Method for stretching and folding extension jib in wheeled type crane
US4595108A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1983 |
| Grant date | Jun 17, 1986 |
| Priority date | — |
| Expiry date | Jan 24, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T403/32008
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
An apparatus for stretching and folding an extension jib in a wheeled type crane including a telescopic boom, and a suspension-rod-supported compression column type extension jib to be supported in a flat posture at the fore end of the boom in stretched state through right and left jib foot portions rotatably engaged with horizontal boom point pins extending transversely of the boom at the fore end thereof, the method including the steps of (a) providing on opposite sides of the extension jib right and left jib foot portions disengageably engageable with the boom point pins, one of the jib foot portions being rotatable relative to the boom about an axis extending in the axial direction of the jib; (b) stretching the jib from a folded position in which the top and bottom sides of the jib are disposed in an upright posture along one side of the boom, by engaging the one jib foot portion with the boom point pin on the folding side and turning the boom into an inclined position from a horizontal position, rotating the jib around the axis of the boom point pin into a vertically suspended position; (c) turning the jib in the vertically suspended position through a predetermined angle abo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.