OFF-HOOK TELEPHONE SENSING SYSTEM
 Inventor: Michael L. Sears, Redondo Beach, Calif.
 Assignee: Transaction Technology, Inc., Santa Monica, Calif.
 Appl. No.: 207,660
 Filed: Nov. 17,1980
 Int. C1.3 H04M 11/00
 U.S. Ci 179/2 DP; 179/18 AB
 Field of Search 179/2 DP, 18 AB, 90 B,
179/90 BB, 90 BD, 175.2 C, 2 A, 2 AM
 References Cited
U.S. PATENT DOCUMENTS
4,224,478 9/1980 Fahey et al 179/2 DP X
4,306,116 12/1981 McClure et al 179/2 DP
4,321,429 3/1982 Takatsuki et al 179/2 DP
Primary Examiner—G. Z. Rubinson
Assistant Examiner—W. J. Brady
Attorney, Agent, or Firm—Charles H. Schwartz;
Ellsworth R. Roston
An off hook telephone sensing system for use with a
voice and data transmission system, including a transaction terminal coupled to a telephone line for data transmission, a telephone instrument coupled to the telephone line for voice transmission, an off hook telephone sensing device coupled to the telephone instrument for detecting the on-hook or off-hook condition of the instrument and for providing an output signal having values in accordance with the on-hook or off-hook condition of the instrument, a switching means coupled to the telephone instrument and to the telephone line for connecting or disconnecting the telephone instrument to or from the telephone line, the transaction terminal including means coupled to the off-hook sensing device and responsive to the output signal for producing an interrupt signal when the off-hook sensing device detects the off-hook condition of the telephone instrument and with the telephone instrument disconnected from the telephone line, and the transaction terminal including means coupled to the switching means and responsive to the interrupt signal for controlling the switching means to connect the telephone instrument to the telephone line after the reception of the interrupt signal and after the termination by the transaction terminal of the data transmission.
6 Claims, 4 Drawing Figures