| 摘要 |
<p>The invention relates to apparatus (1) in the form of a tractor unit (2) for transporting equipment (3) along the interior of a conduit (4) such as a mains water pipe, the tractor unit (2) comprising a rotatable device by which the apparatus (1) is driven along the conduit, and which device (2) has enhanced frictional engagement with the conduit (4) whereby the apparatus (1) can be transported and positioned as desired in the conduit (4). The conduit (4) is usually an iron pipe, which may have a polyethylene liner (5) and the enhanced frictional engagement of the apparatus (1) with the conduit (4) or liner (5) is in the embodiment(s) achieved using a magnetic tractive unit (2). This comprises in the preferred embodiment a ring magnet (6), the most powerful being a permanent magnetic made of rare earth mixtures, mounted between two rotatable devices in the form of soft iron pole pieces or wheels (7), around the circumference of which is trained a cover element in the form of a rubber tyrelike element (8).</p> |
