Telephone range expander

Abstract

An extension telephone is coupled to a telephone line through a control unit which receives and forwards by radio incoming calls and is fully controlled from the extension unit for outgoing calls. Incoming calls ring the remote mobile unit which is then coupled for conversation to the line through a control unit actuated from the extension unit. The mobile unit transmits actuation and dialing signals to the control unit for outgoing calls from the mobile unit in response to successively transmitted tone modulations to dial any party on the telephone line and thereupon connects the mobile microphone and receiver directly to the line.

I claim: 
     
       1. Extension telephone apparatus for connecting a mobile telephone to a telephone line at a subscriber's station, comprising: mobile transmitter and receiver means including a means for transmitting first and second tones alternatively and for connecting transmitter and receiver elements in the talk mode,   control unit means at said station for receiving said transmitted tones and transmitting to the mobile receiver signals on said line,   filter switch means operable in response to receipt of said first tone,   stepping switch means response to operation of said filter switch means, having first, second and third operated positions,   means connected to said first position for applying to said line dialing pulses according to intervals during which said second tone is received,   means connected to said second position for energizing transmitting means in said control unit and for connecting said line to last said transmitter means,   means connected to said third position for resetting said stepping switch means to nonoperated position, and   means in said control unit for generating ringing signals for transmission to said mobile means in response to ringing signals on said line.   
     
     
       2. Apparatus according to claim 1 said transmitter and receiver means comprising: means in said extension unit for selectively generating for transmission a first frequency switching mode modulation signal and a second frequency dialing mode modulation signal,   means in said extension unit for applying voice mode acoustic signals as a modulating signal when neither the switching mode nor the dialing mode signal is transmitted,   switching means in said extension unit for selecting either of said generated signals or said voice signal in accordance with said modes, and   means in said fixed station for detecting each occurrence of said switching signals and for thereupon completing a corresponding coupling to a telephone line, according to one of said modes.   
     
     
       3. In a system according to claim 2, said detecting means comprising tone selective filter means for operating a switch whenever a tone corresponding to said switching signal is generated, a switch operably connected to said tone selective filter means and operatively connected to further means in said fixed station for controlling the interconnection of the transmitter and receiver therein with said line for conveying signals to and from the extension unit according to the selected mode. 
     
     
       4. In a system according to claim 2, said detecting means including switch means responsive to said switching signal for connecting said fixed station transmitting and receiving means to said line in accordance with mode selected at the extension unit. 
     
     
       5. In a system according to claim 2, means at said fixed station for switching according to said modes comprising a stepping switch having a normal position and a plurality of operated positions, one said operated position being connected to enable circuit means for pulsing said line according to said dialing mode signal and another operated position being connected to couple fixed station transmitter and receiver means to said line whereby said extension unit is coupled to said line in a talk mode. 
     
     
       6. In a system according to claim 5, relay means connected responsively to said fixed station receiver when said stepping switch is on said one position, said relay having closed contacts connected across said line when actuated by a ringing signal. 
     
     
       7. In a system according to claim 5, means at said fixed station to disconnect fixed station transmitter from its battery during dialing mode, when said stepping switch steps to the dial circuit position. 
     
     
       8. Extension telephone apparatus for receiving and initiating calls from a subscriber's station under control of a mobile telephone unit, comprising: mobile unit means for transmitting to and receiving from said station voice and ring signals,   mobile unit tone generator means for alternatively producing first and second tones,   means for applying said tones when produced to cause transmission thereof to said station,   means in said mobile unit for interrupting one of said tones when produced according to a dialing code,   mobile unit means for operating said tone generator to produce at the operator's election said first or said second tone and for disabling the tone generator during desired intervals of telephone reception from said station,   subscriber's station means for receiving transmission from said mobile unit,   telephone line control means responsive to receipt of said first tone for coupling the receiving means to a telephone line during a first interval,   said coupling means including means for coupling a dialing code signal to the line and for coupling said line to station transmitting means during a second interval,   station transmitting means for conveying signals received to said mobile unit, and   means for coupling said line to said station transmitting means during a third interval in response to receipt of two pulses of said first tone,   said control means including a stepping switch connected to couple the line to the station transmitter in one position of advancement and to couple outgoing ringing signals to the line in another position of advancement, and including a third position having automatic resetting means coupled therethrough.   
     
     
       9. Apparatus according to claim 8 said station including filter switch means operative only when said first tone is received to advance said stepping switch by one position each time the tone is received. 
     
     
       10. Apparatus according to claim 8 operative when said stepping switch is not advanced to couple incoming ringing signals to said station transmitter. .Iadd.11. Extension telephone apparatus for remotely using a telephone line at a subscriber's station comprising: a mobile unit including: mobile transmitter means,   mobile receiver means;   tone means for alternatively generating a first tone and a second tone; and   selector means for selectively connecting said tone means to said mobile transmitter means to cause said tones generated by said tone means to be transmitted through said mobile transmitter means; and,     a control unit at the subscriber's station including: control transmitter means for transmitting to said mobile receiver means signals on said telephone line;   control receiver means for receiving said first and second tones transmitted by said mobile transmitter means;   filter switch means connected to said control receiver means and operable in response to receipt of said first tone;   stepping switch means responsive to operation of said filter switch means having normal, first and second operated positions;   ringing circuit means operatively associated with said normal position of said stepping switch means and said control transmitter means for generating ringing signals in response to ringing signals on the telephone line and causing said control transmitter means to transmit said generated ringing signals;   dialing means operatively associated with said first position of said stepping switch means for applying dialing pulses to the telephone line in response to receipt of said second tone by said control receiver; and   talk means operatively associated with said second position of said stepping switch means for connecting said control transmitter means to the telephone line and energizing said control transmitter means.     
     
     
        .Iaddend..Iadd.12.  The apparatus of claim 11 wherein said ringing circuit means includes: light emitting means electrically connected to the telephone line constructed and arranged to be illuminated in response to ringing signals on the telephone line; and,   a photocell optically associated with said light emitting means constructed and arranged to cause an electrical signal output to be generated in response to illumination of said light emitting means, the ringing signals on the telephone line being electrically isolated from the electrical signal output of said photocell. .Iaddend. .Iadd.13. The apparatus of claim 12 wherein said light emitting means includes a neon bulb. .Iaddend..Iadd.14. The apparatus of claim 13 wherein said ringing circuit means further includes:   oscillator means for generating an oscillating output signal when energized, said output of said oscillator means operatively connected to said control transmitter means; and   ringing switch means operatively connected to the electrical signal output of said photocell, said oscillating means and said transmitter means to cause said oscillator means to generate the oscillating output signal and said control transmitter means to transmit said oscillating output signal to said mobile unit when said neon bulb is illuminated. .Iaddend..Iadd.15. The apparatus of claim 11 wherein said selector means in said mobile unit is effective to cause said filter switch means in said control unit to operate said stepping switch means in said control unit and selectively cause said stepping switch means to assume said normal, first or second positions. .Iaddend..Iadd.16. The apparatus of claim 15 wherein said stepping switch means is sequentially stepped between said normal, first and second positions with said switch means stepping to the next of said operated positions in response to each receipt of said first tone by said filter switch means. .Iaddend.