Patent Leaderboard
USPTO Patent Rankings Data through Dec 31, 2025
Home › Method and apparatus for preventing pay telephone fraud and reducing handset vandalism

Method and apparatus for preventing pay telephone fraud and reducing handset vandalism

US Patent 4989239 · Granted Jan 29, 1991

Assignee

Inventors

View full patent text on Google Patents →

More Patents by These Inventors

Vending audit system2006
Configurable vending machine audit module2002
Vending machine fluorescent tube monitor2001
Multi-function optical sensor for a document acceptor2000
Monitoring and reporting system using cellular carriers2000
Use of security coupons in connection with locking mechanisms for vending and ga1999
Method and apparatus for keyboard adaptation to a low power controller in a coin1991
Method and apparatus for retrofitting a standard coin operated telephone employi1991
Coin operated telephone operation monitoring switch mounting arrangement1990
Low power control apparatus for a coin operated telephone1990
Auxiliary window element1980