Noise testing device for gears and transmissions

Claim 1

IN A NOISE TESTING INSTALLATION FOR GEARS AND TRANSMISSIONS IN WHICH THE GEARS ARE RUN TOGETHER AND THE NOISE DEVELOPED THEREBY DETECTED BY A MICROPHONE, AND HAVING AN AMPLIFIER WHICH IS FED BY THE MICROPHONE: FIRST AND SECOND SPINDLES FOR SUPPORTING SAID GEARS, A PLURALITY OF BAND FILTERS IN PARALLEL FED BY THE SAID AMPLIFIER OPERABLE TO SUBDIVIDE THE FREQUENCY OF THE AMPLIFIER OUTPUT, A PLURALITY OF VARIABLE SECOND AMPLIFIERS RESPECTIVELY CONNECTED TO BE SUPPLIED BY SAID BAND FILTERS, A PLURALITY OF RELAYS RESPECTIVELY CONNECTED TO SAID SECOND AMPLIFIERS TO BE RESPONSIVE TO THE OUTPUTS THEREOF, OPTICAL AND OCOUSTICAL SIGNALING MEANS ELECTRICALLY CONNECTED TO SAID RELAYS OPERABLE IN RESPONSE TO ACTUATION OF THE RELAYS WHICH OCCURS WHEN THE PERMISSIBLE NOISE LEVEL OF THE GEARS BEING TESTED IS EXCEEDED IN ANY OF THE FREQUENCY RANGES OF SAID BAND FILTERS, AND MEANS FOR CONTROLLING THE TORQUE BETWEEN THE GEARS BEING TESTED INCLUDING SWITCH AND CONTROL MEANS AND COMPRISING: A DIRECT CURRENT MOTOR DRIVING ONE SPINDLE, A GENERATOR SERIALLY CONNECTED IN CIRCUIT WITH THE MOTOR, A RESISTOR SERIALLY CONNECTED WITH THE MOTOR AND GENERATOR AND HAVING AN INTERMEDIATE TERMINAL, A MEASURING BRIDGE TO WHICH THE SAID INTERMEDIATE TERMINAL OF THE RESISTOR IS CONNECTED, TIMER MEANS, A SWITCH OPERATIVELY CONNECTED TO SAID TIMER MEANS SO AS TO BE ACTUATED BY THE TIMER MEANS, A DIRECT CURRENT SOURCE, A PAIR OF ADJUSTABLE POTENTIOMETER SUPPLIED BY SAID SOURCE EACH HAVING AN INTERMEDIATE TERMINAL, AN ELECTRICAL UNIT CONNECTED TO SAID BRIDGE AND ALSO CONNECTED FOR SUPPLYING CURRENT FOR THE FIELD EXCITATION OF SAID GENERATOR, THE MAGNITUDE OF THE CURRENT SO SUPPLIED AND, THEREFORE, THE TORQUE BETWEEN THE GEARS BEING TESTED BEING DETERMINED BY ADJUSTMENT OF SAID POTENTIOMETERS, SAID POTENTIOMETERS AND SAID RESISTANCE BEING ADAPTED FOR HAVING THE VOLTAGES OF THEIR RESPECTIVE INTERMEDIATE TERMINALS COMPARED BY SAID BRIDGE, SAID SWITCH WHEN ACTUATED BY SAID TIMER MEANS BEING OPERABLE FOR SELECTIVELY INDIVIDUALLY CONNECTING SAID INTERMEDIATE TERMINALS OF THE POTENTIOMETERS TO SAID BRIDGE, THE VOLTAGE DIFFERENCE IN SAID BRIDGE CONTROLLING SAID ELECTRICAL UNIT, AND A DRIVE MOTOR FOR THE OTHER OF SAID SPINDLES.