Encoder-decoder device for selective calling

Claim 1

AN ENCODER-DECODER UNIT FOR USE IN COMBINATION WITH TWO-WAY RADIO APPARATUS, SAID UNIT COMPRISING TUNED VIBRATORY REED MEANS HAVING AT LEAST TWO REEDS OF DIFFERENT NATURAL FREQUENCIES OF VIBRATION AND A COIL SIMULTANEOUSLY IN INDUCTIVE RELATION TO BOTH OF SAID REEDS, SAID REEDS BEING ELECTRICALLY RELATION TO BOTH OF SAID REEDS, SAID FIXED CONTACTS RESPECTIVELY ENGAGEABLE BY SAID REEDS, SAID VIBRATION THEREOF, A SOURCE OF ELECTRTIC POTENTIAL CONNECTED TO ONE OF SAID FIXED CONTACTS AND NOT TO THE OTHER, RELAY MEANS CONNECTED TO THE OTHER OF SAID FIXED CONTACTS, SAID REEDS UPON VIBRATION BEING ELECTRICALLY IN SERIES BETWEEN SAID POTENTIAL SOURCE AND SAID RELAY MEANS, CONNECTION MEANS FOR CONNECTION TO SUCH TWO-WAY RADIO APPARATUS, SWITCH MEANS, MEANS SELECTIVELY INTERCONNECTING SAID SWITCH MEANS AND SAID CONNECTION MEANS WITH SAID SWITCH MEANS IN ONE POSITION FOR RENDERING SAID RADIO APPARATUS OPERATIVE IN ITS NORMAL FASHION, MEANS SELECTIVELY INTERCONNECTING SAID SWITCH MEANS, SAID COIL AND SAID CONNECTION MEANS WITH SAID SWITCH MEANS IN ANOTHER POSITION TO TRANSMIT A CODED SIGNAL BY SAID RADIO APPARATUS UPON SUBSTANTIALLY SIMULTANEOUS VIBRATION OF BOTH OF SAID REEDS, MEANS FOR SUBSTANTIALLY SIMULTANEOUSLY VIBRATING BOTH OF SAID REEDS TO INDUCE A SIGNAL CODE IN SAID COIL, AND MEANS INTERCONNECTING SAID CONNECTION MEANS, SAID SWITCH MEANS, SAID COIL AND BOTH OF SAID REEDS IN A FURTHER POSITION OF SAID SWITCH MEANS WITH THE LOUDSPEAKER OF SAID RADIO APPARATUS RENDERED INOPERATIVE TO EFFECT SUBSTANTIALLY SIMULTANEOUS VIBRATION OF BOTH OF SAID REEDS IN RESPONSE TO RECEIPT BY SAID RADIO APPARATUS OF A CODED SIGNAL, AND MEANS INCLUDING SAID RELAY MEANS EFFECTIVE UPON SUCH VIBRATION TO RENDER THE LOUDSPEAKER OF SAID RADIO APPARATUS OPERATIVE.