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:
Mar. 14, 2000
Filed:
Sep. 25, 1997
Ryuji Otani, Osaka, JP;
Isao Fuwa, Osaka, JP;
Masahiro Ikegami, Osaka, JP;
Noboru Kusano, Osaka, JP;
Toshikazu Hamada, Shiga, JP;
Kyoichiro Nakayama, Shiga, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
A cutting tool is provided which includes a steel metal body and a cemented carbide cutting tip secured to the metal body by a metallic layer. The metallic layer has a high-strength metallic portion and a high-toughness metallic portion. The high-strength metallic portion is made of a metal having a thermal expansion rate between a thermal expansion rate of the metal body and the thermal expansion rate of the cutting tip. The high-toughness metallic portion is located between edge portions of a securing region of the metal body and the cutting tip and has toughness larger than that of the high-strength metallic portion. The cutting tool can decrease the possibility of cracks being generated at the edge portions of the securing region by selecting a thermal expansion rate of the metallic layer so as to decrease the thermal stress caused during the cooling process after welding, and further by positioning a high-toughness metallic layer at the edge portions of the securing region where stress is concentrated and positioning a high-strength metallic layer meeting the strength requirement at the remaining portion of the securing region.