The invention relates to an equipment used for
processing inverted beveled edges of flexible sheet and
cut pieces by an
envelope method and a method thereof, which comprises a body, a vacuum chuck, a large arm, a small arm, a lifting arm, a cutter head and a drive control device, wherein, the vacuum chuck is arranged on a
vacuum chamber on the body; the large arm is arranged on the body through guide tracks at the two sides of the body; the small arm is arranged on the large arm; the lifting arm is vertically arranged on the small arm; transmissions are realized by a ball guide screw or a cog belt or a
pinion and rack between the large arm and the body, the small arm and the large arm and the lifting arm and the small arm and a straight feed motion is realized by the guide track between the large arm and the body, the small arm and the large arm and the lifting arm and the small arm; a circular cutter holder is arranged on the lifting arm and a swing arm is arranged on the circular cutter holder; a spindle motor is arranged on the swing arm and the cutter head is arranged on a spindle head of the spindle motor. In the method, a disc shape cutter is used and the
diameter of the disc shape cutter is smaller than the minimum curvature
radius of pieces to be processed; in the process, the spindle motor drives the disc shape cutter to rotate continuously and keeps tangency between a
cutting blade and a curve edge of the pieces to be processed. The invention can carry out operation of linear and arc converse beveled edges automatically and the angle of the beveled edges can be adjusted optionally, thus saving materials.