crown gear involute

Hello soldiworks teachers,
I am trying to create a zipper like the one shown in the image below:
the idea is to create a zipper as I already mentioned.
but how to generate the teeth envelope for the crown and pinion.
I have found examples in grabcad but none of them explain how the geometry of the teeth is created.
Could you help me understand how to build my custom geometry, to make a functional mechanism?

Captura de pantalla 2020-03-06 a las 20.24.12

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