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:
Oct. 04, 1977
Filed:
Dec. 05, 1975
John A Barber, San Jose, CA (US);
C Norman Dion, San Jose, CA (US);
Richard N James, San Jose, CA (US);
Dysan Corporation, Santa Clara, CA (US);
Abstract
An improved flexible magnetic recording disc assembly comprising an envelope and a flexible recording disc rotatably received in the envelope, the disc having an annular reinforcement member concentrically arranged adjacent the central mounting aperture of the disc. Two embodiments are disclosed: a first having a single annular reinforcement member secured to the spindle side of the flexible disc; and a second having a pair of annular reinforcement members disposed on opposite surfaces of the disc. The reinforcement member has an axial thickness in the range from about 2 to about 7 mils to provide sufficient structural rigidity to resist crinkling and flaring during use; a static and dynamic coefficient of friction not less than about 0.3, and a total electrical resistance measured in the longitudinal axial direction in the range of about 1 ohm to about 50 megohms to facilitate dissipation of static electrical charges which may build up on the recording surfaces of the disc. The reinforcement member is adhered to the flexible disc by means of a cement which is preferably electrically conductive, also to promote static charge dissipation.