Patent US4891636A successfully refreshed from Google Patents.
US4891636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic keylock system
Assignee: NCR Voyix Corp
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Filing: 1989-04-13
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Granted: 1990-01-02
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Expires: 2009-04-13
Abstract
Abstract An electronic keylock system comprises a key which includes a precision resistance, a receiver for receiving the key, an analog-to-digital converter coupled to the receiver for measuring the resistance of the precision resistance of the key, circuitry for controlling the analog-to-digital converter, decoding logic for receiving data from the analog-to-digital converter and decrypting the data to provide information with respect to the type of key applied to the receiver, and circuitry for controlling the decoding logic. Two system embodiments are disclosed, one of which employs separate components, and the other of which employs a microcontroller combining several functions.
Inventors
- 👤 David A. Rieker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:03
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00658; G07C9/00714; G07C9/20
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
306 words
An electronic lock and key system comprising: a plurality of key means including a plurality of different first precision resistor means; receiving means for receiving said key means, said receiving means comprising a receptacle for said key means, a precision source of potential, second precision resistor means and precision reference means, said receiving means being capable of producing a plurality of output voltages representative of a plurality of first precision resistor means of different resistances in said plurality of different key means which are received by the receptacle of said receiving means; analog-to-digital conversion means operatively coupled to said receiving means and capable of converting said plurality of output voltages representing different key means to a corresponding plurality of digital output values and having a plurality of outputs for outputting a plurality of different digital values greater than zero; first control means for controlling said analog-to-digital conversion means to cause it to measure the resistances of the first precision resistor means of said key means which are operatively engaged with the receptacle of said receiving means, said first control means comprising control logic means; address latch means; microprocessor means coupled to said control logic means and said address latch means for applying inputs thereto; and additional logic means coupled to said control logic means and said address latch means to receive inputs therefrom and to provide output signals to said analog-to-digital conversion means; programmable array logic means operatively coupled to said plurality of outputs of said analog-to-digital conversion means for receiving said digital output values from said analog-to-digital conversion means and decrypting said digital values to provide information on output means of said programmable array logic means relating to identification of different key means which are operatively engaged with the receptacle of said receiving means; and second control means for controlling the programmable array logic means.
Claim 2
Dependent Claim
306 words
An electronic lock and key system comprising: a plurality of key means including a plurality of different first precision resistor means; receiving means for receiving said key means, said receiving means comprising a receptacle for said key means, a precision source of potential, second precision resistor means and precision reference means, said receiving means being capable of producing a plurality of output voltages representative of a plurality of first precision resistor means of different resistances in said plurality of different key means which are received by the receptacle of said receiving means; analog-to-digital conversion means operatively coupled to said receiving means and capable of converting said plurality of output voltages representing different key means to a corresponding plurality of digital output values and having a plurality of outputs for outputting a plurality of different digital values greater than zero; first control means for controlling said analog-to-digital conversion means to cause it to measure the resistances of the first precision resistor means of said key means which are operatively engaged with the receptacle of said receiving means, said first control means comprising control logic means; address latch means; microprocessor means coupled to said control logic means and said address latch means for applying inputs thereto; and additional logic means coupled to said control logic means and said address latch means to receive inputs therefrom and to provide output signals to said analog-to-digital conversion means; programmable array logic means operatively coupled to said plurality of outputs of said analog-to-digital conversion means for receiving said digital output values from said analog-to-digital conversion means and decrypting said digital values to provide information on output means of said programmable array logic means relating to identification of different key means which are operatively engaged with the receptacle of said receiving means; and second control means for controlling the programmable array logic means.
Claim 3
Dependent Claim
19 words
The electronic lock and key system of claim 1, in which the programmable array logic means is read protected.
Claim 4
Dependent Claim
21 words
The electronic lock and key system of claim 1, in which the maximum potential across the key means is 6 volts.
Claim 5
Dependent Claim
32 words
The electronic lock and key system of claim 1, in which said resistor means comprises a precision one percent resistor contained within a male headphone type connector attached to a plastic handle.
Claim 6
Dependent Claim
29 words
The electronic lock and key system of claim 1, in which the output means of the programmable array logic means is operatively coupled to a point of service terminal.
