. The housing contains a battery and a circuit board, which contains the electronic circuitry controlling the lock. The keypad is on the outside of the housing so as to be accessible to the user. A cable typically extends between the keypad and the circuit board for transmitting signals between the two components. 
         [0008]    Traditional electronic keypads generally include ten keys that correspond with the numbers “0” through “9.” One drawback of this type of traditional keypad design arises from the fact that as users repeatedly enter the correct, authorized access combination on the keypad, the keys representing correct numbers in the combination begin to show signs of visible wear. As a result, an unauthorized individual may figure out the correct access combination. To prevent this, the combination must periodically be changed such that each of the keys on the keypad are used at some point in time and, as a result, all keys show signs of wear. However, having to periodically change the correct, authorized access combination may create confusion for authorized users who must repeatedly remember new combinations. 
         [0009]    Another drawback to traditional electronic locks having a display is that as the user enters the correct, authorized access combination, the access code may be visible to unauthorized users who thereafter may access the safe. 
         [0010]    Thus, there is a need for an improved access combination system and method that may be accessed by a user while preventing unauthorized entry and maintaining a high level of security. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention solves the foregoing problems by providing a method of inputting a user access combination in order to gain authorized entry into a secure location. The present invention provides an electronic lock assembly comprising a housing, an input dial, and a microprocessor in communication with the input dial. The housing includes a front wall, a rear wall, and a generally cylindrical side wall disposed between the front and rear walls. The rear wall of the housing is attachable to a secure container. The dial is attachable to the front wall of the housing. The lock also includes a top-reading display. The display displays user input characters and randomly generated characters. The microprocessor has memory for storing the user input characters and the randomly generated characters. The microprocessor may also be configured to control operation of a latch mechanism, wherein the latch mechanism is movable from a locked position to an unlocked position upon the microprocessor determining that a valid or correct access combination has been input through the dial. 
         [0012]    A method of inputting an authorized access code is also provided. In one aspect of the inventive method, the sequence begins when the rotatable dial is turned in a clockwise or counter-clockwise direction. If the super capacitor is fully charged it activates and turns on the display. As a result, a randomly generated number or other symbol is shown on the display. 
         [0013]    Next, the user rotates dial in a clockwise or counter-clockwise direction in order to change the numerical value displayed in display to the first character or number of the user input code. 
         [0014]    During a pre-determined period of time, typically one to four seconds, the user input character is stored in RAM, the display blinks and a second random character is generated and displayed in display. Those of skill in the art will appreciate that the user does not have the option of changing the first user input character to select a different character after the random character is generated. 
         [0015]    The method continues when the user again rotates dial clockwise or counter-clockwise until the second user input number is displayed in display. The process discussed above is repeated during the pre-determined period of time, typically one to four seconds, while the second character input by the user is stored in RAM and a third random character is generated and displayed in display. 
         [0016]    This process is repeated until the entire user input code is input into the lock. Typically this will be three characters. However, while a two-digit code is used here for purposes of illustration, those of skill in the art will appreciate that an access code may comprise three integers or digits or may comprise any number of digits. After all user input characters are inputted, the microprocessor compares the user inputted access code stored in RAM with the valid access code stored in ROM to determine if the codes match. If the user inputted access code matches the correct stored access code, the display provides a visual indication to the user, such as “OP” or “+” to indicate that the lock is ready to be opened. In addition, and depending on the lock being used the microprocessor may send a signal to a latch or bolt drive indicating that authorized entry has been confirmed, thereby allowing the latch or other bolt to be retracted into to the open position by a user. The user will then turn the dial to the right to cause the latch or bolt to disengage from the container or safe door. In another aspect of the invention, the display may provide a visual indication to the user, such as “NOP” or “−” or “00” indicating that the correct access code has not been entered and the lock is not opened. If a valid access code has not been input by the user the device powers off. 
         [0017]    These and other aspects of the invention will now be described in detail with reference to the accompanying Figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view of an electronic lock according to the present invention. 
           [0019]      FIG. 2  is a front perspective view of one embodiment of the electronic lock according to the invention showing the top reading display showing a first character having been entered by a user. 
           [0020]      FIG. 3  is a front perspective view of an embodiment of the electronic lock according to the invention showing the top reading display showing a randomly generated character generated by the lock. 
           [0021]      FIG. 4  is a front perspective view of an embodiment of the electronic lock according to the invention showing the top reading display showing a visual indicia that the lock is open after a valid access code has been verified. 
           [0022]      FIG. 5  is a block diagram of various components of an electronic lock in accordance with the invention. 
