| 摘要 |
<p>The leading and lower cutting edges of a reciprocating cutting blade on a sheet material cutting apparatus are sharpened by elevating the blade from a cutting region proximate the sheet material supporting surface of the apparatus to a sharpening region above the cutting region and reciprocating the blade within the sharpening region. The apparatus includes two sharpening wheels mounted on a pivoted yoke and supported at opposite sides of the blade. One of the sharpening wheels is biased toward the blade to bring a face of the one wheel into sharpening engagement with one side of the leading cutting edge of the blade. The face of the one wheel is maintained in sharpening engagement with the leading cutting edge during a substantial portion of the blade sharpening stroke in either direction, however, as the blade approaches the upper limit of its sharpening stroke the one sharpening wheel is moved under the leading edge of the blade to bring a peripheral edge portion of the wheel into sharpening engagement with the lower cutting edge of the blade. The peripheral edge of the wheel is maintained in engagement with the lower cutting edge during the remaining portion of the upward sharpening stroke and during the initial portion of the downward sharpening stroke. The other sharpening wheel is moved in like manner to sharpen the other side of the leading and lower edges of the blade.</p> |
