an operator for adjustment of the tool a pivot shaft in the form of a headed bolt 220 extends through a central aperture 222 of the lever body section through the hole 207 of the bushing and through a hole 226 of the central portion 180 of the mounting bracket 178 a nut 228 is threaded on the end of the pivot bolt 220 shaft 220 is coaxial with cam opening 204 and therefore is slightly above the center of hub 202 and slightly above the center of yoke opening 196 the unstressed axial length of bushing 206 is greater than the distance between the facing inner surfaces of the mounting bracket 178 and lever 212 when the parts are assembled accordingly upon assembly the bushing is axially compressed and since it is circumferentially restrained the compression forces the bushing inwardly against the pivot shaft 220 and outwardly against the inner surface of circular hole 204 of the cam member lever 212 is formed with an index marker 230 that is lined up with the numeral 1 of the yoke plate when the lever 212 is in its limiting counterclockwise position as illustrated in solid lines in fig7 in this position.