Ratcheting Harness Strap Adjuster With One-Way Webbing Lock
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Solution Overview
Problem
Existing safety harness adjustment mechanisms are often difficult to use, leading to improper fitting and increased risk of injury during falls, and they can result in excess webbing dangling freely, causing snag or entanglement hazards.
Innovation Solution
The development of ratcheting strap adjusters that allow for single-handed adjustment of safety harness webbing, featuring a captive arm locking mechanism and return springs to restrict webbing rotation in one direction, preventing accidental loosening and maintaining webbing containment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a traditional safety harness adjustment mechanism is used, then the harness can be adjusted, but the adjustment process is difficult and time-consuming, leading to improper fitting
Solution Approach 1:
The adjuster mechanism uses a dynamic ratcheting system with a movable pawl that allows easy one-way adjustment while preventing reverse movement. The spring-loaded pawl automatically engages with ratchet teeth to maintain adjustment position, enabling quick and intuitive length changes without complex operations
Solution Approach 2:
The adjuster mechanism is designed to be self-regulating through the ratchet and pawl system. Once adjusted, the spring-loaded pawl automatically locks the position without requiring additional user action. The system self-maintains the adjustment state, eliminating the need for continuous user intervention or complex locking procedures
2Device complexity
If excess webbing is allowed to dangle from the adjuster, then the adjustment mechanism can be simple, but it creates snag and entanglement hazards
Solution Approach 1:
The adjuster mechanism extracts and contains the excess webbing within its housing structure. The ratchet mechanism and housing work together to trap and secure any loose webbing, preventing it from dangling externally. This eliminates the hazard while maintaining mechanical simplicity through the integrated design
3Ease of operation
If the harness adjustment mechanism allows easy length changes, then user comfort is improved, but the risk of accidental loosening increases
Solution Approach 1:
The ratchet mechanism employs asymmetric tooth geometry that permits easy movement in the tightening direction while blocking reverse movement. The pawl engages with the asymmetric ratchet teeth to allow webbing to be pulled tight but prevents any accidental loosening, creating one-way adjustment security
Solution Approach 2:
The spring-loaded pawl is pre-positioned to engage with the ratchet teeth before any loosening force is applied. This preliminary engagement creates an automatic counter-force that prevents accidental loosening from occurring in the first place, rather than merely reacting after loosening begins
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
Enables easy, single-handed adjustment of safety harness webbing, reducing the risk of improper fitting and minimizing loose webbing, thereby enhancing user safety and reducing the likelihood of snag or entanglement hazards.
Implementation Method 1
return springs to restrict webbing rotation in one direction, preventing accidental loosening
Implementation Method 2
captive arm locking mechanism and return springs to restrict webbing rotation in one direction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A ratcheting strap adjuster (10, 100) comprising a bracket (11), a webbing plate (12), and one or more captive members (15). The webbing plate is rotatably coupled to the bracket. Each of the one or more captive members is moveable between an engaged position and a disengaged position, wherein the one or more captive members restrict rotation of the webbing plate in one direction when the one or more captive members are in the engaged position and allow rotation of the webbing plate in the one direction and in an opposite second direction when the one or more captive members are in the disengaged position.