Refrigeration – Automatic control – Refrigeration producer
Reexamination Certificate
1999-10-01
2001-02-13
Wayner, William (Department: 3744)
Refrigeration
Automatic control
Refrigeration producer
C062S524000
Reexamination Certificate
active
06185948
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a refrigerator-freezer provided with two evaporators, that is, a first evaporator for cooling an atmosphere in a refrigerating compartment and a second evaporator for cooling an atmosphere in a freezing compartment.
2. Description of the Prior Art
There have conventionally been provided refrigerator-freezers in which a liquid refrigerant having passed through a compressor and a condenser is further supplied to an evaporator to be evaporated such that the evaporator is cooled. A cold air produced by the evaporator is supplied to a freezing compartment by a blower so that an atmosphere in the freezing compartment is cooled and so that the cold air is also supplied to a refrigerating compartment via a damper so that an atmosphere in the refrigerating compartment is cooled. When a temperature in the refrigerating compartment drops to a lower limit temperature (for example, 1° C.), the damper is closed so that the supply of cold air to the refrigerating compartment is interrupted. When the temperature in the refrigerating compartment increases to an upper limit temperature (for example, 5° C.), the damper is opened so that the supply of cold air to the refrigerating compartment re-started. As a result, the temperature in the refrigerating compartment is controlled so as to be maintained at a predetermined temperature (for example, 3° C.). Further, the operation of the compressor is stopped when a temperature in the freezing compartment drops to a lower limit temperature (for example, −22° C.). The operation of the compressor is re-started when the temperature in the freezing compartment increases to an upper limit temperature (for example, −18° C.). As a result, the temperature in the freezing compartment is controlled so as to be maintained at a predetermined temperature (for example, −20° C.).
In the above-described refrigerator-freezer, however, the operation of the compressor is automatically stopped when the temperature in the freezing compartment drops to the lower limit temperature as described above. Accordingly, the operation of the compressor may be stopped even when the temperature in the refrigerating compartment is relatively high. In such a case, when the temperature in the freezing compartment thereafter increases to the upper limit temperature such that the operation of the compressor is re-started, the temperature in the refrigerating compartment exceeds the upper limit temperature. Accordingly, thereafter, it takes a lot of time for each of the temperatures in the respective refrigerating and freezing compartments to drop to the corresponding preset temperature. This results in a reduction in the operating efficiency of the compressor, whereupon food cannot be cooled efficiently.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a refrigerator-freezer which comprises a first evaporator for cooling the atmosphere in the refrigerating compartment and a second evaporator for cooling the atmosphere in the freezing compartment so that an operating efficiency of the compressor can be improved.
The present invention provides a refrigerator-freezer comprising a refrigerating compartment, a freezing compartment, a refrigerating cycle including a compressor compressing a refrigerant, a condenser condensing the refrigerant supplied from the compressor, a first evaporator cooling an atmosphere in the refrigerating compartment, a second evaporator cooling an atmosphere in the freezing compartment, and a valve switching a cooling operation between a first operation mode in which the refrigerant compressed by the compressor is supplied at least to the first evaporator and a second operation mode in which the refrigerant compressed by the compressor is supplied at least to the second evaporator, and a controller controlling the compressor and the valve, the controller controlling the valve so that the first and second operation modes are carried out alternately, the controller stopping the operation of the compressor when a temperature in either one of the refrigerating and freezing compartments for which the cooling operation is unexecuted is below a predetermined upper limit temperature in a case where a temperature in the other compartment for which the cooling operation is in progress drops to a predetermined lower limit temperature.
According to the above-described refrigerator-freezer, the controller stops the operation of the compressor when a temperature in either one of the refrigerating and freezing compartments for which the cooling operation is unexecuted is below a predetermined upper limit temperature in a case where a temperature in the other compartment for which the cooling operation is in progress drops to a predetermined lower limit temperature. The temperature in the refrigerating or freezing compartment for which the cooling operation is unexecuted is sufficiently low when the compressor is stopped. Accordingly, the temperature in the refrigerating or freezing compartment for which the cooling operation is unexecuted can be prevented from being excessively increased until the operation of the compressor is re-started. Consequently, the operating efficiency of the compressor can be improved.
In a preferred form, the controller controls the compressor so that a performance of the compressor is varied, and the controller stops the operation of the compressor when the compressor is at a lowest performance and the temperature in the compartment for which the cooling operation is unexecuted is below the predetermined upper limit temperature in a case where the temperature in the compartment for which the cooling operation is in progress drops to the lower limit temperature.
In another preferred form, the controller switches the cooling operation to the second operation mode when a temperature in the refrigerating compartment drops to a predetermined lower limit temperature while the cooling operation is under performance in the first operation mode and thereafter, the controller stops the compressor when a temperature in the freezing compartment drops to a predetermined lower limit temperature and the temperature in the refrigerating compartment is below a predetermined upper limit temperature while the cooling operation is in progress in the second operation mode.
REFERENCES:
patent: 4242116 (1980-12-01), Aschberger et al.
patent: 4439998 (1984-04-01), Horvay et al.
patent: 5272884 (1993-12-01), Cur et al.
patent: 5465591 (1995-11-01), Cur et al.
patent: 5715693 (1998-02-01), van der Walt et al.
patent: 6016662 (2000-01-01), Tanaka et al.
patent: 0 246 465 (1987-11-01), None
Kishimoto Takuya
Kusunoki Atsushi
Niki Shigeru
Kabushiki Kaisha Toshiba
Pillsbury Madison & Sutro LLP
Wayner William
LandOfFree
Refrigerator freezer with two evaporators for respective... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Refrigerator freezer with two evaporators for respective..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refrigerator freezer with two evaporators for respective... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2565735