Push-Push Button

Pink bar is pivoted on the base.
The groove profile of blue slider ensures that the upper pink pin moves cloclwise along heart-shaped groove when the blue button is pushed and released.
Pay attention to the followings (the letters on the sketch denote corners of the profiles):
a’ is on the right of a
b’ is on the left of b
c’ is on the right of c
d’ is on the left of d