Strap Winding Brake Assembly for Safe Webbing Retraction
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Solution Overview
Problem
Existing tensioners lack effective braking mechanisms to control the speed of webbing retraction, posing a safety risk during automatic rewinding, and often have complex structures that increase production costs and friction.
Innovation Solution
A tensioning device with intelligent safety control featuring a brake assembly, including a limit tooth and pendulum tooth, that synchronously rotates with the reeling shaft to regulate winding speed, combined with a coiling spring assembly and pawl mechanism for manual and automatic webbing control, and a front cover with limit walls to prevent handle interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If automatic rewinding function is added to the tensioning device, then productivity is improved, but safety risk increases due to uncontrolled webbing retraction speed
Solution Approach 1:
The brake assembly incorporates a feedback mechanism where the pendulum tooth responds to the rotational speed of the reeling shaft. When the reeling shaft rotates too quickly during automatic rewinding, the pendulum tooth swings outward due to centrifugal force and engages with the brake groove on the limit tooth, automatically applying braking force to control the retraction speed and prevent webbing swinging that could injure the operator.
Solution Approach 2:
The brake assembly is designed as a self-regulating system that automatically activates when needed. The pendulum tooth, eccentrically mounted on the reeling shaft, self-adjusts its position based on rotational speed without external control. During normal operation, it remains in the linkage groove allowing free rotation; during rapid retraction, it automatically swings to engage the brake groove, providing self-service safety control.
2Reliability
If a brake mechanism is added to control webbing retraction speed, then safety is improved, but device complexity increases
Solution Approach 1:
The brake assembly is merged with the existing coiling spring cartridge structure. The limit tooth is integrated into the coiling spring cartridge, and the pendulum tooth is eccentrically mounted on the reeling shaft within the same space. This merging approach allows the brake mechanism to share structural elements with the coiling spring assembly, providing safety control without significantly increasing overall device complexity.
Solution Approach 2:
The limit tooth serves multiple functions: it provides the brake surface for the pendulum tooth to engage during rapid retraction, and it also serves as a structural component of the coiling spring cartridge. The pendulum tooth simultaneously acts as a speed-sensing element and a brake actuator. This multi-functionality reduces the need for separate dedicated brake components, thereby limiting the increase in device complexity.
3Device complexity
If the brake assembly is integrated into the coiling spring cartridge, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The brake groove on the limit tooth and the pendulum tooth geometry are designed to work together as a self-aligning mechanism. The diagonal over-section between the linkage groove and brake groove, combined with the outer contour tooth on the pendulum tooth, creates a self-guiding interface that naturally positions the components correctly during assembly and operation, reducing the need for extremely tight manufacturing tolerances while maintaining reliable brake engagement.
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 effectively prevents webbing swinging, ensures operator safety, reduces production costs, and enhances operational smoothness by minimizing friction and deformation, while maintaining safety through a safety mechanism at the hook opening.
Implementation Method 1
one end of the reeling shaft is connected to a coiling spring assembly, the coiling spring assembly includes a coiling spring and a coiling spring cartridge sleeved on the coiling spring
Implementation Method 2
the brake assembly includes a limit tooth and a pendulum tooth... the pendulum tooth rotates synchronously with the reeling shaft... when automatically retracting the long webbing, it is necessary to carefully control the retraction speed to prevent the long webbing from swinging
Data Source
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AI summary
A tensioning device with intelligent safety control for a webbing is provided, including a handle assembly (1), a base assembly (2), and a long webbing (3). The handle assembly (1) includes a handle (4) and ratchet wheels (5), the base assembly (2) includes a base (6), the handle (4) and the base (6) are pivotally connected with each other through a reeling shaft (7), the ratchet wheels (5) are fixedly mounted on the reeling shaft (7), a reel (8) is fixed between the ratchet wheels (5), the ratchet wheels (5), the reel (8), and the reeling shaft (7) rotate synchronously, the reel (8) is sleeved outside the reeling shaft (7) and disposed coaxially, one side of the reel (8) is provided with an opening for the long webbing (3) to pass through, one end of the long webbing (3) is sleeved on the reeling shaft (7), and the other end of the long webbing (3) is led out from one end of the base (6), one end of the reeling shaft (7) is connected to a coiling spring assembly (9); the coiling spring assembly (9) includes a coiling spring (91), a coiling spring cartridge (92), and a coiling cartridge cover (93), the coiling cartridge cover (93) is disposed on the coiling spring cartridge (92), and a brake assembly (10) is disposed in the coiling spring cartridge (92); one end of the reeling shaft (7) is provided with a C-shaped opening (71), an eccentric shaft (72), or a concentric screw hole (40), depending on the structure of the brake assembly (10), thereby preventing the long webbing (3) from whipping and injuring operators, ensuring personal safety.