Electronic security system

US5280518A · kind A · utility

Assignee

• Supra Products, Inc. · US

Inventors

• Richard W. Danler · Corvallis, US
• John W. Sherman · Houston, US
• David Babler · Battle Ground, US
• Ron Chapin · Gervais, US
• John M. Kniffin · Tualatin, US
• Kenneth L. Reviea · Salem, US
• Lynn L. Schreiner · Corvallis, US

Key dates

• Filing date: Aug 5, 1991
• Grant date: Jan 18, 1994
• Expiry date: Aug 5, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G07C2209/08
• WIPO field: Control
• WIPO sector: Instruments

Abstract

An electronic real estate lockbox system includes a number of operational features, including facsimile reporting capability, bilateral locking solenoids, improved shackle latching capabilities, improved key-compartment release operation, two-wire bilateral lock-key communications, improved case design, viral lockout list propagation, an update code grace period, packet formatted data transmission with error recovery, FSK audio data downloading, and high security challenge-response authorization procedures. A variety of other operational features are also disclosed.