           [0023]      FIG. 6  is a flowchart of one embodiment of an input method for an electronic lock according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    Referring now to the drawings and as best seen in  FIG. 1 , a device  10  for preventing unwanted opening of a locked enclosure according to a preferred embodiment of this invention has an external user-accessible housing  12  conveniently provided with a display  14  and a manually rotatable input knob or dial  16  for dialing the access code. Housing  12  is attached to the casing  18  by means known to those of skill in the art. Housing  12  is shown as being generally cylindrical in shape, although numerous other shapes are also contemplated. Typically, casing  18  is attached to the back side of a door  19  disposed between the housing  12  and the casing  18  while the housing  12  is mounted on the outside of the door for easy access for a user. The door  19  of the container or safe typically will include a door handle (not shown), which may be grasped and turned for opening the safe when a locking latch mechanism or similar device is retracted from a closed position to an open position as will be explained in more detail to follow. 
         [0025]    Display  14  is shown as being flush with housing  12  but in other embodiments it may be recessed in housing  12 . The display  14  functions to display first, second, and third (or more) characters. The display may be configured to display, for example, numerical values between “0” and “9.” In other embodiments, display  14  may be configured to display two digit numerical values. For example as shown in  FIG. 2  display  14  is displaying the number “25,” while in  FIG. 3  the display  14  is displaying the number “44.” In other embodiments, the display may be configured to display letters, symbols, or many other types of characters. For example, in  FIG. 4  display  14  displays letters “OP” indicating that the correct access code has been entered and the lock is now ready to be opened by a user. Those of skill in the art will appreciate however that symbols, such as “+”, may also be used to provide a visual indication to a user that the correct access code has been entered. Similarly, if an incorrect access code has been entered a symbol such as “−” may be displayed or the letters “NO” or “NOP” may be displayed or the numbers “00” may be displayed. 
         [0026]    Housing  14  of electronic lock  10  may be constructed from numerous materials. However, the material will typically be a metal, such as brass or stainless steel, but can also be plastic. Furthermore, the outer surfaces of housing  14  may be chrome-plated or painted, or the unplated metal surface can be polished or brushed for aesthetics. Casting may be a preferred way of forming the housing. 
         [0027]      FIG. 5  illustrates a block diagram of electronic lock  10  detailing various control components and the data communication between those components. In particular, as shown in  FIG. 6 , electronic lock  10  is controlled by electronic logic circuit  50 , which is powered by super capacitor  52 . Logic circuit  50  generally includes microprocessor  54 , read only memory (ROM)  56 , random access memory (RAM)  58 , interface unit  59 , latch driver  60 , and solenoid  62 . Logic circuit  50  is responsive to a coded input signal entered via input dial  16  mounted to housing  12  as the dial in rotated to a correct access number. In particular, logic circuit  50  causes a solenoid plunger or latch  64  to move between closed and open positions when the coded input signal is received via a user entering a correct access code from dial  16 . 
         [0028]    The ROM  56  has at least one correct access code stored therein which must be retrieved for comparison purposes with the access code entered by the user via dial  16 . The RAM  58  is coupled between microprocessor  54  and interface unit  59  via a common data bus  66 , and is configured for receiving and storing the user input access code. 
         [0029]    In order to enable microprocessor  54  to control operation of latch or bolt  64 , latch driver  60  is coupled between microprocessor  54  and solenoid  62 . Solenoid  62  is configured to move latch  64  between closed and open positions whenever microprocessor  54  sends an actuation signal to latch driver  60 . The operation of latch driver  60  and solenoid  62  is known to those skilled in the art and such operation will not be described in greater detail. In one embodiment, latch driver  60  is a solenoid driver. However, it is contemplated that other types and kinds of driver, such as a motor driver, may be employed. 
         [0030]    In one aspect of the electronic lock  10  in accordance with the invention, whenever the user enters the correct access code, microprocessor  54  will generate a pulsed correct indication signal on conductor path  68  that causes an access indicator  70  to indicate that the correct access code has been entered. Similarly, whenever the user enters an incorrect access code via dial  16 , microprocessor  54  will generate an incorrect indication signal on conduction path  68  that causes access indicator  70  to indicate that an incorrect access code has been entered. It is contemplated that access indicator  70  is operably coupled to display  14  to display a visual indication that the correct (or incorrect) access code has been entered. In other embodiments, the electronic lock  10  does not include a display  14  or an access indicator  70 , and the user simply attempts to open door  19  after entering the access code. In that case, when the user enters the correct access code, latch  64  will retract to the open position providing an audible signal to the user, thereby allowing the user to open door  19 . However, if the user input access code does not match the correct access code, latch  64  will remain in the closed position, and the user will be unable to open door  14 . 
