Abstract:
A method of inputting a user input access combination in order to gain authorized entry into a secure location comprises providing an input device having first and second input keys as well as a display, randomly generating a first character and a second character on the display, inputting the user input access combination into the input device, and comparing the user input access combination with an authorized access combination. The user input access combination includes a first user input character and a second user input character. The step of inputting the user input access combination comprises pressing the first input key to change the first randomly generated character to the first user input character, and pressing the second input key to change the second randomly generated character to the second user input character.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to keypad assemblies and methods of inputting lock combinations, primarily for safes and other secure containers. 
     2. Description of the Related Art 
     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. 
     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. 
     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. 
     Generally, the keypad is on the outside of the keypad housing and parallel to the safe or container wall. Thus, it usually is in a vertical plane. Often, the user&#39;s eyes are higher than the keypad so he or she looks down and at an angle to the keypad. Accordingly, having a flat keypad with its surface parallel to the door may make the keypad more difficult to see. 
     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 wear. As a result, in order to reduce the chances that an unauthorized individual may figure out the correct access combination, 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, 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. 
     Thus, there is a need for an improved access combination system and method that may be easily visualized and accessed by a user. There is a further need for a system and method that reduces the number of input keys required to enter an access combination while maintaining a high level of security. 
     SUMMARY OF THE INVENTION 
     The present invention solves the foregoing problems by providing a method of inputting a user input access combination in order to gain authorized entry into a secure location, the method comprising providing an input device having first and second input keys as well as a display, randomly generating a first character and a second character on the display, inputting the user input access combination into the input device, and comparing the user input access combination with an authorized access combination. The user input access combination includes a first user input character and a second user input character. The step of inputting the user input access combination comprises pressing the first input key to change the first randomly generated character to the first user input character, and pressing the second input key to change the second randomly generated character to the second user input character. 
     The present invention also provides a top reading keypad assembly comprising a housing, a keypad, and a microprocessor in communication with the keypad. 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 keypad is attachable to the side wall of the housing, and includes a display, a first input key, and a second input key. The display includes a first display portion for displaying a first character and a second display portion for displaying a second character. The first input key is configured for changing the first character displayed in the first display portion, while the second input key is configured for changing the second character displayed in the second display portion. The microprocessor is 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 correct access combination has been input through the keypad. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a pictorial view of an electromechanical lock and keypad assembly according to the present invention illustrating the keypad assembly affixed to a door of a safe. 
         FIG. 2  is a front perspective view of one embodiment of a top reading input keypad assembly according to the present invention. 
         FIG. 3  is a block diagram of the various components of the keypad assembly of  FIG. 2 . 
         FIG. 4  is a flowchart of one embodiment of an input method for a keypad input device according to the present invention. 
         FIGS. 5A-5C  are diagrams illustrating a display of the keypad assembly of  FIG. 2  displaying the output at various steps throughout the input method. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIGS. 1 and 2  thereof, there is shown a top reading keypad assembly  10  which is constructed and configured to operate in accordance with the present invention. Keypad assembly  10  generally comprises housing  12  which is adapted to be mounted to an outside of door  14  by means not shown. Door  14  includes door handle  16 , which may be grasped and turned for opening door  14  when a latch or similar device is retracted from a closed position to an open position as will be explained in more detail to follow. 
     As shown in  FIG. 2 , housing  12  includes front wall  18 , side wall  20 , front edge  22 , rear edge  24 , top portion  26  of housing  12 , bottom portion  28  of housing  12 , recessed portion  30 , and keypad  32 . Side wall  20  is generally cylindrical in shape, although numerous other shapes are also contemplated. Front edge  22  may have a chamfer or rounded surface between front wall  18  and side wall  20  to avert a sharp edge at the intersection of the walls. 
     Keypad  32  is configured to be disposed within recessed portion  30  of housing  12 . Thus, when top reading keypad assembly  10  is coupled to door  14 , keypad  32  may be positioned to face upward in a generally horizontal plane relative to door  14 , which is in a generally vertical plane, such that a user standing next to door  14  is able to look down toward housing  12  and easily view and have access to keypad  32 . As illustrated in  FIG. 2 , keypad  32  includes display  34 , first key  36 , and second key  38 . Display  34  includes first display portion  40  for displaying a first character, and second display portion  42  for displaying a second character. First and second display portions  40  and  42  may each be configured to display, for example, numerical values between “0” and “9.” As shown in  FIG. 2 , first display portion  40  is displaying the number “5,” while second display portion  42  is displaying the number “3.” In other embodiments, first and second display portions  40  and  42  may be configured to display a different range of numerical values or, alternatively, letters, symbols, or many other types of characters. 
     First and second keys  36  and  38  are sealed and covered with flexible material, and pressing one of the keys makes electrical contact within the key. In addition, first and second keys  36  and  38  both include an “arrow” symbol to indicate that pressing the keys will cause an increase or change in the numerical value or other character displayed in first and second display portions  40  and  42 . However, such a symbol is not necessary and may be removed from first and second keys  36  and  38 . Alternatively, other symbols or characters may replace the arrow symbol such as, for example, a “plus” sign. 
     Housing  12  of top reading keypad assembly  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  12  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. 
       FIG. 3  illustrates a block diagram of keypad assembly  10  detailing various control components and the data communication between those components. In particular, as shown in  FIG. 3 , keypad assembly  10  is controlled by electronic logic circuit  50 , which is powered by battery  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 keypad  32  mounted to housing  12 . 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 combination from keypad  32 . 
     The ROM  56  has at least one correct access combination stored therein which must be retrieved for comparison purposes with the access combination entered by the user via keypad  32 . 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 combination. 
     In order to enable microprocessor  54  to control operation of latch  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. 
