PUNCH Russian patent published in 2004 - IPC

FIELD: perforating or punching apparatus.

SUBSTANCE: punch comprises housing, hollow working member with cutting edge and chamfering on the outer side of the working member, and side port for waste. The outer side of the working member is provided with double straight chamfering, and the inner side has straight chamfering. According to the first version, the angles between the outer and inner chamferings, which form cutting edge, and straight line passing through the cutting edge and parallel to the axis of the punch are equal to 21-27^o. The angle between the second part of the double straight chamfering and the straight line is 4-14^o. According to the second version, double straight chamfering is provided on the inner side of the working member. According to the third version, double straight chamferings are made on the outer and inner sides of the working member. The angles between the parts of the inner and outer chamferings, which form cutting edge, and the straight line are equal to 21-27^o. The angle between the parts of double chamferings adjacent to the outer and inner sides is 8-28^o.

EFFECT: enhanced precision of punching and prolonged service life of the punch.

6 cl, 3 dwg