ABSTRACT
We shall begin by turning to Figure 4 and find that at µ=0.40, region 1 extends from α=0.38485 radians=22.051° to α=0.79482 radians= 45.540° (as read with the aid of the Trace feature provided by Mathcad). From Figure 3 we note that the torque is greater at α=22.051° than it is at α=45.54°, which suggests that a smaller a would be preferred. Hence, we shall initially consider two designs, one for α=24° and one for α=45°. A slightly larger a was selected for the smaller of the two angles to ensure that no retraction force will be needed even with a manufacturing error of −0.5°.