     In one embodiment of keypad assembly  10 , whenever the user enters the correct access combination, 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 combination has been entered. Similarly, whenever the user enters an incorrect access combination via keypad  32 , microprocessor  54  will generate a pulsed incorrect indication signal on conduction path  68  that causes access indicator  70  to indicate that an incorrect access combination has been entered. It is contemplated that access indicator  70  may include any number of indicating means known in the art such as, for example, sound, light, or other visual-type indicators. In other embodiments, keypad assembly  10  does not include an access indicator, and the user simply attempts to open door  14  after entering the access combination. In that case, when the user enters the correct access combination, latch  64  will retract to the open position, thereby allowing the user to open door  14 . However, if the user input access combination does not match the correct access combination, latch  64  will remain in the closed position, and the user will be unable to open door  14 . 
     In one embodiment of keypad assembly  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 combination 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 combination only once. 
     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 . 
     Now that a brief description of a top reading keypad assembly has been provided, one embodiment of a method of input for a top reading keypad according to the present invention will be described in detail. In particular,  FIG. 4  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 top reading keypad assembly  10 , although one skilled in the art will appreciate that input method  100  may be utilized in conjunction with keypads other than top reading keypad assembly  10  such as, for example, keypads placed on a front surface of a keypad assembly. 
     The sequence begins at step  102  when either first key  36  or second key  38  is pressed to power-up keypad assembly  10 . In particular, powering-up key pad assembly  10  activates and turns on display  34 . As a result, in step  104 , two randomly generated numbers between “0” and “9” are shown on display  34 . For example, the randomly generated numbers may include the number “5” displayed in first display portion  40  and the number “3” displayed in second display portion  42  as illustrated in  FIG. 5A . 
     Next, in step  106 , the user presses first key  36  in order to change the numerical value displayed in first display portion  40  to the first number in the correct access combination. In particular, momentarily pressing first key  36  causes the number displayed in first display portion  40  to increase with each actuation of first key  36 , while pressing first key  36  in a continuous manner causes first display portion  40  to scroll through the numbers sequentially until the number “9” is reached, at which point first display portion  40  will begin counting up once again beginning with “0.” Thus, the user may repeatedly press first key  36  until the desired number is displayed on first display portion  40 , or the user may press and hold first key  36  until the desired number appears on first display portion  40 , at which point the user may cease pressing first key  36  such that the desired number remains displayed in first display portion  40 . For example, if the first number in the combination is “1,” the user may change the number displayed in first display portion  40  by either of the above methods until the number “1” appears. At that point, display  34  will display the number “1” in first display portion  40  and the number “3” in second display portion  42  as illustrated in  FIG. 5B . One skilled in the art will appreciate that, in other embodiments, actuating first key  36  may alternatively result in the numerical value decreasing with each actuation of first key  36  in order to “count down” instead of “counting up.” 
     Next, in step  108 , the user then presses second key  38  to lock the number “1” into first display portion  40  such that the user may not go back and modify the first combination number selected in step  106  above. Pressing second key  38  stores the number selected by the user in RAM  58 . In other embodiments, the user may have the option of changing the first number selected in step  106  by, for example, pressing first key  36  again to scroll through and select a different number. 
     The method continues at step  110  where the user scrolls through the numbers displayed in second display portion  42  by pressing second key  38  until the second number in the combination is displayed. As discussed above, the user may scroll through the numbers either by repeatedly pressing second key  38  or by continuously pressing and holding second key  38 . For example, if the second number in the correct access combination is “2,” the user may change the number displayed in second display portion  42  until the number “2” appears. At that point, display  34  will display the number “1” in first display portion  40  and the number “2” in second display portion  42  as illustrated in  FIG. 5C . Once the second number in the access combination is input by the user and displayed in second display portion  42 , the user may then press first key  36  in step  112  in order to lock the number “2” in second display portion  42  and to store the number in RAM  58 . 
     Next, in step  114 , microprocessor  54  compares the user input access combination stored in RAM  58  with the correct access combination stored in ROM  56  to determine if the combinations match. If the user input access combination matches the correct access combination, microprocessor  54  sends 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 . 
     Although method  100  has been described with reference to a display configured to display only two numbers, 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 embodiment, the correct access combination is formed by two numbers. In other embodiments, the correct access combination is formed by more than two numbers. Furthermore, the total quantity of numbers that form the correct access combination may be either odd or even. In addition, if the correct access combination is of a length such that more than two numbers must be entered by the user, method  100  may include control loop  116  as illustrated in  FIG. 4 . In step  116 , microprocessor  54  determines if the user has entered a total quantity of access combination numbers equal to the total quantity of combination numbers in the correct access combination. If microprocessor  54  determines that additional access combination numbers must be entered, method  100  enters control loop  116 , which causes the input method to return to step  104  where one or more additional random numbers are generated on display  34 . Microprocessor  54  will continue to run through control loop  116  of input method  100  until microprocessor  54  determines that the user has entered the correct quantity of combination numbers in the correct access combination. 
     Input method  100  may also include bypass steps  118  and  120 . If, for example, the first randomly generated number happens to coincide with the first number of the correct access combination, bypass  118  allows the user to simply press second key  38  (step  108 ) to lock the number into first display portion  40 . Similarly if the second randomly generated number happens to coincide with the second number of the correct access combination, bypass  120  allows the user to simply press first key  36  (step  112 ) to lock the number into second display portion  42 . Furthermore, if both of the randomly generated numbers happen to coincide with the first (or only) two numbers of the correct access combination, the user may simply press second key  38  (bypass  118 ) followed directly by first key  36  (bypass  120 ), which locks the first and second randomly generated numbers into first and second display portions  40  and  42 , respectively. 
     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.