Electronically controlled beverage dispenser

• US 5,732,563 A
• Filed: 05/23/1994
• Issued: 03/31/1998
• Est. Priority Date: 09/22/1993
• Status: Expired due to Term

• Current Assignee: IMI Cornelius Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: IMI Cornelius Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Bethuy, Timothy W., Goulet, Douglas P.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/247,613
• Time in Patent Office: 1,408 Days
• Field of Search: 62/59, 62/138, 62/139, 137/392, 324/446, 324/444
• US Class Current: 62/139
• CPC Class Codes: F25C 2700/04 Level of water
• CPC Class Codes: F25D 21/02 Detecting the presence of frost or condensate
• CPC Class Codes: F25D 31/003 with immersed cooling element
• CPC Class Codes: Y10T 137/7306 Electrical characteristic sensing

Abstract

An electronic control for the operation of a beverage dispenser of the refrigerated ice bank type is shown. The control provides for reliable determinations of when ice production is needed and when it is not needed. A microprocessor receives information from an ice bank probe and from a temperature probe located within the ice bank. Data collected by the microprocessor from both the ice bank probe and the temperature probe is used to determine if the ice bank is either insufficient in size and should be increased or is of sufficient size such that the compressor can be turned off. A carbonator level probe is also shown and connected to the microprocessor. The microprocessor is programmed whereby the carbonator probes are sampled in a manner to accurately determine the level of water in the carbonator and therefore the need for turning on or turning off any water pump connected thereto Both the operation of the compressor and the water pump are controlled by the microprocessor wherein the programming thereof provides for adequate hysteresis protection so that short cycling of the compressor and water pump is avoided.

Claims

1. A control device for regulating the size of an ice bank in a beverage dispenser, the dispenser having a tank for holding a volume of water and an evaporator coil, the evaporator coil connected to refrigeration means for providing cooling thereof for forming the ice bank thereon, the control comprising:

a control means, the control means connected to the refrigeration means for providing operating thereof,

an ice sensing means connected to the control means and positioned within the tank at a first predetermined position,

a temperature sensing means connected to the control means and positioned within the tank and adjacent the evaporator coil at a second predetermined position so that when the ice bank forms on the evaporator coils the temperature sensing means is located within the ice bank, and the control means periodically determining the presence of ice at the first predetermined position as indicated by the ice sensing means and determining a thickness of ice between the first predetermined position and an outer surface portion of the ice bank as a function of the sensed temperature at the second predetermined position for turning the refrigeration means off if ice is sensed at the first predetermined position and if the sensed temperature at the second predetermined position indicates that ice of sufficient thickness has formed between the first predetermined position and the outer surface portion of the ice bank.

2. The control device as defined in claim 1, and the ice sensing means including a pair of probes at the first predetermined position and the control means for periodically directing a flow of electrical current there between and the ice sensing means including means for sensing the degree of resistance to the electrical flow between the probes so that the control means can determine if ice is present at the first predetermined position as a function of that sensed resistance.

3. The control device as defined in claim 2, and the control means providing for no electrical potential between the probes except when directing the electrical flow there between.

4. The control device as defined in claim 3, and the control means providing for alternating the direction of electrical flow between the probes.

5. The control device as defined in claim 4, and the control means having predetermined high and low resistance set points wherein the refrigeration means is operated if the sensed resistance is below the low resistance set point and wherein the refrigeration means is not operated if the sensed resistance is above the predetermined high resistance set point and wherein the operation of the refrigeration means is not changed if the sensed resistance is between the high and low resistance set points.

6. The control device as defined in claim 5, and the control means sensing the resistance between the probes by sampling the resistance there between a plurality of times and throwing out a predetermined number of the high and low samples and averaging the remaining samples for determining the sensed resistance.

7. The control device as defined in claim 6, and the control means adding a predetermined temperature value to the temperature sensed by the temperature sensing means when the ice sensing means first senses ice at the first predetermined position and continuing the operating of the refrigeration means for a period of time until a later sensed temperature value equals the sum of the sensed temperature when the ice sensing means first senses ice at the first predetermined position plus the predetermined temperature value after which the refrigeration means is turned off.

8. The control device as defined in claim 2, and the control means providing for alternating the direction of electrical flow between the probes.

9. The control device as defined in claim 8, and the control means providing for no electrical potential between the probes except when directing the electrical flow there between.

