ASSA Twin Combi sidebar rotation code

How does the rotational part of the ASSA Twin Combi sidebar code work? Unfortunately all my Twin Combi's are in use so I can't disassemble one and find out.
Looking at the key, there isn't anything obviously controlling the rotation in the sidebar code itself. The cuts all seem the same angle etc.
So, what rotates the pins? Are they simply rotated as they pass "up/downhill" over the side cuts?
Looking at the key, there isn't anything obviously controlling the rotation in the sidebar code itself. The cuts all seem the same angle etc.
So, what rotates the pins? Are they simply rotated as they pass "up/downhill" over the side cuts?