Electronic refrigeration control system

• US 6,223,817 B1
• Filed: 07/08/1999
• Issued: 05/01/2001
• Est. Priority Date: 04/25/1996
• Status: Expired due to Term

• Current Assignee: Royal Vendors Incorporated (COIN Acceptors Incorporated)
• Original Assignee: Royal Vendors Incorporated (COIN Acceptors Incorporated)
• Inventors: Oden, Kenneth Woodward, Selfridge, Glenn Decker
• Primary Examiner(s): Ford, John K.
• Application Number:
  US09/349,448
• Time in Patent Office: 663 Days
• Field of Search: 165/232, 165/233, 165/254, 165/259, 165/263, 221/150 R, 221/150 HC, 62/157, 62/155, 62/131, 62/158, 62/162
• US Class Current: 165/232
• CPC Class Codes: F25D 21/006 with electronic control circuits
• CPC Class Codes: F25D 2400/36 Visual displays
• CPC Class Codes: F25D 2700/02 Sensors detecting door opening
• CPC Class Codes: F25D 2700/12 Sensors measuring the inside temperature
• CPC Class Codes: F25D 2700/14 Sensors measuring the temperature outside the refrigerator or freezer
• CPC Class Codes: F25D 29/00 Arrangement or mounting of control or safety devices
• CPC Class Codes: G07F 9/105 Heating or cooling means, for temperature and humidity control, for the conditioning of articles and their storage dispensers for food articles requiring a processing by temperature treatment or conditioning before they are ready for dispensing G07F17/0064

Abstract

The present invention is direct to a system and method for electronically controlling the refrigeration and/or heating of the product storage compartment in a vending machine. The system includes a temperature sensor for sensing the temperature in the product storage compartment, and a door sensor for sensing whether the door is open or closed. The control method includes the steps of activating a defrost mode, which is a timed period with no heating or cooling activity, when the door to the vending apparatus is open. The defrost mode is also activated whenever the cooling element has been running continuously for several hours. Further, the control method includes a step of cycling the cooling element “on” whenever a predetermined high temperature is reached. When the cooling element is “off” for more than 6 hours and the predetermined high temperature has not been reached, the heater is turned “on” to prevent the products in the vending machine from freezing.

Claims

1. A method for electronically controlling refrigeration and heating of a product storage compartment in a vending apparatus, comprising the steps of:

sensing a temperature in the product storage compartment;

determining whether the product storage compartment is open or closed; and

maintaining the product storage compartment in one of a defrost mode, a passive refrigeration mode, a passive heating mode, an active refrigeration mode, and an active heating mode based on said sensing of the temperature and said determining whether the product storage compartment is open,

monitoring a refrigeration temperature of the product storage compartment in said passive refrigeration mode, switching to said active heating mode when said passive refrigeration mode exceeds a passive predetermined time period, and switching to said active refrigeration mode when the refrigeration temperature reaches a predetermined refrigeration cut-in temperature,

refrigerating the product storage compartment for an active predetermined time period in said active refrigeration mode, switching to said defrost mode when refrigerating the product storage compartment reaches a predetermined refrigeration cut-out temperature and switching to said defrost mode when refrigerating the product storage compartment reaches the active predetermined time period,

monitoring a heating temperature of the product storage compartment in said passive heating mode, switching to said active heating mode when the heating temperature drops to a predetermined heating cut-in temperature and switching to said active refrigeration control when the heating temperature reaches the predetermined refrigeration cut-in temperature,

heating the product storage compartment in said active heating mode and switching to said passive heating mode when the heating temperature during the heating of the product storage compartment reaches a predetermined heating cut-out temperature, and

maintaining refrigeration and heating control of the product storage compartment inactive for a predetermined defrost time period in said defrost mode and switching to said passive refrigeration mode when the predetermined defrost time period is reached and the product storage compartment is determined to be closed.

2. A method for electronically controlling the refrigeration and heating of a product storage compartment as claimed in claim 1, wherein said defrost mode further includes maintaining the refrigeration and heating control of the product storage compartment inactive for a predetermined door-open safety time period and switching to said passive refrigeration mode when the predetermined door-open safety time period is reached and the product storage compartment is determined to be open.

3. A method for electronically controlling the refrigeration and heating of a product storage compartment as claimed in claim 1, wherein said passive refrigeration mode further includes determining whether the temperature of the product storage compartment is lower than the predetermined refrigeration cut-out temperature by a predetermined difference, and setting a cold error flag warning when the temperature of the product storage compartment is lower than the predetermined refrigeration cut-out temperature by the predetermined difference.

4. A method for electronically controlling the refrigeration and heating of a product storage compartment as claimed in claim 1, wherein said active refrigeration mode further includes determining if a current temperature of the product storage compartment is less than a prior temperature, determining if the current temperature of the product storage compartment has been less than the prior temperature for a predetermined cooling time period, and setting a not-cooling error flag warning when the current temperature of the product storage compartment is determined to having been less than the prior temperature for the predetermined cooling time period.

