Adjustable Spanner Jaw Recesses Prevent Nut Apex Rounding

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Solution Overview

Problem

Existing adjustable spanners are not suitable for nuts of different specifications due to their fixed jaw designs, which can lead to rounding of nut apexes during operation.

Innovation Solution

The adjustable spanner features a jaw structure with a cambered or trapezoidal protrusion and recess system, where the fixing and movable surfaces are parallel, and an inclined resisting surface, allowing the nut apexes to be received in recesses without contact with the spanner, preventing rounding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the inner surfaces of the jaws are formed with protrusions and recesses, then the nut apex rounding is prevented for specific nut types, but the spanner cannot be used for various nuts of different specifications

Engineering Contradiction:
Improveprevention of nut apex roundingVSAvoidapplicability to various nut specifications
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The jaw structure is designed with a universal recess system that can accommodate nuts of different specifications. The recesses are positioned and dimensioned to receive nut apexes across various sizes, pitch, and helix angles, allowing a single spanner design to serve multiple nut types while preventing apex rounding through the recess reception mechanism

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If the recesses in the inner surfaces of the two jaws are positioned for specific nut sizes, then nut apex rounding is prevented for those nuts, but the apexes of nuts of different specifications cannot fall into the recesses

Engineering Contradiction:
Improveprecise positioning of nut apexes in recessesVSAvoidcompatibility with different nut sizes and specifications
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The jaw inner surfaces feature strategically positioned recesses with specific local geometries tailored to receive nut apexes. The recesses are located at precise positions and have dimensions optimized for preventing apex rounding while maintaining adaptability through the overall jaw design that accommodates various nut specifications

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If the jaw surfaces are made parallel, then the nut gripping stability is improved, but the ability to accommodate different nut sizes is reduced

Engineering Contradiction:
Improvestability of nut grippingVSAvoidadjustability to different nut sizes
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The spanner employs an adjustable jaw mechanism that maintains parallel jaw surfaces during operation for stable gripping, while allowing the jaw position to be dynamically adjusted through the adjustment mechanism to accommodate nuts of different sizes. The parallel surfaces are achieved through the geometric relationship between the movable and fixed jaws rather than being fixed in position

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP1918070B1Adjustable spanner for preventing nut from rounding apex
Publication Date: 2010.12.15 PROXENE TOOLS CO LTD
  • EP1918070B1 patent drawingFigure 1
  • EP1918070B1 patent drawingFigure 2
  • EP1918070B1 patent drawingFigure 3~5

AI summary

An adjustable spanner (1) comprises a handle (10); one end of the handle having an enlarged head (20); an upper side of the head being formed with a sliding surface (221); a fixing jaw (21) extending from one end of the head; the fixing jaw having a fixing surface (211); a fixing protrusion (212) being formed at an upper side of the fixing surface; a movable jaw (24) installed in a sliding trench (22); the movable jaw having a movable surface (241); a directional control element (25) being installed in a receiving groove (23) and engaged with the movable jaw; a movable protrusion (242) being formed at a lower side of the movable surface; a line Y being defined from a top end of the fixing surface along the fixing surface towards the sliding surface; a line X being defined to be an axial line of the sliding trench, the angel Θ between the line Y and the line X is between 65° and 85°, preferably is 74°.