| 摘要 |
An adjustable frame configured to receive a standard grate includes a plurality of threaded openings that may be threadably engaged with bolts to adjust an elevation of the frame. The threaded openings may be configured to have a desired thread pitch, which in turn dictates how much the frame may be lowered or raised with one full turn of the bolt. Optionally, threaded bushings may be installed into the frame to engage with the bolts. |
