US 4,460,293 A · Mine shaft liner

Abstract

In the mining of minerals from the earth, it is necessary to drill deep bore holes typically between 3000 and 6000 feet in the earth. In order to protect those entering the hole for additional mining operations, after drilling the hole, the hole is lined with a stack of specially constructed lining segments. These segments are formed of either prestressed concrete or steel. The segments are lowered one at a time into the bore hole so as to build up a stack within the hole, thereby lining the hole. The segments are carried to the hole on a transporter and then lowered by the transporter into the hole. Guide cables are threaded through guide conduits provided within the segments so as to maintain the orientation of such segments during the operation. The weight of the segment as it is lowered is supported by fluid, normally the drilling mud, that fills the hole and the transporter until the segment comes into contact with the top of the uppermost segment on the stack of those segments already placed into the hole. Grout is then placed between the lining segments and the inner wall of the bore hole. The grouting process is periodically carried out after every few segments have been placed into the hole. After the lining operation has been completed, the miners can enter the bore hole for other mining operations.

Claims30

Dependent claims

A system for use in transporting and stacking a plurality of large diameter cylindrical segments, each of the cylindrical segments having a plurality of radially extending openings at a location near its base, said system comprising:

a mandrel;
a plurality of retractable engagement arms, said arms being elongated and radially extending from a lower end of said mandrel;
each of said arms including an elongated housing attached to said mandrel and a slidable member arranged within said housing for longitudinal axial movement therein;
means for causing each of said slidable members to project in a radial direction so as to extend into a corresponding radial opening in a segment for supporting such segment to be transported and added to a stack;
means for retaining the weight of the segment being added to the stack on said system before the segment is in contact with the stack;
retraction means for causing said slidable members to be radially retracted from the openings in the segment in response to the transfer of the weight of said segment to the stack, said retraction means including gusset means coupled to said slidable members for retracting said slidable members from such radial openings in a cylindrical segment;
and means for preventing retraction of said slidable members until the weight of the segment has been transferred from said system to the stack, said means for preventing retraction acting between said elongated housings and said slidable members and positioned to prevent retraction until direct contact of the stack therewith.

4 more elements

A system for use in transporting and stacking a plurality of large diameter cylindrical segments, said system comprising:

a mandrel;
a plurality of retractable engagement arms radially extending from a lower end of said mandrel;
each of said arms includes an elongated housing attached to said mandrel and a slidable member arranged for longitudinal axial movement within said housing;
means for causing each of said slidable members to project into engagement with a segment to be transported and added to a stack of segments;
means for causing said slidable members to be retracted from engagement with the segment in response to the transfer of the weight of said segment to the stack;
said means for retracting said slidable members includes a plurality of gussets;
each of said gussets being coupled between said mandrel and one of said slidable members of said arms;
each of said slidable members has a pin member coupled thereto;
said pin member is arranged in engagement with a corresponding one of said gussets;
and, each of said gussets including means for causing the respective said pin to retract the corresponding said slidable member when said mandrel moves in a downward direction, and means for preventing retraction of both said slidable members until the weight of the segment has been transferred from said system to the stack, said means for preventing retraction acting between said elongated housings and said slidable members and positioned to prevent retraction until direct contact of the stack therewith.

7 more elements

A method for lining a bore hole with a stack of cylindrical lining segments wherein the system or carrying out the lining operation includes a plurality of cylindrical lining segments, each of the segments having a plurality of radially extending openings at a location near its base and a plurality of longitudinally extending openings that form conduits through the segment, the provision of a substantial quantity of fluid within the hole during a lining operation, and a transporting mechanism for lifting each of the segments one at a time from a location adjacent to the hole and lowering the segment into the hole, said procedure comprising the steps of:

substantially filling the hole to be lined with fluid;
lifting the segments for forming the hole liner one at a time from a location adjacent to the hole and lowering such segment into the hole;
supporting the weight of the segment being lowered into the hole by the fluid within the hole and the transporting mechanism;
retaining the segment being lowered into the hole on the transporting mechanism by radial arms of the transporting mechanism projecting into the radial openings in the segment;
and retaining the arms of the transporting mechanism in contact with the segment and withdrawing the retaining arms from the radial openings in response to the transfer of the weight of said segment to the stack of segments already in the hole.

2 more elements

Dependencies are inferred from the claim text.

Mine shaft liner

Life of this patent

Mine shaft liner

Life of this patent

Abstract

Claims30