Hinged Axle Pulley Release for Lower-Force Fire Pull Stations
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Solution Overview
Problem
Existing manual activation systems for fire suppression systems require a large amount of force to operate due to the tension from the cable acting on the pulley, making them difficult for users to activate.
Innovation Solution
A manual activation system with a rotatable bracket and pulley mechanism that allows for reduced tension release through a pivoting bracket and optional biasing mechanism, enabling easier operation by allowing the pulley to move from an inactive to an active position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a pin is used to support the pulley in a simple mechanical mechanism, then the structure is simple and easy to manufacture, but a large amount of force is required to remove the pin making the system difficult to operate
Solution Approach 1:
The support mechanism is segmented into a bracket with a first axis of rotation and a pulley with a second axis of rotation. The bracket can rotate relative to the pulley, dividing the support function into two independent rotational components. This segmentation allows the activation member to engage with the bracket at a specific orientation, reducing the force required compared to a fixed pin support.
Solution Approach 2:
The bracket is made rotatable about a first axis, transforming the static pin support into a dynamic mechanism. The bracket can rotate between different configurations, allowing the activation member to engage and disengage smoothly. This dynamic capability reduces the peak force required during activation compared to a fixed support structure.
2Device complexity
If all tension from the cable acts on the pulley and pin, then the mechanism is simple, but the force required to operate the system increases significantly
Solution Approach 1:
The bracket acts as an intermediary between the pulley and the activation member. Instead of the activation member directly opposing the full cable tension on the pulley, the bracket mediates this interaction by providing a rotational interface. The activation member engages with the bracket at a favorable angle, reducing the effective force required to initiate movement.
Solution Approach 2:
The mechanism introduces a first axis of rotation for the bracket, adding a dimensional degree of freedom. This allows the activation member to engage with the bracket in a specific orientation that is more favorable for force application. By changing the dimensional arrangement from a direct linear tension path to a rotational interface, the required activation force is reduced.
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 system facilitates easier activation by reducing the required force, minimizing the risk of jamming, and ensuring smooth operation of the fire suppression system.
Implementation Method 1
The pulley is rotatable about a second axis. The pulley is movable between an inactive position and an active position.
Implementation Method 2
a bracket rotatable about a first axis between a first configuration and a second configuration
Implementation Method 3
a biasing mechanism is operably coupled to the bracket, the biasing mechanism being operable to apply a biasing force to the bracket to rotate the bracket towards the second configuration
Data Source
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AI summary
A manual activation system (34) includes a bracket (52) rotatable about a first axis (X) between a first configuration and a second configuration and a pulley (40) movable between an inactive position and an active position. The pulley (40) is mounted to the bracket (52) and is rotatable about a second axis (Y). A tension member (52) is wrapped about the pulley (40) and has a tensile force acting on the pulley. An activation member (60) is configured to cooperate with the bracket (52) to selectively oppose the tensile force.