Patent ID: 9440301
Filing Date: 2016-09-13
CPC Classification: B23H

Claim Text:
1. A sinker electric discharge machining apparatus, comprising: a quill to which a tool electrode is attached and a linear motor device configured to generate a linear movement of the quill towards a workpiece, wherein the quill comprises a plate member made of a metal or an alloy, a first reinforcing member fixed to a front surface of the plate member, a second reinforcing member fixed to the front surface of the plate member, a third reinforcing member fixed to a back surface of the plate member and disposed opposite to the first reinforcing member across the plate member, and a fourth reinforcing member fixed to the back surface of the plate member and disposed opposite to the second reinforcing member across the plate member, and the quill has a cross-section that is symmetric in a width direction of the plate member, wherein the first, second, third, and fourth reinforcing members are made of one of carbon fiber reinforced plastic or ceramics, and wherein the linear motor device comprises a first linear motor mover attached to the front surface of the plate member between the first and second reinforcing members, and a second linear motor mover attached to the back surface of the plate member between the third and fourth reinforcing members and disposed opposite to the first linear motor mover across the plate member.