Snap-Fit Joints for Plastics - A Design Guide - MIT
Snap-Fit Joints for Plastics - A Design Guide - MIT
Snap-Fit Joints for Plastics - A Design Guide - MIT
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Fig. 17: Relationship between deflection <strong>for</strong>ce and mating <strong>for</strong>ce<br />
Mating Force<br />
During the assembly operation, the deflection<br />
<strong>for</strong>ce P and friction <strong>for</strong>ce F have to be overcome<br />
(see Fig. 17).<br />
The mating <strong>for</strong>ce is given by:<br />
W = P • tan (� + p) = P µ + tan �<br />
1 – µ tan �<br />
µ + tan �<br />
The value <strong>for</strong> 1—µtan�can be taken directly<br />
from Fig. 18. Friction coefficients <strong>for</strong> various<br />
materials are given in Table 3.<br />
In case of separable joints, the separation <strong>for</strong>ce<br />
can be determined in the same way as the mating<br />
<strong>for</strong>ce by using the above equation. The angle of<br />
inclination to be used here is the angle �'<br />
Page 14 of 26 <strong>Snap</strong>-<strong>Fit</strong> <strong>Joints</strong> <strong>for</strong> <strong>Plastics</strong> - A <strong>Design</strong> <strong>Guide</strong><br />
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