Railguy

My seat belts constantly tighten.Kinda like ratchet once they they pull in they stay there.Is this normal? If you ever saw that movie,I think it was Winnebago?I'm not sure.When he had to pull the belt out just right,to fast and it locked.Then he had to let it pull back in and start over.That's what mine do to a "T".Is that the way there suppose to work?Is there a"fix"or a "cure"or something?It's a 74 Omega.
railguy