Icemaker Harvest Control for Premature Freeze Release

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Solution Overview

Problem

Conventional icemaker control systems often result in premature ice harvests, leading to the formation of hollow or deformed ice cubes, inaccurate ice level detection, and potential jamming of dislodging devices due to inaccurate temperature sensing and inconsistent ice production rates.

Innovation Solution

An icemaker assembly with a controller that initiates a forced harvest prevention cycle based on signals from an ice cube storage bin sensor, disconnecting communication during a harvest prevention command and reconnecting only after a predetermined time or when the ice level drops below a threshold, ensuring ice cubes are fully frozen before harvesting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a temperature sensing device is used to detect when ice cubes are fully frozen, then premature harvest can be prevented, but the temperature sensing is inaccurate because air temperature threshold does not correlate with water freezing temperature

Engineering Contradiction:

Improveharvest timing accuracyVSAvoidtemperature sensing accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the temperature sensing mechanism with a time-based control mechanism. Instead of using a temperature sensor to detect when water freezes, the system uses a timer to track the duration of the freeze cycle. The harvest is triggered after a predetermined time interval has elapsed since water was supplied to the mold, eliminating the need for temperature measurement while maintaining reliable harvest timing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from temperature to time. The harvest initiation is no longer based on detecting a specific temperature threshold but rather on whether a predetermined time interval has passed. This parameter change resolves the measurement accuracy issue by using a parameter (time) that can be measured precisely without the complexities of temperature sensing in the icemaker environment.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a time component is added to temperature sensing to prevent premature harvest, then harvest timing can be improved, but the method remains inaccurate due to temperature sensing errors and produces inconsistent ice production rates

Engineering Contradiction:

Improveharvest timing controlVSAvoidice production consistency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent completely replaces the temperature sensing system with a time-based control system. The controller initiates a freeze cycle, supplies water to the mold, and then starts a timer. After the predetermined time interval elapses, the harvest cycle is automatically initiated. This substitution eliminates temperature sensing errors entirely and ensures consistent ice production by relying on the precise timing capability of the controller's internal clock rather than variable temperature measurements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If harvest cycle is initiated before ice cubes are fully frozen, then ice cube production rate increases, but hollow or deformed ice cubes are formed and dislodging devices can become jammed

Engineering Contradiction:

Improveice cube production rateVSAvoidice cube quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements preliminary timing action to ensure ice cubes are fully frozen before harvest. The controller is programmed with a predetermined time interval that represents the minimum freezing duration required. The harvest cycle is only initiated after this time has elapsed, ensuring ice cubes are completely frozen before attempting to dislodge them. This preliminary time-based action prevents the formation of hollow or deformed ice cubes while maintaining consistent production rates.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution prevents premature ice harvests, ensuring consistent ice cube size, shape, and production rate, reducing damage to the icemaker assembly by ensuring ice cubes are fully formed before dislodging, and maintaining efficient operation.

Implementation Method 1

a freeze cycle timer can be initiated and the freeze cycle can be terminated after a predetermined time interval has elapsed

Methodology Applied

Scientific EffectTime measurement:

Implementation Method 2

actuating the heater to the on-state to heat the ice cube mold

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

actuating the water valve to provide water to the ice cube mold

Methodology Applied

Scientific EffectFluid flow control:

Data Source

PatentUS8857198B2Icemaker shut off method for premature harvest reduction

Publication Date: 2014.10.14 HAIER US APPLIANCE SOLUTIONS INC

AI summary

A system and method for controlling an icemaker assembly to prevent premature ice harvests is provided. In particular implementations, normal icemaker operations, including ice cube harvesting, can be suspended when an ice cube level in an ice cube storage bin is detected to exceed a predetermined threshold or when a command is received to prevent harvesting. When a command to prevent harvesting is received, communication from an ice cube storage bin sensor can be disconnected, for instance, after a current harvesting cycle is complete. The communication from the ice cube storage bin sensor can be reconnected following a time interval or after receiving a command to re-start the normal operations.