Resources Contact Us Home
Web handling apparatus

Image Number 7 for United States Patent #3948425.

A web handling mechanism is described for incrementally feeding a web of stretchable material (e.g., plastic film) to a processing station. The web feed rollers are driven by a motor incorporated in a servo system which electronically controls the feed rate, length of increment, dwell at processing station, etc. Variations in the speed and elasticity of a moving web are accommodated by means of a vacuum box adapted to accumulate a loop of the web material in the box and maintain proper tension on the web as supplied to the feed rollers. A detector in the vacuum box responds to a predetermined length of web accumulated in the box to trip a control circuit which actuates the feed roller motor to move the desired length of web through the processing station and then stop for a preselected interval. The circuit also controls the processing station to synchronize its operation with that of the web feed and the entire sequence is repetitive at high speed. Complete flexibility of operation is provided by the control circuit.

  Recently Added Patents
Methods to fabricate a photoactive substrate suitable for microfabrication
Image scanner and image forming apparatus
Remote management of networked systems using secure modular platform
Process for the preparation of ethylene homopolymers or copolymers in a high-pressure reactor controlled by a model based predictive controller
Inducement of organogenetic tolerance for pancreatic xenotransplant
Electrode structure and its manufacturing method, and semiconductor module
Vending machine
  Randomly Featured Patents
Computer monitor screen
Organic electroluminescence device
Quantization functional device utilizing a resonance tunneling effect and method for producing the same
Rotary wax transfer decorating system
Olefinic hydrocarbon separation process
Methods of forming metal silicide
Process for producing optically active amine
Method of manufacturing multi-channel optical attenuator
Method and circuit for initializing a de-skewing buffer in a clock forwarded system
Polyester surfactant composition employing polyoxyalkylated alkylene diamine