Tape head fine positioning system for a tape backup drive

A tape head fine positioning system for positioning a magnetic tape head in a back-up tape cartridge drive system, said system comprising:

• a chassis for mounting said back-up system;
• an elongated lever arm engaging said chassis, said elongated lever arm having a first end and a second end an a longitudinal axis passing from the first end to the second end;
• means attached to said chassis to move said first end of said lever arm in a vertical axis, wherein said vertical axis intersects and is substantially perpendicular to said longitudinal axis, wherein said lever arm moving means includes:
• i) a lead screw;
• ii) means to bi-directionally rotate said lead screw;
• iii) means on the first end of said lever arm for engaging said lever arm moving means at a plurality of points wherein said plurality of points lie in a horizontal plane that is substantially perpendicular to and intersects both the vertical axis and the longitudinal axis,
• said engaging means on said first end of said lever arm comprising a follower nut threadingly engaging said lead screw, said first end of said lever arm engaging said follower nut to constrain the rotational movement of said follower nut to force said follower nut and said first end of said lever arm to more vertically as said lead screw rotates;
• elongated horizontal slots formed on two opposing parallel sides of said follower nut, each of said slots having one end open and the other end closed, and load bearing surfaces extending radially outwardly from the lower edge of each of said slots;
• a U-shaped yoke formed on said first end of said lever arm having a guide pin formed on each arm of said yoke spaced from the outer end of each yoke arm and extending radially inwardly from said yoke arms, said pins formed approximately the same diameter as the width of said slots and extending radially inwardly a distance approximately the same as the depth of said slots;
• said pins engage in said slots to guide said lever arm into engagement with said follower nut;
• said pins when fully engaged in said slots lie in said horizontal and vertical planes;
• a first surface formed on each of said yoke arms extending longitudinally inwardly and downwardly to said pin formed on each of said yoke arms;
• a second surface formed on each of said yoke arms extending longitudinally inwardly and upwardly from said pin formed on each of said yoke arms;
• each of said surfaces formed approximately the same width as said radially outwardly extending surfaces of said follower nut;
• said lever arm surfaces interacting with said follower nut surfaces to balance said force distribution between said lever arm and said follower nut and eliminate said cantilevered loading;
• a tape head mounting unit mounted on said chassis to move vertically;
• means on the second end of said lever arm for engaging said tape head mounting unit such that said tape head mounting unit is moved vertically as said first end of said lever arm is moved vertically;
• and
• a tape head mounted in said tape head mounting unit.

A tape head fine positioning system for positioning a magnetic tape head in a back-up cartridge drive system, said system comprising:

• a chassis for mounting said back-up system;
• a tape head mounting unit mounted on said chassis to move vertically, said tape head mounting unit having an upper portion and having a plurality of contact surfaces for engaging the chassis, wherein the contact surfaces are located in a first vertical plane;
• an elongated lever arm having a first end and a second end, said elongated lever arm engaging said chassis and having a longitudinal axis passing from the first end to the second end, the lever arm being positioned so that the longitudinal axis is perpendicular to the first vertical plane;
• means attached to said chassis to move the first end of said lever arm in a vertical axis;
• means on a second end of said lever arm for engaging said tape head mounting unit to move said tape head mounting unit as said first end of said lever arm is moved in said vertical axis, wherein the means for engaging contacts the upper portion of said tape head mounting unit substantially in the first vertical plane;
• means on said tape head mounting unit to align said tape head mounting unit to said chassis thereby minimizing positional error;
• a tape head mounted in said tape head mounting unit;
• and
• means on said system to reduce the torsional forces on said tape head mounting unit.

A tape head fine positioning system for positioning a magnetic tape head in a back-up tape cartridge drive system, said system comprising:

• a chassis for mounting said back-up system;
• a tape head mounting unit mounted on said chassis to move vertically, said tape head mounting unit having an upper portion;
• an elongated lever arm having a first end and a second end, said elongated lever arm engaging said chassis and having a longitudinal axis passing from the first end to the second end;
• means attached to said chassis to move the first end of said lever arm in a vertical axis;
• means on a second end of said lever arm for engaging said tape head mounting unit to move said tape head mounting unit as said first end of said lever arm is moved in said vertical axis, wherein the means for engaging contacts the upper portion of said tape head mounting unit;
• means on said tape head mounting unit to align said tape head mounting unit to said chassis thereby minimizing positional error;
• a tape head mounted in said tape head mounting unit,
• means on said system to reduce the torsional forces on said tape head mounting unit;
• wherein said means to reduce torsional forces includes:
• a double coil torsional spring having two free ends and a center portion, wherein said center portion engages said tape head mounting unit in a first vertical plane containing said engaging means on said second end of said lever arm to upwardly bias said tape head mounting unit against said lever arm second end engaging means thereby decreasing the positional tracking error;
• and
• said two free ends engage said chassis in said first vertical plane so the forces acting on said tape head mounting unit substantially lie within said first vertical plane.

