Patent ID: 6915676
Filing Date: 2005-07-12
Classification: B21D,B21K,G11B,H05K

Abstract:
1. A method of forming a protruded shaft for an electronic memory device equipped with an approximately dish-shaped metal base on which a mechanism such as a head actuator or a drive motor for supporting and rotating an information storage medium is arranged and the base being provided with the protruded shaft for supporting or positioning the mechanism, and a top cover closing an aperture portion of the base to keep the interior formed between the base and the top cover in an airtight state, comprising the steps of: pressing the metal base by a taper part of a taper-shaped pressing tool from one face side of the metal base placed on a die that is provided with a hole having a predetermined inner diameter; moving wall material of the metal base into the hole of the die by the pressing step; forming a protruded part having a hollow part inside and a closed tip by the pressing step; next, pressing the protruded part with a second flat pressing tool having a diameter greater than an inside diameter of the hollow part at the one face side of the metal base to form a recessed part on the one face side of the base and further moving the wall material into the hole of the die in order to extend the protruded part, a tip face of the second flat pressing tool being formed in a flat or an approximately spherical shape; and next, pressing the protruded part by an extending tool to further move the wall material into the hole of the die for further extending the protruded part to form the protruded shaft; wherein said closed tip of said metal base is airtight.