Brake crawler for elevator-type hard disk drives
A brake crawler for an elevator-type hard disk drive generally includes a first and second set of clamp arms vertically arranged, each of the first and second sets of clamp arms being capable of exerting a clamping force on a shaft or slider via activation or deactivation of an actuator element associated with each set of clamp arms. The brake crawler further includes an actuator element disposed between the first and second set of clamp arms which allows for movement of the first set of clamp arms away from the second set of clamp arms upon a change in state of the actuator element. Via a specific sequence of activating and deactivating various of the actuator elements associated with the brake crawler, the brake crawler is capable of inch worm-type movement up and down the shaft.
1. A brake crawler assembly configured for vertically moving an arm assembly along a slider shaft in a hard disk drive, comprising:
a first set of clamp arms comprising:
a first base portion including a recess within which is disposed a first actuator element; and
a first clamp arm extending from one end of the first base portion and a second clamp arm extending from a second end of the first base portion in the same direction as the first clamp arm, an open area provided between the first and second clamp arms;
a second set of clamp arms positioned below the first set of clamp arms, the second set of clamp arms comprising:
a second base portion including a recess within which is disposed a second actuator element; and
a first clamp arm extending from one end of the second base portion and a second clamp arm extending from a second end of the second base portion in the same direction as the first clamp arm of the second set of clamp arms, an open area provided between the first and second clamp arm of the second set of clamp arms; and
a third actuator element disposed between the first base portion of the first set of clamp arms and the second base portion of the second set of clamp arms.
2. The brake crawler assembly of claim 1 , wherein each of the first actuator element, the second actuator element and the third actuator element is a piezoelectric element.
3. The brake crawler assembly of claim 2 , wherein the first piezoelectric element and the second piezoelectric element are configured to expand at least in a direction towards the ends of the first and second base portions, respectively, when activated, such expansion causing terminal ends of the first clamp arms and the second clamp arms to move closer together and provide a clamp force against an object located in the open area of the first set of clamp arms and the second set of clamp arms.
4. The brake crawler assembly of claim 2 , wherein the third piezoelectric element is configured to expand at least in a direction towards the first set of clamp arms and the second set of clamp arms when activated, such expansion causing the distance between terminal ends of the first and second clamp arms of the first set of clamp arms and terminal ends of the first and second clamp arms of the second set of clamp arms to change.
5. The brake crawler assembly of claim 2 , wherein the first piezoelectric element and the second piezoelectric element have different expansion profiles when activated.
6. The brake crawler assembly of claim 1 , wherein the brake crawler assembly is monolithic.
7. The brake crawler assembly of claim 2 , wherein the first clamp arm and the second clamp arm of each of the first set of clamp arms and the second set of clamp arms are hingedly connected with the first and second base portions, respectively.
8. The brake crawler assembly of claim 7 , wherein the first clamp arm and second clamp arm of each of the first set of clamp arms and the second set of clamp arms pivot about the hinged connection upon activation of the first and second piezoelectric element, respectively.
9. The brake crawler assembly of claim 7 , wherein the hinged connections are biased towards a non-clamp position such that when the first and second piezoelectric elements are deactivated, the hinged connections return the first and second set of clamp arms to the non-clamp position.
10. The brake crawler assembly of claim 2 , wherein the first clamp arm and the second clamp arm of each of the first set of clamp arms and the second set of clamp arms are spring mounted with the first and second base portions, respectively.
11. The brake crawler assembly of claim 10 , wherein the spring mounts recoil to pull the first clamp arm and the second clamp arm of each of the first set of clamp arms and the second set of clamp arms back to a non-clamp position when the first and second piezoelectric elements are deactivated.
12. The brake crawler assembly of claim 10 , wherein the first clamp arm and the second clamp arm of each of the first set of clamp arms and the second set of clamp arms are hingedly connected with the first and second base portions, respectively.
13. The brake crawler assembly of claim 10 , wherein the first clamp arm and the second clamp arm of each of the first set of clamp arms and the second set of clamp arms are not hingedly connected with the first and second base portions, respectively.
14. The brake crawler assembly of claim 2 , wherein the first set of clamp arms and the second set of clamp arms are hingedly connected.
