Matsushita Electric Works, Ltd.

Toshikazu Hamada

Isao Fuwa

Ryuji Otani

Masahiro Ikegami

Noboru Kusano

Kyoichiro Nakayama

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.

Cutting tool and method for making the same

An outer cutter assembly for an electric shaver comprises an outer shearing foil, a base frame on which the outer shearing foil is mounted with its peripheral edge supported thereby. The outer shearing foil is formed with a plurality of hair entrance peripheral perforations arranged along the periphery thereof to be in hair shearing relation with an inner blade. A comb forming member is located between the peripheral edge of the outer shearing foil and the upper end of the base frame to have its lower portion connected to the base frame. The comb forming member is provided at its upper portion with a comb having teeth defining between the adjacent ones thereof slits each being in open communication with each of the peripheral perforations and being located inside thereof to be in alignment with each of a plurality of webs which separates the peripheral perforations from one another. Each tooth of the comb is kept in intimate contacting relation with each of the webs to thereby prevent the occurrence of any gap between the teeth of the comb and the adjacent webs in the peripheral portion of the outer shearing foil. Accordingly, the outer cutter assembly can assure intimate contacting relation between the comb and the outer shearing foil to eliminate the presence of an undesirable gap therebetween, giving rise to an efficient shaving operation without irritatingly pulling hairs of the user.

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Shiga, Japan

Toshikazu Hamada