Saw Chain Tensioning Buffer for Bidirectional Cutting
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Solution Overview
Problem
Existing cross-cut saws, like chainsaws, face inefficiencies due to the need for idle strokes when reversing direction, as they can only efficiently cut with the incoming section of the saw chain, leading to suboptimal utilization of operating time.
Innovation Solution
A sawing device with a tensioning device and buffer arrangement between the chain drive wheel and deflection section, featuring a locking device that adjusts the buffering effect to allow efficient cutting with both the incoming and outgoing sections of the saw chain, optimizing chain tension and reducing stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the chainsaw is moved back to home position without making a cut after completing the cut, then the chainsaw returns to starting position, but idle stroke leads to inefficient use of operating time
Solution Approach 1:
The patent enables continuous cutting action by allowing the saw chain to cut efficiently in both forward and reverse directions. The buffer arrangement maintains optimal chain tension during direction changes, eliminating the need for idle return strokes and enabling the cutting process to continue uninterrupted throughout the entire circular path of the saw chain.
Solution Approach 2:
The buffer arrangement dynamically adjusts chain tension based on the direction of movement and cutting forces. By allowing controlled movement of the deflection section relative to the chain drive wheel, the system adapts chain tension in real-time to maintain optimal cutting conditions regardless of whether the incoming or outgoing section is leading, thereby eliminating idle strokes.
2Productivity
If a pivoting device is used to always guide the chainsaw through the sawing area with the incoming section leading, then the utilization of operating time is improved, but the pivoting operation takes time during which the chainsaw cannot make a cut and device complexity increases
Solution Approach 1:
The patent extracts the tensioning function from a complex pivoting mechanism and implements it through a simpler buffer arrangement consisting of a deflection section that can move relative to the chain drive wheel. This buffer arrangement naturally maintains optimal chain tension without requiring active pivoting control, thereby eliminating the need for complex pivoting devices while maintaining high productivity.
Solution Approach 2:
The buffer arrangement is self-regulating and automatically maintains optimal chain tension based on the cutting forces and direction of movement. The deflection section moves freely within its range to accommodate tension variations, eliminating the need for external control systems or pivoting devices to manage chain tension during direction changes.
3Reliability
If the buffer arrangement allows full buffering effect, then the saw chain is protected from overloads, but efficient cutting with the outgoing section is not possible
Solution Approach 1:
The buffer arrangement dynamically adapts its buffering effect based on the cutting direction. When the outgoing section is leading, the deflection section moves to provide optimal tension for efficient cutting. When the incoming section is leading or during potential overload conditions, the buffer arrangement absorbs shocks and protects the chain. This dynamic behavior allows the system to optimize for either cutting efficiency or protection depending on operational conditions.
Solution Approach 2:
The patent changes the tension parameter of the saw chain dynamically based on the cutting phase. The buffer arrangement allows the chain tension to vary within a controlled range, providing high tension for efficient cutting with the outgoing section while maintaining sufficient tension for protection during incoming section operation. This parameter variation enables both efficient cutting and chain protection without compromise.
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 enhances operational efficiency by enabling effective cutting with both sections of the saw chain, reducing idle strokes and preventing overloading, thus improving overall sawing performance and reducing the risk of chain breakage.
Implementation Method 1
The buffer arrangement can optionally have a spring effect and/or a damping effect so that the distance between the chain drive wheel and the deflection section decreases if the set tensioning force of the saw chain is exceeded
Implementation Method 2
The buffer arrangement can optionally have a spring effect and/or a damping effect so that the distance between the chain drive wheel and the deflection section decreases if the set tensioning force of the saw chain is exceeded
Implementation Method 3
The tensioning device is optionally configured to exert an adjustable or predetermined tensioning force on the saw chain
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a sawing device comprising a saw chain (1) and a chain drive wheel (2) for driving the saw chain (1), wherein the saw chain (1) is guided circumferentially, optionally along an elongated contour (3), starting from the chain drive wheel (2) via an exiting section (4), a deflection section (5) and an entry section (6) back to the chain drive wheel (2), wherein a tensioning device (7) is provided between the chain drive wheel (2) and the deflection section (5), which is configured to exert an adjustable tensioning force on the saw chain (1), and wherein the tensioning device (7) comprises a buffer arrangement (8) such that, if the set tensioning force is exceeded, the distance between the chain drive wheel (2) and the deflection section (5) is reduced along a length-variable displacement section (9).wherein a locking device (10) is provided for at least partially locking the buffering effect of the buffer arrangement (8), and wherein the locking device (1) can assume a locking position and a release position. The invention further relates to a saw arrangement and a method.