Tubular lost borehole closure

A lost borehole closure, especially for injection of a suitable media, such as for instance plastic, into boreholes for consolidation of rock, comprising a tube having a leading and a trailing end, each provided with an outer screw thread;

• a one-way valve having a housing threadingly connected to the leading of said tube;
• extension means for placing said tube at a selected distance from the outer end of said borehole and comprising a plurality of tube sections and connecting bushings for connecting said tube sections with different restraining forces respectively to each other and to said trailing end of said tube;
• holding means and sealing means surrounding said tube rearwardly of said housing, said holding means and said sealing means being axially compressible and radially expansible by turning said tube, said holding means comprising a spreading cone having an inner screw thread threadingly engaged with said outer screw thread at the leading end of said tube and abutting with one end against said housing and spreadable means having an inner conical surface, a portion of said spreading cone opposite said one end thereof engaging with its outer surface said inner conical surface of said spreadable means, said sealing means comprising a sleeve of rubber adjacent said spreadable means and including slide disks respectively sandwiched between one end of said spreadable means and the facing end of said sealing means and the opposite end of said sealing means and an end face of that connecting bushing which connects said trailing end of said tube with a tube section adjacent thereto;
• and a screw nipple connected to the outer end of said one tube section for turning said tube sections and said tube to thereby axially compress and radially expand said sealing and said holding means.

A lost borehole closure, especially for injection of suitable media, such as for instance plastic, into boreholes for consolidation of rock, comprising a tube having a leading and a trailing end, each provided with an outer screw thread;

• a one-way valve having a housing threadingly connected to the leading end of said tube;
• holding means and sealing means surrounding said tube rearwardly of said housing, said holding means and sealing means being axially compressible and radially expansible by turning said tube;
• extension means for placing said tube at any selected distance from the outer end of the borehole and comprising a plurality of tube sections and connecting bushings for connecting said tube sections with different restraining forces respectively to each other and to said trailing end of said tube;
• a plurality of sealing elements of different construction in said connecting bushing between facing ends of said tube sections and between said trailing end of said tube and said facing end of the tube section adjacent thereto, the sealing element between said trailing end of said tube and the facing end of the tube section adjacent thereto being an O-ring and the sealing elements between facing ends of said tube sections being sealing disks providing a greater friction than said O-ring;
• and a screw nipple connected to the outer end of said one tube section for turning said tube sections and said tube to thereby axially compress and radially expand said sealing means and said holding means.

A lost borehole closure, especially for injection of suitable media, such as for instance plastic, into boreholes for consolidation of rock, comprising a tube having a leading end and a trailing end, each provided with an outer screw thread;

• a one-way valve having a housing threadingly connected to the leading end of said tube;
• holding means and sealing means surrounding said tube rearwardly of said housing, said holding means and said sealing means being axially compressible and radially expansible by turning said tube, said sealing means comprising a sleeve of rubber of a shore hardness of 40-80 and sheet metal shells surrounding opposite ends of said sleeve;
• extension means for placing said tube at any selected distance from the outer end of the borehole and comprising a plurality of tube sections and connecting bushings for connecting said tube sections with different restraining forces respectively to each other and to said trailing end of said tube, with one of said tube sections projecting beyond the outer end of the borehole;
• and a screw nipple connected to the outer end of said one tube section for turning said tube sections and said tube to thereby axially compress and radially expand said sealing means and said holding means.