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:
Sep. 19, 1978
Filed:
Jun. 16, 1977
Applicant:
Inventors:
Abram N Spanel, Princeton, NJ (US);
Leonard F Shepard, Dover, DE (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ; H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ; 179 / ; 179 / ;
Abstract
A telephone adapter for hands-free telephony, adapted for use with a telephone handset having structure including an earpiece, comprising: a transmit signal path comprising, in series, a microphone, amplification means, disabling means and a transducer; a receive signal path having means for amplifying sound energy from said earpiece, said receive path comprising, in series, a coupler, amplification means, disabling means and speaker means; bias means for maintaining said transmit path in an active state when no signals are present; and, means for interrupting said circuit paths in a complementary manner.