Web threading system
AssigneeCrown Zellerbach Corporation
InventorImants Reba
Life of this patent
Estimating the term…
Abstract
A system for directing the tail of a web of flexible material to a predetermined location including a wall element having side edges and a web entry end and a web exit end and a Coanda nozzle located at the wall element web entry end to direct a gaseous flow therealong toward the web exit end. Venting means in the form of opposed foil elements extend from the Coanda nozzle toward the wall element side edges for laterally venting portions of the gaseous flow past the side edges to exert lateral forces on the web and spread it as the web is propelled along the wall element.
Claims10
Apparatus for directing a web of flexible material to a predetermined location comprising:
- a wall element having side edges and a web entry end and a web exit end;
- a Coanda nozzle located at the wall element web entry end to direct a gaseous flow therealong toward said web exit end;
- venting means in operative association with said wall element and extending from said Coanda nozzle to a location between the web entry and web exit ends of said wall element for laterally venting portions of said gaseous flow past opposed side edges of the wall element whereby a web will have lateral forces exerted thereupon by said gaseous flow portions to spread and stabilize said web as the web is propelled forward by the remainder of said gaseous flow.
A method of directing a web of flexible material to a predetermined location comprising:
- flowing a pressurized gas through an elongated fluid flow exit defined by a Coanda nozzle so that a gaseous flow is induced thereby along a predetermined path defined by a wall element adjacent to said nozzle;
- operatively engaging said web and the gaseous flow induced by said Coanda nozzle;
- propelling said web along said wall element by entraining said web with said gaseous flow;
- venting portions of said gaseous flow in opposed lateral directions during the step of propelling said web;
- and
- spreading and stabilizing said web during propulsion thereof by entraining the edges of said web with said gaseous flow portions.
Dependencies are inferred from the claim text.