Claim 7
Dependent Claim
30 words
The electronic lock and key system of claim 5, in which key means having resistor means of different resistances may be provided for use by different classes of key holders.
Claim 8
Dependent Claim
19 words
The electronic lock and key system of claim 6, in which said different classes include operators, programmers and supervisors.
Claim 9
Dependent Claim
30 words
The electronic lock and key system of claim 1, in which said second control means effectively alters the inputs to the programmable array logic means from the analog-to-digital conversion means.
Claim 10
Dependent Claim
296 words
An electronic lock system comprising: receiving means for receiving a plurality of different keys which include a plurality of different first precision resistor means, said receiving means comprising a receptacle for said keys, a precision source of potential, second precision resistor means and precision reference means, said receiving means being capable of producing a plurality of output voltages representative of a plurality of first precision resistor means of different resistances included in different ones of said keys which are received by the receptacle of said receiving means; analog-to-digital conversion means operatively coupled to said receiving means and capable of converting said plurality of output voltages to a corresponding plurality of digital output values and having a plurality of outputs for outputting a plurality of different digital values greater than zero; first control means for controlling said analog-to-digital conversion means to cause it to measure the resistances of the first precision resistor means included in said keys which are operatively engaged with the receptacle of said receiving means, said first control means comprising control logic means; address latch means; microprocessor means coupled to said control logic means and said address latch means for applying inputs thereto; and additional logic means coupled to said control logic means and said address latch means to receive inputs therefrom and to provide output signals to said analog-to-digital conversion means; programmable array logic means operatively coupled to said plurality of outputs of said analog-to-digital conversion means for receiving said digital output values from said analog-to-digital conversion means and decrypting said digital values to provide information on output means of said programmable array logic means relating to identification of different keys which are operatively engaged with the receptacle of said receiving means; and second control means for controlling the programmable array logic means.
Claim 11
Dependent Claim
296 words
An electronic lock system comprising: receiving means for receiving a plurality of different keys which include a plurality of different first precision resistor means, said receiving means comprising a receptacle for said keys, a precision source of potential, second precision resistor means and precision reference means, said receiving means being capable of producing a plurality of output voltages representative of a plurality of first precision resistor means of different resistances included in different ones of said keys which are received by the receptacle of said receiving means; analog-to-digital conversion means operatively coupled to said receiving means and capable of converting said plurality of output voltages to a corresponding plurality of digital output values and having a plurality of outputs for outputting a plurality of different digital values greater than zero; first control means for controlling said analog-to-digital conversion means to cause it to measure the resistances of the first precision resistor means included in said keys which are operatively engaged with the receptacle of said receiving means, said first control means comprising control logic means; address latch means; microprocessor means coupled to said control logic means and said address latch means for applying inputs thereto; and additional logic means coupled to said control logic means and said address latch means to receive inputs therefrom and to provide output signals to said analog-to-digital conversion means; programmable array logic means operatively coupled to said plurality of outputs of said analog-to-digital conversion means for receiving said digital output values from said analog-to-digital conversion means and decrypting said digital values to provide information on output means of said programmable array logic means relating to identification of different keys which are operatively engaged with the receptacle of said receiving means; and second control means for controlling the programmable array logic means.
Claim 12
Dependent Claim
17 words
The electronic lock system of claim 9, in which the programmable array logic means is read protected.
Claim 13
Dependent Claim
27 words
The electronic lock system of claim 9, in which the output means of the programmable array logic means is operatively coupled to a point of service terminal.
Claim 14
Dependent Claim
27 words
The electronic lock system of claim 9, in which keys having resistor means of different resistances may be provided for use by different classes of key holders.
Claim 15
Dependent Claim
17 words
The electronic lock system of claim 12, in which said different classes include operators, programmers and supervisors.
Claim 16
Dependent Claim
27 words
The electronic lock system of claim 9, in which said second control means effectively alters the inputs to the programmable array logic from the analog-to-digital control means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-01 | 1993-07-03 | 1994-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-01 | 1997-07-03 | 1998-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-01 | 2001-07-03 | 2002-01-02 | $7700.00 | Window Closed / Lapsed |