The Plessey Company PLC
Patent Owner
Stats
- 0 US PATENTS IN FORCE
- 0 US APPLICATIONS PENDING
- Jul 14, 1992 most recent publication
Details
- 0 Issued Patents
- 0 Issued in last 3 years
- 0 Published in last 3 years
- 364 Total Citation Count
- Jan 23, 1978 Earliest Filing
- 19 Expired/Abandoned/Withdrawn Patents
Patent Activity in the Last 10 Years
Technologies
- No Technology to Display
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Recent Publications
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Recent Patents
- No Recent Patents to Display
Expired/Abandoned/Withdrawn Patents
Patent #
Title
Status
Filing Date
Issue/Pub Date
Intl Class
4893309 Digital interface between at least two subscriber line interface circuits and a processing unitExpiredJan 25, 88Jan 09, 90[H04J]
4881226 Digital interface of an integrated subscriber line interface circuitExpiredJan 25, 88Nov 14, 89[H04J]
4858223 Security arrangement for a telecommunications exchange systemExpiredMay 20, 88Aug 15, 89[H24J]
4794644 Method of secured communications in a telecommunications systemExpiredDec 11, 86Dec 27, 88[H04K]
4685783 Polychromic tetracyclo-spiro-adamatylidene derivatives, and polychromic lens incorporating said compoundsExpiredSep 05, 84Aug 11, 87[C09K, C07D, G03C]
4576766 Photochromic compounds and their use in photoreactive lensesExpiredSep 07, 83Mar 18, 86[B29D]
4535442 Digital switching network for telecommunications exchangeExpiredApr 22, 83Aug 13, 85[H04Q, H04T]
4393490 Digital telecommunications switches network with in-built fault identificationExpiredAug 07, 80Jul 12, 83[H04Q, H04J]
4387456 Alarm monitoring arrangements for digital telecommunications switching networksExpiredAug 07, 80Jun 07, 83[H04J]
4368531 Frame aligner for digital telecommunications exchange systemExpiredAug 06, 80Jan 11, 83[H04J]
4300230 Digital switching arrangements for stored program control telecommunications systemsExpiredOct 15, 79Nov 10, 81[H04Q, H04J]
4289939 Longitudinal balance arrangements for two-to-four wire telecommunication line circuitsExpiredDec 28, 79Sep 15, 81[H04M]
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