Apparatus and technique for installing an elongated rod in an earth formation

In the process of installing an elongated rod in an earth formation, the steps of:

• installing in a tunnel in the earth formation, an elongated tubular casing having a longitudinally extending bore therethrough, a cap which is connected to the distal end portion of the casing so as to close the distal end of the bore to the earth formation, but is removable from the casing by relative endwise displacement thereof, and a piston-like insert in the bore which is displaceable relatively endwise of the bore to displace the cap relatively endwise of the casing and then eject into the tunnel from the casing at the distal end of the bore,
• relatively telescopically advancing the rod into the bore of the casing at the proximal end thereof,
• charging a pressurized fluid medium into the bore to displace the insert in the direction of the distal end of the bore and thereby remove the cap from the casing and eject the insert into the tunnel from the distal end of the bore to open the same for the advance of the rod into the tunnel therethrough, and
• relatively advancing the rod into the tunnel from the casing at the distal end of the bore to dismount the rod relatively tandemly ahead of the casing in the tunnel.

Apparatus for installing an elongated rod in an earth formation, comprising:

• an elongated tubular casing having a longitudinally extending bore therethrough,
• means for installing the casing in a tunnel in the earth formation, so that the rod can be relatively advanced telescopically through the length of the casing in the bore thereof, and thence into the tunnel from the casing at the distal end of the bore, to the extent that a portion of the rod is projected into the tunnel relatively tandemly ahead of the casing,
• means for anchoring the rod to the wall of the tunnel at the relatively tandemly projected portion of the rod, and
• means for retracting the casing in the direction of the mouth of the tunnel to uncover the casing from around the remainder of the rod while the rod is anchored to the wall of the tunnel.

An anchoring device for use on the distal end of an elongated rod when the rod is dismounted from an elongated tubular casing in a tunnel in an earth formation, comprising:

• an elongated carrier device securable at one end to the distal end of the rod,
• means on the carrier device defining a laterally outwardly opening recess therein,
• a pair of elongated harpoon-like detents rotatably mounted on opposing sides of the carrier device so as to be retractable relatively into the recess when the carrier device is relatively advanced on the rod telescopically through the length of the casing in the longitudinally extending bore thereof, and
• means for yieldably biasing the detents to reciprocate laterally outwardly of the recess into engagement with the wall of the tunnel when the carrier device is relatively advanced into the tunnel from the casing at the distal end of the bore.

In apparatus for installing an elongated rod in an earth formation,

• an elongated tubular casing for installation in a tunnel in the earth formation,
• said casing having a longitudinally extending bore therethrough,
• a cap which is connected to the distal end portion of the casing so as to close the distal end of the bore, but is removable from the casing by relatively endwise displacement thereof,
• a piston-like insert in the bore which is displaceable relatively endwise thereof to displace the cap relatively endwise of the casing and then eject into the tunnel from the casing at the distal end of the bore, and
• means for charging a pressurized fluid medium into the bore to displace the insert in the direction of the distal end of the bore and thereby remove the cap from the casing and eject the insert into the tunnel from the distal end of the bore to open the same for the advance of the rod into the tunnel therethrough when the rod has been relatively advanced telescopically through the length of the casing in the bore thereof.

For use in apparatus for installing an elongated rod in an earth formation, a casing component comprising:

• an elongated tubular casing for installation in a tunnel in the earth formation,
• said casing having a longitudinally extending bore therethrough,
• a cap which is connected to the distal end portion of the casing so as to close the distal end of the bore, but is removable from the casing by relatively endwise displacement thereof, and
• a piston-like insert in the bore which is displaceable relatively endwise thereof to displace the cap relatively endwise of the casing and then eject into the tunnel from the casing at the distal end of the bore, whereby a pressurized fluid medium can be charged into the bore to displace the insert in the direction of the distal end of the bore and thereby remove the cap from the casing and eject the insert into the tunnel from the distal end of the bore to open the same for the advance of the rod into the tunnel therethrough when the rod has been relatively advanced telescopically through the length of the casing in the bore thereof.