摘要 |
A cylindrical brush for scrubbing the inside surface of a pipe is made of bristles attached to a springy helix. The diameter of the brush is greater than the inside diameter of the pipe. When the brush is pushed through the pipe the helix collapses and compacts the bristles to scrub the surface. When the brush is released in the pipe, the helix expands and spreads the bristles; thereby aiding in release of debris collected on the bristles during the scrubbing.
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