| 摘要 |
<p>959,323. Sawing. E. A. HAYDEN. June 5, 1961 [Jan. 10, 1961], No. 20142/61. Heading B5L. A portable log saw assembly comprises an inverted substantially U- shaped frame having a tie-rod 230, Fig. 2, from the ends of which depend leg portions 208, 210, having elongated bars 242, 244 slidable thereon, and a plurality of rollers mounted for rotation between its bars, the rollers including leading and trailing rollers 258, 262 and at least one intermediate roller 268 normally coplanar therewith but releasable out of coplanar relationship. The rollers support the assembly on a log which a chain saw driven by means S about a bar 238 cuts the log in a plane below the rollers as described in Specification 963,425. The bars 242, 244 are adjustable relative to the bar by screw-and-nut mechanisms 252 to determine the thickness of a board to be cut from the log. The intermediate roller 268 is eccentrically mounted in the bars and its axis is movable out of coplanar relation with leading and trailing rollers by levers 286, 288. The assembly is laterally guided during sawing by rollers 314, 316 mounted on a bar secured to the foot 236 of one of the leg portions, the rollers 316 beneath the saw bar being screwthreaded to act on the log as the assembly is moved along the log during sawing to pull the assembly into contact with the log. In operation, during initial engagement of the saw with the log, the intermediate roller 268 is locked in coplanar relation with the leading and trailing rollers and the assembly supported on the log by the leading and intermediate rollers 258, 268. When the saw has engaged the log sufficiently for the trailing roller 262 also to support the assembly, the intermediate roller is raised by the levers out of coplanar relationship. Towards the end of the cut, the intermediate roller 268 is returned to its coplanar position and the assembly is supported by the intermediate and trailing rollers.</p> |
