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:
May. 03, 1988
Filed:
Jun. 23, 1986
James L Wales, Caversham, GB;
Robert A Woolley, Uxbridge, GB;
EMI Limited, Hayes, GB;
Abstract
Transverse bowing of a plastics web coated with a magnetic thin metal film is substantially eliminated by laterally stretching the coated web such that the lateral stress applied to the metal film exceeds the tensile strength of the film and the lateral stress applied to the plastics web lies within the yield point of the plastics material. The coated web is stretched by passage over a curved roll adjusted to provide a lateral strain of at least 1% and typically 1.8% in the web, and such stretching may cause a pattern of interlaced micro-cracks to occur in the metal film. Recording tapes slit from such stretched webs exhibit negligible cupping, and the pressure of micro-cracks has no adverse effect on recording performance or wear.