Crank Sweep Milling Machine.
<a href="https://en.wikisource.org/wiki/Author:E._L._Ahrons" class="extiw" title="s:Author:E. L. Ahrons">E. L. Ahrons</a>
<i>Original:</i> Steam Locomotive Construction and Maintenance p. 59, Fig. 25.<br><i>Scan:</i> Internet Archive – <a rel="nofollow" class="external free" href="https://archive.org/details/steamlocomotivec00ahrorich">https://archive.org/details/steamlocomotivec00ahrorich</a>