Barrier
US6244324A · kind A · utility
17Cited by
12References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1999 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Sep 27, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB61D17/20
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A barrier extendable and retractable beneficially in response to a changing environment of use, is disclosed. In use, the barrier is attached at its ends to support surfaces. An extension and retraction mechanism for the barrier beneficially exerts substantially constant force regardless of the barrier extent. In a preferred embodiment, a ball screw, an axially movable ball screw nut, and gas springs are used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.