Drilling apparatus and methods
US8463421B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2007 |
| Grant date | Jun 11, 2013 |
| Priority date | — |
| Expiry date | Jan 7, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/165
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The present invention provides a method of drilling a hole in a workpiece in order to control breakthrough of the workpiece comprising the steps of: a) initiating contact between a drill bit of a drill unit and the workpiece; b) operating the drill unit to rotate the drill bit to drill the workpiece; c) during drilling of the workpiece measuring the force, F and torque, T, experienced by the drill bit; d) calculating a variable F′, based on the measured force, F, representing the rate of change of F; e) calculating a variable, T′ based on the measured torque, T, representing the rate of change of T; f) calculating a variable F″ representing the rate of change of F′; g) calculating a variable T″ representing the rate of change of T″; h) detecting the onset of breakout of the workpiece by use of the variables F′, F″, T′ and T″; i) thereby controlling the speed of rotation of the drill bit during breakthrough of the workpiece to control the degree of breakout of the drill bit from the workpiece. A drilling system is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.