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:
Aug. 21, 2001
Filed:
May. 03, 1999
Ji-Guang Zhang, Cerritos, CA (US);
Khoon Cheng Lim, Los Angeses, CA (US);
Macro Energy-Tech, Inc., Redondo Beach, CA (US);
Abstract
The slitting assembly includes a grinding wheel with a wide flat grinding face for first cutting a multilayer sheet of soft and compressible, electronic device material, such as lithium-ion polymer material for a uni-cell battery, to a first depth and includes a cutting wheel with a blade-like edge for completing the slit by cutting through uncut layers of the multilayer sheet. The grinding face has a width of at least the thickness of the multilayer sheet, and in practice, the depth of the cut is preferably one half the sheet thickness, which in a uni-cell battery sheet is midway through a separator layer. The grinding wheel is positioned to apply cutting forces to the multilayer sheet in a direction that is substantially parallel to the feed direction to control the application of compressive forces that may compress the soft sheet material and if uncontrolled, may create short circuits between electrically conductive layers. Further, the unique combination of cut width and cut depth function to prevent shorting of the electrically conductive sheet layers during the second cutting by the blade-like edge of the cutting wheel which is completed by resiliently forcing the edge through the final layers of the sheet. In another preferred embodiment, a single, multistage or stepped grinding stone is utilized in the slitting assembly to concurrently grind, and provide lateral support to maintain separation of, multiple layers of a multilayer sheet of electronic device material such as material for a bi-cell lithium ion polymer battery. Alternatively, a single, sloped or angled grinding wheel may be included to provide two grinding faces that establish a grinding angle sufficient to enable concurrent grinding of multiple layers of soft electronic material without compressing or pinching the layers into a shorting contact. Furthermore, a more symmetric cutting or slitting can be made by a slitting assembly having two grinding wheels to concurrently slit a soft, multilayered sheet from opposing sides of the sheet.