Single-Step Rolling Process for Screws and Bolts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing manufacturing processes for screws, bolts, and lockbolts are costly due to the need for multiple steps like cold forming and subsequent washing, which can be simplified and made cheaper by exploring alternative production methods.

Innovation Solution

Producing screws, bolts, and lockbolts exclusively through a single rolling process that includes thread formation, flange creation, and optional captive washer integration, eliminating the need for pressing and washing steps, leveraging strain hardening in suitable steels to achieve required strength values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If cold forming (pressing) is used to manufacture screws, bolts, or locking ring bolts, then the required strength values are achieved through strain hardening, but multiple production steps including pressing and washing are required, increasing manufacturing cost and complexity

Engineering Contradiction:
Improvestrength valuesVSAvoidproduction steps
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent combines multiple manufacturing operations (thread rolling, flange forming, captive washer attachment) into a single rolling process. The rolling machine performs all these functions simultaneously in one production step, eliminating the need for separate pressing and washing operations that were required in conventional cold forming methods.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple production steps (pressing, washing, dephosphating, heat treatment) are used, then required strength and surface properties are achieved, but production cost and process complexity increase

Engineering Contradiction:
Improvestrength and surface propertiesVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates unnecessary production steps (washing, dephosphating, heat treatment) from the manufacturing process. By using a single rolling process that achieves both the required strength through strain hardening and the necessary surface properties, these additional costly steps are completely removed, significantly reducing production cost while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If conventional cold forming processes are used, then connecting elements are produced with required mechanical properties, but the manufacturing cost remains high due to multiple process steps

Engineering Contradiction:
Improvemechanical propertiesVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing approach from multi-step cold forming with subsequent treatments to a single rolling process. By adjusting the rolling parameters and using suitable steel materials that achieve the required strength through strain hardening during rolling, the process eliminates costly intermediate steps while maintaining or improving mechanical properties.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If separate processes are used for thread formation, flange creation, and washer attachment, then each feature is precisely formed, but production time and complexity increase

Engineering Contradiction:
Improvefeature formation precisionVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges thread rolling, flange forming, and captive washer attachment into a single simultaneous rolling operation. The rolling machine is designed to perform all these functions in one production step, achieving precise feature formation while dramatically improving productivity by eliminating sequential operations.

Inventive Principle:
Principle #5Merging (Combining)

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 approach significantly reduces production costs and simplifies the process by eliminating multiple manufacturing steps, making rolling the cheapest method for producing these connecting elements.

Implementation Method 1

Both connecting elements according to the invention are produced in a single production step exclusively by rolling

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

whose strain hardening during cold forming is sufficiently large to obtain the required strength values ​​for the connecting element according to the invention

Methodology Applied
Scientific EffectStrain hardening: Cold-forming

Data Source

PatentEP2046514B1Screw, bolt or locking ring bolt
Publication Date: 2010.12.08 ACUMENT GMBH & CO OHG (DE)
  • EP2046514B1 patent drawingFigure 1~2

AI summary

Screw (10), bolt or locking ring bolt (20), in each case produced solely by rolling, and production method for such a screw (10), such a bolt or locking ring bolt (20).