Battery Box Handle Cord Closure with Force Deflection Bevel

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional handle cords for battery boxes are prone to accidental opening under extreme loads and high temperatures, posing a risk of the battery box falling and causing injury or damage, especially in automated assembly processes where accelerations of up to 6 G can occur.

Innovation Solution

The handle cord features a closure system with a first closure part having a larger diameter than the cord, which is inserted into a second closure part with a transverse through-opening and axial constriction, and a force deflection bevel on the chamber wall or the first closure part to ensure the closure part remains secured by generating a force component acting upwards when subjected to tensile loads, even at elevated temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the first closure part is inserted into the chamber of the second closure part with the chamber being narrower than the width of the first closure part, then the closure is secured against accidental release, but under extreme loads and high temperatures the first closure part may jump out of the chamber

Engineering Contradiction:
Improveclosure securityVSAvoidresistance to extreme loads and temperatures
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The force deflection bevel is pre-formed on the wall of the first closure part before assembly. When the closure part is inserted into the chamber, the bevel is already positioned to interact with the chamber wall, creating a mechanical interlock that prevents jumping out under extreme loads and temperatures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The closure parts are made from plastic material selected for its properties at elevated temperatures. The force deflection bevel geometry works in conjunction with the material properties to maintain structural integrity and prevent ejection under thermal and mechanical stress conditions.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the plastic material softens at elevated temperatures above 50°C, then the material becomes more flexible, but the first closure part can no longer be securely held in the second closure part under high tensile loads

Engineering Contradiction:
Improvematerial flexibilityVSAvoidholding security
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The force deflection bevel creates an asymmetric geometry where the contact surface between the first closure part and chamber wall is not perpendicular to the insertion axis. This asymmetric angle generates a mechanical locking effect that maintains holding security even when the plastic material softens at elevated temperatures.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The force deflection bevel introduces a dimensional element by creating an angled surface that converts radial forces into axial retaining forces. This geometric feature adds a force component in the direction of the chamber axis that prevents ejection, independent of material temperature-dependent properties.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3557657B1Handle cord for a battery box
Publication Date: 2023.07.26 CLARIOS GERMANY GMBH & CO KG
  • EP3557657B1 patent drawingFigure 1~3
  • EP3557657B1 patent drawingFigure 4~5
  • EP3557657B1 patent drawingFigure 6a~6b

AI summary

The invention relates to a handle (15) for a battery box (1). The handle (15) has a cord (5) and a closure protected against accidental opening, consisting of two closure parts (6, 7) attached to both ends of the cord (5). The first closure part (6) consists of a body (16) with a larger diameter than the cord (5), which can be inserted into a chamber (10) in the second closure part (7). To allow the body (16) to be inserted into the chamber (10), the second closure part (7) has a through-opening (8) arranged transversely to its longitudinal axis (L), permitting the passage of the body (16). The chamber (10) is open towards the underside (14) of the through-opening (8) but closed towards the top (13) of the through-opening (8).In order to ensure that accidental opening of the closure of the handle cord (15) can be reliably prevented even under high loads, the invention provides that the first closure part (6) and/or the second closure part (7) are designed such that, in a state when the body (16) of the first closure part (6) is received in the chamber (10) of the second closure part (7), a force component acting on the body (16) of the first closure part (6) in the direction of the top (13) of the chamber (10) is generated when the cord (5) is under tension.