Seat Belt Locking Tongue Curved Guide Path

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Solution Overview

Problem

Existing locking tongues for seat belts often jam due to the clamping element being drawn into the webbing passage by tensile force, making it difficult to release the webbing after a restraining event, especially when tensile force is still acting on the webbing.

Innovation Solution

A locking tongue design featuring a clamping element with a curved guide path and a clamping surface that moves perpendicularly against the webbing passage wall, allowing for full-surface contact and independent release from tensile force, preventing jamming and enabling easy release of the webbing, even under tension. The clamping element is supported by a spring for reversible blocking and comfort during normal driving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clamping element is drawn into the webbing passage by tensile force to clamp the webbing, then the webbing is clamped securely, but the clamping element gets jammed and cannot be released easily

Engineering Contradiction:

Improveclamping reliabilityVSAvoidrelease ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

Instead of allowing the clamping element to be drawn axially into the webbing passage (conventional design), the invention inverts the movement direction by guiding the clamping element along a curved path that moves it perpendicular to the webbing passage wall. This inversion prevents the clamping element from being drawn into the passage and jammed, while still achieving secure clamping through full-surface contact.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention employs a curved guide path for the clamping element's movement, transitioning from linear axial movement to curved perpendicular movement. This curvature allows the clamping element to approach the webbing passage wall from a direction that ensures full-surface contact while avoiding the jamming issue that occurs with axial insertion.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Device complexity

If the clamping element moves axially into the webbing passage, then the structure is simple, but the clamping element jams and requires webbing movement for release

Engineering Contradiction:

Improveguide path complexityVSAvoidrelease reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The invention inverts the conventional axial movement direction of the clamping element, guiding it perpendicular to the webbing passage wall instead. This inversion resolves the jamming issue and enables reliable release independent of webbing movement, justifying the added curved guide path complexity.

Inventive Principle:

Principle #13The other way round (Inversion)

3Object-affected harmful factors

If the clamping element has a large clamping surface for full contact, then wear on webbing is reduced, but the construction height increases

Engineering Contradiction:

Improvewebbing wearVSAvoidconstruction height

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The invention changes the dimensional approach by guiding the clamping element to move perpendicular to the webbing passage wall rather than axially. This dimensional change allows a large clamping surface for full contact with the webbing while maintaining compact construction height, as the clamping force is applied from the side rather than from the end.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 design ensures quick and reliable release of the webbing after a restraining event, reduces wear on the webbing, and minimizes construction height, providing improved comfort and operational efficiency by avoiding punctual or linear loads on the webbing.

Implementation Method 1

a spring element (38) which acts upon the clamping element (22) and forces the clamping element (22) into the non-blocking position

Methodology Applied

Scientific EffectSpring: Spring

Implementation Method 2

the clamping element (22) is drawn into the webbing passage (20) by the webbing (16) due to the increased friction between the clamping element and the webbing

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10285473B2Latch plate and method for producing a latch plate

Publication Date: 2019.05.14 ZF AUTOMOTIVE GERMANY GMBH

AI summary

A locking tongue for a seat belt has a deflecting portion for a webbing. The deflecting portion includes a webbing passage and a clamping element. The clamping element is displaceable between a home position in which the webbing is freely movable and a blocking position in which the clamping element is displaced against a wall of the webbing passage so that the webbing is clamped between the clamping element and the wall of the webbing passage. The clamping element includes a clamping surface which in the blocking position clamps the webbing against the wall of the webbing passage. The clamping element is guided along a curved guide path extending in an area of the blocking position substantially perpendicularly to the wall so that in the blocking position the clamping element is moved against the wall substantially perpendicularly with the clamping surface.