Patent Leaderboard
USPTO Patent Rankings Data through Dec 31, 2025
Home › Anti-fraud device for use with a coin operated telephone instrument

Anti-fraud device for use with a coin operated telephone instrument

US Patent 4862494 · Granted Aug 29, 1989

Assignee

No assignee recorded.

Inventors

View full patent text on Google Patents →

More Patents by These Inventors

Pay type telephone station volume control push-button switch1994
Pay type telephone station volume control push-button switch1994
Battery and holder assembly for use with a battery operated touch pen1994
Communication apparatus utilizing digital optical signals1994
Apparatus for optically coupling a terminal unit to the public telephone network1989
Telephone amplifier with switchable gain control1988