The patent’s assignee for patent number 9004372 is L. B. Foster Company (Pittsburgh, PA).
News editors obtained the following quote from the background information supplied by the inventors: “Direct fixation fasteners are mainly used in transit railroad tracks to connect railroad rails to the underlying structure. These fasteners serve to three main purposes: (1) maintain integrity of track and gauge during operations; (2) reduce noise and vibration caused by train wheels; and (3) create electrical insulation between the rails and the ground. There are two main design approaches to achieve the desired properties: (1) two steel components bonded to each other by layer a rubber element in between (a.k.a. bonded direct fixation fastener) with both steel parts are also largely encapsulated in rubber during the manufacturing process; and (2) multiple elements assembled together without the incorporation the bonding process (a.k.a. non-bonded direct fixation fastener).(…)
via Patent Issued for Dual Hardness Bonded Direct Fixation Fastener.