Supply control rotating stretch wrapping apparatus and process
US4676048A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1986 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | May 20, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65B11/008
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A rotatable film wrapping apparatus for wrapping a load on a conveyor with an overwrap of stretched plastic film web, having a ring-mounted film web pre-stretch mechanism which stretches and dispenses film at a varying speed controlled independently of variations in film tension and speed between the pre-stretch mechanism and the load, and a supply speed control mechanism which varies the supply speed of web from the pre-stretch mechanism as the ring rotates. The supply speed control mechanism is configured as a predetermined model of the load to minimize variation in film elongation and containment as successive load edges intercept film web during wrapping, thereby locking in these characteristics at predetermined levels for film web wrapped across the load side which ends at the edge. The pre-stretch mechanism comprises a downstream roller across which the film is drawn at a speed which varies, an upstream roller engaging the film and linked by gears to the downstream roller so that the upstream roller rotates at a fixed fraction of the downstream roller speed to stretch film between the rollers, and a power pulley or roller which extends to one side of the pre-stretch mechanism…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.