| 摘要 |
A seismic drilling bit designed for insertion for use in enlarging an upper end of a pre-drilled hole for receiving and securely retaining an anchor therein. The bit is rotatably mounted onto a drill or can be mounted onto a mounting assembly which in turn is rotatably mounted to the drill. The bit also has a pivot ring which permits limited tilting movement of the bit body during a drilling process to enlarge the lowermost end of the drill hole. In this manner, an anchor can be inserted within the pre-drilled hole, and, when the anchor has been flanged outwardly by conventional means within the hole, the flange portions of the anchor will rest within the enlarged area, thus securely retaining the anchor in place.
|
