Electric heater unit

Claim 2

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, means interconnecting said bars adjacent opposite ends thereof to permit circulation of fluid from one bar to another, each of said bars having a pair of fins projecting from each of the front, rear and side faces thereof, said fins being substantially coextensive in length with said bars, means carried by said heater unit for heating the fluid adapted to circulate through said bars, a pair of elongated covers disposed between each next adjacent pair of bars and respectively adjacent the front and rear sides thereof, means for connecting said covers to said next adjacent bars whereby said pairs of covers and adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, each of said covers being generally channel-shaped in cross section, and means carried by the legs of each channel-shaped cover for securing the same to a pair of opposed side fins of the next adjacent bars.

Claim 3

A heater unit according to claim 1 wherein the passages in the bars define a closed system for circulating fluid.

Claim 4

A heater unit according to claim 2 wherein said heating means includes a heating element secured along one side of one of said bars.

Claim 5

The heater unit according to claim 1 wherein said opposite side fins have beads projecting along their edges in a direction away from one another and defining grooves therewith, the legs of said covers having beads along their edges projecting toward one another, said legs being flexible to permit the beads carried thereby to snap past the beads carried by said fins for engagement within said grooves.

Claim 6

A heater unit according to claim 1 including means for sealing the ends of the passages in said bars and including a flexible element in the ends of said passages, means for compressing said flexible element in a direction generally parallel to the axis of said bar to laterally enlarge said element into sealing engagement against the walls of said bar defining said passage to thereby seal the latter.

Claim 7

A heater unit according to claim 1 including means for closing the ends of said bars thereby providing a closed circulation system, said heating means including an electrical heating element, a thermostat connected to said heating element for activating said heating element in response to the sensing of a specified ambient air temperature, and control means for periodically activating and deactivating said heating element during the time said heating element is activated by said thermostat.

Claim 8

A heater unit according to claim 6 wherein said control means includes temperature responsive means responsive to heater unit temperature for activating said heating element in response to sensing a first predetermined temperature and for deactivating said heating element in response to sensing a second predetermined temperature higher than said first predetermined temperature.

Claim 9

A heater unit according to claim 7 wherein said predetermined first and second temperatures constitute the surface temperatures of one of said bars adjacent said control means.

Claim 10

A heater unit according to claim 1 including means carried thereby for circulating air through said ducts.

Claim 11

A heater unit according to claim 1 including a heat exchange fluid in the passages of said bars and in said interconnecting means.

Claim 12

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, each of said bars having a pair of fins projecting from each of the front, rear and side faces thereof, said fins being substantially coextensive in length with said bars, means interconnecting said bars adjacent opposite ends thereof to permit circulation of a fluid from one bar to another, means for closing the ends of said bars thereby providing a closed path for circulating fluid through the unit, means carried by said heater unit for heating the fluid adapted to circulate through said bars including an electrical heating element, a thermostat connected to said heating element for activating said heating element in response to sensing a specified ambient air temperature, control means including temperature responsive means responsive to heater unit temperature for periodically activating and deactivating said heating element during the time said heating element is activated by said thermostat, said temperature responsive means being responsive to sensing a first predetermined heater unit temperature for activating said heating element and responsive to sensing a second predetermined heater unit temperature higher than said first predetermined temperature for deactivating said heating element whereby said heating element is operated cyclically during the time the heating element is activated by said thermostat, a pair of elongated covers disposed between each next adjacent pair of said bars and respectively adjacent the front and rear sides thereof, means for connecting said covers to said next adjacent bars whereby said pair of covers and next adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, each of said covers being generally channel-shaped in cross section, and means carried by the legs of said channel-shaped covers for securing the same to a pair of the opposed side fins of the next adjacent bars.

Claim 13

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, each of said bars having a pair of fins projecting from each of the front, rear and side faces thereof, said fins being substantially coextensive in length with said bars, means interconnecting said bars adjacent opposite ends thereof to permit circulation of a fluid from one bar to another, means for closing the ends of said bars thereby providing a closed path for circulating fluid through the unit, means carried by said heater unit for heating the fluid adapted to circulate through said bars including an electrical heating element, a thermostat connected to said heating element for activating said heating element in response to sensing a specified ambient air temperature, control means including temperature responsive means responsive to heater unit temperature for periodically activating and deactivating said heating element during the time said heating element is activated by said thermostat, said temperature responsive means being responsive to sensing a first predetermined heater unit temperature for activating said heating element and responsive to sensing a second predetermined heater unit temperature higher than said first predetermined temperature for deactivating said heating element whereby said heating element is operated cyclically during the time the heating element is activated by said thermostat, a pair of elongated covers disposed between each next adjacent pair of said bars and respectively adjacent the front and rear sides thereof, means for connecting said covers to said next adjacent bars whereby said pair of covers and next adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, each of said covers being generally channel-shaped in cross section, and means carried by the legs of said channel-shaped covers for securing the same to a pair of the opposed side fins of the next adjacent bars.

