Process for drilling chamfered holes
US4818834A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1988 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | Mar 21, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/52
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A process for drilling chamfered holes includes the steps of directing noncontact energy onto the outer surface of the part to form a recessed crater-like entrance with chamfered walls and thereafter directing a small diameter wire electrode adjacent the substrate and spark eroding the base without removing material from the chamfered walls so as to produce a combined passage through the part with a chamfered entrance leading to a smaller outlet. In one embodiment the part has a ceramic coating which is initially removed from the part by either focusing a laser beam to a penetration depth which removes the ceramic coating while forming the entrance and in another embodiment the coating is initially removed by imposing a high voltage pulse thereagainst from a spark erosion electrode of electrical discharge machining equipment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.