         [0031]    In another aspect of the invention, whenever the user enters a correct number that is part of the correct access code, microprocessor  54  will generate a correct indication signal on conductor path  68  that causes an access indicator  70  to indicate that the correct number of the access code has been entered. This may be displayed on display  14  or no symbols or letters are displayed until the entire correct access code is entered. 
         [0032]    In one embodiment of device  10 , when latch  64  is actuated to the open position, latch  64  remains retracted for a sufficient period of time to permit the user to open door  14  but not a sufficient period of time to permit the user to lock door  14  once it has been opened. In that case, the user must reenter the correct access code to enable door  14  to be once again locked in a closed position. However, in other embodiments, the above-mentioned period of time may be adjusted such that opening and closing door  14  may be accomplished by entering the correct access code only once. 
         [0033]    It is also contemplated that latch  64  may be in a normally open position instead of a normally closed position. Thus, the operation to cause latch  64  to be extended to the closed position for locking door  14  may be accomplished in substantially the same manner as described above for causing latch  64  to be retracted to the open position for unlocking door  14 . 
         [0034]    The present invention has been described as having a latch  64  for locking door  14 . However, those of skill in the art will appreciate that rotary bolts and other types of latching means may be substituted and are contemplated to be within the scope of the invention. 
         [0035]    Now that a brief description of the electronic lock in accordance with the invention has been provided, a method of input for the lock according to the present invention will be described in detail. In particular,  FIG. 6  illustrates a flowchart of a sample control logic sequence of an input method  100  according to the present invention. In particular, input method  100  will be described with reference to lock  10 . 
         [0036]    The sequence begins at step  102  when dial  16  is turned in the clockwise or counter-clockwise direction to power-up electronic lock  10 . The microprocessor senses the voltage of the super capacitor at step  104 . If the super capacitor is fully charged, the lock  10  is activated and display  14  powers on in step  106 . As a result, a randomly generated two-digit number or other symbol is shown on display  14 . 
         [0037]    Next, in steps  108 ,  110 , the user rotates dial  16  in either the clockwise or counter-clockwise direction in order to change the numerical value displayed in display  14  to the first number in the access code being input by the user. During a two to four second delay  111 , the microprocessor stores the first two-digit number entered by the user in RAM  58 . After storing the number in RAM  58 , the display will generate a symbol or blink once or twice indicating to the user that the number has been stored at step  112 . As a result a second random two-digit number will be displayed on the display  14 . 
         [0038]    The method continues at steps  114 ,  116  where the user again rotates dial  14  in the clockwise or counter-clockwise direction until the second two-digit number in the access code being input by the user is displayed on display  14 . The user then stops turning the dial  16  and during a two to four second delay the microprocessor stores the second two-digit number input by the user into RAM  58 , the display blinks once or twice and then generates a third random two digit number which displays in the display  14 . 
         [0039]    The method continues at steps  122 ,  124  where the user again rotates dial  14  in the clockwise or counter-clockwise direction until the third two-digit number in the access code being input by the user is displayed on display  14 . The user then stops turning the dial  16  and during a two to four second delay  126  the microprocessor stores the third two-digit number input by the user into RAM  58 , the display blinks once or twice at step  128 . 
         [0040]    At step  130 , microprocessor  54  compares the user input access code stored in RAM  58  with the correct access code stored in ROM  56  to determine if the codes match. If the user input access code matches the valid access code in ROM  56 , the display  14  provides a visual indication to the user, such as “OP” or “+” to indicate that the lock  10  is open with a right arrow in the display indicating that the user may turn the dial to the right to open the lock. Depending on the type of lock or bolt involved microprocessor  54  may also a signal to latch drive  60  indicating that authorized entry has been confirmed, thereby retracting or otherwise moving latch  64  to the open position in order to allow the user to open door  14 . 
         [0041]    Although method  100  has been described with reference to a display configured to display a two digit number, one skilled in the art will appreciate that the input method according to the present invention may be modified for use with a display that may be configured to display any quantity of numbers, letters, symbols, or other characters. In one aspect of the invention, the correct access code is formed by three two-digit numbers. In other aspects of the invention, the correct access code is formed by more than three numbers and those numbers may be single digits. Furthermore, the total quantity of numbers that form the correct access code may be either odd or even. 
         [0042]    Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.