It shall be unlawful and a violation of this article for any person to deposit or cause to be deposited, in any parking meter installed under the provisions of this article, any coin for the purpose of increasing or extending the parking time of any vehicle beyond the legal parking time of 15 minutes in any fifteen-minute parking meter zone, 1/2 hour in any one-half-hour parking meter zone, one hour in any one-hour parking meter zone, or two hours in any two-hour parking meter zone.