Patent ID: 9610699
Date: 2017-04-04
CPC Classifications: B23D,B27B

Claim:
1. A chainsaw guide bar adapted for rounding and contouring workpiece surfaces comprising: an elongated guide bar body including a peripheral guide rail slot configured to slidably engage a circulating saw chain and extending at least partially around the guide bar; a broadened proximal mounting end defining a longitudinal axis and configured for mounting to a power drive unit; a narrow distal working end; an intermediate portion extending between the mounting and working ends; the guide bar body defining a concave shaped and downwardly open elongated recess extending axially between the mounting and working ends that provides an unsupported flexible span of saw chain between the mounting and working ends, the saw chain being movable into and out of the recess between an undeflected position defining a first path and a deflected position defining a second path; and an idler sprocket mechanism rotatably disposed in the mounting end of the guide bar body adjacent to the elongated recess, the sprocket mechanism configured and arranged to engage a return run of the saw chain and being operative to guide the saw chain into a portion of the guide rail slot disposed on a bottom edge of the mounting end; wherein the unsupported span of saw chain is operable to conform to a shaped surface of a workpiece and round the surface.