Vacuum and tractor drive for paper web
US5595334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1995 |
| Grant date | Jan 21, 1997 |
| Priority date | — |
| Expiry date | Oct 16, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65H20/22
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
Apparatus for transporting a web of paper having tractor holes along only one margin thereof. The apparatus includes: a tractor drive having a first pair of pulleys and a first belt mounted on the first pair of pulleys, the first belt having a plurality of sprockets for engaging the paper tractor holes; and an auxiliary vacuum drive system for engaging the marginal portion of the web of paper without tractor holes, the auxiliary drive system having (a) a second pair of pulleys and a second belt mounted on the second pair of pulleys, the second belt having a plurality of apertures at equally spaced intervals extending longitudinally of the length of the second belt, the second belt having an upper and lower reach, (b) a device for applying a vacuum to the apertures in the upper reach of the second belt, (c) a device for varying the amount of vacuum applied and (d) a device for driving the upper reach of the second belt at about the same linear velocity as the linear velocity of the tractor drive sprockets, whereby the vacuum can be turned off during constant velocity or deceleration motions of the web, thereby dissipating tolerance build-up between the tractor drive and the auxiliar…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.