Auto-Reverse Ratchet Mechanism Eliminates Slippage
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Solution Overview
Problem
Existing power wrenches either lack the ability to automatically reverse the ratcheting direction or require complex linkage systems that are prone to breakage and slippage.
Innovation Solution
A ratchet mechanism with a pawl positioner that automatically repositions the ratcheting pawl relative to the driving head when the motor's rotational direction reverses, utilizing a gear-on-gear design to eliminate slippage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a ratcheting power wrench is used to apply torque to fasteners, then torque can be transmitted to the user for controlling the tightening/loosening process, but the operator's hand can be whipped into an obstruction or sharp object causing bodily injury
Solution Approach 1:
The tool is segmented into two distinct operational modes: a powered mode for high-speed torque application and a manual ratcheting mode for controlled operation. The pawl positioner automatically separates these modes by repositioning the pawl relative to the gear teeth, allowing the system to switch between powered rotation (where the pawl is disengaged) and manual ratcheting (where the pawl engages), thereby eliminating the whipping effect while preserving torque control capabilities
Solution Approach 2:
The pawl positioner dynamically repositions the pawl based on the operational mode. During powered operation, the pawl positioner rotates to disengage the pawl from the gear teeth, allowing free rotation without torque transmission to the user's hand. During manual operation, the pawl positioner allows the pawl to engage with the gear teeth, enabling controlled ratcheting and torque feedback, thus adapting the torque transmission characteristics to the operational requirements
2Ease of operation
If an oscillating yoke design is used in a ratcheting power wrench, then the tool can reverse rotational direction, but slippage occurs due to wear and tension requirements
Solution Approach 1:
The invention extracts and eliminates the oscillating yoke component from the system entirely. Instead of using a yoke that oscillates to reverse direction, the patent employs a direct pawl positioner mechanism that rotates to reposition the pawl relative to the gear. This removal of the yoke eliminates the source of slippage while maintaining the ability to reverse rotational direction through the pawl's selective engagement and disengagement from the gear teeth
Solution Approach 2:
The complex oscillating yoke mechanical system is replaced with a simpler direct pawl positioner mechanism. The pawl positioner directly rotates to reposition the pawl without requiring the intermediate oscillating motion of a yoke. This substitution eliminates the tension requirements and wear-associated slippage inherent in yoke designs, providing more reliable directional reversal through direct pawl-to-gear interaction
3Extent of automation
If numerous components and linkage are used for auto-shift reversing mechanism, then automatic direction reversal can be achieved, but the components are susceptible to breakage
Solution Approach 1:
The invention merges the reversing function directly into the pawl positioner mechanism itself, eliminating the need for separate linkage systems. The pawl positioner simultaneously performs two functions: positioning the pawl for engagement/disengagement and enabling automatic direction reversal through its own rotation. This consolidation of functions into a single integrated component reduces the total number of parts while maintaining full automation capability
Solution Approach 2:
The pawl positioner is designed as a multi-functional component that combines several operations: it positions the pawl radially inward for powered operation, repositions the pawl for manual ratcheting, and enables automatic direction reversal. By making the pawl positioner universal and multi-functional, the design eliminates the need for dedicated reversing linkage and other separate components, reducing overall device complexity while maintaining automatic reversal capability
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 a reliable and efficient auto-reverse ratchet mechanism that reduces the risk of operator injury and tool damage, while maintaining high speed and torque capabilities.
Implementation Method 1
The presently disclosed technology also does not employ or require coupling linkage or an oscillating yoke. The presently disclosed technology avoids the slippage inherent to the design of U.S. Pat. No. 9,038,504 due to a gear-on-gear design.
Data Source
AI summary
A ratchet mechanism of a reversible tool head can include a driving member extending along a first longitudinal axis. The driving member is configured to be driven by a motor or other power source. A driving head can extend along a second longitudinal axis. The first longitudinal axis extends transversely to the second longitudinal axis. The driving member is configured to operatively connect to the driving head. A pawl positioner can surround a portion of the driving head and can be fixedly attached to the driving head. A pawl can include a plurality of teeth selectively engageable with teeth of the tool head. The pawl positioner can be configured to automatically reposition the pawl relative to the driving head when a rotational drive direction of the driving member is reversed.