Abstract A space heater particularly for motor vehicles comprises an inner tubular enclosure for a heat source, a first jacket defining a first annular space surrounding the tubular enclosure and traversed by heating air, a second jacket surrounding the first jacket and defining a second annular space, the second jacket having an open end and an axially opposite closed end spaced axially from the adjacent end of the first jacket and first annular space, a fresh air inlet communicating with the open end of the second annular space, and a heating air outlet communicating with that end of the first annular space adjacent the open end of the second annular space. The fresh air inlet and the heating air outlet preferably are concentric with each other and are arranged at one and the same end of the space heater or heating device. Fresh air enters through the inlet connection, flows through the second annular space to the closed end of the second jacket, then flows in the counter direction through the first annular space, and is discharged through the outlet connection. The tubular enclosure for a heat source may be a combustion chamber to which combustion air is admitted and exhausted by lateral connections extending across the heating air passage. The heater controls may be mounted in a hood secured adjacent a lateral opening in the second jacket.
In an axially elongated heating device for heating the interiors of automotive vehicles, of the type including an elongated tubular combustion chamber, supplied with fuel and independent of the engine, and an elongated jacket defining a cylindrical annular space surrounding the tubular combustion chamber and traversed by heating air to deliver warm air to an outlet means at one end of the annular space, the improvement comprising, in combination; a second jacket surrounding said first-mentioned jacket and defining therewith a second annular space having an open end adjacent said outlet means and an axially opposite closed end spaced axially from the adjacent end of said first-mentioned jacket and communicating with said adjacent end of said first-mentioned annular space; and a fresh air inlet conduit communicating with the open end of said second annular space; said heating air outlet means comprising an outlet conduit extending concentrically through said inlet conduit in radially spaced relation to said inlet conduit; whereby fresh air enters through said fresh air inlet conduit means, flows in a first axial direction through said second annular space to the closed end of said second annular space, then reverses flow direction to flow in the counter axial direction through said first-mentioned annular space, and is discharged through said heating air outlet conduit, so that the admission and discharge of heating air is effected at the same end of said heating device and said fresh air inlet conduit and said heating air outlet conduit extend together from the same axial end of said heating device a bypass duct positioned in said heating air outlet means adjacent the discharge end thereof, and damper means in said heating air outlet means for proportioning the flow between the bypass duct and the heating air outlet means.
Claim 2
Dependent Claim
293 words
In an axially elongated heating device for heating the interiors of automotive vehicles, of the type including an elongated tubular combustion chamber, supplied with fuel and independent of the engine, and an elongated jacket defining a cylindrical annular space surrounding the tubular combustion chamber and traversed by heating air to deliver warm air to an outlet means at one end of the annular space, the improvement comprising, in combination; a second jacket surrounding said first-mentioned jacket and defining therewith a second annular space having an open end adjacent said outlet means and an axially opposite closed end spaced axially from the adjacent end of said first-mentioned jacket and communicating with said adjacent end of said first-mentioned annular space; and a fresh air inlet conduit communicating with the open end of said second annular space; said heating air outlet means comprising an outlet conduit extending concentrically through said inlet conduit in radially spaced relation to said inlet conduit; whereby fresh air enters through said fresh air inlet conduit means, flows in a first axial direction through said second annular space to the closed end of said second annular space, then reverses flow direction to flow in the counter axial direction through said first-mentioned annular space, and is discharged through said heating air outlet conduit, so that the admission and discharge of heating air is effected at the same end of said heating device and said fresh air inlet conduit and said heating air outlet conduit extend together from the same axial end of said heating device a bypass duct positioned in said heating air outlet means adjacent the discharge end thereof, and damper means in said heating air outlet means for proportioning the flow between the bypass duct and the heating air outlet means.