Positioning mechanism

Claim 1

AN ADJUSTABLE POSITIONING MECHANISM FOR A CONCAVE GUIDE MECHANISM UTILIZED IN MATING, SPACED APART RELATIONSHIP FOR A ROTATING HEAD ASSEMBLY IN A WIDEBAND RECORDING AND REPRODUCING SYSTEM IN WHICH THE ROTATING HEAD ASSEMBLY ROTATES ABOUT AN AXIS OF ROTATION AND THE CONCAVE GUIDE MECHANISM MAINTAINS THE MAGNETIC TAPE IN CUPPED CONTACTING RELATION TO THE MAGNETIC HEAD ASSEMBLY AS THE TAPE IS MOVED LONGITUDINALLY PARALLEL THE MAGNETIC HEAD ASSEMBLY, INCLUDING THE COMBINATION OF A FRAME, A PIVOTED SUPPORT BRACKET MOUNTED ADJACENT THE CONCAVE GUIDE MECHANISM IN THE FRAME AND PIVOTABLE WITH RESPECT THERETO, THE BRACKET BEING PIVOTABLE BETWEEN FIRST AND SECOND POSITIONS CLOSE TO AND SPACED APART FROM THE ROTATING HEAD ASSEMBLY, CANTILEVER LEAF SPRING ARMS AXIALLY ADJUSTABLY MOUNTED ON THE BRACKET AND COUPLED AT THEIR FREE ENDS TO THE CONCAVE GUIDE MECHANISM, THE CANTILEVER LEAF SPRING ARMS BEING SPACED APART SUCH THAT WHEN THE BRACKET IS IN THE FIRST POSITION THE CANTILEVER LEAF SPRINGS URGE THE CONCAVE GUIDE MECHANISM CONSTRAINING THE CONCAVE GUIDE MECHANISM TO A CURVILINEAR TRANSLATION IN WHICH THE PARTS OF THE CONCAVE GUIDE MECHANISM REMAIN IN PARALLELISM RELATIVE TO THE ROTATING HEAD ASSEMBLY AS THE CONCAVE GUIDE MECHANISM IS MOVED TOWARD OR AWAY FROM THE ASSEMBLY, A PAIR OF PIVOTED CONTROL ARMS EACH PIVOTALLY MOUNTED AT A DIFFERENT POINT SPACED SYMMETRICALLY WITH RESPECT TO A CENTRAL PLANE PASSING THROUGH THE AXIS OF ROTATION OF THE ROTATING HEAD ASSEMBLY AND THE CENTRAL LONGITUDINAL AXIS OF THE MAGNETIC TAPE, AND INCLUDING CONTACTING SURFACES SYMMETRICALLY ENGAGING THE CYLINDRICAL SURFACE OF THE CONCAVE GUIDE MECHANISM, ADJUSTABLE CAM FOLLOWER MEANS MOUNTED IN EACH OF THE CONTROL ARMS AND INCLUDING CAM FOLLOWER SURFACES DISPOSED IN ADJACENT RELATION, TAPER CAM MEANS INCLUDING A TAPER CAM SURFACE ENGAGING THE CAM FOLLOWER SURFACES, THE TAPER CAM MEANS BEING LONGITUDINALLY MOVABLE IN THE DIRECTION OF TRANSLATION OF THE CONCAVE GUIDE MECHANISM, A SLIDABLE YOKE MECHANISM ADJUSTABLY COUPLED TO THE TAPER CAM MEANS, ECCENTRIC BEARING MEANS ENGAGING THE SLIDABLE YOKE FOR INCREMENTALLY VARYING THE POSITION OF THE SLIDABLE YOKE AND THE COUPLED TAPER CAM MEANS, THEREBY TO CHANGE THE POSITION OF THE CONTACT POINT RELATIVE TO THE CYLINDRICAL SURFACE AND TO EFFECT TRANSLATION OF THE CONCAVE GUIDE MECHANISM AND RETRACTING MEANS SELECTIVELY COUPLED TO THE CONTROL ARMS FOR PIVOTING THE CONTROL ARMS TO A SELECTED POSITION IN WHICH THE CONCAVE GUIDE MECHANISM IS MAINTAINED SPACED APART FROM THE ROTATING HEAD ASSEMBLY SUCH THAT THE TAPE IS OUT OF CONTACT WITH THE ROTATING HEAD ASSEMBLY.