The ODS is a two part eccentric overburden drilling system designed for the simultaneous installation of casings to support unstable ground conditions.
The bit holder is fitted into the hammer in the same way as a conventional button bit would be.The eccentric button bit is locked into the bit holder by means of a double ‘Seloc’ pin arrangement which can be removed when the bit needs either regrinding or replacing.
Bulroc only supply threaded casings but the system can also be used with less expensive welded casings when the casing is required to be left in the hole.
When the ODS system has been drilled to the required depth, the eccentric bit can be closed to its concentric position by pulling up against the casing shoe and counter rotating
180 degrees, and the complete system withdrawn from the casing. If required, it is then possible to drill on into solid rock using a conventional button bit of a diameter equal to the system size.
Bulroc manufactures a range of bit holders, eccentric bits, casing shoes and stabilisers, to accompany our ODS drilling systems.