Organ portamento system

Claim 1

A PORTAMENTO SYSTEM FOR A MUSICAL INSTRUMENT OF THE KEYBOARD TYPE COMPRISING, MEANS PROVIDING A GROUP OF TONE SIGNAL SOURCES OF THE TYPE IN WHICH THE FREQUENCIES SUPPLIED BY THE SOURCES VARY WITH AN ELECTRICAL CONDITION EXISTING AT A TERMINAL COMMON TO ALL OF THE SOURCES IN SAID GROUP, MEANS FOR ESTABLISHING A NOMINAL ELECTRICAL CONDITION AT SAID TERMINAL, CIRCUIT MEANS CONNECTED TO SAID TERMINAL AND ADAPTED WHEN ACTUATED FOR CHANGING THE ELECTRICAL CONDITION AT SAID TERMINAL AWAY FROM SAID NOMINAL CONDITION ABRUPTLY IN ONE DIRECTION AND THEN RETURNING THE CONDITION AT SAID TERMINAL SLOWLY TO SAID NOMINAL ELECTRICAL CONDITION, SAID CIRCUIT MEANS HAVING A CONTROL CONNECTION ADAPTED TO ACTUATE SAID CIRCUIT MEANS WHEN A CONDITION AT SAID CONTROL CONNECTION IS SHIFTED IN ONE DIRECTION FROM A NOMINAL CONDITION BY MORE THAN A CERTAIN AMOUNT, SAID CIRCUIT MEANS BEING DEACTIVATED WHEN SAID CONTROL CONNECTION IS AT THE LAST SAID NOMINAL CONDITION OR A CONDITION WHICH IS SHIFTED FROM THE LAST SAID NOMINAL CONDITION BY NO MORE THAN THE SAID CERTAIN AMOUNT, CIRCUIT MEANS INCLUDING A MECHANISM ACTUATED BY A PLURALITY OR PLAYING KEY ACTUATED SWITCHES CONNECTED TO SAID CONTROL CONNECTION AND ADAPTED TO SHIFT THE CONDITION AT SAID CONTROL CONNECTION BY NO MORE THAN SAID CERTAIN AMOUNT WHEN A SINGLE ONE OF ANY OF SAID SWITCHES IS ACTUATED BUT TO SHIFT THE CONDITION AT SAID CONTROL CONNECTION BY AN AMOUNT WHICH IS MORE THAN SAID CERTAIN AMOUNT IF A PLURALITY OF SAID SWITCHES ARE ACTUATED TOGETHER.