Question

5. A holding fixture for a work piece 1.5 inch thick at clamp location is being designed. The detail of one of the clamps is shown in the figure. The spring is required to drive the clamp upward while removing or inserting a work piece. A clamping force of 10 lbf is satisfactory. The base plate is 5/8 inch thick. The clamp screw has a 7/16 in-20 UNF thread. Allow 0.05 inch diametral clearance between screw and the inner coil diameter of the spring. It is useful to have the free length Lo short enough so that the clamp screw can compress the spring upon fixture reassembly during inspection and service, say LoS1.5 +3/8 inch. The spring cannot close solid at a length greater than 1.25 inch. The safety factor when compressed solid should be 2 1.2, and at service load ni 2 1.5. Design a suitable helical coil compression spring for this fixture. Start *20* with 0.08 inch diameter, A 227-47 HD steel spring. Clamp screw Spherical washer Clamp Slot Groove Workpiece

Answer 1

3 16 0-08 8DNO Gid 115 Y 10%(008 8 x 26 63 (6.56 Na20? +2. 14 07 canned w CS CamScanner

1 199 LyCS 48108316 ps81 0R ksi : 226 2 i d) 81 08 6 sued and cloed 14-02 c0.13 12.o4 Col'S cs Scanned with CamScanner