| 摘要 |
PROBLEM TO BE SOLVED: To provide a punching device which does not promote abrasion due to invasion of paper powder into a bearing hole during vertical reciprocation of a punch member having a punching blade at a tip part. SOLUTION: A cutting edge end face of the punching blade is structured into a circular shape in cross section and a shape forming wavy irregular parts in the circumferential direction. An upper frame has a bearing member for bearing at least a lower end of a rod shaft and an upper guide face for regulating a front paper face of a sheet to be punched. The bearing member has a sleeve-shaped bearing face for fitting and supporting the rod shaft and a recess-shaped opening which is continuous to the bearing face and whose diameter is larger than a bearing inner diameter. The recess-shaped opening is located at an upper position of the upper guide face downward of the bearing face. The top dead center of the punch member is defined so that the cutting edge end face positioned at the top end is located downward of the bearing face and the cutting edge end face positioned at the bottom end is located upward of the upper guide face. COPYRIGHT: (C)2010,JPO&INPIT
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