US 4,393,425 AGranted

Linear head actuator

AssigneeDisctron, Inc.

InventorHarold T. Wright

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Abstract

An actuator for linearly moving magnetic heads in which an open-ended carriage assembly extends down both sides of the magnet structure in order to provide a much shorter actuator assembly than is typical is described. The loading mechanism is not mounted upon the carriage assembly, thereby allowing the actuator to have a higher resonant frequency than those actuators which carry a more complex structure on the carriage assembly. The magnet structure is in the shape of an E with the motor coil, which is mounted across the open end of the carriage assembly, moving along this center section of the magnet structure. Alignment pins located at the other end of the carriage assembly allow the magnetic head arms to be mounted and aligned quickly and with precision.

An actuator for translating at least one magnetic head comprising:

a moveable carriage element carrying said at least one magnetic head having two parallel sides, a closed end and an open end, said carriage element being generally U-shaped and carrying bearing means located along the outside of each of said two parallel sides;
a stationary first guide rod adjacent and parallel to a first of said two parallel sides of said moveable carriage element cooperating with said bearing means located along said first of said two parallel sides;
a second guide rod adjacent and parallel to the second of said two parallel sides of said moveable carriage element cooperating with said bearing means located along said second of said two parallel sides, said second guide rod being non-moveable in a direction along its length, said carriage element being moveable linearly on said bearing means along said guide rods;
biasing means spaced from said moveable carriage for forcing said second guide rod against said bearing means located along said second of two parallel sides;
an electrical coil mounted across said open end of said moveable carriage element, said coil oriented in a plane generally perpendicular to the parallel sides of the moveable carriage element;
and
a stationary magnet structure positioned between said stationary first guide rod and said second guide rod, said stationary magnet structure having a first member extending within said coil and between said parallel sides of said moveable carriage element, said coil being moveable along almost the entire length of said first member, said stationary magnet structure having at least one other member in addition to said first member extending outside said coil parallel to said first member and connected to said first member at one end, said members defining a magnetic flux path with a magnetic flux gap therebetween in which said coil is located so that when current passes through said coil, magnetic flux crossing said gap will cause said coil to experience a force, said force causing said coil to move along said first member extending within said coil, the direction of movement of said coil depending on the direction of said current in said coil, thereby moving said moveable carriage element along said guide rods.

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Abstract

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