Key-Releasable Strap Locking Head with Pawl Mechanism

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Solution Overview

Problem

Traditional cable ties are non-reusable and require cutting to release, posing safety risks and limitations in securely restraining objects or people, as they can only be used once and are prone to damage when attempting to release them.

Innovation Solution

A key-releasable securing device with a flexible strap and locking head that includes a pawl mechanism, where the pawl is biased for engagement with the strap's teeth, allowing the strap to be easily released by progressive insertion of a key without the need for rotation, and featuring a guide means to prevent key twisting and ensure axial movement, along with a cap for enhanced security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional cable tie with ratchet mechanism is used, then the device can maintain a tightened condition and prevent loosening, but the device can only be used once and requires cutting to release

Engineering Contradiction:
Improvesecurity of restraintVSAvoidreusability and release safety
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent transforms the static, single-use ratchet mechanism into a dynamic, reversible system. The pawl member can engage with teeth to prevent loosening, but can also be disengaged by inserting a key that moves the pawl away from the teeth, allowing the strap to be released and the device reused multiple times without cutting

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a key as an intermediary tool to operate the release mechanism. The key engages with the pawl member and applies force to move it out of engagement with the teeth, providing a safe and controlled method to release the strap without requiring cutting tools that pose safety risks

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a key rotation mechanism is used to release the pawl, then the pawl can be moved out of engagement, but the key is subjected to torque that may cause bending or breaking

Engineering Contradiction:
Improverelease mechanism functionalityVSAvoidkey structural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

Instead of rotating the key to release the pawl (which subjects the key to bending torque), the patent inverts the mechanism: the key is inserted axially and pushes the pawl directly out of engagement with the teeth. This linear pushing action avoids the torque and bending stresses that would occur with rotational movement, preserving key structural integrity

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If the locking mechanism is accessible without restriction, then the device can be easily operated, but the device is vulnerable to tampering and unauthorized release

Engineering Contradiction:
Improveaccessibility of locking mechanismVSAvoidtampering and unauthorized access
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent segments the locking head into two parts: a cap that covers and protects the internal mechanism, and the main body containing the pawl and teeth. The cap can be removed with the key to access the release mechanism, providing both protection against tampering and controlled access for authorized operation

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3497028B1A key-releasable securing device
Publication Date: 2020.07.15 PLUS 8 IND
  • EP3497028B1 patent drawingFigure 1A~1B
  • EP3497028B1 patent drawingFigure 2
  • EP3497028B1 patent drawingFigure 3A~3B

AI summary

A key-releasable securing device A key-releasable securing device (1) has a flexible strap (3) having a plurality of teeth (11) and a locking head (7). The locking head (7) has a cavity (21) in which the flexible strap (3) is insertable into and through to form a securing loop (14) of adjustable dimension. The flexible strap (3) is slidably movable in first or second directions to reduce or increase, respectively, the dimension of the securing (loop14). A pawl member (20) is located inside the locking head (7) so as to engage with the teeth (11) of the flexible strap (3) to allow movement in the first direction but prevent movement in the second direction. Asa release key (40) is inserted into the locking head (7), the release key (40) is guided by guide means into engagement with the pawl member (20), so as to move the pawl member (20) out of engagement with the teeth (11) of the flexible strap (3) to allow the strap (3) to move in the second direction.