| 摘要 |
<p>A clean out block assembly includes a clean out block having a back wall integral with two opposed end walls defining an opening therebetween and a separate front wall adapted to block the opening defined between the front ends of the end walls, blocking means on the end walls for blocking outward passage of the front wall from the clean out block when the front wall is disposed substantially parallel to the rear wall, and spacing means for spacing the front wall from the back wall and juxtaposed the blocking means. Preferably, the spacing means includes resilient support means in the form of a high compliance coil spring for urging the front wall towards the blocking means and is interposed between the front and rear walls for resiliently urging the front wall into engagement with the blocking means which is constituted by a groove or flange extending vertically across the inwardly facing sides of each respective end wall. The support means may be in the form of a coil spring coiled in the shape of a waisted cylinder, such as a bed spring and a step or rebate is provided on each end of the front wall, the length of the front wall being such that it may be inserted into the clean out block betwixt the respective end walls at an angle skewed about a vertical axis, with the space between the end walls permitting the front wall to be inserted into the clean out block beyond the blocking means when skewed relative to the back wall.</p> |
