With the boom in road and building construction since the early 1950's there has been a strong demand for increasing numbers of larger and more efficient earth moving equipment. Greater equipment efficiency demanded developments in hydraulic cylinders in the form of higher pressure capabilities, longer strokes, more demanding tolerances and finishes, and better materials.
Environment also has influenced cylinder design, leading to significant developments in protective devices and materials. Black oxide, chrome plating, protective oils, boots, wipers, and rod scrapers are some examples.
This paper deals with two of these protective devices - wipers and scrapers. It explores the history and design considerations under which the wiper used in the cleaner atmosphere has given way to a more specialized scraper designed for use in abrasive environments. It traces the development of the standardized bonded polyurethane scraper through laboratory testing to today's severe application.