Patent ID: 7381013
Filing Date: 2008-06-03
Classification: E21D

Abstract:
1. An apparatus for post-grouting a rock bolt comprising: an elongate sleeve having first and second ends and being adapted to receive a rock bolt with a first end thereof extending beyond said sleeve first end and a second end thereof extending beyond said sleeve second end; an end fitting attached to said sleeve second end, said end fitting having a central aperture for receiving said rock bolt and one or more group passages communicating the exterior of said end fitting with the interior of said sleeve; and seal means for sealing said one or more said group passages, said seal means being displaceable between open and closed positions; wherein said seal means is biased towards said closed position at which said one or more passages is/are substantially sealed and injection of grout into said end fitting via said passage(s) deflects said seal means to said open position enabling flow of grout through said one or more passages and into said sleeve; and wherein said end fitting comprises: a female component secured to said sleeve second end and defining a concavity facing away from said sleeve, and a male component adapted to be threaded onto said rock bolt second end and to be received within said female component concavity so as to transfer compressive loads between said male and female components, wherein said one or more grout passages is/are defined between said male and female components and said male component is provided with a nut drive surface for threading said male component onto said rock bolt second end to tension said rock bolt.