Lightweight extendable and retractable pole
US5333422A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1992 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Dec 2, 2012 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04H12/182
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A lightweight extendable and retractable telescopic pole is disclosed comprising a plurality of non-metallic telescoping cylinders with sliding and sealing surfaces between the cylinders, a first plug member on the upper end of the smallest cylinder, and a second plug member on the lower end of the largest cylinder, whereby fluid pressure admitted to the largest cylinder will cause the telescoping cylinders to slide relative to one another causing the pole to extend. An elastomeric member connects the first plug member with one of the intermediate cylinders to urge the cylinders back into a collapsed position when the fluid pressure in the cylinders is vented. Annular elastomer members are provided which seal one cylinder to another when the pole is fully extended and further serve to provide a cushion to prevent damage to the cylinders when the pole is urged back into its retractable position by the elastomeric members and the venting of the pressure. A value mechanism associated with the pole is provided to admit a fluid under pressure to the interior of the telescoping cylinders of the pole while pressurizing a pressure relief port having an opening larger than the inlet port in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.