Air defrost housing

Claim 1

In a refrigeration system having an evaporator, a mechanism for defrosting the evaporator, a housing for the evaporator and mechanism which is adapted for mounting on an exterior wall of a refrigerator compartment, and a circulating fan for circulating air through the evaporator and compartment, the improvement wherein said housing comprises a preformed unitary body section comprising a rear wall which is adapted to facially confront the exterior wall of the refrigerator compartment, a front wall which is spaced apart from said rear wall, and a pair of opposite side walls that are spaced apart and formed integral with the front and rear walls, said body section having a chamber with upper and lower ends and which is centrally located between the front and rear walls and open to the exterior of the body section between said upper and lower ends at each of said opposite side walls, a pair of cylindrical valve chambers between said front and rear walls and which are respectively located above and below said centrally located chamber and communicate therewith at said upper and lower ends respectively, a first pair of passages that communicate with the respective valve chambers and with the exterior of the body section at said front wall, a second pair of passages that communicate with the respective valve chambers and with the exterior of the body section at said back wall, said evaporator being supported by the body section within said centrally located chamber and being adapted for withdrawal from said centrally located chamber to the exterior of the body section through the opening in one of said opposite side walls, said fan being mounted on the body section and being located and arranged within and at the upper end of said centrally located chamber for withdrawing air from the centrally located chamber and delivering it to the valve chamber thereabove, said fan being adapted for withdrawal from said centrally located chamber to the exterior of the body section through the opening in said one of said opposite side walls, said mechanism comprising a pair of arcuate valve members that are arranged in the respective valve chambers to close the respective passages of said first pair, said arcuate valve members being rotatably movable in the respective valve chambers to open the respective passages of said first pair and simultaneously close the respective passages of said second pair, means linking said arcuate members in movement, and means drivingly connected to the linking means and actuatable to simultaneously rotatably move said arcuate members.