Blow Mould Locking Mechanism for Rapid Cycle Times

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Solution Overview

Problem

Existing blow-moulding technologies face inefficiencies and reliability issues due to complex locking mechanisms that require significant rotation and multiple linkages, leading to increased locking time and potential breakage.

Innovation Solution

A simplified locking system for blow-moulding machines where a second fastening element with a protrusion is inserted into an indentation on the first fastening element, allowing for quick and automatic locking and unlocking with minimal rotation, eliminating the need for levers and linkages, and utilizing an elastic element to maintain the locked position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shaft is rotated by 180 degrees from unlocked to locked position, then the locking is secure, but the locking time increases and productivity decreases

Engineering Contradiction:
Improvelocking securityVSAvoidlocking speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Instead of rotating the locking element 180 degrees as in prior art, the invention inverts the approach by using a 90-degree rotation where the shaft rotates perpendicular to the half-mould opening direction. This inversion of the rotation geometry achieves secure locking with half the rotation angle, thereby doubling the locking speed and productivity.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If two linkages are used to move the shaft between locked and unlocked positions, then the locking mechanism is complete, but the device complexity increases and reliability decreases

Engineering Contradiction:
Improvelocking mechanism completenessVSAvoidnumber of linkages
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates one of the two linkages required in prior art by redesigning the shaft rotation mechanism. The shaft now rotates about a fixed axis perpendicular to the half-mould opening direction, requiring only a single linkage connected to the free end of the shaft, thereby reducing complexity and removing a potential failure point while maintaining complete locking functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the shaft abuts against a matching surface of the first half-mould, then the locking is effective, but the shaft rotation angle must be 180 degrees increasing locking time

Engineering Contradiction:
Improvelocking effectivenessVSAvoidlocking time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention changes the dimension of shaft rotation from parallel to the half-mould opening axis (requiring 180 degrees) to perpendicular to the opening axis (requiring only 90 degrees). This dimensional change in the rotation geometry allows the shaft to achieve effective locking with half the rotation angle, significantly reducing locking time while maintaining security.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution significantly reduces locking time, enhances reliability, and provides a strong reaction against pressure forces, improving the overall efficiency and durability of the blow-moulding process.

Implementation Method 1

an elastic element connected to the second half-mould and to the second fastening element to move and normally keep the second fastening element in the locked position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2149446B1Mould and method for blowing containers
Publication Date: 2015.03.25 SACMI COOPERATIVA MECCANICI IMOLA SOC COOP ARL
  • EP2149446B1 patent drawingFigure 1
  • EP2149446B1 patent drawingFigure 2~3
  • EP2149446B1 patent drawingFigure 4~6

AI summary

A blow mould (1) for making plastic containers from respective parisons comprises: a first and a second half-mould (2, 3) hinged to rotate about a longitudinal axis (4) between an open position and a closed position; a first fastening element (5) fixed to the first half-mould (2); a second fastening element (6) associated with the second half-mould (3) to rotate about an axis parallel to the longitudinal axis (4) between a position where it locks the two half-moulds (2, 3) and abuts against the first fastening element (5) and a position where it unlocks the half-moulds. The second fastening element (6) comprises a protrusion (9) which, in the locked position, is operatively inserted in an indentation (8) made in the first fastening element (5), said protrusion (9) being positioned behind the axis of rotation of the second fastening element (6) relative to the free end of the second half-mould (3).