Claim 14

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, each of said bars having a pair of fins projecting from each of the front, rear and side faces thereof, said fins being substantially coextensive in length with said bars, means interconnecting said bars adjacent opposite ends thereof to permit circulation of a fluid from one bar to another, means for closing the ends of said bars thereby providing a closed path for circulating fluid through the unit, means carried by said heater unit for heating the fluid adapted to circulate through said bars including an electrical heating element, a thermostat connected to said heating element for activating said heating element in response to sensing a specified ambient air temperature, control means including temperature responsive means responsive to heater unit temperature for periodically activating and deactivating said heating element during the time said heating element is activated by said thermostat, said temperature responsive means being responsive to sensing a first predetermined heater unit temperature for activating said heating element and responsive to sensing a second predetermined heater unit temperature higher than said first predetermined temperature for deactivating said heating element whereby said heating element is operated cyclically during the time the heating element is activated by said thermostat, a pair of elongated covers disposed between each next adjacent pair of said bars and respectively adjacent the front and rear sides thereof, means for connecting said covers to said next adjacent bars whereby said pair of covers and next adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, each of said covers being generally channel-shaped in cross section, and means carried by the legs of said channel-shaped covers for securing the same to a pair of the opposed side fins of the next adjacent bars, said closing means including a plurality of flexible elements in the ends of each of the bars, means for compressing said flexible elements in a direction generally parallel to the axis of said bar to laterally enlarge said elements into sealing engagement against the walls of said bar defining said passage thereby sealing the latter, a vent hole in one of said bars, a pressure relief valve for the closed circulation system including one of said sealing means compressed to a lesser extent than the other of said sealing means for sliding engagement along the associated bar thereby uncovering said vent hole.

Claim 15

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, each of said bars having a pair of fins projecting from each of the front, rear and side faces thereof, said fins being substantially coextensive in length with said bars, means interconnecting said bars adjacent opposite ends thereof to permit circulation of a fluid from one bar to another, means for closing the ends of said bars thereby providing a closed path for circulating fluid through the unit, means carried by said heater unit for heating the fluid adapted to circulate through said bars including an electrical heating element, a thermostat connected to said heating element for activating said heating element in response to sensing a specified ambient air temperature, control means including temperature responsive means responsive to heater unit temperature for periodically activating and deactivating said heating element during the time said heating element is activated by said thermostat, said temperature responsive means being responsive to sensing a first predetermined heater unit temperature for activating said heating element and responsive to sensing a second predetermined heater unit temperature higher than said first predetermined temperature for deactivating said heating element whereby said heating element is operated cyclically during the time the heating element is activated by said thermostat, a pair of elongated covers disposed between each next adjacent pair of said bars and respectively adjacent the front and rear sides thereof, means for connecting said covers to said next adjacent bars whereby said pair of covers and next adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, each of said covers being generally channel-shaped in cross section, and means carried by the legs of said channel-shaped covers for securing the same to a pair of the opposed side fins of the next adjacent bars, said closing means including a plurality of flexible elements in the ends of each of the bars, means for compressing said flexible elements in a direction generally parallel to the axis of said bar to laterally enlarge said elements into sealing engagement against the walls of said bar defining said passage thereby sealing the latter, a vent hole in one of said bars, a pressure relief valve for the closed circulation system including one of said sealing means compressed to a lesser extent than the other of said sealing means for sliding engagement along the associated bar thereby uncovering said vent hole.

Claim 16

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, means interconnecting said bars adjacent opposite ends thereof to permit circulation of fluid from one bar to another, each of said bars having a pair of fins projecting from each of the front and side faces thereof, said fins being substantially coextensive in length with said bars, means carried by said heater unit for heating the fluid adapted to circulate through said bars, an elongated cover disposed between each next adjacent pair of bars adjacent the front sides thereof, means for connecting said covers to said next adjacent bars whereby said covers and adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, means carried by said heater unit along the rear side of said bars and defining the rear surfaces for said air ducts, each of said covers being generally channel-shaped in cross section and means carried by the legs of each channel-shaped cover for securing the same to a pair of opposed side fins of the next adjacent bars.

Claim 17

A heater unit comprising a plurality of elongated bars disposed in spaced generally parallel side by side relation one to the other with each bar defining a passage for containing a heating fluid, means interconnecting said bars adjacent opposite ends thereof to permit circulation of fluid from one bar to another, each of said bars having a pair of fins projecting from each of the front and side faces thereof, said fins being substantially coextensive in length with said bars, means carried by said heater unit for heating the fluid adapted to circulate through said bars, an elongated cover disposed between each next adjacent pair of bars adjacent the front sides thereof, means for connecting said covers to said next adjacent bars whereby said covers and adjacent bars define air ducts for circulating air heated by the fluid adapted to circulate through said passages, means carried by said heater unit along the rear side of said bars and defining the rear surfaces for said air ducts, each of said covers being generally channel-shaped in cross section and means carried by the legs of each channel-shaped cover for securing the same to a pair of opposed side fins of the next adjacent bars.

Claim 18

A heater unit according to claim 13 including means for closing the ends of said bars thereby providing a closed circulation system, said heating means including an electrical heating element, a thermostat connected to said heating element for activating said heating element in response to the sensing of a specified ambient air temperature, and control means for periodically activating and deactivating said heating element during the time the heating element is activated by said thermostat.

Claim 19

A heater unit According to claim 14 wherein said control means includes temperature responsive means responsive to heater unit temperature for periodically activating and deactivating said heating element, said temperature responsive means being responsive to sensing a first predetermined heater unit temperature for activating said heating element and responsive to sensing a second predetermined heater unit temperature higher than said first predetermined temperature for deactivating said heating element, whereby said heating element is operated cyclically during the time the heating element is activated by said thermostat.