Mine roof anchor assembly having an expansion shell assembly with a friction reducing means
US5076733A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 4, 1990 |
| Grant date | Dec 31, 1991 |
| Priority date | — |
| Expiry date | May 4, 2010 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B2200/79
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A mechanical expansion shell assembly has an expansion shell with a plurality of leaves and a plug with a plurality of sloped surfaces. The inner surfaces of the leaves are positioned in overlying relation with the sloped surfaces of the plug. A friction reducing material is positioned between the overlying surfaces and is arranged to reduce the torque applied to the roof bolt connected to the expansion shell assembly to obtain a preselected lateral force on the expansion shell leaves. In another embodiment, a friction reducing material is positioned between a nut threaded on the roof bolt and the underside of the expansion shell ring portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.