15. The brake crawler assembly of claim 14 , wherein the hinged connection is biased towards a separated position such that when the third piezoelectric element is deactivated, the hinged connection returns the first set of clamp arms and the second set of clamp arms to the separated position.
16. A method of moving an arm assembly of a hard disk drive vertically along a slider shaft of a hard disk drive, the method comprising:
providing the arm assembly through which the slider shaft passes such that the arm assembly is capable of moving vertically along the slider shaft, the arm assembly having a brake crawler incorporated therein, the brake crawler comprising:
a first set of clamp arms comprising:
a first base portion including a recess within which is disposed a first actuator element; and
a first clamp arm extending from one end of the first base portion and a second arm extending from a second end of the first base portion in the same direction as the first clamp arm, the slider shaft being disposed between the first clamp arm and the second clamp arm;
a second set of clamp arms positioned below the first set of clamp arms, the second set of clamp arms comprising:
a second base portion including a recess within which is disposed a second actuator element; and
a first clamp arm extending from one end of the second base portion and a second clamp arm extending from a second end of the second base portion in the same direction as the first clamp arm of the second set of clamp arms, the slider shaft being disposed between the first clamp arm and the second clamp arm of the second set of clamp arms; and
a third actuator element disposed between the first and second base portions;
activating the first actuator element such that the first set of clamp arms exerts a clamp force against the slider shaft;
deactivating the third actuator element such that terminal ends of the first and second clamp arms of the second set of clamp arms moves away from terminal ends of the first and second clamp arms of the first set of clamp arms;
activating the second actuator element such that the second set of clamp arms exerts a clamp force against the slider shaft;
deactivating the first actuator element such that the first set of clamp arms releases the slider shaft; and
activating the third actuator element such that the terminal ends of the first and second clamp arms of the first set of clamp arms moves closer to the terminal ends of the first and second clamp arms of the second set of clamp arms.
17. The method of claim 16 , wherein the first set of clamp arms and the second set of clamp arms are hingedly connected.
18. The method of claim 17 , wherein the hinged connection is biased towards a separated position such that when the third actuator element is deactivated, the hinged connection returns the first set of clamp arms and the second set of clamp arms to the separated position.
19. A method of moving an arm assembly of a hard disk drive vertically along a slider shaft of a hard disk drive, the method comprising:
providing the arm assembly through which the slider shaft passes such that the arm assembly is capable of moving vertically along the slider shaft, the arm assembly having a brake crawler incorporated therein, the brake crawler comprising:
a first set of clamp arms comprising:
a first base portion including a recess within which is disposed a first actuator element; and
a first clamp arm extending from one end of the first base portion and a second clamp arm extending from a second end of the first base portion in the same direction as the first clamp arm, the slider shaft being disposed between the first clamp arm and the second clamp arm;
a second set of clamp arms positioned below the first set of clamp arms, the second set of clamp arms comprising:
a second base portion including a recess within which is disposed a second actuator element; and
a first clamp arm extending from one end of the second base portion and a second clamp arm extending from a second end of the second base portion in the same direction as the first clamp arm of the second set of clamp arms, the slider shaft being disposed between the first clamp arm and the second clamp arm of the second set of clamp arms; and
a third actuator element disposed between the first and second base portions;
activating the first actuator element such that the first set of clamp arms exerts a clamp force against the slider shaft;
activating the third actuator element such that terminal ends of the first and second clamp arms of the second set of clamp arms moves away from terminal ends of the first and second clamp arms of the first set of clamp arms;
activating the second actuator element such that the second set of clamp arms exerts a clamp force against the slider shaft;
deactivating the first actuator element such that the first set of clamp arms releases the slider shaft; and
deactivating the third actuator element such that the terminal ends of the first and second clamp arms of the first set of clamp arms moves closer to the terminal ends of the first and second clamp arms of the second set of clamp arms.
20. The method of claim 19 , wherein the first set of clamp arms and the second set of clamp arms are spring mounted with each other and the spring mount recoils to pull together the first set of clamp arms and the second set of clamp arms when the third actuator element is deactivated.