Cam-Locking Strap Clasp for Vibration-Resistant Cargo Fastening
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Solution Overview
Problem
Existing strap fasteners are cumbersome to use and prone to coming unsecured due to vehicle acceleration, vibration, and load shifting, making them inefficient for securing cargo.
Innovation Solution
A clasp assembly with a main body and a rotatably coupled bail that includes a cam portion to engage and disengage a flexible element, along with a lock assembly to securely lock the bail in place, preventing unwanted disengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ratchet strap is used to secure a load, then the strap can be adjusted to the desired tension, but the strap is cumbersome to operate with one hand when loose due to lack of stiffness
Solution Approach 1:
The bail is designed to be rotatable between a first configuration (locked) and a second configuration (unlocked). When unlocked, the bail can be easily manipulated to engage or disengage the cam portion. When locked, the bail maintains structural integrity to prevent accidental opening while remaining operable with one hand.
Solution Approach 2:
The fastening device is divided into distinct functional components: the bail (for engagement/disengagement), the cam portion (for securing), and the ratchet mechanism (for tensioning). This segmentation allows each component to be optimized independently, with the bail providing lever arm stiffness for easy operation while the cam provides secure locking.
2Reliability
If a ratchet strap is used to secure a load, then the strap can be tightened, but the strap may come unsecured due to vehicle acceleration, vibration, turning, or load shifting
Solution Approach 1:
The lock assembly is designed to preemptively counteract forces that might cause accidental disengagement. The resilient member maintains constant engagement pressure on the pawl, and the cam portion's geometry creates mechanical interference that prevents backward movement, countering vibrations, accelerations, and load shifts before they can cause failure.
Solution Approach 2:
The resilient member acts as a cushioning element that absorbs and dampens the effects of vibrations and sudden forces. By providing continuous elastic engagement, it prevents the rigid connection from transmitting harmful shocks that could cause disengagement, while still allowing controlled operation when needed.
3Ease of operation
If a bungee cord is used to secure a load, then the cord can be easily applied, but the cord can easily come loose as the strap flexes while a load is in transit
Solution Approach 1:
The bail provides controlled flexibility through its rotational movement, allowing the strap to accommodate load movement while maintaining security. The cam portion's asymmetric geometry ensures that flexing forces drive the cam deeper into engagement rather than allowing disengagement, combining operational ease with secure locking.
4Reliability
If a lock assembly with resilient member is used to prevent accidental disengagement, then the fastener becomes more secure, but the structure becomes more complex
Solution Approach 1:
The lock assembly merges multiple functions into a single integrated structure: the resilient member provides both the locking force and the disengagement mechanism, the pawl serves as both a latch and a lever, and the cam portion combines tensioning with security. This integration reduces the number of separate components while maintaining high reliability.
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 solution provides a secure and easy-to-use adjustable fastener that effectively prevents the load from becoming unsecured, even under conditions of vehicle movement, by engaging the flexible element and locking the bail in place.
Implementation Method 1
the resilient member has a resilient property and deflects away from and into the recess as the bail is moved from the second configuration to the first configuration
Data Source
AI summary
In one embodiment a clasp assembly includes a main body with a receptacle formed in therein and adapted to receive a flexible element and a bail rotatably coupled to the main body. The bail includes a cam portion configured to engage the flexible element in a first rotational configuration, a lock assembly configured to releasably engage the main body to secure the cam portion in the first rotational configuration.