Composite Wrench Handle via Plastic Injection Molding

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Solution Overview

Problem

Conventional wrench manufacturing processes are lengthy and costly due to multiple complex steps and materials, making it difficult to maintain price competitiveness.

Innovation Solution

A method involving a combination of metallic and nonmetallic materials, where the handle is made from nonmetallic materials like carbon fibers or aluminum alloys, and the movable jaw is made of metal, connected via plastic injection, reducing the number of processes and incorporating anti-rusting layers, with heat treatment and surface treatments to streamline production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metallic materials and multiple complex processes are used to make the wrench, then the wrench has good strength and durability, but the production time is too long and cost is high

Engineering Contradiction:

Improvewrench strength and durabilityVSAvoidproduction time

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The wrench is divided into multiple components (handle, head, movable jaw, adjusting member) that are manufactured separately and then assembled. This allows parallel production of different parts, reducing overall production time while maintaining quality through specialized manufacturing processes for each component.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The handle is made from composite material (carbon fibers or glass fibers reinforced plastic) combining metallic and nonmetallic materials. This provides sufficient strength and durability while reducing weight and enabling faster, less complex manufacturing processes compared to traditional solid metal construction.

Inventive Principle:

Principle #40Composite materials

2Reliability

If conventional metallic materials and multiple complex processes are used to make the wrench, then the wrench has good strength and durability, but the manufacturing cost is high

Engineering Contradiction:

Improvewrench strength and durabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Dividing the wrench into separately manufacturable components allows each part to be produced using optimal, cost-effective processes. The handle can be molded from composite materials in one step, while metal components are produced through standard machining, reducing overall manufacturing cost.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Using composite materials for the handle reduces material cost and eliminates multiple finishing processes (sand spraying, grinding, polishing) required for solid metal, significantly reducing manufacturing cost while maintaining sufficient strength and durability.

Inventive Principle:

Principle #40Composite materials

3Productivity

If the handle is made of nonmetallic material and connected by plastic injection, then the production process is simplified and time is reduced, but the connection strength between parts may be compromised

Engineering Contradiction:

Improveproduction efficiencyVSAvoidconnection strength

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The plastic injection process merges the handle and head into a single integrated component with strong mechanical bonding. The molten plastic flows around and bonds to the metal head, creating a unified structure that is as strong as or stronger than traditional mechanical fastening methods.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The plastic injection creates a composite structure where nonmetallic handle material bonds to metallic head. This composite connection provides sufficient strength for wrench application while enabling the simplified, fast production process.

Inventive Principle:

Principle #40Composite materials

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 method significantly reduces production time and cost, resulting in a lightweight wrench that is more competitive in the market while maintaining performance.

Implementation Method 1

making a body by way of injection, a material for making the body being different from material of the mediate member

Methodology Applied

Scientific EffectPlastic injection:

Implementation Method 2

a step of heat treatment: applying heat treatment to the mediate member, the movable jaw and the adjusting member

Methodology Applied

Scientific EffectHeat treatment: Heat Treatment

Implementation Method 3

coating a anti-rusting layer on the mediate member, the movable jaw and the adjusting member

Methodology Applied

Scientific EffectCoating: Coatings

Data Source

PatentUS7607372B2Method for making a wrench

Publication Date: 2009.10.27 PROXENE TOOLS CO LTD

AI summary

A method for making a wrench includes a step of making a mediate member, a movable jaw and an adjusting member, a step of applying heat treatment to the mediate member, the movable jaw and the adjusting member, a step of cleaning respective surfaces of the mediate member, the movable jaw and the adjusting member, and coating a anti-rusting layer on the mediate member, the movable jaw and the adjusting member, and a step of combination to put the mediate member in a mold and making a body by way of injection to integrally connect the mediate member to a head of the main body, the movable jaw and the adjusting member are installed to the body.