Work Tool Coupler Four-Bar Linkage Actuation
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Solution Overview
Problem
Existing work vehicle couplers lack efficient mechanisms for securely attaching and detaching various work tools, often requiring high forces and complex actuation to maintain tool retention and prevent unwanted movement during operations.
Innovation Solution
A work tool coupler incorporating a four-bar linkage and cam-follower system with a retention pin and lever, which uses a coil spring for enhanced engagement and disengagement control, ensuring secure tool attachment and easy switching between tools through an over-center configuration and precise force management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional retention mechanism is used to securely attach work tools, then tool retention reliability is improved, but the actuation force required and operational complexity increase
Solution Approach 1:
The patent applies a four-bar linkage mechanism that transforms the actuation motion into a dynamic retention system. The linkage includes a first bar connected to the retention pin, a second bar connected to the first bar, a third bar connected to the second bar, and a fourth bar connected to the third bar, creating a dynamic mechanical advantage system that reduces the force needed to engage and disengage the retention pin while maintaining secure tool attachment during operation
Solution Approach 2:
The patent utilizes a cam mechanism that changes the geometric parameters of the retention system during actuation. The cam profile transforms the actuation force into controlled motion of the retention pin, varying the mechanical advantage throughout the engagement cycle to minimize peak actuation forces while ensuring positive locking when engaged
2Reliability
If a traditional retention mechanism is used to prevent unwanted movement, then tool security is improved, but the mechanism complexity and number of components increase
Solution Approach 1:
The patent combines the retention pin actuation mechanism with the tool attachment function into an integrated system. The four-bar linkage and cam mechanism work together with the retention pin to provide both the locking action and the attachment function, reducing the need for separate retention and actuation systems while maintaining tool security
Solution Approach 2:
The patent divides the retention mechanism into distinct functional segments: the retention pin for direct tool engagement, the four-bar linkage for motion transformation, and the cam mechanism for force multiplication. This segmentation allows each component to be optimized for its specific function while working together as a coordinated system, reducing overall complexity compared to monolithic retention designs
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 solution provides secure attachment and easy detachment of work tools, reducing operational forces and preventing unwanted movement, while allowing for precise control of the actuation forces across the coupler's range, enhancing usability and design flexibility.
Implementation Method 1
a coil spring, wherein the spring is connected to the linkage via the cam
Implementation Method 2
a cam-follower system with a coil spring
Implementation Method 3
a four-bar linkage may include a first member, a second member, a third member, and a fourth member
Data Source
AI summary
A work tool coupler for a work vehicle may include a rigid body, a retention pin, a four-bar linkage, and a lever. The retention pin may be configured to engage a work tool when the coupler is in an engaged position. The four-bar linkage may include a first member pivotally connected to the retention pin and at least one of a second member and a third member, the second member pivotally connected to at least one of the first member and the third member, the third member pivotally connected to at least one of the first member and the second member and a fourth member, and the fourth member pivotally connected to the third member. The lever may be attached to the fourth member.