Magnetic recording heads

Claim 1

A MECHANISM FOR MOVING A MAGNETIC HEAD SUCCESSIVELY FROM ONE TRACK TO ANOTHER ON A MARKED MAGNETIC TAPE IN A TAPE RECORDER HAVING FRAMEWORK, COMPRISING A SCREW TO MOVE SAID MAGNETIC HEAD TRANSVERSELY OF SAID TAPE, FIRST SPRING MEANS TO URGE SAID SCREW TO ROTATE AND MOVE SAID HEAD, MANUALLY OPERATED MEANS TO WIND UP SAID FIRST SPRING MEANS BY ROTATING SAID SCREW WHEREBY SAID MAGNETIC HEAD IS MOVED TO A DESIRED TRACK ON SAID TAPE, AN ESCAPEMENT COMPRISING A TOOTHED ESCAPE WHEEL CONNECTED TO SAID SCREW AND TWO CO-OPERATING PALLETS ON A PALLET PLATE, THE ONE OF SAID PALLETS WHICH NORMALLY HOLDS SAID ESCAPEMENT WHEEL BEING PIVOTED, SECOND SPRING MEANS TO KEEP SAID ONE PALLET IN ITS WORKING POSITION, WHEREBY SAID ONE PALLET IS MOVED CLEAR OF EACH TOOTH OF SAID ESCAPEMENT WHEEL WHEN SAID FIRST SPRING MEANS IS WOUND UP BY ROTATION OF SAID SCREW, A YOKE IN WHICH SAID MAGNETIC HEAD IS MOUNTED, TWO ARMS PIVOTALLY COUPLED AT ONE END TO SAID YOKE AND PIVOTALLY COUPLED AT THE OTHER END TO SAID FRAMEWORK OF SAID RECORDER ARRANGED SO THAT THE AXES OF THE FOUR PIVOTS OF SAID ARMS DEFINE A PARALLELOGRAM, AND MEANS ENGAGING SAID PALLET PLATE AND RESPONSIVE TO THE PASSAGE OF A MARK ON SAID TAPE TO ALLOW SAID ESCAPEMENT TO ROTATE BY ONE TOOTH TO ENGAGE THE ADJACENT TRACK ON SAID TAPE.