Hairspring terminal curves

[klevay]

Hello,
Could anybody tell me where to find the Phillips terminal curve diagrams to form or correct the Breget overcoil hairsprings? Something similar to the one shown in the picture.

 

[praezis]

There were different authors of diagrams with different design.
These are from Helwig, Glashutte.
Regards,
Frank

 

[klevay]

Frank, thank you very much!