Aircraft collision avoidance

Claim 1

A SYSTEM FOR PREVENTING AIRCRAFT COLLISIONS COMPRISING: MEANS CONVERTING ATMOSPHERIC PRESSURE INTO MECHANICAL MOTION, MOUNTED IN A FIRST AIRCRAFT; A RADIO TRANSMITTER MOUNTED IN SAID FIRST AIRCRAFT AND OPERATING AT A PREDETERMINED FIXED CARRIER FREQUENCY; MODULATING MEANS FOR SAID TRANSMITTER; MEANS MECHANICALLY COUPLING SAID MECHANICAL MOTION TO SAID MODULATING MEANS FOR VARYING THE MODULATION OF SAID CARRIER FREQUENCY IN ACCORDANCE WITH THE BAROMETRIC ALTITUDE OF SAID FIRST AIRCRAFT; A RADIO RECEIVER MOUNTED IN SAID FIRST AIRCRAFT AND TUNED TO SAID PREDETERMINED FIXED CARRIER FREQUENCY FOR RECEIVING THE SIGNALS FROM A LIKE FIXED CARRIER FREQUENCY TRANSMITTER MOUNTED IN A SECOND, PROXIMATE AIRCRAFT AND MODULATED IN ACCORDANCE WITH THE BAROMETRIC ALTITUDE THEREOF, SAID RADIO RECEIVER INCLUDING A DETECTOR, INDICATING MEANS OPERATED FROM SAID DETECTOR AND PROVIDING A PERCEPTORY SIGNAL INDICATIVE OF THE PROXIMITY OF SAID SECOND AIRCRAFR; A LIMITER CONNECTED TO SAID DETECTOR AND RECEIVING THE DETECTED MODULATING FREQUENCY THEREFROM; A COMPARING CIRCUIT RECEIVING THE LIMITED MODULATING FREQUENCY AND HAVING MECHANICALLY VARIABLE CAPACITANCE MEANS; AND LINKAGE MEANS MECHANICALLY COUPLING SAID MECHANICAL MOTION TO SAID CAPACITANCE MEANS WHEREBY SAID COMPARING CIRCUIT PROVIDES AN OUTPUT INDICATIVE OF THE RELATIVE ALTITUDE BETWEEN SAID FIRST AND SECOND AIRCRAFT.

Claim 2

A SYSTEM FOR PREVENTING AIRCRAFT COLLISIONS COMPRISING: MEANS CONVERTING ATMOSPHERIC PRESSURE INTO MECHANICAL MOTION, MOUNTED IN A FIRST AIRCRAFT; A RADIO TRANSMITTER MOUNTED IN SAID FIRST AIRCRAFT AND OPERATING AT A PREDETERMINED FIXED CARRIER FREQUENCY; MODULATING MEANS FOR SAID TRANSMITTER; MEANS MECHANICALLY COUPLING SAID MECHANICAL MOTION TO SAID MODULATING MEANS FOR VARYING THE MODULATION OF SAID CARRIER FREQUENCY IN ACCORDANCE WITH THE BAROMETRIC ALTITUDE OF SAID FIRST AIRCRAFT; A RADIO RECEIVER MOUNTED IN SAID FIRST AIRCRAFT AND TUNED TO SAID PREDETERMINED FIXED CARRIER FREQUENCY FOR RECEIVING THE SIGNALS FROM A LIKE FIXED CARRIER FREQUENCY TRANSMITTER MOUNTED IN A SECOND, PROXIMATE AIRCRAFT AND MODULATED IN ACCORDANCE WITH THE BAROMETRIC ALTITUDE THEREOF, SAID RADIO RECEIVER INCLUDING A DETECTOR, INDICATING MEANS OPERATED FROM SAID DETECTOR AND PROVIDING A PERCEPTORY SIGNAL INDICATIVE OF THE PROXIMITY OF SAID SECOND AIRCRAFR; A LIMITER CONNECTED TO SAID DETECTOR AND RECEIVING THE DETECTED MODULATING FREQUENCY THEREFROM; A COMPARING CIRCUIT RECEIVING THE LIMITED MODULATING FREQUENCY AND HAVING MECHANICALLY VARIABLE CAPACITANCE MEANS; AND LINKAGE MEANS MECHANICALLY COUPLING SAID MECHANICAL MOTION TO SAID CAPACITANCE MEANS WHEREBY SAID COMPARING CIRCUIT PROVIDES AN OUTPUT INDICATIVE OF THE RELATIVE ALTITUDE BETWEEN SAID FIRST AND SECOND AIRCRAFT.