Show renewal of patents patents may be renewed only by act of congress a thing practically unheard of patenting ot of an im provement pro does not extend the life of a patent at the end of 17 years after grant of a patent the in passes into public domain and may be made used or sold by anyone inco incorporating rp orating every tea fea ture disclosed in the patent sixty five to 75 per cent of the bunc dional components of the modern motor vehicle have originated with independent inventors and are made complete by independent smaller manufacturers |