| 摘要 |
<p>The coal pick fits into a rectangular hole in a pick carrier which has a groove around the inside of the hole. It has a locating hole in the smaller side of the coal pick stem (2a), i.e the axis of this hole is in the working direction of the coal pick (1a). In one design, the stem has a hole in both small sides of the stem, each hole holding a locating ball. Behind each ball is a block of elastic material such as a polymer or other plastics material, acting as a spring.</p> |
