P4.6 The bell-crank mechanism shown in Figure P4.6 is supported by a single-shear pin connection at B and a roller support at C. A load P acts at an angle of θ = 40° at joint A. The pin at B has a diameter of 0.375 in., and the bell crank has a thickness of 0.188 in. The ultimate shear strength of the pin material is 28 ksi, and the ultimate bearing strength of the crank material is 52 ksi. A minimum factor of safety of 3.0 with respect to shear and bearing is required. Assume that a = 9.0 in. and b = 5.0 in. What is the maximum load P that may be applied at joint A of the bell crank?
Bell crank
R
b
FIGURE P4.6