Data reading apparatus

Claim 1

A DATA READER FOR USE WITH AN OSCILLOGRAM SHEET HAVING A GENERALLY LONGITUDINAL TRACE THEREON AND HAVING A LONGITUDINAL REFERENCE LINE THEREON IN PREDETERMINED TRANSVERSELY SPACED RELATIONSHIP TO A ZERO POSITION FOR SAID TRACE WHICH DATA READER COMPRISES IN COMBINATION, A FRAME ADAPTED TO BE LOCATED ABOVE SUCH AN OSCILLOGRAM SHEET, A LOCATING INDICATOR IN FIXED RELATIONSHIP WITH THE FRAME AND ADAPTED UPON TRANSVERSE ADJUSTMENT OF THE FRAME TO REGISTER WITH A KNOWN ZERO POSITION FOR THE OSCILLOGRAM TRACE, A SLIDE GUIDED FOR TRANSVERSE RECTILINEAR MOVEMENT RELATIVELY TO THE FRAME, A MEASURING INDICATOR CONNECTED TO SAID SLIDE AND HAVING A LONGITUDINAL HAIRLINE THEREON, MANUALLY OPERABLE MEANS FOR MOVING THE SLIDE TRANSVERSELY TO BRING SAID MEASURING INDICATOR INTO REGISTER WITH A SELECTED POINT ON SAID TRACE WHILE SAID LOCATING INDICATOR REMAINS AT SAID ZERO POSITION, AN ELECTRIC CIRCUIT INCLUDING A VARIABLE RESISTANCE CONSTITUTING A VOLTAGE DIVIDER, MEANS CONNECTED WITH SAID RESISTANCE FOR VARYING IT OT CHANGE THE VOLTAGE PROPORTIONATELY TO THE EXTENT OF MOVEMENT OF SAID SLIDE AND OF SAID MOVABLE INDICATOR, AN ELECTRICAL INDICATING DEVICE CONNECTED IN CIRCUIT WITH SAID RESISTANCE AND RESPONSIVE TO VOLTAGE CHANGES RESULTING FROM RESISTANCE VARIATIONS WHICH DEVICE SERVES TO INDICATE THE AMPLITUDE VALUES REPRESENTED BY THE DISTANCE FROM SAID ZERO POSITION TO SAID SELECTED POINT ON SAID TRACE, AND A SUPPLEMENTAL LOCATING INDICATOR ON THE FRAME WHICH IS ADDITIONAL TO THE FIRST SAID LOCATING INDICATOR AND WHICH IS TRANSVERSELY ADJUSTABLE RELATIVELY TO THE FRAME, SAID SUPPLEMENTAL LOCATING INDICATOR BEING REGISTRABLE WITH SAID LONGITUDINAL REFERENCE LINE TO FACILITATE THE SUBSEQUENT RELOCATION OF SAID HEAD WITH THE FIRST SAID LOCATING INDICATOR IN REGISTER WITH SAID ZERO POSITION.