Handling: hand and hoist-line implements – Grapple – Expanding
Patent
1984-03-21
1987-04-21
Schmidt, Frederick R.
Handling: hand and hoist-line implements
Grapple
Expanding
269 481, B66C 144
Patent
active
046591265
ABSTRACT:
A tool inserted within a circular duct is adapted to securely engage the inner surface of the duct to facilitate drawing the duct through a conduit. The tool includes a screw inserted within a hollow tube-like member open at a first end and having a threaded inner surface along the length thereof for engaging the screw. A second, closed end of the tube-like member includes an expanded end portion. Positioned on the screw adjacent the first end of the tube-like member is a nut. Located along the length on the outside of the tube-like member are a plurality of alternately arranged rigid cylindrical spacers and compressible tubular sleeves. Displacement of the nut along the screw toward the hollow tube-like member causes the nut to abut and displace an immediately adjacent cylindrical spacer. Further rotation of the nut produces an abutting linear arrangement of the alternating cylindrical spacers and tubular sleeves causing the longitudinal compression of each of the tubular sleeves. In response to this longitudinal compression, the tubular sleeves expand radially outward and firmly engage the inner surface of the duct. The free end of the screw is provided with a link for attaching the tool to a cable for drawing the duct lengthwise through the conduit. After the duct is drawn through and positioned within the conduit, the rotation of the nut is reversed in relieving the compressive force upon the tubular sleeves permitting the tool to be easily removed from the duct.
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Armbruster George E.
Breck Steven E.
Illinois Bell Telephone Company
Schad Steven P.
Schmidt Frederick R.
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