Excavator Coupler Blocking Bar Mechanism for Hydraulic Failure Safety
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Solution Overview
Problem
Existing couplers for excavators with hydraulically operated latching hooks lack an effective safety mechanism to prevent attachment disengagement in case of hydraulic failure, posing a risk of accidental detachment during operation.
Innovation Solution
A coupler design featuring a latching member and a blocking member, where the blocking member is urged into a blocking state by an attachment pin, and a lever mechanism that engages with the latching hook to retain the blocking member in place, ensuring the attachment remains secured even if the latching hook retracts due to hydraulic failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a hydraulically operated latching hook is used to engage with attachment pins, then the coupling operation is automated and efficient, but the system lacks adequate safety mechanism to prevent accidental disengagement in case of hydraulic failure
Solution Approach 1:
The blocking member is pre-positioned to block the first pin-receiving recess, preventing pin insertion. The lever is pre-configured to automatically engage the blocking member when the latching hook moves from latched to unlatched position, creating a preliminary safety barrier before any disengagement can occur
Solution Approach 2:
The lever acts as an intermediary mechanical component that translates the motion of the latching hook into engagement of the blocking member. This mechanical intermediary ensures that when hydraulic power fails and the latching hook moves, the blocking member is automatically activated to prevent attachment disengagement
2Reliability
If a blocking member is added to prevent accidental disengagement, then safety is improved, but the device complexity increases
Solution Approach 1:
The lever combines multiple functions: it holds the blocking member out of the blocking state during normal operation, and automatically engages the blocking member when the latching hook moves to the unlatched position. This merging of functions reduces the need for separate control mechanisms
Solution Approach 2:
The lever is resiliently biased to automatically engage the blocking member when the latching hook moves, without requiring external control or additional actuators. The system uses its own operational motions to trigger the safety mechanism, making it self-regulating
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 enhanced safety by maintaining the attachment securely engaged with the coupler, preventing accidental disengagement and ensuring operational reliability even in the event of hydraulic failure, while allowing controlled disengagement when necessary.
Implementation Method 1
the lever being resiliently biased into contact with the rear of the latching hook
Data Source
AI summary
A coupler for an excavator, the coupler comprising first and second recesses for receiving the pins of an attachment, a latching hook movable into and out of a latching state in which it closes the second pin-receiving recess, and a blocking bar movable into and out of a blocking state in which a portion of the blocking bar closes the first recess. The arrangement is such that, when the blocking bar is engaged in use by an attachment pin contained within the first recess, the action of the pin on the blocking bar urges the blocking bar into its blocking state. The blocking bar is further arranged so that, in the blocking state, it lies in the path of the latching hook and that, upon movement of the latching hook out of the latching state, the latching hook engages with the blocking bar to retain it in the blocking state.