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:
Dec. 28, 1982
Filed:
Jun. 25, 1980
Albert C Francis, Bennington, GB;
Aerpat A.G., Zug, CH;
Abstract
A mandrel for a blind rivet is made by first forming a mandrel blank from wire stock in a series of cold heading operations which include forming an enlarged head at one end of an elongate stem, and then scraping material from the peripheral surface of part of the head adjacent to the stem and moving the material in a direction away from the stem so as to leave a core and to form a circumferential flange-like boss from the scraped material. The mandrel blank thus produced is then subjected to a rolling operation in which the mandrel blank is rolled between contoured mandrel-rolling dies and thereby formed into a finished mandrel. In particular, the contours of the rolling dies are such as to form a breaker groove at the junction between the head and stem of the blank and to cause the material of the flange-like boss to flow over the scraped surface of the core of the head and towards the stem and form a skirt peripherally of the core while confining the material of the boss so that it does not flow across the breaker-groove. Pulling grooves are rolled in the mandrel stem and the external surface of the skirt is rolled to a cylindrical shape with, optionally, a peripheral groove therein.