Patent ID: 6032558
Filing Date: 2000-03-07
Classification: B26D,G05B,Y10T

Abstract:
A rotary knife for cutting a plurality of individual sheets in succession from a longitudinally traveling continuous web of material, the rotary knife comprising:a frame;a first tubular rotatable knife cylinder and a second tubular rotatable knife cylinder, each of the tubular knife cylinders having a blade mounted on an outer cylindrical wall of the respective knife cylinder, the blades engaging each other as the tubular knife cylinders rotate to cut the web;a first stationary support shaft located concentrically within the first tubular knife cylinder and fixed to the frame;support bearings located between the first stationary support shaft and the first tubular knife cylinder to rotatably support the first tubular knife cylinder on the first stationary support shaft; andan active tuned mass damping system for the first knife cylinder includinga tuned mass,a spring arm having one end coupled to the tuned mass and another end coupled to the first stationary support shaft,a knife vibration sensor that monitors vibration of the first knife cylinder and generates a signal in response thereto,a tuned mass vibration sensor that monitors vibration of the tuned mass and generates a signal in response thereto,an electronic control unit that inputs the signals from the first knife vibration sensor and the tuned mass vibration sensor and outputs one or more command signals, andan actuator that provides a force on the tuned mass in response to the one or more command signals from the electronic control unit.