Method and apparatus for use in ultrasonic rail testing

Claim 1

APPARATUS FOR PROVIDING A PROGRESSIVE PICTORIAL REPRESENTATION OF THE INTERNAL STRUCTURAL CHARACTERISTICS OF LENGTHWISE SUCCESSIVE PORTIONS OF A TRACK RAIL AND COMPRISING ULTRASONIC EQUIPMENT INCLUDING MEANS FOR EMITTING SUCCESSIVE ULTRASONIC TEST SIGNAL PULSES AT A PREDETERMINED REPETITION RATE AND FOR RECEIVING ECHOES OF SAID PULSES, MEANS FOR PROGRESSING THE ULTRASONIC EQUIPMENT ALONG THE RAIL TO SUCCESSIVELY ESTABLISH SUCH EQUIPMENT IN ELASTIC WAVE TRANSMITTING AND RECEIVING RELATION WITH LENGTHWISE SUCCESSIVE PORTIONS OF THE RAIL TO ENABLE SUCH ULTRASONIC EQUIPMENT TO PRODUCE A SET OF ECHO SIGNALS CORRESPONDING TO EACH SAID TEST SIGNAL PULSE AND CONSTITUTING AN A-SCAN PULSE ECHO SIGNAL PATTERN REPRESENTATIVE OF LENGTHWISE SUCCESSIVE SECTIONS OF THE RAIL, A MEMORY TYPE CATHODE RAY TUBE HAVING A FLUORESCENT SCREEN, MEANS FOR PROJECTING A BEAM OF CATHODE RAYS ON TO SAID SCREEN AND MEANS FOR DEFLECTING SAID BEAM IN TWO COORDINATE DIRECTIONS, TWO COORDINATE SCANNING MEANS FOR SAID TUBE AND INCLUDING FIRST MEANS OPERABLE AT SAID REPETITION RATE AND AT A CERTAIN SCAN SPEED FOR REPEATEDLY DEFLECTING SAID BEAM ALONG ONE COORDINATE DIRECTION FOR A CERTAIN SCAN TIME, SECOND MEANS OPERABLE AT A REPETITION RATE AND SCAN SPEED MANY TIMES LOWER THAN THE FIRST NAMED REPETITION RATE AND SCAN SPEED FOR REPEATEDLY DEFLECTING SAID BEAM ALONG ANOTHER COORDINATE DIRECTION FOR A SCAN TIME MANY TIMES GREATER THAN THE FIRST NAMED SCAN TIME, MEANS FOR VARYING THE INTENSITY OF THE BEAM IN ACCORDANCE WITH THE INTENSITY OF THE SAID SETS OF ECHO SIGNALS RECEIVED BY SAID RECEIVING MEANS, AND MEANS OPERABLE BY SAID SECOND MEANS FOR APPLYING AN ERASE SIGNAL TO SAID TUBE IN SYNCHRONIZED RELATION WITH SAID SECOND MEANS TO ERASE STORED TRACE INTELLIGENCE FROM SAID SCREEN PRIOR TO APPLICATION OF NEW TRACE INTELLIGENCE.