Method and apparatus for maintaining proper perforation phasing
US5417638A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1994 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Mar 15, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB31B2160/10
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
In an apparatus for making plastic bags or the like from a continuous film of material comprising a sealing drum having at least one seal bar for imparting transverse seals to the film at regularly spaced intervals and a perforator having a rotatable perforator blade for imparting transverse perforations to the film at regularly spaced intervals, an apparatus and method are disclosed for tracking the positions of each seal and each perforation and comparing the difference between these positions to a desired difference and thereafter adjusting the rate of rotation of the perforator blade until the difference between the positions of each seal and each perforation is equal to the desired difference to thereby maintain a desired spacing between each seal and each perforation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.