The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 15, 1990
Filed:
Oct. 14, 1988
David M Sanford, Dallas, TX (US);
Other;
Abstract
An inexpensive, reliable telephone answering device screens out undesirable calls, screens the calls that are dialed out and inhibits preprogrammed call prefixes from being dialed, adds the 'hold' function and a simulated call transfer function to all telephones (activated by depressing a TOUCH TONE key on a standard telephone set), provides a way to use the telephones in the home as an intercom system, and provides other advanced PBX functions at low cost in a home or small business environment. A power off failsafe feature prevents power loss to the device from interrupting normal telephone operation. Several caller access codes and several dial inhibit codes can be programmed from a conventional unmodified subscriber Touch Tone telephone set, and a personal access code prevents system programming from being changed by unauthorized persons or accidentally. These and other advanced functions previously available only in a complex, expensive telephone PBX system are made available in a low cost, optimally designed device.