Nut runner for removing and installing reactor pressure vessel head closure nuts
US5692418A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 1995 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | May 24, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B21/002
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A nut runner tool is used to engage, turn, capture and lift the RPV head closure nuts from the RPV studs. The tool is also used to capture, lift and transport the nuts from the storage tray to the RPV head closure studs. The nut runner system enables a single operator to remove and install head closure nuts quickly and safely. The nut runner is powered by a remotely operated air driver. The reaction torque is transferred safely through the tool into the top of the closure stud. The air driver unthreads the nut, then a nut holding device is actuated, and the nut and tool are lifted from the top of the stud with a hoist attached to a trolley. The nut and tool are moved radially from the stud location to the storage position in the nut rack. When positioned over the storage location, the lowering of the nut into the rack is performed by the hoist, eliminating the need to manhandle the nuts into and out of the storage rack. After lowering the nut into the nut rack, the nut holding device is released and the nut runner is moved to the next location. The reverse of this process reinstalls the nuts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.