Rotary drill bit with improved shirttail and seal protection
US5570750A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 20, 1995 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | Apr 20, 2015 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/22
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rotary cone drill bit for forming a borehole having a bit body with an upper end portion adapted for connection to a drill string. A number of angularly-spaced support arms formed to extend from the bit body. Each support arm has an inside surface with a spindle connected thereto and an outer shirttail surface. A number of cutter cones equal to the number of support arms are rotatably mounted on respective spindles. Each of the cutter cones includes an internal cylindrical cavity for receiving the respective spindle. A gap with a generally cylindrical portion is formed between the spindle and the cavity with a seal element disposed within the gap. The gap has an opening contiguous with the bottom edge of the shirttail surface and extending outwardly from the spindle. A shirttail ring is disposed on the exterior of each spindle between the cutter cone and the inside surface of the respective support arm with a portion of the shirttail ring extending from the respective shirttail surface. A seal ring may be disposed on the exterior of the spindle adjacent to the shirttail ring. The seal ring cooperates with the sealing element to form a fluid barrier between the spindle and the cav…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.