| 摘要 |
<p>APPARATUS AND METHOD FOR INSTALLING LINE IN CONDUIT Pull lines are utilized for installing electric wires in electrical conduit between junction boxes by attaching a pull line to the near end of a hollow-core line carrier having its forward end closed by a collapsible bag-like member of highly flexible plastic film or fabric. The bag-like member has a cross-section greater than that of the conduit and is inflatable through the trailing end of the line carrier so to maintain a yieldable continuous contact with the conduit interior wall about the line carrier as the carrier is moved through the conduit in response to a pressure differential created at one end of the conduit. In one form, the line carrier is a tubular sleeve of rigid or shape retaining material to which the pull line to be installed is attached; and, in a second form, it is a roll of the line itself which is disposed within the open end of the bag-like member. In a modification of the first form, the bag-like member is collapsed for storage within the sleeve.</p> |
