Issued Patents All Time
Showing 1–18 of 18 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5756704 | Nucleosides and nucleoside derivatives containing enzymatically cleavable protecting groups | Armin Reidel, Axel Heuser, Klaus Muehlegger, Herbert von der Eltz, Christian Birkner | 1998-05-26 |
| 5677441 | Nucleosides, nucleotides and oligonucleotides containing enzymatically cleavable protecting groups | Armin Reidel, Axel Heuser, Klaus Muehlegger, Herbert von der Eltz, Christian Birkner | 1997-10-14 |
| 5426691 | Method and apparatus for detecting a prescribed audio frequency actuating signal applied on to a telecommunication line | — | 1995-06-20 |
| 5402481 | Abbreviated and enhanced dialing apparatus and methods particularly adapted cellular or other types of telephone systems | — | 1995-03-28 |
| 5311175 | Method and apparatus for pre-identification of keys and switches | — | 1994-05-10 |
| 5274693 | Abbreviated and enhanced dialing apparatus and methods particularly adapted for cellular or other types of telephone systems | — | 1993-12-28 |
| 5168517 | Apparatus and methods for selectively forwarding telephone calls | — | 1992-12-01 |
| 5157719 | Automatic area code dialing apparatus and methods particularly adapted for cellular or other types of telephone systems | — | 1992-10-20 |
| 5131031 | Hold circuits for telephone systems | — | 1992-07-14 |
| 4941166 | Muting circuit for telephone answering machine | Kalman Drebin | 1990-07-10 |
| 4768224 | Single telephone line call forwarding device | — | 1988-08-30 |
| 4726048 | Telephone privacy circuit | Kalman Drebin | 1988-02-16 |
| 4670900 | Single line telephone call forwarding device | — | 1987-06-02 |
| 4626630 | Telephone call forwarding device | — | 1986-12-02 |
| 4540984 | Energy saving control circuit for a light switch and a method therefor | — | 1985-09-10 |
| RE31643 | Hold circuit for telephone system | — | 1984-08-07 |
| 4251692 | Telephone call restricting apparatus | — | 1981-02-17 |
| 4243844 | Hold circuit for telephone system | — | 1981-01-06 |