Extension jib for a boom
US4828124A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1988 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Oct 5, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66C23/702
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A retractable extension jib for a telescopic boom has frame body rotatably mounted on an end of the boom so as to be rotated about a rotary axis, a horizontal shaft provided at a lower portion of the frame body and rotatably connecting a base portion of the extension jib. A pair of oil hydraulic cylinders are provided between a base portion of the extension jib and an upper portion of the frame body so as to rotate the jib about the horizontal shaft. The hydraulic cylinders are so arranged as to rotate the extension jib from a retracted position to a lower position where a longitudinal axis of the jib is substantially parallel with the rotary axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.