Car Door Handle Assembly with Strain-Gauge Constraint Sensing

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Solution Overview

Problem

Existing car door opening systems with electronic sensing units can decrease user experience quality due to non-intuitive placement and require multiple movements for operation, necessitating a better integration of electronic sensing units in handles.

Innovation Solution

A car access assembly with an electronic sensing unit comprising a sensor attached to an extension portion or bracket of the handle, which transmits constraints applied to the handle through strain gauges for intuitive one-motion door operation, using strain gauges to detect pushing or pulling motions for locking and unlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a sensing unit is added to a car door to unlock it for opening, then the door can be unlocked with less force, but the user experience quality decreases because the sensing unit could be located in a place that is not intuitive for the user

Engineering Contradiction:
Improveforce required to unlock doorVSAvoiduser experience quality
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent combines the sensing unit with the handle assembly, integrating the electronic sensing functionality into the mechanical handle structure. The sensor is positioned within the handle body, allowing it to detect user interaction naturally during handle operation, thereby maintaining intuitive user experience while reducing the force needed to unlock the door.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a mechanical arrangement as an intermediary between the handle and the sensing unit. This mechanical arrangement transmits the user's gripping force and motion to the sensor, enabling the sensor to detect user intent without requiring direct contact with the sensing unit surface, thus maintaining natural handling behavior.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Force

If a sensing unit is implemented in a handle to facilitate user command, then the door can be opened with less force, but another opening method requires practice for the user involving two different movements in a precise order

Engineering Contradiction:
Improveforce required to open doorVSAvoidoperation simplicity
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent merges the sensing unit with the handle assembly, allowing the sensor to detect user interaction during natural handle operation. This integration enables the door to be opened with a single intuitive motion (gritting the handle) rather than requiring separate actions like pushing a button followed by pulling the door, thereby maintaining operation simplicity while reducing force requirements.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If the sensor is attached directly to the handle, then the constraint applied to the handle is transmitted to the sensor, but the sensor placement may not be intuitive for users

Engineering Contradiction:
Improveconstraint detection accuracyVSAvoiduser intuitiveness
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces a mechanical arrangement as an intermediary element between the handle and the sensor. This mechanical arrangement serves as a mediator that transmits the constraint applied to the handle to the sensor while positioning the sensor in a way that maintains user intuitiveness. The mechanical arrangement ensures accurate constraint detection without compromising the natural user interaction experience.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables efficient and intuitive one-motion operation of car doors by integrating sensors that measure handle constraints, enhancing user experience and maintaining a compact design without additional thickness.

Implementation Method 1

The sensor includes at least one strain gauge, said at least one strain gauge being configured to be deformed when the constraint is applied to the handle

Methodology Applied
Scientific EffectStrain gauge deformation: Piezoresistive Effect

Data Source

PatentEP4336004B1Car access assembly comprising a handle of a car door
Publication Date: 2025.10.29 MINEBEA ACCESSSOLUTIONS ITALIA SPA
  • EP4336004B1 patent drawingFigure 1~2
  • EP4336004B1 patent drawingFigure 3~4
  • EP4336004B1 patent drawingFigure 5~6

AI summary

Car access assembly (1) comprising a handle (3) configured to be attached on a car door and an electronic sensing unit (7), the electronic sensing unit (7) comprising a sensor (9) configured to be attached on an extension portion of the handle (3) and/or to a bracket (13) configured to cooperate with the handle (3), said extension portion and/or said bracket (13) being configured to be installed on or facing an internal side of a part of the car door extending according to a reference plane (19); a fixing mechanism (21) for the sensor (9) so that a constraint applied to the handle (3) is transmitted to the sensor (9) for detection of a command via the extension portion and/or the bracket (13).