Rotary drill bit with improved cutter and seal protection
US5452771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1994 |
| Grant date | Sep 26, 1995 |
| Priority date | — |
| Expiry date | Mar 31, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/50
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rotary cone drill bit for forming a borehole having a body with an underside and an upper end portion adapted for connection to a drill string. The drill bit rotates around a central axis of the body. A number of angularly-spaced arms are integrally formed with the body and depend therefrom. Each arm has an inside surface with a spindle connected thereto and an outer shirttail surface. Each spindle projects generally downwardly and inwardly with respect to the central axis, has a generally cylindrical upper end portion connected to the inside surface, and has an inner sealing surface within the upper end portion. A number of rotary cone cutters equal to the number of arms are each mounted on one of the spindles. Each of the cutters includes an internal generally cylindrical wall defining a cavity for receiving the spindle, a gap with a generally cylindrical first portion defined between the spindle and cavity wall, an outer sealing surface in the cavity wall concentric with the inner sealing surface, and a seal element spanning the gap and sealing between the inner and outer sealing surfaces. The gap has an opening contiguous with and directed outwardly from the shirttail surface…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.