Heating system for a railway car for utilizing waste heat from an engine

Claim 1

In combination with an engine which generates heat and a liquid circulating loop including a heat exchanger to provide cooling for said engine, a heating system for providing heat for a compartment, comprising: (a) heating elements in said compartment to generate heat in response to hot liquid passing therethrough, (b) a pump for circulating liquid through said heating elements through a first and second parallel path, (c) said heat exchanger being connected in said first parallel path so that liquid circulated therethrough by said pump through said heating elements will receive heat, from said heat exchanger (d) said second path by-passing said heat exchanger, and (e) switching means including temperature responsive means to selectively switch the liquid from said pump to one of said first and second paths, said switching means further including a first valve positioned in said first parallel path between said pump and said heat exchanger, and said switching means being responsive to a predetermined temperature in said compartment for permitting liquid to flow through said first valve, a second valve positioned in said second parallel path, adjacent said pump and by-passing said heat exchanger and being biased to normally closed position and responsive to liquid pressure for permitting liquid to flow therethrough whenever the temperature in said compartment exceeds a predetermined temperature, said first valve will close and such restricted flow of liquid causing the pressure in said first and second paths to increase thereby causing said second valve to open and permit the liquid to flow through said second path and by-pass said heat exchanger.