| 摘要 |
A cleaning tool having a height adjustment mechanism which may be overridden to prevent damage to the cleaning tool in the event an excessively high force is applied to an exterior surface of the cleaning tool. The height adjustment mechanism forms an overrideable clutch having a manually adjustable thumbwheel, a biasing member and a clutch member. The height adjustment assembly is operably associated with a roller assembly which supports the cleaning tool on a work surface at a desired height above the work surface. The application of a predetermined excessive force to an exterior surface of the cleaning tool causes the height adjustment assembly to be de-clutched to allow the lower surface of the cleaning tool to come in contact with the work surface, thereby preventing damage to the various internal components of the cleaning tool. |
