Stacked actuator arm assembly clamp
View Patent ↗A stacked actuator assembly has symmetrical actuator arms and spacers stacked on a rotatable sleeve. The assembly may have circuit elements or other elements attached on one side of the assembly. The weight of these elements is counter balanced by a screw or pin mounted on the other side of the assembly. The screw passes through the stacked armature arms and spacers to clamp the arms and spacers relative to each other and prevent them from rotating relative to each other. In addition, the spacers may be position registered relative to each other by registration members molded into the spacers. The registration members in adjacent spacers mate with each other to register the spacers relative to each other. The stacked actuator assembly may be assembled on a jig. The jig has a mounting hole or post to receive the sleeve for the stacked actuator assembly, and it has a post to register the arms when they are stacked on the sleeve. It has a spacer registration member to register the first spacer stacked on the sleeve; thereafter, the additional spacers stacked on the assembly register relative to each other. Alternatively, the jig may have a second post to register the position of the spacer that carries the coil of the voice coil motor.
1. In a disc drive having a rotatable disc mounted on a spindle and driven by a spindle motor mounted on a base, a stacked actuator arm assembly rotatably driven to position read/write heads over the disc in the disc drive, said stacked actuator assembly comprising:
an actuator arm and a spacer stacked on a sleeve rotatably mounted on the base;
a load beam for each actuator arm with a proximal end attached to the actuator arm and a distal end supporting a read/write head; and
a flex circuit attached to one side of the actuator arm assembly, the flex circuit providing read/write circuit elements for the read/write heads;
a pin positioned on the opposite side of the stacked assembly from the flex circuit and registering with an aligned hole through the actuator arm and the spacer; the pin providing at least in part a counter balancing weight for the flex circuit.
2. The actuator assembly of claim 1 , wherein the actuator arm and load beam comprises a metallic material.
3. The actuator assembly of claim 1 wherein the actuator arm is substantially-symmetrical about a center line from the axis of the sleeve to the distal end of the actuator arm.
4. The actuator assembly of claim 1 and in addition:
a plurality of actuator arms and one or more spacers are mounted on the sleeve; and
the pin prevents the actuator arms and the one or more spacers from rotating relative to each other.
5. The actuator assembly of claim 4 wherein the sleeve has a flange on one end and threads on the other end and the actuator assembly further comprises:
a spacer between a first and second actuator arm; and
a nut spacer between the second actuator arm and a nut threaded on the sleeve to hold the stacked actuator arm assembly together.
6. The actuator assembly of claim 5 , wherein each of the actuator arms and spacers have a hole through which the pin passes.
7. The actuator assembly of claim 6 , wherein the spacer between the actuator arms has an overmold extension to carry a coil of a voice coil motor that provides the motive force to rotate the actuator arm.
8. The actuator assembly of claim 7 , wherein the overmold extension is shaped to engage an extension on the nut spacer so as to register the nut spacer position relative to the spacer between the actuator arms.
9. A disc drive comprising a plurality of rotatable discs and a stacked actuator assembly operable to move at least one read/write head over each recording surface of the rotatable discs, the actuator assembly comprising:
a plurality of actuator arms, each arm carrying a read/write head;
a sleeve rotatable mounted on the disc drive and carrying the actuator arms in stacked array along the axis of the sleeve;
each of said actuator arms being substantially-symmetrical about a center line from the axis of the sleeve to a distal end of the actuator arm;
one or more spacers also mounted on the sleeve, a spacer being mounted between actuator arms carrying read/write heads for opposite sides of a rotatable disc so that the spacer provides separation between the arms to accommodate the rotatable disc positioned between the arms; and
a screw for clamping the actuator arms and spacers relative to each other and providing a counter weight to balance the weight of elements mounted on the opposite side of the actuator assembly from the screw.
10. The actuator assembly of claim 9 further comprising:
one of said spacers carrying a motive element which provides a motive force to rotate the actuator assembly to move the read/write heads across the recording surfaces of the discs.
11. The actuator assembly of claim 10 , wherein said elements mounted on the opposite of the actuator assembly comprises:
a printed circuit board and a flex circuit providing electrical connection to the read/write heads.
12. The actuator assembly of claim 9 wherein said spacers comprise:
first spacers having a registration extension; and
second spacers alternately stacked along the sleeve with the first spacers and having a registration slot designed to receive registration extensions from adjacent first spacers whereby the first and second spacers are registered relative to each other.
13. The actuator assembly of claim 12 wherein the sleeve has a flange at one end and screw threads at the other end and the assembly further comprises:
a threaded nut for threading onto the end of the sleeve to hold the stacked actuator assembly together; and
a nut spacer between a last armature arm on the sleeve and the threaded nut, the nut spacer position registered relative to the other spacers and having a threaded hole to receive the screw.