10. The control device as defined in claim 2, and the control means having predetermined high and low resistance set points wherein the refrigeration means is operated if the sensed resistance is below the low resistance set point and wherein the refrigeration means is not operated if the sensed resistance is above the predetermined high resistance set point and wherein the operation of the refrigeration means is not changed if the sensed resistance is between the high and low resistance set points.

11. The control device as defined in claim 10, and the control means sensing the resistance between the probes by sampling the resistance there between a plurality of times and throwing out a predetermined number of the high and low samples and averaging the remaining samples for determining the sensed resistance.

12. The control device as defined in claim 1, and the control means adding a predetermined temperature value to the temperature sensed by the temperature sensing means when the ice sensing means first senses ice at the first predetermined position and continuing the operating of the refrigeration means for a period of time until a later sensed temperature value equals the sum of the sensed temperature when the ice sensing means first senses ice at the first predetermined position plus the predetermined temperature value after which the refrigeration means is turned off.

13. The control device as defined in claim 1, and the second predetermined position located so that the temperature sensing means is positioned substantially centrally in the ice bank.

14. The control device as defined in claim 1, and the control means stopping the operation of the refrigeration means if the temperature sensed by the temperature sensing means at the second predetermined position goes below a predetermined low temperature value.

15. A control device for regulating the size of an ice bank in a beverage dispenser, the dispenser having a tank for holding a volume of water and an evaporator coil, the evaporator coil connected to refrigeration means for providing cooling thereof for forming the ice bank thereon, the control comprising:

a control means,

a pair of probes, the probes held at a first predetermined position,

and the probes connected to the control means, the control means providing for a flow of electrical current between the probes, and the control means including means for sensing and determining the magnitude of resistance to the flow of electrical current between the probes,

a temperature sensing means connected to the control means and positioned at a second predetermined position wherein the temperature sensing probe is located within the ice bank formed on the evaporator coil, and the control means for determining the presence of ice at the first predetermined position as a function of the magnitude of the resistance of the flow of electrical current between the probes, and the control means for determining the temperature sensed by the temperature sensing means and determining the thickness of the ice between the first predetermined position and an outer surface portion on the ice bank as a function of the sensed temperature for turning the refrigeration means off if ice is sensed at the first predetermined position and if the sensed temperature indicates that ice of sufficient thickness has formed between the first predetermined position and the ice bank outer surface portion.

16. The control device as defined in claim 15, and the control means providing for no electrical potential between the probes except when directing the electrical flow there between.

17. The control device as defined in claim 16, and the control means providing for alternating the direction of electrical flow between the probes.

18. The control device as defined in claim 17, and the control means having predetermined high and low resistance set points wherein the refrigeration means is operated if the sensed resistance is below the low resistance set point and wherein the refrigeration means is not operated if the sensed resistance is above the predetermined high resistance set point and wherein the operation of the refrigeration means is not changed if the sensed resistance is between the high and low resistance set points.

19. The control device as defined in claim 18, and the control means sensing the resistance between the probes by sampling the resistance there between a plurality of times and throwing out a predetermined number of the high and low samples and averaging the remaining samples for determining the sensed resistance.

20. The control device as defined in claim 19, and the control means adding a predetermined temperature value to the temperature sensed by the temperature sensing means when the ice sensing means first senses ice at the first predetermined position and continuing the operating of the refrigeration means for a period of time until a later sensed temperature value equals the sum of the sensed temperature when the ice sensing means first senses ice at the first predetermined position plus the predetermined temperature value after which the refrigeration means is turned off.

21. The control device as defined in claim 16, and the control means having predetermined high and low resistance set points wherein the refrigeration means is operated if the sensed resistance is below the low resistance set point and wherein the refrigeration means is not operated if the sensed resistance is above the predetermined high resistance set point and wherein the operation of the refrigeration means is not changed if the sensed resistance is between the high and low resistance set points.

22. The control device as defined in claim 21, and the control means sensing the resistance between the probes by sampling the resistance there between a plurality of times and throwing out a predetermined number of the high and low samples and averaging the remaining samples for determining the sensed resistance.

23. The control device as defined in claim 15, and the control means adding a predetermined temperature value to the temperature sensed by the temperature sensing means when the ice sensing means first senses ice at the first predetermined position and continuing the operating of the refrigeration means for a period of time until a later sensed temperature value equals the sum of the sensed temperature when the ice sensing means first senses ice at the first predetermined position plus the predetermined temperature value after which the refrigeration means is turned off.

