Charles I Herman

US Patent:

42429153, Jan 6, 1981

Filed:

Aug 16, 1979

Appl. No.:

6/066999

Inventors:

Charles Herman - Pompano Beach FL

Assignee:

The United States of America as represented by the Secretary of the
Interior - Washington DC

International Classification:

G01N 3324

US Classification:

73784

Abstract:

An extensometer anchor for use in a mine borehole. The anchor has an anchor body that, when in an operative mode, is placed in the borehole. Extending at least partially around the outer surface of the body are one or more grooves whose major plane is generally perpendicular to the length of the borehole. Seated within each groove is a compressible resilient anchor member, like a ring, which remains loaded by a retaining device, such as a cotter pin, extending through it. Upon being pulled from outside of the borehole, the retaining device unloads the compressed anchor which then moves to expand outwardly in the borehole and firmly anchor the anchor body and attached extensometer within the mine borehole.