5. A method for electronically refrigerating and heating a product storage compartment in a vending apparatus which has a door, a cooling element and a heater, said method comprising the steps of:

sensing a temperature in the product storage compartment;

determining whether the door of the vending apparatus is open or closed;

maintaining refrigeration and heating of the product storage compartment inactive for a first predetermined defrost time period;

passively refrigerating the product storage compartment with the cooling element in an OFF state when the first predetermined defrost time period is reached and the product storage compartment is determined to be closed;

monitoring the temperature of the product storage compartment during said passive refrigerating for a passive predetermined time period;

actively refrigerating the product storage compartment with the cooling element in an ON state when the temperature of the product storage compartment reaches a predetermined refrigeration cut-in temperature for an active predetermined time period;

switching to maintaining refrigeration and heating of the product storage compartment inactive for the first predetermined defrost time period when said active refrigerating of the product storage compartment reaches a predetermined refrigeration cut-out temperature;

switching to maintaining refrigeration and heating of the product storage compartment inactive for a second predetermined defrost time period when said active refrigerating of the product storage compartment reaches the active predetermined time period;

actively heating the product storage compartment with the heater in an ON state when the passive predetermined time period is reached;

passively heating the product storage compartment with the heater in an OFF state after actively heating the product storage compartment when the temperature of the product storage compartment reaches a predetermined heating cut-out temperature;

monitoring the temperature of the product storage compartment during said passive heating;

actively heating the product storage compartment with the heater in the ON state when the temperature of the product storage compartment drops to a predetermined heating cut-in temperature during said passive heating; and

actively refrigerating the product storage compartment with the cooling element in an ON state when the heating temperature reaches the predetermined refrigeration cut-in temperature during said passive heating.

6. A method for electronically refrigerating and heating a product storage compartment as claimed in claim 5, further comprising the steps of:

maintaining refrigeration and heating of the product storage compartment inactive for a predetermined door-open safety time period if the door is determined to be open; and

passively refrigerating the product storage compartment when the predetermined door-open safety time period is reached and the door is determined to be open.

7. A method for electronically refrigerating and heating a product storage compartment as claimed in claim 5, wherein said step of passively refrigerating includes determining whether the temperature of the product storage compartment is lower than the predetermined refrigeration cut-out temperature by a predetermined difference, and setting a cold error flag warning when the temperature of the product storage compartment is lower than the predetermined refrigeration cut-out temperature by the predetermined difference.

8. A method for electronically refrigerating and heating a product storage compartment as claimed in claim 5, wherein said step of actively refrigerating includes determining if a current temperature of the product storage compartment is less than a prior temperature, determining if the current temperature of the product storage compartment has been less than the prior temperature for a predetermined cooling time period, and setting a not-cooling error flag warning when the current temperature of the product storage compartment is determined to having been less than the prior temperature for the predetermined cooling time period.

9. A method for refrigerating and heating a storage compartment in a vending machine which has a door, said method comprising the steps of:

sensing a temperature in the storage compartment;

sensing whether the door is open or closed;

maintaining refrigeration and heating of the storage compartment inactive for a first predetermined defrost time period;

refrigerating the storage compartment for a predetermined refrigerating time period when the first predetermined defrost time period is reached and the storage compartment is determined to be closed;

switching to maintaining refrigeration and heating of the storage compartment inactive for the first predetermined defrost time period when the temperature of the storage compartment during said refrigerating of the storage compartment reaches a predetermined refrigeration cut-out temperature;

switching to maintaining refrigeration and heating of the storage compartment inactive for a second predetermined defrost time period when said refrigerating of the storage compartment reaches the predetermined refrigerating time period;

heating the storage compartment when the temperature of the storage compartment drops to a predetermined heating cut-in temperature and until a predetermined heating cut-out temperature is reached; and

switching to refrigerating the storage compartment after said heating when the temperature of the storage compartment reaches the predetermined refrigeration cut-in temperature.

10. A method for refrigerating and heating a storage compartment as claimed in claim 9, said method further comprising the steps of:

maintaining refrigeration and heating of the storage compartment inactive for a predetermined door-open safety time period if the door is determined to be open; and

refrigerating the storage compartment when the predetermined door-open safety time period is reached and the door is determined to be open.

11. A method for refrigerating and heating a storage compartment as claimed in claim 9, wherein said step of refrigerating includes determining whether the temperature of the storage compartment is lower than the predetermined refrigeration cut-out temperature by a predetermined difference, and setting a cold error flag warning when the temperature of the storage compartment is lower than the predetermined refrigeration cut-out temperature by the predetermined difference.

12. A method for refrigerating and heating a storage compartment as claimed in claim 9, wherein said step of refrigerating includes determining if a current temperature of the storage compartment is less than a prior temperature, determining if the current temperature of the storage compartment has been less than the prior temperature for a predetermined cooling time period, and setting a not-cooling error flag warning when the current temperature of the storage compartment is determined to having been less than the prior temperature for the predetermined cooling time period.