System for controlling cooling and heating of a loading space

Claim 2

In refrigeration apparatus which produces a cooling cycle according to the vapor-compression cycle and which delivers air, that is selectively cooled or heated in an evaporator of the apparatus, to a loading space, a compressor delivery hot gas to a three-way valve which is selectively operable between two positions, the valve in a first position permitting a flow of hot gas to a condenser and on to the evaporator for a cooling cycle and in a second position permitting the hot gas to flow directly to the evaporator for a heating cycle, the three-way valve being under the control of a thermostat unit sensing the temperature of the air being delivered to the loading space and operating to achieve a set point temperature of the air by controlling the three-way valve to produce alternating cooling and heating cycles, the improvement which comprises: a. Valve means operatively connected between the evaporator and compressor; b. Actuating means for selectively opening and closing said valve means, said valve means in an open position permitting a flow, to the evaporator, of a portion of the hot gas delivered from the compressor during both heating and cooling cycles of the apparatus; and c. means in the thermostat unit operatively connected to said actuating means for urging said valve means to an open position only during the time the thermostat unit senses delivered air temperatures which are within a range of temperatures lying between a predetermined temperature which is above the set point temperature, as set at the thermostat unit, and a predetermined temperature below this set point temperature.

Claim 3

An arrangement as defined in claim 1, wherein said actuating means is a solenoid.

Claim 4

An arrangement as defined in claim 1, wherein said means in the thermostat unit is an electro-mechanical switch.

Claim 5

An arrangement as defined in claim 1, wherein the range of temperatures lies between 2* above the set point temperature and 2* below this temperature.

Claim 6

In a refrigeration apparatus carried on a vehicle and including a blower for selectively delivering cooled or heated air to a loading space in the vehicle, the apparatus including a compressor for supplying hot gas to a solenoid operated three-way valve which is selectively operable between two positions, the valve in a first position permitting a flow of hot gas to a condenser, and on through a receiver, and an expansion valve to an evaporator for cooling the air, and in a second position permitting the hot gas to flow directly to the evaporator for heating the air, a return line for Gas from the evaporator to the compressor, the blower being disposed to force air through the evaporator and into the bottom of the loading space and to recirculate the air discharged from the top of the loading space, and a thermostat unit having a sensor disposed downstream of the evaporator in the path of circulating air, the thermostat unit operating to achieve a set point temperature of the air and including an electrical switch operatively connected to the solenoid of the three-way valve to move the valve between its first and second positions in response to the temperature of the air moving past the sensor, the improvement comprising: a. A valve operatively connected between the compressor and the evaporator; b. Actuating means for moving said valve between open and closed positions, said valve in an open position permitting a portion of the hot gas delivered by the compressor to flow directly to the evaporator during both heating and cooling cycles in the apparatus; and c. control means in the thermostat unit operatively connected to said actuating means for opening said valve to permit a flow of hot gas to the evaporator only during that period of time in which the temperature of the air moving past the sensor lies in a range between a predetermined temperature lying above the set point temperature, and a predetermined temperature below this set point temperature.

Claim 7

In a refrigeration apparatus carried on a vehicle and including a blower for selectively delivering cooled or heated air to a loading space in the vehicle, the apparatus including a compressor for supplying hot gas to a solenoid operated three-way valve which is selectively operable between two positions, the valve in a first position permitting a flow of hot gas to a condenser, and on through a receiver, and an expansion valve to an evaporator for cooling the air, and in a second position permitting the hot gas to flow directly to the evaporator for heating the air, a return line for Gas from the evaporator to the compressor, the blower being disposed to force air through the evaporator and into the bottom of the loading space and to recirculate the air discharged from the top of the loading space, and a thermostat unit having a sensor disposed downstream of the evaporator in the path of circulating air, the thermostat unit operating to achieve a set point temperature of the air and including an electrical switch operatively connected to the solenoid of the three-way valve to move the valve between its first and second positions in response to the temperature of the air moving past the sensor, the improvement comprising: a. A valve operatively connected between the compressor and the evaporator; b. Actuating means for moving said valve between open and closed positions, said valve in an open position permitting a portion of the hot gas delivered by the compressor to flow directly to the evaporator during both heating and cooling cycles in the apparatus; and c. control means in the thermostat unit operatively connected to said actuating means for opening said valve to permit a flow of hot gas to the evaporator only during that period of time in which the temperature of the air moving past the sensor lies in a range between a predetermined temperature lying above the set point temperature, and a predetermined temperature below this set point temperature.