Earth boring apparatus with multiple welds
US4273159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1978 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | Mar 16, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12979
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A box tool joint member of generally tubular configuration is adapted for securement by welding to one end of a steel tube to form a drill pipe. The box tool joint member comprises a body having a cylindrical outer periphery, an internally threaded socket at one end of the body, and a weld neck of smaller outer diameter than the body adjacent to the other end of the body. A tapered transition piece connecting the neck with the adjacent end of the body provides an elevator shoulder. A correlative pin tool joint member is welded to the opposite end of the tube to complete the drill pipe. The box tool joint member has an annular band of hard facing over the outer periphery of the transition piece and extending down over the adjacent part of the weld neck and up around the adjacent part of the body. The hard facing is corrosion resistant and has a smooth finished surface. Underneath the hard facing and extending beyond both ends of the hard facing is an annular butter layer of non-hardenable steel. The tool joint member is hardened and tempered after the butter layer is welded into a body groove and before the hard facing is welded on .The butter layer is grooved before the hard facing…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.