Patent ID: 7454918
Filing Date: 2008-11-25
Classification: F25D

Abstract:
1. In a freezer having a refrigeration system including a compressor, an evaporator coil, an evaporator fan to circulate air over the evaporator coil and into a compartment of the freezer, a defrost heater for periodically removing frost build-up from the evaporator coil, and a timer control system controlling the operation of the compressor, evaporator fan, and defrost heater, the timer control system comprising: a switch arrangement including a compressor control blade, an evaporator fan control blade, a defrost heater control blade, and a common blade; a rotatable cam having a profiled surface in operable communication with the switch arrangement controlling a relative positioning of the blades of the switch arrangement such that the compressor control blade and evaporator fan control blade contact the common blade in a first cycle, the defrost heater control blade connects with the common blade in a second cycle, and wherein the cam provides a third cycle between the first cycle and the second cycle delaying the defrost heater control blade from contacting the common blade for a period of time after the first cycle.