Tow Bar Locking Mechanism Spring Arrangement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing trailer hitch systems require an additional spring to load the locking body into its blocking position, complicating the locking mechanism and increasing the risk of unintentional unlocking.

Innovation Solution

The spring arrangement that loads the locking body into its locking position also loads the locking actuator, eliminating the need for an additional spring and simplifying the locking mechanism by directly transmitting force to the locking body through the actuator, allowing for a two-stage unlocking process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an additional spring is used to load the locking body into its blocking position, then the locking reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvelocking reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the function of loading the locking actuator and the locking body into a single spring arrangement. The spring arrangement (49) is supported on the connection piece (52) and acts on both the locking actuator (54) and the locking body (38), eliminating the need for separate springs while maintaining reliable locking functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single spring arrangement (49) performs multiple functions: it loads the locking actuator (54) into its locked position and simultaneously loads the locking body (38) into its blocking position. This multi-functional design reduces component count while ensuring reliable operation of the locking mechanism.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a power transmission element like a pressure Bowden cable is used to actuate the lock, then the locking range is extended, but the vulnerability to external damage increases

Engineering Contradiction:
Improvelocking rangeVSAvoidexternal damage risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the vulnerable power transmission element (pressure Bowden cable) from the locking system. Instead, the locking device (22) is actuated directly by pulling element (24) through the locking actuator (54), with all critical components localized within the bearing head (30) where they are protected from external damage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The locking actuator (54) serves as an intermediary that translates the pulling force from element (24) into the movement of the locking body (38). This intermediary mechanism allows for direct actuation without requiring vulnerable power transmission cables, while still achieving the desired locking range and functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the locking device is simplified by removing additional springs, then the ease of manufacture is improved, but the reliability against unintentional unlocking may worsen

Engineering Contradiction:
Improveease of manufactureVSAvoidanti-unlocking reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent merges the loading function for both the locking actuator (54) and locking body (38) into a single spring arrangement (49). This simplification reduces manufacturing complexity while maintaining reliability through the geometric design of the transmission surfaces (86) that ensure proper sequencing of locking operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring arrangement (49) is pre-configured to automatically load both the locking actuator (54) and locking body (38) into their correct positions. The transmission surfaces (86) on the locking actuator are designed to first unlock the locking body from its blocking position before allowing movement into the unlocked position, preventing unintentional unlocking while maintaining simple construction.

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 configuration enhances safety by ensuring the locking device remains localized, reducing the risk of external damage and providing a reliable mechanism for preventing unintentional unlocking, while maintaining a simple and efficient structure.

Implementation Method 1

a spring arrangement (49) which loads the locking body (38) into its locking position (V)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

The spring arrangement thus acts on the locking body via the locking actuator (54)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2277724B1Tow bar
Publication Date: 2013.11.20 WESTFALIA AUTOMOTIVE
  • EP2277724B1 patent drawingFigure 1~2
  • EP2277724B1 patent drawingFigure 3
  • EP2277724B1 patent drawingFigure 4~8

AI summary

The coupling (10) has a holder (13) fastened to a motor vehicle and holding a coupling arm (15). A locking device (22) comprises a blocking body (64) that is adjustable between a release position and a blocking position (S) and actuated by a lock-actuator (54). The body blocks movement of a locking body (38) from a locking position (V) to an unlocking position. A spring arrangement (50) loads the locking body in the locking position and loads the blocking body in the blocking position by the lock-actuator.