Jib stretching and folding device
US4953724A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1989 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Jun 29, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66C23/702
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
In a crane capable of folding a strut type jib along a vertical side surface of a boom and also capable of stretching the jib from such a folded condition in a so-called twisting fashion, a jib stretching and folding device includes a twist shaft for jib stretching and folding operation located below a lower member of the jib under the jib folded condition, so as to fold the jib at an upper position aside the boom. Furthermore, the twist shaft is movable toward and away from the forward end of the boom, so as to fold the jib at a position shifted to the base end of the boom. The advance condition of the twist shaft to the forward end of the boom can be fixed so as to prevent movement of the jib to the forward end of the boom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.