The patent describes a flexible shield for protecting excavating activities in a tunnel from roof falls which is made mobile by its drivable underlying support structure. Double acting hydraulic jacks, which are retained upright by pivotal and flexible members in each section of a train of sections comprising the support structure, underpin the flexible shield, and are operable to alternately apply the flexible shield in close proximity to the tunnel roof and maintain it free from engagement with the roof to facilitate its displacement along the tunnel with the support structure. A webbing of interlaced straps which take shape within edge supporting cables form panels corresponding to the sections, and these panels are integrated by nonrigid connections at the jack structures to make a canopy arrangement constituting the flexible shield.

  • Supplemental Notes:
    • Also includes report no. DOCKET/MIN-1982.
  • Corporate Authors:

    Department of the Interior

    1849 C Street, NW
    Washington, DC  United States  20240
  • Authors:
    • Barrett, A L
  • Publication Date: 0

Media Info

  • Pagination: 11 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00094321
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: PAT-APPL-357 737 Patent
  • Files: TRIS
  • Created Date: Mar 29 1976 12:00AM