A tape head fine positioning system for positioning a magnetic tape head in a back-up tape cartridge drive system, said system comprising:

• a chassis for mounting said back-up system;
• a tape head mounting unit mounted on said chassis to move vertically;
• an elongated lever arm engaging said chassis and having a first end, a second end, and a longitudinal axis passing through the first end and the second end;
• means attached to said chassis for moving the first end of said lever arm in a vertical axis;
• means on the second end of said lever arm for engaging said tape head mounting unit to move said tape head mounting unit as said first end of said lever arm is moved in said vertical axis;
• means on said tape head mounting unit to align said tape head mounting unit to said chassis thereby minimizing positional error;
• a tape head mounted in said tape head mounting unit;
• and
• said means for moving said first end of said lever arm includes means for mounting said first end of said lever arm to said means for moving, said means for mounting located in a substantially horizontal plane including the longitudinal axis and in a substantially vertical plane including the vertical axis, said substantially vertical plane being substantially perpendicular to said longitudinal axis of said lever arm so as to balance the force distribution between said lever arm and said lever arm moving means and eliminate cantilevered loading in the system.

A tape head fine positioning system for positioning a magnetic tape head in a back-up tape cartridge drive system, said system comprising:

• a chassis for mounting said back-up system;
• a tape head mounting unit mounted on said chassis to move vertically;
• an elongated lever arm engaging said chassis and having a first end, a second end, and a longitudinal axis passing through the first end and the second end;
• means attached to said chassis for moving the first end of said lever arm in a vertical axis;
• means on the second end of said lever arm for engaging said tape head mounting unit to move said tape head mounting unit as said first end of said lever arm is moved in said vertical axis;
• means on said tape head mounting unit to align said tape head mounting unit to said chassis thereby minimizing positional error;
• a tape head mounted in said tape head mounting unit;
• wherein said means for moving said first end of said lever arm includes a lead screw, means to bi-directionally rotate said lead screw, a follower nut threadingly engaging said lead screw and means for mounting said first end of said lever arm to said means for moving,
• wherein said mounting means are located in a substantially horizontal plane including the longitudinal axis and in a vertical plane including the vertical axis and said means for mounting further comprise means to constrain rotational movement of said follower nut thus forcing said follower nut and said lever arm to move vertically as said lead screw rotates;
• elongated horizontal slots formed on two opposing parallel sides of said follower nut, each of said slots having one end open and the other end closed, and a load bearing surface extending radially outwardly from the lower edge of each of said slots;
• a U-shaped yoke formed on said first end of said lever arm having guide pins formed on each of the arms of said yoke arm spaced from the outer end of each of said yoke arms and extending radially inwardly from said yoke arms, said pins formed approximately the same diameter as the width of said slots and extending radially inwardly a distance approximately the same as the depth of said slots, said pins engage in said slots to guide said lever arm into engagement with said follower nut;
• a first surface formed on each of said yoke arms extending longitudinally inwardly and downwardly to said pin formed on each of said yoke arms;
• a second surface formed on each of said yoke arms extending longitudinally inwardly and upwardly from said pin formed on each of said yoke arms;
• each of said surfaces formed approximately the same width as said outwardly extending load bearing surfaces of said follower nut, whereby said lever arm surfaces interact with said follower nut surfaces to balance force distribution between said lever arm and said follower nut and eliminate cantilever loading on said system.

A tape head fine positioning system for positioning a magnetic tape head in a back-up tape cartridge drive system, said system comprising:

• a chassis for mounting said back-up system, said chassis having precisely molded reference surfaces to eliminate the need for azimuth adjustment;
• said reference surfaces having a precise dimensional tolerance of plus or minus 0.0005 inches or less,
• a tape head mounting unit mounted on said chassis to move vertically;
• a tape head mounted in said tape head mounting unit;
• a lever arm engaging said chassis;
• means engaging a first end of said lever arm to move said first end of said lever arm vertically;
• means on the second end of said lever arm to move said tape head mounting unit vertically on said chassis as said first end of said lever arm moves, wherein said chassis includes a substantially rectangular shaped structure formed near the front end of said chassis having two parallel side walls, a rear wall and a front wall, said front wall having a vertical slot formed in the center of said front wall extending the full height of said front wall, said vertical slot includes inner side walls forming guides for said tape mounting head unit to move vertically on;
• said reference surfaces include said sides of said slot precisely aligned with tape cartridge alignment surfaces formed on said chassis to align said tape head mounted in said tape head mounting unit with a tape cartridge aligned by said tape cartridge alignment surfaces.

A tape head fine positioning system for positioning a magnetic tape head in a back-up tape cartridge drive back-up system, said system comprising:

• a chassis for mounting said back-up system, said chassis including precisely molded reference surfaces;
• a tape head mounting unit slidably mounted against said reference surfaces on said chassis to move vertically;
• means on said tape head mounting unit to align said tape head mounting unit to said chassis to eliminate the need for azimuth adjustment of said tape head mounting unit in said chassis;
• means on said system to reduce the torsional forces on said tape head mounting unit;
• a tape head mounted in said tape head mounting unit;
• an elongated lever arm engaging said chassis, said elongated lever arm including a first end, a second end engaging said tape head mounting means, and a longitudinal axis passing through the first end and the second end;
• means attached to said chassis for moving said first end of said lever arm in a vertical axis;
• and
• means on said first end of said lever arm for mounting said means for moving to said lever arm, said means for mounting located in a substantially horizontal plane including the longitudinal axis and in a substantially vertical plane including the vertical axis and substantially perpendicular to said longitudinal axis of said lever arm so as to balance about said vertical axis force applied by said lever arm to said means for moving and eliminate cantilevered loading in the system.