Tree Felling Head Bunching Finger Spring Mechanism
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Solution Overview
Problem
Current tree felling head designs face inefficiencies and premature component failures due to unpredictable motion of the bunching finger, which affects the accumulation area sweeping and tree retention, and the extension spring's geometry leads to excessive stress and frequent failures.
Innovation Solution
A biasing member, such as a spring, is coupled between the inner arm and the frame to provide a constant force urging the inner arm towards the accumulation area, ensuring synchronized rotation with the outer arm and reducing stress on components by allowing for proper sizing of the spring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an extension spring is used to rotate the outer arm back to its starting position during reset, then the outer arm can be returned to position, but the spring experiences excessive stress and frequent failures
Solution Approach 1:
The patent extracts the biasing function from the extension spring and relocates it to a dedicated biasing member (compression spring) that is always in contact with the inner arm. This separates the reset function (performed by the actuator) from the biasing function (performed by the compression spring), allowing the spring to be properly sized for compression rather than extreme extension, thereby reducing stress and improving reliability.
Solution Approach 2:
The patent changes the operational parameters of the spring from an extension spring experiencing excessive elongation to a compression spring operating within its optimal compression range. The biasing member is configured to apply constant force during the entire rotation cycle, changing the spring's working parameters from extreme stretch to controlled compression, which significantly improves reliability.
2Productivity
If the inner arm rotates to the extent of its rotation towards the accumulation area, then the bunching finger can sweep the accumulation area, but the motion becomes unpredictable when direction is reversed
Solution Approach 1:
The patent applies preliminary action by having the biasing member continuously urge the inner arm towards the accumulation area throughout the entire rotation cycle. This constant biasing force ensures that the inner arm maintains its proper rotational position and direction, preventing unpredictable motion when the actuator reverses direction. The spring is already in place and applying force before any position indeterminacy can occur.
3Ease of operation
If the bunching finger uses a hinged member configuration, then it can hold severed trees in the accumulation area, but the inner arm rotation changes the position of the outer arm relative to the frame
Solution Approach 1:
The patent implements feedback through the biasing member that continuously monitors and corrects the inner arm's position. As the actuator moves the outer arm, the biasing member provides continuous feedback force to the inner arm, ensuring it maintains the correct rotational position relative to the frame. This feedback mechanism compensates for any position changes caused by the hinged configuration, maintaining manufacturing precision.
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
This solution ensures accurate sweeping of the accumulation area and proper tree retention, reducing operational inefficiencies and extending the lifespan of components by minimizing stress and improving the reliability of the bunching finger's motion.
Implementation Method 1
A biasing member, such as a spring, is coupled between the inner arm and the frame to provide a constant force urging the inner arm towards the accumulation area
Data Source
AI summary
A tree felling head including a gathering arm and a bunching finger. In various embodiments the bunching finger may include inner and outer arms pivotally coupled together with the inner arm also pivotally coupled to a frame portion of the felling head. A biasing member, e.g. a compression spring, urges pivotal movements of the inner arm toward (and/or away from) the accumulation area of the felling head. An actuator connected to the outer arm reciprocally helps urges movement of the finger into and out of the accumulation area of the felling head. In various embodiments, a coupling of the actuator to the outer arm permits folding pivotal movement between the arms when retraction occurs and a tree inhibits outer sweeping movement of the outer finger. Said folding resulting in withdrawal of the outer finger from behind the inhibiting tree.