Film perforator
US4928562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1989 |
| Grant date | May 29, 1990 |
| Priority date | — |
| Expiry date | Apr 19, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T83/4635
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Disclosed is a film perforator having a punch unit, a pad roller and a feed roller which are disposed at the upstream side of the punch unit and support a film by nipping it between them, and a sprocket which is disposed at the downstream side of the punch unit and comes into engagement with punch-finished perforations, the sprocket and the feed rollers are connected by a pulley and the line speed of the sprocket is adjsuted to be a little higher than that of the feed rollers so that the film is caused to slip from its nipped position between the feed roller and the pad roller, whereby the film is exerted with backward tension so as to keep its proper flatness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.