Rotatable Oven Door Handle with Auto-Return to Prevent Hand Contact

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing oven door handles often require users to reach around or over-tighten, leading to contact with the oven door, which can be uncomfortable and potentially hazardous, especially when hot, and do not automatically return to a convenient position after use.

Innovation Solution

A rotatable door handle with a handle bar that can be rotated up to 90 degrees in both directions, featuring end stops to prevent over-tightening and an automatic return mechanism using a restoring spring or damping element, ensuring ergonomic wrist positioning and safe operation without manual resetting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the door handle is freely rotatable to enable ergonomic wrist flexion, then the ease of operation is improved, but the user's hand may come into contact with the door due to over-tightening

Engineering Contradiction:
Improveergonomic wrist flexionVSAvoidhand contact with door
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by introducing end stops that pre-limit the rotation range of the handle bar. These end stops prevent the handle from rotating beyond a safe angle, thereby preemptively avoiding the harmful effect of hand contact with the door while still allowing sufficient rotation for ergonomic operation.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent implements dynamics by making the handle bar rotatable within a controlled range. The handle bar can rotate dynamically during the opening process to accommodate wrist flexion, but the rotation is bounded by end stops that engage at predefined positions, creating a dynamic yet constrained system.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the handle bar can rotate in both directions from zero position, then the ease of operation is improved, but the device complexity increases due to additional components needed

Engineering Contradiction:
Improvebidirectional rotationVSAvoidend stop mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies merging by integrating the end stop mechanism directly into the handle bar structure. The end stops are combined with the rotation axis and handle bar components, creating a unified assembly that reduces the number of separate parts while maintaining bidirectional rotation capability with controlled limits.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the handle bar is held in fixed position at zero position, then the reliability is improved, but the ease of operation decreases as user must manually reset the handle

Engineering Contradiction:
Improveconsistent zero positionVSAvoidmanual resetting
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements self-service by incorporating a restoring spring that automatically returns the handle bar to its zero position after use. This self-resetting mechanism eliminates the need for manual resetting by the user, while the end stops ensure the handle consistently returns to the correct position, improving both reliability and ease of operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent applies feedback through the restoring spring mechanism that provides tactile and positional feedback to the user. The spring continuously exerts a restoring force that guides the handle bar back to the zero position, and the end stops provide mechanical feedback when the limit positions are reached, creating a self-regulating system.

Inventive Principle:
Principle #23Feedback

4Ease of operation

If the handle bar rotates approximately 90 degrees in both directions, then the ease of operation is improved for ergonomic positioning, but the manufacturing precision requirements increase to ensure proper end stop engagement

Engineering Contradiction:
Improveergonomic wrist positioningVSAvoidend stop positioning
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-positioning the end stops at the correct 90-degree rotation points during manufacturing. The end stops are installed at predetermined locations on the rotation axis, ensuring that the handle bar can rotate exactly 90 degrees in each direction without requiring high-precision adjustment during assembly or use.

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

The solution allows for comfortable, ergonomic opening and closing of the oven door without hand contact with the door, preventing over-tightening and ensuring the handle returns to a convenient position automatically, enhancing user safety and convenience.

Implementation Method 1

The restoring element is preferably designed as a restoring spring, so that after the user has released the handlebar in a structurally simple manner, the handlebar can be returned to its zero position from any angular position.

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the handle bar automatically returns from any angular position between the zero position and the respective end stop position to its zero position by means of a damping element, so that in particular loud noises when turning the handle bar back are avoided

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP2317229B1Cooking oven
Publication Date: 2017.08.09 MIELE & CO KG
  • EP2317229B1 patent drawingFigure 1~2
  • EP2317229B1 patent drawingFigure 3~4

AI summary

The device (2) i.e. baking oven (1), has a housing (3), and a door (5) pivotably held around a pivoting axis (6). A door handle (7) is rotatably supported around a rotation axis (11) and comprises a handle rod (10). The handle rod is rotated around the rotation axis from a zero position up to a defined limit stop position in two rotary directions. The handle rod is automatically returned from an angle position between the zero position and the defined limit stop position into the zero position by a return element i.e. return spring. The handle is made of metal or plastic and/or wood.