Mobile lift crane with variable position counterweight
US7967158B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2008 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Feb 24, 2028 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66C23/76
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A mobile lift crane includes a carbody, a rotating bed, a boom, a moveable counterweight unit, at least one linear actuation device and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit. In one method of operation, the counterweight is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody. One embodiment includes a counterweight movement structure having a rectangular rack with at least first and third pinion gears engaged with teeth on one side and second and fourth pinion gears engaged with teeth on the opposing side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.