Abstract: A free-standing, compressed, hardened porous, resilient sheath of sound absorbing fibrous material for use in silencer or muffler pipes as the intermediate sound absorbing element between the inner perforated and outer sleeve elements of a three-element pipe is formed by (a) wrapping an uncompressed pad of fibrous material containing a thermo-setting hardening agent around a shaped mandrel having outside surface shape and dimensions conforming the outside surface shape and dimensions of the inner three-element muffler pipe, (b) subjecting the wrapped mandrel and sheath of uncompressed material to a pressure sufficient to conform the outside surface of the compressed pad to the inside surface shape and dimensions of the outer muffler pipe sleeve element, and to a temperature sufficient to set the thermo-setting hardening agent; and (c) removing the mandrel.

Abstract: A pull type asphalt paver for spreading asphalt onto a road surface is disclosed as having means to avoid dump truck damage to the paver during operation and transporting thereof, means to readily enlarge the width of an asphalt layer on a road surface, and means to facilitate the metering and control of asphalt discharged by the paver on a road surface.