Open-End Wrench Jaw Design for Hexagonal Fastener Stability
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Solution Overview
Problem
Conventional open-end wrenches fail to stably clamp and screw hexagonal screw members due to incomplete side engagement, leading to instability and ease of screw member slippage during operation.
Innovation Solution
The open-end wrench features a push head with inclined guide and clamping surfaces and a C-like jaw with entrance and exit guide surfaces, along with an elastic member, to securely clamp five sides of the hexagonal screw member, preventing slippage during screwing and unscrewing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional open-end wrench with a jaw opening is used, then the wrench can be operated continuously, but at least a pair of sides of the hexagonal screw member cannot be applied with force, affecting operation stability
Solution Approach 1:
The jaw is divided into multiple clamping surfaces (first clamping surface, second clamping surface, third clamping surface, fourth clamping surface) that correspond to different sides of the hexagonal screw member. Each clamping surface is independently positioned to engage with specific sides, allowing five sides to be simultaneously clamped while maintaining continuous operation capability.
Solution Approach 2:
Different portions of the jaw have different geometric characteristics tailored to specific functions. The clamping surfaces are angled to match the included angles between adjacent sides of the hexagonal screw member, while the jaw opening is shaped to guide the screw member. This local optimization ensures that each side of the screw member receives appropriate clamping force.
2Ease of operation
If the jaw opening is normally open for backswing operation, then continuous operation is enabled, but the hexagonal screw member may slide out of the jaw opening easily, affecting operation stability
Solution Approach 1:
The jaw is designed with multiple clamping surfaces that actively prevent the screw member from sliding out before it can escape. The angled clamping surfaces create friction and mechanical interlocking that counteract the tendency of the screw member to slide, while the normally open jaw opening allows for easy backswing operation when needed.
Solution Approach 2:
The jaw opening is normally open to allow dynamic backswing operation, but the multiple clamping surfaces dynamically adjust to maintain engagement. The elastic member allows the jaw to flex slightly during operation, maintaining continuous contact with the screw member while allowing for necessary movement during tightening and backswing operations.
3Reliability
If an extension sleeve with a bent end surface is used to prevent slippage, then the screw member cannot slide out, but the design affects or hinders the hexagonal screw member from entering the jaw opening
Solution Approach 1:
The jaw is segmented into distinct functional surfaces: the jaw opening for insertion, the inclined guide surface for guiding, and multiple clamping surfaces for securing. This segmentation allows the screw member to be guided into the correct position while maintaining an open structure that facilitates easy insertion without requiring a bent extension sleeve.
Solution Approach 2:
The inclined guide surface acts as an intermediary between the jaw opening and the clamping surfaces. It guides the screw member into the correct orientation and position, facilitating easy insertion while the normally open jaw opening maintains accessibility for backswing operations.
4Reliability
If the jaw is designed to clamp five sides of the hexagonal screw member, then operation stability is enhanced, but the structure becomes more complex
Solution Approach 1:
Multiple clamping surfaces are merged into a single jaw structure that can be actuated by a single pivot mechanism. The first, second, third, and fourth clamping surfaces are all part of the same jaw piece, allowing five sides to be clamped simultaneously without requiring multiple separate clamping mechanisms or complex linkages.
Solution Approach 2:
The jaw is designed as a multi-functional component that performs guiding, clamping, and retention functions. The inclined guide surface guides the screw member, while the multiple clamping surfaces simultaneously clamp five sides, and the elastic member provides retention. This consolidation reduces the need for separate components and simplifies the overall structure.
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 design allows for stable and convenient screwing and unscrewing of hexagonal screw members by ensuring complete side engagement and preventing slippage, enhancing operational stability and ease of use.
Implementation Method 1
The push end surface is biased by the elastic member so that the swing limit end surface abuts against the front end of the inclined guide surface to restrict the jaw from swinging in a direction on the push head
Data Source
AI summary
An open-end wrench is provided. A push head of an operating handle is accommodated in a coupling slot of a jaw. A portion of an inclined guide surface, first and second clamping surfaces and a swing support point normally extend to a jaw opening. When the open-end wrench is used to screw or unscrew a hexagonal screw member, a first entrance guide surface and a second entrance guide surface of the jaw guide a pair of sides of the hexagonal screw member for the hexagonal screw member to enter the jaw opening, and five sides of the hexagonal screw member can be clamped quickly to enhance the convenience for screwing or unscrewing the hexagonal screw member. In addition, the hexagonal screw member won't slide out of the jaw opening during the backswing process of the operating handle so as to screw or unscrew the hexagonal screw member stably.