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
Servo write assembly
Methods and apparatus for dynamic identification (ID) assignment in wireless networks
Low-complexity motion vector prediction systems and methods
Phase locking loop
Method of treating lung cancer
Gangable electrical box and leveling assembly
Plasmon generator includes three metal layers for thermally-assisted magnetic recording
  Randomly Featured Patents
Substituted ureas and thioureas and pharmaceutical compositions thereof
Low dielectric constant porous materials having improved mechanical strength
Power supply device and lighting equipment provided with power supply device
Neisseria meningitidis serogroup B glycoconjugates and methods of producing the same
Acoustooptic mode-locker frequency doubler
Dual composition bed liner
Semiconductor device
Polymerization process
Method for the preparation of cis-nonen-6-yl chloride
Esterification catalysts