Interpolating arrangements especially for the automatic control of machine tools

Claim 1

IN INTERPOLATING ARRANGEMENT COMPRISING TWO INTERPOLATING MEANS HAVING TERMINALS FOR INPUT SIGNALS SO ARRANGED THAT SETS OF INPUT SIGNALS CAN BE APPLIED ALTERNATELY TO SAID MEANS AND OUTPUT TERMINALS FOR SIGNALS DERIVED FROM SAID INPUT SIGNALS BY SAID INTERPOLATING MEANS, A SELECTOR MOVEABLE TO "CONNECT WITH SAID OUTPUT TERMINALS SELECTIVELY AND DERIVE THEREFROM" AN OUTPUT SIGNAL ALTERNATELY FROM SAID MEANS IN SUCH A WAY THAT THE OUTPUT SIGNAL VARIES TO REPRESENT INTERPOLATED VALUES OF FUNCTIONS DEFINED BY THE SETS OF INPUT SIGNALS AND BY THE INTERPOLATING MEANS, AND BLENDING MEANS INCLUDING MEANS MECHANICALLY COUPLED TO SAID SELECTOR MEANS FOR SELECTIVELY ADDING TO SAID OUTPUT SIGNAL A PROPORTION OF THE DIFFERENCE IN SIGNAL CHANGE BETWEEN TWO OUTPUT TERMINALS OF ONE INTERPOLATING MEANS AND THE SIGNAL CHANGE BETWEEN TWO OUTPUT TERMINALS OF THE OTHER INTERPOLATING MEANS, SAID PROPORTION BEING DEPENDENT ON THE POSITION OF SAID SELECTOR MEANS, SO AS TO CAUSE THE OUTPUT SIGNAL TO VARY IN ACCORDANCE WITH A SMOOTH CURVE FROM A VALUE OF THE FUNCTION INTERPOLATED BY ONE INTERPOLATING MEANS TO A VALUE OF THE FUNCTION INTERPOLATED BY THE OTHER INTERPOLATING MEANS WHILST THE SELECTOR MOVES THROUGH A RANGE OF POSITIONS WHICH INCLUDES THE CHANGEOVER FROM ONE INTERPOLATING MEANS TO THE OTHER BUT IS SMALL COMPARED WITH THE TOTAL RANGE OF POSITIONS OF THE SELECTOR.