Abstract: A head and gimbal assembly (“HGA”) for supporting a pair of read/write heads at a desired fly height above a pair of adjacent discs. The HGA includes a rigid support arm, and a pair of thin, sheet metal suspensions mounted on opposed surfaces of the support arm. An end of each of the suspensions extends beyond an end of the support arm. These overhanging end portions include cutout sections defining a pair of back-to-back gimbals on which the read/write heads may be mounted. The suspensions may additionally include electrical connectors etched into the surface for transferring electrical signals between the read/write heads and the control electronics of the disc drive. In operation, a single HGA may be located between two adjacent discs, so that one of the heads on the HGA performs read/write operations on one of the two adjacent discs, and the other of the heads performs read/write operations on the other of the two adjacent discs.

Abstract: A method and apparatus for adjusting fly height between a disc surface of a magnetic storage system disc and a slider supported on a flexure arm in a magnetic disc drive. The slider carries a transducing head. The disc drive is rotated at a reduced testing RPM. The flexure arm is heated using a laser to achieve a desired flexure arm bend which corresponds to a desired fly height. Desired bend is achieved at the point when the slider is just in contact with asperities on the disc surface. Following heating, the disc is operated at a normal RPM rate of rotation which is greater than the testing RPM, thereby insuring that the slider flies in close proximity to the disc surface but without contacting the disc surface. Contact between the slider and the disc surface is determined by detecting acoustic noise on the flexure arm.

Abstract: A slider lifter for a disc drive is disclosed which utilizes a shape memory element to lift a slider away from the surface of a disc. The slider is supported adjacent the surface of the disc by a flexure which has a lifting wire attached thereto. The lift wire extends past the edge of the rotating disc through a hole in a leaf spring cantilevered adjacent the disc's edge and terminates in a crimped portion or stopper. The stopper is separated from the rear surface of the leaf spring by an unload space. A shape memory metal wire is attached to the leaf spring at a point spaced apart from the lift wire and extends back to a fixed support wall. Energization of the shape memory wire causes a phase change in the shape memory wire which restores the wire to its original length. The shortening of the shape memory wire pulls the leaf spring across the unload space so as to pick up the crimped portion of the lift wire.

Abstract: An improved flexure mounting arrangement is provided for disc drive systems. The disc drive's head positioning assembly has one or more platform each one of which has an aligned opening therein. The flexure assemblies each include a mounting portion having an opening therein that is aligned with the platform openings. A shape-memory tube formed from a shape memory alloy material is swaged within the aligned openings to firmly couple the flexure assemblies to the head positioner assembly. The shape memory alloy material has martensitic and austenitic phase conditions. In one of the phase conditions, the shape-memory tube is firmly swaged within the aligned openings, while in the other phase condition, the shape-memory tube loosely fits within the aligned openings such that it may be readily inserted and removed. In a preferred aspect of the invention, the shape-memory tube is in the first phase condition at ambient temperatures and may be transformed to the second phase condition only by significant cooling.

Abstract: A slider lifter arrangement is provided for conventional disc drive assemblies. The slider lifter includes a wire support having a pair of wire support arms extending outward from a head positioning assembly adjacent opposite sides of a flexure arm that carries a slider. A lifting wire is strung between the opposing wire support arms in the space between the flexure arm and the disc surface. The lifting wire is formed from a shape memory alloy having martensitic and austenitic phase conditions. The wire is arranged to lift the flexure arm sufficiently to lift the slider off of the disc surface when the wire is in a first phase condition while allowing the slider to rest on the disc surface when the wire is in a second phase condition. The wire is selectively electrically heated to change its state from one phase condition to the other. The wire support is preferably formed integrally with the flexure assembly. The lifting wire is also preferably coated with an insulating material.

Abstract: A slider lifter for a disc drive is disclosed which utilizes an element of a shape memory alloy to lift multiple transducer heads away from the surfaces of a plurality of stacked discs. The slider lifter includes a support post and a pair of opposing combs carried by the post. The combs are adapted to move in opposite directions between first and second relative positions. In one of the relative positions, the combs engage the flexures to physically lift the transducers carried by the flexures from the surfaces of their associated discs. A biasing mechanism cooperates with shape memory alloy having martensitic and austenitic phase conditions to move the combs back and forth between the first and second positions. When the shape memory element is in a first phase condition, the biasing means forces the combs to their first relative position and when the shape memory alloy element is in the second phase condition, the combs are held in their second relative position.

