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:
Jul. 09, 1991
Filed:
Dec. 04, 1989
John L Beck, Rochester, MN (US);
Charles A Brown, San Jose, CA (US);
Todd P Fracek, Rochester, MN (US);
Nigel F Misso, Rochester, MN (US);
Leo Volpe, Palo Alto, CA (US);
Herman R Wendt, San Jose, CA (US);
Thomas A Gregory, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The magnetic disk drive chemical breather filter of the present invention affords protection with respect to chemical vapors and gases in addition to trapping particulate pollutants. The chemical filter as described, protects against both organic vapors and inorganic gases. In addition particulate filters are interposed between the chemical filters and both the exterior atmosphere and internal atmosphere. The combined filter is isolated from both external and internal atmosphere by extended length diffusion passages. Both difffusion passages are composed of multiple parallel paths to prevent the blockage of any single path from impairing the functioning of the filter. Chambers formed at each side of the combined filter medium and access thereto by the diffusion passages at the center of one chamber and the periphery of the other enables the length of the air passage through the filter medium to be equal irrespective of the portion of the filter through which the air flow passes. Using an activated carbon fabric chemical filter and coplanar multiple diffusion paths, a low profile, low cost filter assembly is achieved. The use of ultrasonic welding of the parts eliminates connector devices and adhesives as sources of contamination.