Multi-mode wrench pawl switching mechanism
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Solution Overview
Problem
Conventional one-way wrenches face a challenge in balancing convenience and strength, as increasing the number of teeth for easier operation compromises the tool's strength, and vice versa.
Innovation Solution
A multi-mode one-way wrench design featuring a head with cutouts and pawls that allow for alternate engagement with a toothed wheel, utilizing a switch with arched grooves to guide the pawls between modes, enabling efficient rotation with reduced idle stroke angles while maintaining strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the number of teeth on the toothed wheel is increased to reduce the minimum idle rotation angle, then the convenience of operation is improved, but the strength of each individual tooth is reduced
Solution Approach 1:
The invention divides the single pawl-toothed wheel engagement system into multiple independent engagement paths by providing both a leading pawl and a following pawl that can alternately engage with different teeth on the toothed wheel. This segmentation allows the system to achieve fine incremental rotation (equivalent to having many teeth) while each individual tooth maintains its original strength characteristics.
Solution Approach 2:
The invention introduces a dynamic switching mechanism where the pawl can transition between leading and following positions based on the rotation direction. The switch mechanism dynamically reconfigures which pawl engages with the toothed wheel, enabling the system to achieve bidirectional control with a unidirectional toothed wheel design, thereby reducing the minimum idle angle without compromising tooth strength.
2Adaptability or versatility
If a switch mechanism is added to enable multi-mode operation, then the versatility and operational flexibility are improved, but the device complexity increases
Solution Approach 1:
The switch mechanism serves multiple functions simultaneously: it controls the engagement/disengagement of the following pawl, guides the stem movement through arched grooves, and enables mode transitions between leading and following pawl operations. By designing the switch to perform multiple functions within a single component, the invention achieves multi-mode operation capability while minimizing the increase in device complexity.
Solution Approach 2:
The switch acts as an intermediary component that mediates between the user's input force and the pawl-toothed wheel engagement system. Through the arched groove geometry, the switch translates simple linear or rotational user input into complex coordinated movements of the stem and pawl, thereby adding versatility without requiring complex control mechanisms.
Data Source
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AI summary
A multi-mode one-way wrench includes a head, a toothed wheel, a leading pawl, at least one following pawl and a switch. The head includes cutouts in communication with a chamber. The toothed wheel rests in the chamber and includes teeth. The pawls are movably rest in the cutouts and adapted for alternate engagement with the toothed wheel. The following pawl includes a stem. The switch rests on the head and made with at least one arched groove for receiving and guiding the stem to move the following pawl between a first mode for engagement with the toothed wheel and a second mode kept from the toothed wheel. The cutouts are biased from one another by an angle of 360°×(M+1/L)÷N, wherein L is an integer for representing the number of the cutouts, M is any proper integer, and N is an integer for representing the number of the teeth.