||I was told that winding the spring to make the alarm go off is prohibited, because one is making noise using a noise-making instrument (weekday activity). One is allowed to undo the "lock" on the alarm so it will go off to wake a person up for davening or for another mitzvah need, without actually winding it.
Your answer seems to contradict that opinion. Is there a machlokes on this point?
Also, according to your opinion can the alarm hand be moved on a fully mechanical alarm clock to another time on Shabbos and can the spring be rewound to ring again? This would be applicable if one used it to wake up Shabbos morning and then wants to use it to wake up in the afternoon from a Shabbos nap. Also, can you lock the ringer in the middle of the ring by pushing in the pin?