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:
Jan. 29, 1991
Filed:
Jun. 30, 1989
Amarjit S Brar, Edina, MN (US);
Jagdish P Sharma, Bloomington, MN (US);
Magnetic Peripherals Inc., Minnetonka, MN (US);
Abstract
A method for determining the micro impact energy capacity of a disk drive's ceramic heads and its thin film disks. The impact energy capacity of disk drive heads (typically composed of ceramic materials) and disks (higher capacity disks use thin film media) provides a measure of quality and durability of the heads and media. The method includes dropping an indentor of a known weight on a sample surface, measuring the identation surface area and length, increasing the weight and repeating the previous steps at different areas o the surface until surface cracking occurs. The various measurements are plotted to produce a stress-strain curve, the area of which comprises the micro energy capacity of the surface.