Fig. 7.38 shows the mechanism of a quick return motion of the crank and slotted lever type shaping machine. The dimensions of the various links are as follows: OA = 200 mm; AB = 100 mm; OC = 400 mm; and CR = 150 mm. The driving crank AB makes 120° with the vertical and rotates at 60 r.p.m. in the clockwise direction. Find : 1. velocity of ram R, and 2. angular velocity of the slotted link OC. B [Ans. 0.8 m/s; 1.83 rad/s] 0 R B (on crank) B'(on OC) 120° A Fig. 7.38 Q 60° A C(on BD) Fig. 7.39 P