Quick-Coupler Wedge Locking for Pin Retention After Hydraulic Failure
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Solution Overview
Problem
Quick couplers for attachments on earth working machines can fail to securely hold the attachment, leading to the attachment falling off or swinging down due to hydraulic failure, which is a safety hazard.
Innovation Solution
A wedge locking element with a planar pin engagement surface and a clamp device that prevents the pin from applying a loading force on the wedge, combined with a biasing mechanism to maintain the pin's engagement with the wedge, even in the event of hydraulic failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a sloping wedge surface is used to retain the pin, then the wedge can be hydraulically operated to lock and unlock the pin, but hydraulic failure can cause the pin to drive the wedge backward to a release position
Solution Approach 1:
The patent applies preliminary anti-action by designing the wedge with a non-sloping engagement surface that proactively prevents the pin from driving the wedge backward. The engagement surface is oriented perpendicular to the pin axis, creating a mechanical stop that counteracts the harmful effect of hydraulic failure before it can cause pin release.
Solution Approach 2:
The patent changes the geometric parameter of the wedge engagement surface from sloping to non-sloping (perpendicular orientation). This parameter change fundamentally alters the mechanical interaction between the pin and wedge, transforming the wedge from a component that can be driven backward to one that provides a stable, failure-resistant retention mechanism.
2Ease of operation
If the pin engagement surface is sloping, then the wedge can engage the pin smoothly during normal operation, but the pin can apply loading to drive the wedge to a release position during hydraulic failure
Solution Approach 1:
The engagement surface is designed with a non-sloping orientation that preemptively counteracts the harmful loading effect. By positioning the surface perpendicular to the pin axis, the design eliminates the mechanical advantage that would otherwise allow the pin to drive the wedge backward during hydraulic failure.
Solution Approach 2:
The patent changes the angular parameter of the engagement surface from a sloping orientation to a perpendicular orientation. This parameter change removes the component of force that would cause the wedge to move to a release position, while still allowing smooth engagement during normal operation.
3Reliability
If a safety locking device is added to retain the front pin, then the attachment cannot fall completely from the coupler, but the device complexity increases
Solution Approach 1:
The safety locking device is designed to be self-actuating through the clamp mechanism that automatically engages when the wedge moves to a release position. The system uses the wedge's own movement to trigger the safety lock, eliminating the need for separate actuators or complex control systems.
Solution Approach 2:
The safety locking function is merged with the existing wedge and clamp structure. The clamp mechanism is integrated into the wedge assembly, combining the normal locking function with the safety backup function in a single integrated structure rather than adding a completely separate system.
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 effectively reduces the risk of the attachment falling or swinging by ensuring the pin remains engaged with the coupler, enhancing safety and reliability without requiring additional hydraulic actuators.
Implementation Method 1
a biasing mechanism to maintain the pin's engagement with the wedge, even in the event of hydraulic failure
Implementation Method 2
the driving force is hydraulic
Data Source
AI summary
A wedge locking element (10) for a locking device of a quick coupler A for coupling the pin P2 of an attachment to earth working machinery. The wedge locking element (10) has a sloping wedge surface (13). Projecting from the wedge surface (13) is an engagement surface (12) with which the attachment pin P2 can engage but not apply any substantial driving force to the wedge locking element (10) in the event of failure of a force maintaining the wedge locking element (10) in a position where the pin P2 is retained with the coupler A. The pin engagement surface (12) lies in a plane that is substantially in line with the direction in which the locking element (10) is, in use, moved by the driving force.