Apparatus for protecting stretching rollers in synthetic film stretchers
US5191686A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1991 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Feb 13, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C55/06
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Lengthwise stretching machines for thermoplastic synthetic films are equipped with mechanical or opto-electrical devices for detecting a tearing of the film or an accumulation of film on the stretching rollers and for stopping the machine when tearing or accumulation occurs, to protect the stretching rollers. Unallowable loads and possible damage to the roller bearings are avoided by mounting the bearing housings (1, 2) of each roller (3, 4, 5) of a lower roller (7) in the machine frame for cooperation with a force generating device (8) which presses the respective bearing housing (1, 2) toward oppositely located rollers (9, 10, 11) of an upper roller group (12) to an extent permitted by stops (14, 15) rigidly arranged on the machine frame (13). The rollers (3, 4, 5) of the lower group received in the bearing housing (1, 2) can overcome the pressing force of the device (8) to slide in a yielding direction away from the upper rollers, when a roller accumulates film thereon. The rollers should move in the yielding direction so that roller axes remain in parallel to each other. The yielding movement activates a respective mechanically operable electrical limit switch of a plurality of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.