Web handling apparatus
US4070951A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1976 |
| Grant date | Jan 31, 1978 |
| Priority date | — |
| Expiry date | Apr 6, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65H20/24
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.