Pulley Clevis Actuation for Inflatable Emergency Equipment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing manual back-up actuators for inflatable emergency equipment lack mechanical advantage, requiring maximum input force for inflation due to direct attachment to the output load, which is inefficient.
Innovation Solution
Integration of a pulley system into the clevis, where a cable is routed around a pulley with one end fixed at a stationary anchor point and the other connected to an input source, providing counterbalancing force and mechanical advantage for inflation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a direct attachment is used to connect the manual back-up actuator to the output load, then the structure is simple, but the input force required is maximum and inefficient
Solution Approach 1:
A pulley system is introduced as an intermediary mechanism between the manual back-up actuator and the output load. The pulley redirects the cable tension and provides mechanical advantage, reducing the input force required while maintaining structural efficiency. The pulley acts as a mediator that transforms the force application mechanism without significantly increasing overall system complexity.
2Force
If a pulley system is integrated into the clevis, then mechanical advantage is gained and input force is reduced, but the device complexity increases
Solution Approach 1:
The pulley system is merged with the existing clevis structure, integrating the mechanical advantage mechanism into the already-present structural component. By combining the pulley functionality with the clevis, the patent reduces overall system complexity compared to adding a separate, standalone pulley assembly. This merging approach provides force reduction while minimizing the increase in device complexity.
3Loss of energy
If the cable is routed around a pulley with guide surfaces, then friction is reduced and efficiency is improved, but the manufacturing complexity increases
Solution Approach 1:
Low-friction guide surfaces are applied locally at specific contact points where the cable interacts with the pulley system. Rather than requiring the entire pulley or cable system to be made of special low-friction materials, the patent selectively applies low-friction surfaces only where needed to minimize energy loss. This localized approach reduces friction loss while keeping manufacturing complexity manageable by limiting the scope of specialized manufacturing requirements.
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
Reduces the necessary input force required for manual operation by utilizing the pulley system to counterbalance the load, allowing for efficient inflation of inflatable objects even when the main actuator fails.
Implementation Method 1
utilizing the back-up pulley system of the present invention gains mechanical advantage, thus reducing the input force necessarily provided manually
Implementation Method 2
a (preferably low-friction) pulley is integrated into the clevis. A cable may be attached or otherwise fixed at a first end portion to a stationary anchor point and at a second end portion to an input source. In between the two end portions, the cable may be routed around the pulley
Implementation Method 3
A cable may be attached or otherwise fixed at a first end portion to a stationary anchor point and at a second end portion to an input source. In between the two end portions, the cable may be routed around the pulley and, beneficially, along a guide surface that itself preferably is either a low-friction surface or a secondary pulley
Data Source
AI summary
Actuations systems in which pulley systems may be used as redundant (back-up) mechanisms are described. The systems provide mechanical advantage, especially useful when manual input is required to deploy a back-up mechanism. A pulley may be integrated into a clevis, a cable routed about the pulley, and one end of the cable made stationary, causing the pulley to counterbalance approximately twice the input force provided.