Detachable Towing Shank for Full Crash Energy Absorption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing towing devices for motor vehicles often compromise energy absorption during collisions, leading to uneven damage distribution and increased repair costs, as they either reduce the effective 'crash path' for energy absorption or require additional weight and complex assembly due to their placement and design.

Innovation Solution

A towing device with a shank and shank mount that connects only under load, featuring a tubular shank receptacle and locking elements, allowing complete energy absorption during crashes without impairing the vehicle's energy-absorbing elements, and a guide element for secure attachment during normal driving, reducing weight and improving assembly ease.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the towing device is integrated into the energy-absorbing element (crash box), then the towing eye is securely mounted, but the crash path is reduced and energy absorption efficiency becomes unequal depending on whether the towing device is hit

Engineering Contradiction:
Improvetowing device mounting securityVSAvoidenergy absorption efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The towing device is segmented into a detachable shank and shank mount connection. The shank can be connected to or disconnected from the shank mount, allowing the towing device to be separated from the energy-absorbing element when not in use. This segmentation enables the energy-absorbing element to function fully during crashes without the towing device interfering with the crash path.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If the towing device is fastened below the side member to utilize energy-absorbing element deformability, then energy absorption is improved, but additional housing is required increasing weight and assembly complexity

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidhousing and assembly complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The shank mount is designed to serve multiple functions: it provides mounting for the towing shank during normal operation and simultaneously acts as part of the energy absorption system during crashes. The shank mount is integrally formed with the energy-absorbing element, eliminating the need for separate housing structures. This multi-functionality reduces device complexity and weight while maintaining energy absorption capability.

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

3Ease of operation

If the towing device is positioned to allow easy assembly, then ease of operation is improved, but the position may interfere with energy-absorbing element function during crashes

Engineering Contradiction:
Improveassembly easeVSAvoidenergy absorption performance
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The towing device transitions from a static integrated structure to a dynamic detachable system. The shank can be easily connected to and disconnected from the shank mount using simple locking elements (locking balls or locking pins). During normal operation, the towing device is easily accessible for assembly. During crashes, the detachable connection allows the shank to disengage from the shank mount, preventing interference with the energy-absorbing element's deformation and ensuring optimal energy absorption performance.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2248688B1Towing device
Publication Date: 2013.10.09 REHAU AG & CO
  • EP2248688B1 patent drawingFigure 1~2
  • EP2248688B1 patent drawingFigure 3~4
  • EP2248688B1 patent drawingFigure 5~8

AI summary

The towing device comprises a shaft receiver (2) with a recess (4) which is seized by a locking element (5). The locking element is associated with a locking element holder (6). The locking element holder is formed in a counter element (7) connected with a motor vehicle. A positive- or frictional connection is formed between the counter element and the shaft receiver by realizing a connection of a shaft (1) with the shaft receiver. An independent claim is also included for a bodywork element of a motor vehicle.