Abstract: A shape memory metal actuator latch is provided adjacent to a rotating disc within a data storage device for automatically locking the carriage arm in its storage position when power is removed from the drive. The carriage arm is provided with a pin or casting protrusion which normally slides against or past a flexible arm mounted adjacent the carriage arm. A shape memory metal wire is attached to the flexible arm adjacent its hinged point of rotation, i.e. adjacent a point at which the arm flexes under pressure. When the disc drive is operational, the shape memory wire has power applied thereto, heating the wire past its transformation point and causing a change in phase. The resulting force applied to the arm deforms the arm around the hinge point so that the pin on the carriage arm is freed from engagement with the locking arm.

Abstract: There is disclosed a low loss circuit breaker including a housing, two exterior contacts, a pivotable arm, a means for biasing, a bifurcated member and a shape memory alloy element. The pivotable arm has a latching portion and a contact portion with the contact portion in electrical contact with one of the exterior contacts. The means for biasing exerts a biasing force with respect to the pivotable arm. The bifurcated member has a contact arm in touching relationship with the contact portion of the pivotable arm and is in electrical contact with the one of the exterior contacts through the contact portion of the pivotable arm. The bifurcated member further has a flexure arm cooperating with the latching portion of the pivotable arm wherein the flexure arm releasably restrains the pivotable arm against the biasing force exerted by the biasing means.

Abstract: A slider lifter including a support structure, a flexure arm and a resilient means cantilevered from the support structure, and a shape memory alloy element operatively connected between the support structure and the resilient means, wherein the shape memory alloy element has a martensitic condition and an austenitic condition. The shape memory alloy element in one of the martensitic and austenitic conditions cooperates with the resilient means to elastically deform the flexure arm from an undeformed position to a deformed position. The shape memory alloy element in the other of the martensitic and austenitic conditions cooperates with the resilient means to both move away from the fexure arm, thereby allowing the flexure arm to return towards its undeformed position. It is most preferred that when the resilient means moves away from the flexure arm, the flexure arm and the resilient means are not in contact. This allows the flexure arm to return to its completely undeformed position.

Abstract: A shape-memory-effect actuator is provided having a shape-memory-alloy spring and a compensator spring. The alloy spring is operatively connected to a concentrically-mounted compensator spring by the use of a protective support housing which surrounds the alloy spring. The actuator includes a shape-memory-alloy spring and a compensator spring that regulates the operating conditions of the shape-memory-alloy spring to a chosen corresponding memory relaxation curve. The memory relaxation curve defines the actuator's operating stress, stroke and life.

Abstract: Disclosed is a shape memory effect actuator. The actuator comprises a biasing means which is normally biased in a first position and a shape memory alloy actuator element cooperatively engaged with the biasing means. The actuator element in a first unactivated condition is biased in the first position by the biasing means. In a second unactivated condition, the actuator element biases and retains the biasing means in a second position. The actuator element in an activated condition biases the biasing means in the second position. Also disclosed is a method of assembling an actuator and a cooperating apparatus and a method of operating the actuator.

Abstract: A self-regulated actuator is disclosed having a shape-memory element which is heated preferably by passing electrical current therethrough and having a reset mechanism including a circuit-breaking mechanism. The shape-memory element provides the force to retract the actuator when heated. The reset mechanism utilizes a spring-biased latch plunger that resets the actuator as soon as it has retracted a specific distance. The reset mechanism also acts as a circuit-breaking mechanism to electrically interrupt current heating the shape-memory element. The reset mechanism provides near-instant reset time and overcomes the longer wait period otherwise associated with the natural cooling of the shape-memory element. The reset mechanism prevents overheating of the shape-memory element and precludes the necessity for additional hardware to interrupt the circuit after actuation is completed.

Abstract: A shape-memory-effect actuator is provided having a shape-memory-alloy spring and a compensator spring. The alloy spring is operatively connected to a concentrically-mounted compensator spring by the use of a protective support housing which surrounds the alloy spring. The actuator includes a shape-memory-alloy spring and a compensator spring that regulates the operating conditions of the shape-memory-alloy spring to a chosen corresponding memory relaxation curve. The memory relaxation curve defines the actuator's operating stress, stroke and life.