Ratchet Strap Adjuster for Child Seats
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adjuster devices for child vehicle seats cause wear and tear on web straps and do not effectively prevent slippage, while also being cumbersome to use.
Innovation Solution
An adjuster device with a base and operating handle that allows the strap to move freely in both directions when open and securely fastens when closed, utilizing a second pin that is squeezed by the strap's tension to prevent slippage, with specific angles defining the release and fastening positions to facilitate easy tightening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cam type adjuster is used to secure the strap, then the strap can be fastened in position, but the cam ridges cause wear and tear of the web strap
Solution Approach 1:
The patent removes the cam mechanism entirely from the adjuster device. Instead of using a cam with ridges that compress the web, the invention uses a ratchet mechanism with teeth that engage with the web strap, eliminating the harmful compression and ridges that cause wear and tear while maintaining secure fastening capability.
Solution Approach 2:
The patent introduces a ratchet wheel with teeth as an intermediary between the operating handle and the web strap. This ratchet mechanism provides a positive engagement system where the teeth interact with the web strap through a slot, allowing secure fastening without the direct compression contact that causes wear in cam-type adjusters.
2Reliability
If friction is used to prevent strap slippage in the adjuster, then the strap can be secured, but the strap cannot be easily tightened by pulling the free end
Solution Approach 1:
The patent employs a dynamic ratchet mechanism where the direction of web strap movement determines the engagement state. When the web strap is pulled in the tightening direction, the ratchet teeth allow free movement. When pulled in the opposite direction, the teeth engage to prevent slippage. This dynamic behavior automatically provides both easy tightening and secure slippage prevention without requiring additional friction control mechanisms.
3Reliability
If the adjuster uses a complex mechanism to prevent slippage, then security is improved, but the device becomes cumbersome to use
Solution Approach 1:
The patent segments the adjuster mechanism into distinct functional components: an operating handle that pivots, a ratchet wheel with teeth, and a web strap interaction zone. This segmentation allows each component to perform its specific function simply - the handle provides leverage, the ratchet teeth provide one-way engagement, and the web strap carries the load - resulting in a secure but simple overall mechanism.
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 device prevents wear and slippage while allowing easy adjustment and tightening of the strap, ensuring secure fastening without risking unintended movement.
Implementation Method 1
an increased tension on the second strap end causes a restraining action arising at least in part from friction between said parts of the strap
Data Source
AI summary
The invention relates to an adjuster device (1) for adjusting the length and fastening of a web type strap (12), and in particular to an adjuster device (1) intended to be used together with a child restraint harness as part of a child vehicle seat. The adjuster device according to the invention allows, when the adjuster is in the open, release position, the strap to be easily pulled and freely move through the adjuster in both directions whereas the strap, when the adjuster is in the closed, fastening position, is securely fastened (without any risk for slippage) while still allowing the strap to be easily tightened by pulling the strap in one direction only. The present device does not cause wear and tear of the web, prevents slippage and is easy to use.