DYNAMICS OF PACKAGE CUSHIONING 



379 



15. Calculate B = (2W2h)/(Kcn). 



16. Enter Fig. 1.8.4(a) orjb) with/i and lincl d,n/{VcO. 



17. Calculate </„,/^ = Vc-djVcf. 



18. Calculate (/,„ = (-djl 



19. Calculate (djf) + (.Vo/0- 



0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 

 B 

 Fig. 1.8.4(a)— Tension spring package design curve. Equations (1.8.3) and (1.8.4). 



20. Enter Fig. 1.8.5 with (djf) + (.vo/0 and find (e/f) - b. e is the 

 stretch of each spring (in inches) when the displacement is dm inches. 



21. Calculate F^ = k-ie/O-f. This is the ma.ximum load (in pounds) 

 on each spring. 



22. 23, 24, 25, 26. These are the coil diameter, wire diameter, number of 

 turns, fiber stress and length of coils. These quantities are calculated 

 from the ordinary formulas, charts or slide rules for helical springs, 

 using the values of k and F,,, from Lines 14 and 21. 



27. The length inside hooks is entered on Line 27 to group all of the spring 

 specifications. 



