| 摘要 |
<p>An expandable tool 10 suitable for cleaning a pipe comprises: a substantially cylindrical brush 12 formed of brush segments 20; the brush segments 20 can be moved radially between an expanded state (fig 2) and a contracted state (fig 1); a pivot arm 26 is secured to each brush segment 20 to move the segment 20 between the expanded and contracted states; a pivot control device 40 limits the range of pivotal movement of the arm 26 and spring means 42 biases the brush segments 20 into the expanded state. Each pivot arm 26 may be secured at one end to a brush segment 20 via a pivot and at the other end may be in sliding contact with the pivot control device 40. The brush 12 is preferably made up of three segments 20.</p> |
