Apparatus for the remote indication of the position of a rotary shaft

Claim 1

AN OPTICAL SHAFT CONVERTER FOR INDICATING THE ROTARY POSITION OF A SHAFT AS A NUMBER COMPRISING, A SOURCE OF LIGHT, FIRST AND SECOND GROUPS OF PHOTOELECTRIC ELEMENTS UNIFORMLY SPACED ABOUT A PORTION OF THE CIRCUMFERENCE OF FIRST AND SECOND COAXIAL CIRCLES OF DIFFERENT RADII, RESPECTIVELY, A DISC INTERPOSED BETWEEN SAID LIGHT SOURCE AND SAID PHOTOELECTRIC ELEMENTS AND ROTATABLE ABOUT A GIVEN AXIS IN SYNCHRONISM WITH SAID SHAFT, SAID DISC HAVING A SINGLE APERTURE LOCATED AT A FIRST RADIAL DISTANCE FROM SAID AXIS IN ALIGNMENT WITH SAID FIRST GROUP OF PHOTOELECTRIC ELEMENTS AND A PLURALITY OF OTHER APERTURES ARRANGED IN A CIRCLE ABOUT SAID AXIS AT A SECOND RADIAL DISTANCE THEREFORM IN ALIGNMENT WITH SAID SECOND GROUP OF PHOTOELECTRIC ELEMENTS, THE PHOTOELECTRIC ELEMENTS OF SAID FIRST AND SECOND GROUPS BEING DISPOSED RELATIVE TO ONE ANOTHER AND TO SAID APERTURED DISC SO THAT UPON ROTATION OF THE DISC THROUGH AN ANGLE EQUAL TO THE ANGLE SUBTENDED BY TWO ADJACENT PHOTOELECTRIC ELEMENTS OF SAID FIRST CIRCLE ALL OF THE PHOTOELECTRIC ELEMENTS OF SAID SECOND GROUP ARE SUCCESSIVELY ILLUMINATED BY SAID LIGHT SOURCE, AND VISUAL DISPLAY MEANS COMPRISING FIRST AND SECOND GROUPS OF DIGIT INDICATOR ELEMENTS INDIVIDUALLY COUPLED TO SAID FIRST AND SECOND GROUPS OF PHOTOELECTRIC ELEMENTS, RESPECTIVELY, FOR INDICATING SAID SHAFT POSITION AS A PLURAL DIGIT NUMBER.