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:
Nov. 12, 1985
Filed:
Apr. 10, 1984
Robert R Baker, Livonia, MI (US);
Richard L Allor, Livonia, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
To induce fracture under test conditions for a tool bit configuration held in a laterally restrained condition, but with freedom to move up and down, a series of members (hardened steel ball bearings) are selected as to size, butted together, and constrained so that such members make tangential point contact with a constrained bit at locations close to the corners of one end surface supported on the members. When a centralized load is imposed on the opposite end surface of the bit, stress forces can be set up on the bit to result in a body bend fracture or an edge chip fracture, depending on how close the point contacts are to a curved sector. Each point contact is located along a radius bisecting a corner sector, the location being spaced from the sector a distance either (a) of at least one-half the sector radius, but within 0.01875-0.0312 inch, to induce edge chip fracture, or (b) of at least the sector radius, but no less than 0.0625 inch, to induce bend strength fracture.