Reinforced Latch for Automatic Transmission Locking Unit

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Solution Overview

Problem

Automatic transmissions lack a mechanism to prevent unintentional vehicle movement when the engine is switched off, as there is no traction to the drive wheels, necessitating a mechanical locking mechanism for the transmission output shaft to prevent rolling away.

Innovation Solution

A locking unit with a reinforced latch area, enhanced by heat treatment and material reinforcement, is integrated into the automatic transmission's hydraulic circuit to securely lock the piston, thereby preventing unintended movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the locking assembly is designed as a one-piece component to simplify structure, then device complexity is reduced, but the risk of breakage increases under high mechanical loads

Engineering Contradiction:
Improvestructure complexityVSAvoidbreakage risk
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by providing a reinforcement specifically in the catch area of the locking assembly, where mechanical loads are highest. This reinforcement creates a localized strength enhancement without requiring the entire assembly to be more complex or heavier, thus maintaining simplicity while improving reliability at the critical stress point.

Inventive Principle:
Principle #3Local quality

2Reliability

If the catch area is reinforced with additional material to increase strength, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvebreakage resistanceVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The reinforcement is implemented as a separate element that can be integrated into the locking assembly. This segmentation allows the reinforcement to be added only where needed in the catch area, rather than reinforcing the entire assembly, thus improving breakage resistance while minimizing the increase in overall device complexity.

Inventive Principle:
Principle #1Segmentation

3Strength

If the locking assembly is made more robust to withstand high mechanical loads, then strength is improved, but the service life under prolonged use decreases due to increased wear

Engineering Contradiction:
Improvemechanical load capacityVSAvoidservice life
Core Design Contradiction:
StrengthVSDuration of action of moving object

Solution Approach 1:

The patent addresses service life by changing the material parameters of the reinforcement, specifically selecting materials with low friction coefficients and high wear resistance. This allows the catch area to withstand high mechanical loads while minimizing wear during prolonged use, thus extending service life rather than decreasing it.

Inventive Principle:
Principle #35Parameter changes

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 reinforced locking unit significantly extends its service life by reducing the risk of breakage under high mechanical loads, ensuring the vehicle remains securely locked, even under prolonged use.

Implementation Method 1

the locking unit comprises an electromagnet (4) and a latching assembly (6)

Methodology Applied
Scientific EffectElectromagnet: Electromagnet

Implementation Method 2

The spring area (7) has a corresponding elastic design in order to ensure that the latching assembly (6) is positioned radially or at an angle

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

the reinforcement is formed by an increase in the specific strength of the material of the latch area caused by heat treatment

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentEP2636929B1Locking unit
Publication Date: 2017.11.29 SVM SCHULTZ VERWALTUNGS GMBH & CO KG
  • EP2636929B1 patent drawingFigure 1a~1b
  • EP2636929B1 patent drawingFigure 2a~2b
  • EP2636929B1 patent drawingFigure 3a~4c

AI summary

The invention relates to a locking unit for locking the movement of a piston (2) movable by a drive. The locking unit comprises an electromagnet (4) and a detent assembly (6). The detent assembly has a spring section (7) and a latch section (8), wherein the elastic spring section pivots the detent assembly inwards so that the latch section (8), in particular the latch element (13), engages in the undercut on the piston head (5) and blocks the piston in this locked position. In the unlocked position, the movement of the piston is released. The latch section is equipped with at least one reinforcement acting in the direction of movement of the piston.