Self-camming Pulley with Eccentric Sheave for Controlled Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pulleys with locking mechanisms and cord extensions for releasing loads require manual intervention to relieve pressure on toothed cams, making them inefficient for controlled release under load.
Innovation Solution
A self-camming pulley design featuring an eccentrically mounted sheave that freewheels in one direction only, coupled with a lever and torsion spring mechanism, allowing for controlled locking and release of the load without manual intervention, utilizing a ratchet and pawl or one-way bearing for directional control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking mechanism with toothed cam is used to secure the load, then the load can be locked in place when force is released, but manual intervention is required to relieve pressure on the cam before releasing the load
Solution Approach 1:
The pulley system performs the release operation automatically through self-camming action. When the line is paid out, the eccentric sheave rotates and automatically cams the release arm, which moves the cam follower off the toothed cam surface, releasing the load without manual intervention. The system serves itself by using the line tension to drive the release mechanism.
Solution Approach 2:
The cam follower is designed to be movable rather than fixed, allowing it to dynamically respond to line tension changes. The release arm pivots on the eccentric sheave, creating a dynamic linkage that automatically transitions between locked and released states based on the direction of line movement, enabling controlled release under load.
2Productivity
If an eccentrically mounted sheave is used to enable one-way freewheeling, then smooth one-way travel is achieved, but the sheave must be precisely positioned to ensure proper camming action
Solution Approach 1:
The sheave is intentionally mounted eccentrically (off-center) on the axle, creating an asymmetric configuration. This asymmetric mounting is the core of the invention, as it creates the camming action that enables one-way freewheeling and automatic release. The eccentricity transforms rotational motion into radial displacement, driving the cam follower along the toothed cam surface.
3Reliability
If a fixed block is used to lock the line between the sheave and block, then secure locking is achieved, but the release mechanism requires additional components like levers and springs
Solution Approach 1:
The release arm is integrated directly onto the eccentric sheave, sharing a common pivot point. The cam follower is combined with the fixed block assembly, creating a unified locking-release mechanism. This merging reduces the number of separate components and simplifies the overall structure while maintaining reliable locking and controlled release functionality.
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
Enables smooth, efficient one-way travel of loads with secure locking and controlled release, reducing manual effort and improving operational safety and efficiency in block and tackle arrangements.
Implementation Method 1
The pulley includes a torsion spring connected between the lever and the second plate. The torsion spring is adapted to bias the lever from the first position to the second position when a line carried by the eccentrically mounted sheave is released.
Implementation Method 2
An eccentrically mounted sheave is located between the first plate and the second plate and is adapted to freewheel in one direction only. The eccentrically mounted sheave is mounted eccentrically with respect to the axle and is adapted to support a line.
Data Source
AI summary
A pulley is provided having a first plate and a second plate arranged adjacent to the first plate and connected to the first plate by an axle. An eccentrically mounted sheave is located between the first plate and the second plate and is adapted to freewheel in one direction only. The eccentrically mounted sheave is mounted eccentrically with respect to the axle. A fixed block is mounted between the first plate and the second plate and is adapted to fixedly lock a line between the fixed block and the eccentrically mounted sheave.