초록 ▼

An apparatus for freezing and dispensing semi-frozen food products having two freezing chambers, one compressor for supplying refrigerant to both freezing chambers, one beater drive motor for driving the beaters in both chambers, two solenoid valves control flow of refrigerant from the single compre

An apparatus for freezing and dispensing semi-frozen food products having two freezing chambers, one compressor for supplying refrigerant to both freezing chambers, one beater drive motor for driving the beaters in both chambers, two solenoid valves control flow of refrigerant from the single compressor to the evaporators for the freezing chambers and periodic pulse width modulated signals are applied to operate the two solenoid valves alternately during each period and signals are modulated to have substantially equal duty cycles in an initial freeze mode and to have unequal duty cycles when product is dispensed from only one freeze chamber.

대표청구항 ▼

In a soft-serve dispensing apparatus including two freezing chambers each having an evaporator and a rotary beater, dispensing valve means for dispensing semi-frozen product from the freezing chambers, dispense sensing means for sensing when product is dispensed from each freezing chamber, product c

In a soft-serve dispensing apparatus including two freezing chambers each having an evaporator and a rotary beater, dispensing valve means for dispensing semi-frozen product from the freezing chambers, dispense sensing means for sensing when product is dispensed from each freezing chamber, product condition sensing means for sensing a condition of the product in the freezing chambers that is related to a minimum servable product viscosity; product supply means for supplying unfrozen product to the freezing chambers, refrigeration producer means including a compressor having a compressor drive motor, a condenser, a high pressure refrigerant supply means including a refrigerant expansion control means individual to each evaporator means and low pressure refrigerant return line means for returning refrigerant from both evaporator means to the compressor, and beater drive means for driving the beaters, the improvement comprising, the beater drive means has a single drive motor and power transmission means for connecting the drive motor to the beaters in both freezing chambers to drive both beaters concurrently, said refrigerant expansion control means each comprising an on-off solenoid valve, means for starting an auto-cycle operation of the apparatus, and control means for controlling operation of the compressor drive motor and the beater drive motor and the solenoid valves, (a) said control means including means responsive to starting an auto-cycle of the apparatus for operating the apparatus in an initial freeze mode, said control means including means operative in the initial freeze mode for generating and applying peroidic pulse width modulated signals having substantially equal duty cycles PWF1 to the solenoid valves associated with the evaporators for both freezing chambers where the duty cycle PWF1 provides an effective refrigerant flow rate sufficient to increase the viscosity of the product in the freezing chambers, (b) said control means including means responsive to the dispense sensing means for operating apparatus in a first refreeze mode, the control means including means operative in the first refreeze mode when product is dispensed from one of the freezing chambers for generating and for applying a periodic pulse width modulated signal to the solenoid valve associated with said one of the freezing chambers having a duty cycle PWF2 and for generating and applying a periodic pulse width modulated signal to the solenoid valve associated with the other of the freezing chambers having a duty cycle PWH, where the duty cycle PWF2 provides an effective refrigerant flow rate sufficient to increase the viscosity of the product in said one freezing chamber and the duty cycle PWH provides an effective refrigerant flow rate sufficient to substantially maintain the viscosity of the product in said other freezing chamber, (c) said control means further including means responsive to said product condition sensing means for operating the apparatus in a second refreeze mode, said control means including means operative in said second refreeze mode when the product in one freezing chamber is below a minimum servable product viscosity for generating and applying a periodic pulse width modulated signals having a duty cycle PWF2′to the solenoid valve associated with said one of the freezing chambers and for generating and applying a periodic pulse width modulated signals having a duty cycle PWH′to the solenoid valve associated with the other of the freezing chambers where the duty cycle PWF2′provides an effective refrigerant flow rate sufficient to increase the viscosity of the product in said one freezing chamber and the duty cycle PWH′provides an effective refrigerant flow rate to substantially maintain the viscosity of the product in said other freezing chamber.