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. 08, 1990
Filed:
Sep. 11, 1989
Jonathan M Gregory, So Berwick, ME (US);
GTE Products Corporation, Danvers, MA (US);
Abstract
A method for forming a groove in a glass tube without contacting the glass tube in the groove region. The method includes the steps of rotating the glass tube about its longitudinal axis, heating a localized area of the glass tube where a groove is to be formed sufficiently to soften the glass tube in the localized area, stretching the glass tube along its longitudinal axis by a first distance sufficient to cause a reduction in the diameter of the glass tube in the localized area, and compressing the glass tube along its longitudinal axis by a second distance sufficient to produce a groove in the localized area. The glass tube is rotated during the steps of heating, stretching and compressing the glass tube. Heating is preferably performed by directing the flames from one or more torches at the groove area.