Data signalling unit for telephone systems
Patent 3987247 Issued on October 19, 1976. Estimated Expiration Date: 
October 19, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 19, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3674941 3675204 3819862 3854009 3924071 InventorAssigneeApplicationNo. 640346 filed on 12/12/1975US Classes:379/93.15, Having format conversion379/119, Hardcopy record generating (e.g., ticket printing)379/93.17Having station displayExaminersPrimary: Stellar, George G.AbstractA data signalling system for in-house telephone systems of either the rotary dial or the tone dial type responds to conventional digit defining dial signals.Control gates respond to conventional trunk relay signal patterns to trigger various logic functions in conjunction with trunk seize, dialing and hang-up.A numeric printer is fed digital signals from logic circuitry which has accumulated and stored the dialed data and is capable of presenting numeric and alpha display. | |
