Method and device for inputting an access code in an electronic combination lock

Abstract

A method and system 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 and if it is 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.

Claims

1. A method of gaining authorized entry into a secure location comprising: providing an electronic lock including a housing, a display, a rotatable dial and a locking mechanism moveable between a locked position and an unlocked position; providing a microprocessor in the housing, said microprocessor in communication with said electronic lock and said locking mechanism, the microprocessor storing a valid access code and capable of storing a user input code; providing a power source operably coupled to said microprocessor and said electronic lock; rotating said dial by a user in either a clockwise or counter-clockwise direction to activate said power source; wherein upon activation the electronic lock generates a first random character in the display; rotating said dial by the user in either a clockwise or counter-clockwise direction until a first user input character displays in said display; waiting a pre-determined period of time and storing said first user input character in memory; providing a visual indication to the user that the first user input character has been stored in memory; after said first user input character is stored in memory, automatically generating a second random two-digit character and displaying it in the display thereby automatically preventing a changing of the first user two-digit input character stored in memory; rotating said dial by the user in either a clockwise or counter-clockwise direction until a second user input character displays in said display; waiting a pre-determined period of time and storing said second user input character in memory; providing a visual indication to the user that the second user input character has been stored in memory; after said second user input character is stored in memory, automatically generating a third random character and displaying it in the display thereby automatically preventing a changing of the second user input character stored in memory; rotating said dial by the user in either a clockwise or counter-clockwise direction until a third user input character displays in said display; waiting a pre-determined period of time and storing said third user input character in memory; providing a visual indication to the user that the third user input character is stored in memory; automatically preventing a changing of the third user input character stored in memory; causing said microprocessor to compare the first, second and third user input characters with the valid access code stored in memory to determine whether the inputted first, second and third user input characters match the valid access code and if so; generating an indicia on the display to visually indicate to a user that the locking mechanism is capable of moving to the unlocked position.

2. The method of claim 1, wherein said first, second and third user input characters and said first, second and third randomly generated characters are alphanumeric characters.

3. The method of claim 2, wherein the alphanumeric characters are integers.

4. The method of claim 3 wherein the integers are two digit integers.

5. The method of claim 3 wherein the integers are in a range from 0 to 9.

6. The method of claim 1, further comprising the step of moving the lock mechanism from the locked position to the unlocked position upon confirming that the user input code matches the valid access code.

7. The method of claim 1 wherein the valid access code comprises a three digit code.

8. The method of claim 1 further comprising generating an indicia on the display to visually indicate to a user that the user inputted code does not match the valid access code stored in memory if the microprocessor determines that the user input code does not match the valid access code stored in memory.

9. The method of claim 8 further comprising preventing the lock from moving to the unlocked position.

10. The method of claim 9 further comprising automatically powering down the device if the user inputted code does not match the valid access code stored in memory.

11. The method of claim 1 wherein the valid access code comprises a three character code, each character including two digits.

12. The method of claim 1 wherein the pre-determined period of time is 2 to 4 seconds.

13. An electronic lock comprising: a housing having a front wall, a rear wall, and a generally cylindrical side wall disposed between the front and rear walls, wherein the rear wall is attachable to a secure container; a rotatable dial positioned on the front of the housing that allows a user to input a first, second and third user inputted set of characters, together comprising a user inputted code; a display having a display portion for displaying the first, second and third user inputted set of characters comprising the user inputted code and first, second and third randomly generated characters; a lock positioned within said housing and movable between a locked position and an unlocked position; a microprocessor having memory with a valid access code stored in said memory, the microprocessor in communication with the rotatable dial and the lock and configured to (i) upon activation by the source of power randomly generate the first randomly generated character and display the first randomly generated character in the display; (ii) wait a first pre-programmed period of time after the user inputs the first user inputted set of characters and store the first user inputted set of characters in memory; (iii) visually indicate to the user that the first user inputted set of characters has been stored in memory; (iv) generate the second randomly generated character and display the second randomly generated character in the display thereby automatically preventing changing the first user inputted set of characters; (v) wait a second pre-programmed period of time after the user enters the second user inputted set of characters and store the second user inputted set of characters in memory; (vi) visually indicate to the user that the second user inputted set of characters has been stored in memory; (vii) generate the third randomly generated character and display the third randomly generate character in the display thereby automatically preventing changing the second user inputted set of characters; (viii) wait a third pre-programmed period of time after a user enters the third user inputted set of characters and store the third user inputted set of characters in memory; (ix) visually indicate to the user that the third user inputted set of character has been stored in memory; and (ix) compare the first second and third user inputted characters comprising the user inputted code to the stored valid access code and determine whether the user inputted code matches the stored valid access code, wherein upon the microprocessor determining that the user inputted code matches the stored valid access code the locking mechanism is configured to move from a locked position to an unlocked position.

14. The electronic lock of claim 13, wherein the first inputted character and the second randomly generated characters are alphanumeric characters.

15. The electronic lock of claim 14, wherein the alphanumeric characters are integers.

16. The electronic lock of claim 15, wherein the integers are in a range from 0 through 9.

17. The electronic lock of claim 15, wherein the integers are two-digit integers.

18. The electronic lock of claim 13 wherein the valid access code comprises a three character code, each character including two digits.

19. The electronic lock of claim 13 wherein the pre-programmed period of time is 2 to 4 seconds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of an electronic lock according to the present invention.

(2) 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.

(3) 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.

(4) 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.

(5) FIG. 5 is a block diagram of various components of an electronic lock in accordance with the invention.

(6) FIG. 6A and FIG. 6B is a flowchart of one embodiment of an input method for an electronic lock according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) 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.

(8) 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.

(9) 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.

(10) 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.

(11) 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.

(12) 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.

(13) 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.

(14) 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.

(15) 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.

(16) 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.

(17) 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.

(18) 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.

(19) 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.

(20) 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.

(21) 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.

(22) 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.

(23) 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.

(24) 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.

(25) 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.