Printing tapper-head for radioactivity scanners

Claim 1

A MARKING HEAD FOR A RADIOACTIVITY SCANNER COMPRISING: (A) A HOUSING ADAPTED TO BE M OUNTED FOR SCANNING OF A RECORDING SHEET, (B) A PIVOTALLY MOUNTED TAPPER HAVING A STYLUS PORTION ADAPTED TO MARK THE RECORDING SHEET, (C) AN ACTUATOR MEMBER ROTATINALLY MOUNTED ON THE PIVOTAL AXIS OF THE TAPER AND ABUTTING AGAINST THE TAPPER IN THE DIRECTION AWAY FROM THE RECORDING SHEET, THE ACUTATOR MEMBER BEING ROTATABLE RELATIVE TO THE TAPPER IN THE DIRECTION OF ACTUATION AFTER THE TAPPER STRIKES THE SHEET, (D) A FIRST SPRING CONNECTING THE ACTUATOR MEMBER AND THE TAPPER AND URGING THE ACTUATOR MEMBER AND THE TAPPER INTO SUCH ABUTMENT, (E) A SECOND SPRING ACTING BETWEEN THE TAPPER AND THE HOUSING AND INDEPENDENT OF THE ACTUATOR MEMBER URGING THE TAPPER AWAY FROM THE SHEET WITH FORCE LERSS THAN THAT OF THE FIRST SPRING, THE TAPPER THUS FOLLOWING ROTATION OF THE ACUATOR MEMBER TOWARD THE RECORDING SHEET AGAINST THE FORCE OF THE SECOND SPRING, AND (F) PULSE-RESPONSIVE DRIVE MEANS ENGAGING THE ACTUATOR MEMBER TO ROTATE THE ACTUATOR MEMBER IN THE DOWNWARD DIRECTION SUBSTANTIALLY BEYOND THE STRIKING POINT OF THE STYLUS PORTION OF THE TAPER AND THUS INCREASE OF TENSION ON THE FIRST SPRING, (G) THE SECOND SPRING THUS READILY YIELDING TO THE DRIVE MEANS FOR MOTION OF THE TAPPER TOWARD THE STRIKING POINT BUT BEING AIDED BY THE FIRST SPRING IN ACCELERATING THE TAPPER AWAY FROM THE STRIKING POINT UPON TERMINATION OF A PULSE.