Dempsey Cycle Co., Inc. signed by W.L. Dempsey - Stock Certificate

Stock signed by W.L. Dempsey as president. Rare!

The process of producing work from a four-cycle internal combustion engine comprising a cylinder having a piston reciprocable therein and means for supplying a regulated mixture of hydrocarbon and air to said cylinder; which consists in supplying the cylinder with an explosive mixture of hydrocarbon and air over-rich in hydrocarbon, introducing a supplemental amount of air at atmospheric pressure into said cylinder adjacent the end of the piston near the end of the charging stroke sufficient in quantity to produce an approximately constant volumetric charge in said cylinder irrespective of the amount or quality of the charge of explosive mixture and thereby supplying sufficient oxygen to the cylinder to cause approximately complete combustion of the fuel, preventing the escape from the cylinder of any of the supplemental air thus introduced, compressing the charge upon the return stroke of the piston, igniting the charge to impel the piston upon its working stroke exhausting the products of combustion from the cylinder in part by the admission of air into the cylinder at the end of the working stroke. (From Official Gazette of the United States Patent Office, 1924)