The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 2002
Filed:
Jun. 29, 1999
Dennis A. Boismier, Shorewood, MN (US);
Jason R. Heffelfinger, Hutchinson, MN (US);
Hutchinson Technology Incorporated, Hutchinson, MN (US);
Abstract
A method and apparatus for actively controlling the gram load on a disk drive suspension assembly and to a disk drive using the present disk drive suspension assembly. The gram load can be actively changed by changing the applied voltage to one or more multi-layer piezoelectric actuators attached to the head suspension. The active gram control system allows the gram load to be changed on a non-permanent basis and to control the gram load to a much finer scale than can be accomplished using conventional techniques. The disk drive suspension that uses a piezoelectric actuator having two or more layers. Each layer of the multi-layer piezoelectric actuator is poled in such a fashion that when energized, some piezoelectric layers contract while others expand, resulting in a curling motion. By attaching the first and second ends of the piezoelectric actuator to discrete locations on the load beam, while the portion of the piezoelectric actuator between the first and second ends remains unattached to the load beam, a force non-parallel to the load beam can be applied to the head suspension.