24. The control device as defined in claim 15, and the second predetermined position located so that the temperature sensing means is positioned substantially centrally in the ice bank.

25. The control device as defined in claim 15, and the control means stopping the operation of the refrigeration means if the temperature sensed by the temperature sensing means at the second predetermined position goes below a predetermined low temperature value.

26. A method for regulating the size of an ice bank in a beverage dispenser, the dispenser having a tank for holding a volume of water and an evaporator coil, the evaporator coil connected to refrigeration means for providing cooling thereof for forming the ice bank thereon, the steps comprising:

periodically sensing for the presence of ice at a first predetermined position,

periodically sensing temperature at a second predetermined position within the ice bank when sensing for the presence of ice at the first predetermined position,

determining the thickness of ice between the first predetermined position and an outer surface position of the ice bank as a function of the sensed temperature at the second predetermined position,

turning the refrigeration means off if ice is sensed at the first predetermined position and if the sensed temperature at the second predetermined position indicates that ice of sufficient thickness has formed between the first predetermined position and the outer surface position of the ice bank.

27. The method as defined in claim 26, and the control means stopping the operation of the refrigeration means if the temperature sensed by the temperature sensing means at the second predetermined position goes below a predetermined low temperature value.

28. The method as defined in claim 26, and the ice sensing means including a pair of probes at the first predetermined position and including the steps of periodically directing a flow of electrical current between the probes and sensing the degree of resistance to the electrical flow between the probes and determining ice is present at the first predetermined position as a function of the sensed resistance.

29. The method as defined in claim 28, and including the step of alternating the direction of electrical flow between the probes.

30. The method as defined in claim 28, and including the steps of determining high and low resistance set points and operating the refrigeration means if the sensed resistance is below the low resistance set point, stopping the operation of the refrigeration means if the sensed resistance is above the predetermined high resistance set point and not changing the operation of the refrigeration means if the sensed resistance is between the high and low resistance set points.

31. The method as defined in claim 30, and determining the sensed resistance by including the further steps of sampling the resistance between the probes a plurality of times, throwing out a predetermined number of the high and low samples and averaging the remaining samples.

32. The method as defined in claim 28, and including the step of preventing any electrical potential between the probes except when directing the electrical flow there between.

33. The method as defined in claim 32, and including the step of preventing any electrical potential between the probes except when directing the electrical flow there between.

34. The method as defined in claim 32, and including the step of alternating the direction of electrical flow between the probes.

35. The method as defined in claim 34, and including the step of preventing any electrical potential between the probes except when directing the electrical flow there between.

36. The method as defined in claim 35, and including the steps of determining high and low resistance set points and operating the refrigeration means if the sensed resistance is below the low resistance set point, stopping the operation of the refrigeration means if the sensed resistance is above the predetermined high resistance set point and not changing the operation of the refrigeration means if the sensed resistance is between the high and low resistance set points.

37. The method as defined in claim 36, and determining the sensed resistance by including the further steps of sampling the resistance between the probes a plurality of times, throwing out a predetermined number of the high and low samples and averaging the remaining samples.

38. The method as defined in claim 37, and including the further steps of adding a predetermined temperature value to the sensed temperature when ice is first sensed at the first predetermined position, monitoring the temperature at the second predetermined position until that temperature is equal to the sum of the sensed temperature when ice is first sensed at the first predetermined position plus the predetermined temperature value, operating the refrigeration means when ice is first sensed at the first predetermined position until the sensed temperature equal the sum of the sensed temperature when ice is first sensed at the first predetermined position plus the predetermined temperature value and then stopping the operation of the refrigeration means.

39. The method as defined in claim 26, and including the further steps of adding a predetermined temperature value to the sensed temperature when ice is first sensed at the first predetermined position, monitoring the temperature at the second predetermined position until that temperature is equal to the sum of the sensed temperature when ice is first sensed at the first predetermined position plus the predetermined temperature value, operating the refrigeration means when ice is first sensed at the first predetermined position until the sensed temperature equal the sum of the sensed temperature when ice is first sensed at the first predetermined position plus the predetermined temperature value and then stopping the operation of the refrigeration means.

40. The method as defined in claim 26, and including the steps of monitoring the temperature at the second predetermined position and shutting down the operation of the refrigeration means if the sensed temperature at that position goes below a predetermined low temperature.