Spring-Biased Locking Cam for Rope Hauling
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Solution Overview
Problem
Existing pulley rescue systems are complex to operate, especially in confined spaces or with unconscious or disabled accident victims, requiring intricate rope braking and releasing mechanisms that complicate single-handed rescue operations.
Innovation Solution
A load-hauling device with a spring-biased locking cam and trigger mechanism, allowing for easy engagement and disengagement of the pulley rope brake using finger pressure, ensuring uni-directional movement and preventing unwanted rope movement, featuring a detente ball for temporary disengagement and a stop member to prevent over-rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a one-way brake system is used to prevent the pulley system from running in the opposite direction, then the safety and reliability of the rescue operation is improved, but the complexity of the device and difficulty of operation increases
Solution Approach 1:
The patent extracts the braking function from a complex integrated system and implements it through a simple, separate locking cam mechanism that can be independently operated. The locking cam is a discrete component that can be engaged or disengaged without affecting other parts of the pulley system, thereby reducing overall system complexity while maintaining the necessary one-way brake function for safety.
Solution Approach 2:
The locking cam mechanism is designed to be self-actuating through a spring-loaded detente system. Once the cam is rotated to the engaged position, the spring automatically maintains the locked state without requiring continuous input from the rescuer. The system serves itself by maintaining the brake engagement passively until deliberately released, reducing operational complexity during critical rescue phases.
2Ease of operation
If a spring-biased locking cam with trigger mechanism is used to control rope movement, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The spring-loaded detente ball acts as an intermediary element between the rescuer's manual input and the locking cam engagement. The detente mediates the transition from an unengaged to engaged state by providing a mechanical intermediary that clicks into place, making the engagement process intuitive and easy to operate while containing the complexity within a small, localized mechanism rather than distributing it throughout the entire system.
3Reliability
If the locking cam is designed to prevent over-rotation with a stop member, then the reliability and safety are improved, but the device complexity increases
Solution Approach 1:
The stop member is pre-positioned on the cam yoke before the locking cam is operated. This preliminary arrangement of the stop mechanism ensures that when the rescuer rotates the locking cam, the physical limit of rotation is already in place to prevent over-rotation. The safety function is built into the geometry of the system beforehand, requiring only simple additive complexity of a fixed stop rather than a complex active control mechanism.
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
Simplifies the operation of pulley systems by allowing easy control of rope direction with minimal effort, ensuring safe and controlled lifting or lowering of loads while preventing unintended movement, enhancing rescue efficiency in challenging conditions.
Implementation Method 1
the cam includes a cam spring to bias the cam to engage with the rope and permit movement of the rope in one direction while preventing movement of the rope in the other direction
Implementation Method 2
the pulley rope passing sequentially between the pulleys of each pulley array to provide a mechanical advantage at the free end of the pulley rope when the pulley rope is pulled by a user of the device
Implementation Method 3
the locking cam trigger includes a spring-loaded projection, such as a detente ball, at the base of the trigger, the projection being partially engageable with a recess in the cam yoke whereby to temporarily disengage the locking cam from the rope against the bias of the cam spring
Data Source
AI summary
A load-hauling device includes a pair of karabiners, each having an array of pulleys, a pulley rope fixed at one end to one of the karabiners below its respective pulley array, to anchor that end of the rope, the pulley rope passing sequentially between the pulleys of each pulley array to provide a mechanical advantage at the free end of the pulley rope when pulled, a rotatable locking cam mounted between a cam yoke fixed around an end pulley of one of the pulley arrays, wherein the cam includes a cam spring to bias the cam to engage with the rope and permit movement of the rope in one direction while preventing movement of the rope in the other direction, the cam including an integral trigger and locking mechanism to selectively disengage the cam from the rope and allow the device to release a load carried thereby.