Rock bit and method of manufacture
US4187743A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 21, 1978 |
| Grant date | Feb 12, 1980 |
| Priority date | — |
| Expiry date | Apr 21, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23P15/28
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
This technique for manufacturing a rotary rock bit involves forming a rock bit leg segment having an upper pin end and a lower shirttail end including a socket having a semi-cylindrical faying surface transverse to the axis of the rock bit being formed. A separately formed journal insert includes a journal pin for mounting a rock bit cutter cone and a shirttail portion transverse to the axis of the journal pin. The insert has a semi-cylindrical faying surface on the shirttail portion coaxial with the journal pin. The insert is fitted into the rock bit leg segment with the semi-cylindrical faying surface on the insert mated with the semi-cylindrical socket surface on the bit leg segment. The semi-cylindrical faying surfaces are then electron beam welded. A cutter cone is assembled on the journal pin and three such rock bit leg assemblies are welded together to form a rock bit which is completed with conventional machining operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.