All fire engines, hose, hose carriages, ladders, buckets, and all vehicles, machinery, and appliances of every kind used or kept by incorporated cities, villages, or fire companies for the purpose of extinguishing fires are hereby exempt from execution and sale to satisfy any debt, judgment, or decree arising upon contract or otherwise. The provisions of this section shall not affect any voluntary lien created by bill of sale, security agreement as defined in article 9, Uniform Commercial Code, or otherwise, on such property, by the proper owner.