Patent ID: 8075302

Claim:
An apparatus for optimally mixing and injecting a two part urethane foam into or onto a railroad tie, comprising: a dispensing and mixing head; and two or more holding tanks each holding one or more portions of a urethane foam mixture compound which when said portions are mixed, via an actuation of said dispensing and mixing head, react to produce a urethane foam; and said two or more holding tanks having an exiting port; and one or more heating elements positioned to uniformly heat one or more of said portions of said urethane foam mixtures to a temperature wherein a viscosity is reduced and a proper reaction time is obtained; and two or more synchronously coupled pumps each having an intake port capable of suction feeding said portions of said urethane foam mixture; and said synchronously coupled pumps each having a discharge port and capable of positive pumping said portions of urethane mixture through said discharge port, each intake port connected with one of said holding tank exiting ports; and said discharge ports each connected with said dispensing and mixing head and one or more pressure relief valves which recirculate each portion of said urethane foam mixture into the holding tank of origination if said dispensing and mixing head is not actuated; and said dispensing and mixing head having two or more compound valves connected with a valve actuator; and said compound valves each having the form of a valve pin within a bore with an attached end connected with said valve actuator and a tip end which mates with one or more seals between said bore and a compound chamber, said seal preventing said portions of said urethane mixture from entering said compound chambers when said valve actuator is not actuated; and said dispensing and mixing head having at least two compound entrance holes into which each of said portions of said urethane mixture enters said head from said discharge ports via an action of said pumps, and upon actuation of said valve actuator, separately enter said compound chambers and exit two or more mixture exiting holes into a static mixer sealingly connected with said head and exit an open end of said static mixer to produce a thorough urethane mix capable of reacting to produce a urethane foam; and a solvent injection hole within said dispensing and mixing head connected with a solvent passage which is further connected with one or more of said compound chambers; and a cleaning solvent capable of flushing one or more of said portions of said urethane foam mixture compounds; and a solvent injector having a solvent injector valve and a solvent check valve; and said solvent injector valve allowing said cleaning solvent injection into said head and said static mixer after said actuation of said valve actuator; and said solvent check valve substantially prohibiting one or more of said portions of said urethane foam mixture from entering said solvent passage.