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:
Apr. 12, 1994
Filed:
Sep. 14, 1992
Roger B Johnston, Lafayette, CA (US);
Other;
Abstract
A fixture for measuring runout in firearm cartridges, casings and bullets is provided. The fixture holds the cartridge at the tip and forward of the rim for rotation. A self centering tip bearing holds the tip of the cartridge, casing or bullet for rotation about an axis of rotation. The exterior surface of the cartridge, casing or bullet is supported in a V-shaped knife edge bearing. The distance from the knife edge bearing to the tip bearing is adjustable to accommodate various cartridge sizes. Interchangeable tip bearing tools are provided for rotatably holding bullets and casings, and for locating areas of variation in the thickness of the casing wall. The thickness indicating tool has a flat surface offset from the cartridge axis, which rests against the curved interior surface of a casing, forming a chord which supports the interior surface at two points. The gauge arm, placed on the outside of the casing between the two points, can then measure the relative thickness of the casing wall.