Moisture barrier filter seal for hopper rail car hatches
US5794539A · kind A · utility
6Cited by
30References
22Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | May 12, 1997 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | May 12, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D90/36
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A moisture barrier seal for use on a hopper car hatch opening that does not need to be removed before vacuum unloading of the hopper car due to the use of a grained plastic such as vertically drawn or cast polyethylene which will rupture as soon as the seal is subjected to the pressure differential across the seal created by the application of vacuum to the hopper car. The moisture barrier layer when combined with a filter layer forms a combination moisture barrier and filter seal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.