Vehicle Door Handle Transmission Brake for Stable Ready Position

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Solution Overview

Problem

The existing transmission mechanisms for vehicle door handles face issues with maintaining the handle lever in a stable ready position over a wide temperature range and lifespan, leading to reduced quality and potential mechanical failure due to inadequate friction tuning and tolerance variations.

Innovation Solution

A transmission mechanism with a brake mechanism that frictionally engages a rotating element of the reduction stage, using a braking pad and radially protruding finger to stop the handle lever in the ready position, combined with a preconstrained spring and cylindrical spring cage to maintain consistent friction torque, ensuring the handle lever remains stable and prevents unwanted retraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If fine tuning of friction between parts is required to prevent handle lever from returning to flushing position, then the handle lever stability is improved, but the manufacturing precision and tolerance control become excessively difficult over wide temperature range and vehicle lifespan

Engineering Contradiction:
Improvehandle lever stabilityVSAvoidfriction tuning precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent extracts the friction control function from the complex interaction between multiple reduction mechanism parts and implements it through a dedicated brake mechanism with a brake pad and actuating finger. This separates the stability control function into a distinct component that can be independently designed and adjusted, eliminating the need for precise friction tuning across the entire reduction mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The brake pad acts as an intermediary element between the actuating finger and the rotating element. By introducing this intermediate friction interface, the system achieves controlled friction-based stopping without requiring precise friction characteristics from the worm gear and worm wheel interfaces, which are now free to operate with standard tolerances.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the reduction mechanism is made highly irreversible to prevent unwanted retraction, then the handle lever stability is improved, but the risk of complete mechanical failure during reverse actuation increases

Engineering Contradiction:
Improvehandle lever stabilityVSAvoidmechanical failure risk
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The brake mechanism serves as a controlled intermediary that enables temporary, controlled reversibility during normal operation (allowing push-push unit to return lever to ready position) while maintaining stability in the ready position. The brake can be selectively engaged and disengaged, providing a safe intermediate state that prevents both unwanted retraction and complete mechanical failure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system transitions from a static, highly irreversible reduction mechanism to a dynamic system where the brake mechanism can be selectively engaged and disengaged. This allows the system to adapt its reversibility characteristics based on operational requirements, being irreversible during normal operation for stability but reversible when controlled by the push-push unit for manual intervention.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the handle lever is allowed to move freely between positions, then the ease of operation is improved, but the perceived quality and user experience deteriorate due to spontaneous return to flushing position

Engineering Contradiction:
Improvehandle lever operabilityVSAvoidhandle lever position stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent extracts the position control function from the passive friction characteristics of the reduction mechanism and implements it through an active brake mechanism. This allows the handle lever to move freely during operation while the brake mechanism selectively engages to provide stable positioning, separating the motion freedom from position stability.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides a stable ready position over a wide temperature range, reduces wear, and prevents mechanical failure by ensuring the handle lever remains in the ready position, even under conditions of mechanical or electrical failure, thus enhancing the perceived quality and reliability of the vehicle door handle system.

Implementation Method 1

a brake mechanism configured to frictionally engage a rotating element of one of the reduction stages of the reduction mechanism when the lever shaft reaches a rotational braking position comprised between the flush and ready positions of the handle lever, to stop said handle lever in the ready position

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

combined with a preconstrained spring and cylindrical spring cage to maintain consistent friction torque

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3498953B1Vehicle door handle assembly
Publication Date: 2021.06.16 U SHIN DEUTSCHLAND ZUGANGSSYSTEME GMBH
  • EP3498953B1 patent drawingFigure 1~2
  • EP3498953B1 patent drawingFigure 3~4b
  • EP3498953B1 patent drawingFigure 5a~5c

AI summary

The invention relates to a vehicle door handle (1) transmission mechanism (200), configured to be attached on one side to a handle lever (3), the handle lever (3) being movable in particular between a flushing position in which it is flush with an exterior door panel (100) surface and a ready position in which it is protruding and graspable by a user, and on the other side to an electric motor (7), comprising : • a lever shaft (27), configured to be connected to the handle lever (3), the rotation of which causes the motion of the handle lever (3) between the flushing and ready positions, • a reduction mechanism (9), configured to adapt an output torque of the electric motor (7) into a rotational motion of the lever shaft (27), comprising a first reduction stage (91) and a second reduction stage (93), having each a worm drive, the worm drive of the first reduction stage (91) comprising a first worm and a first worm gear (29), and the worm drive of the second reduction stage (93) having a second worm (33) and a worm gear (35) rotationally coupled to the lever shaft (27), wherein the transmission mechanism (200) comprises a brake mechanism (37, 41) frictionally engaging a rotating element (39) of one of the reduction stages (91, 93) of the reduction mechanism (9) when the lever shaft (27) reaches a rotational braking position comprised between the flush and ready positions of the handle lever (3), to stop said handle lever (3) in the ready position.