Connector Cap Mold with Rotating Core for Annular Recesses

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Solution Overview

Problem

Existing methods for molding connectors with cap angles are complex, require compatible materials, and often result in unsightly openings or size limitations, particularly when using collapsing cores or snap-fit mechanisms.

Innovation Solution

A mold design featuring a rotatable and axially movable outer sleeve and inner pin, with cam grooves and followers, simplifies the molding process, allows for the production of annular recesses, and enables the creation of cap angles without complex mechanisms, suitable for smaller components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate cap with cap angle is used and sonically welded to the body, then the connector provides reliable connection, but the manufacturing process requires complex equipment and compatible materials

Engineering Contradiction:
Improveconnection reliabilityVSAvoidwelding equipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the body and cap into a single molded component, eliminating the separate cap and welding process. The cap angle is integrated directly into the body structure through injection molding, merging two previously separate parts and their assembly process into one manufacturing operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mold design with rotatable and axially movable outer sleeve and inner pin serves multiple functions: it forms the cap angle, creates the annular recess, and enables demolding of complex geometries. This multi-functional tooling eliminates the need for separate welding equipment and multiple manufacturing steps.

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

2Ease of operation

If a snap-on cap with tapered surface is used, then the cap can be easily assembled, but the tapered surface provides a ramp that can cause disassembly under high force

Engineering Contradiction:
Improveassembly easeVSAvoidconnection stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Instead of using a tapered surface that slopes inward (which creates a disassembly ramp), the patent uses a radially extending surface that slopes outward. This inverted geometry prevents the cap from being pried off by converting the ramp effect into a locking effect, where force applied to disconnect the cap actually increases the normal force on the snap-fit engagement.

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

3Reliability

If blades are used to form a radial plane surface, then the snap fit problem is solved, but openings are created that are unsightly and allow dirt ingress

Engineering Contradiction:
Improvesnap fit reliabilityVSAvoiddirt ingress
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the blade demolding mechanism and replaces it with a rotatable and axially movable outer sleeve and inner pin system. This removes the harmful effect of openings created by blades while maintaining the ability to form the necessary radial plane surface for reliable snap-fit connection.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If a cap with annular recess is produced, then the cap is firmly held in place by support on internal and external surfaces, but the collapsing core method cannot produce such recesses

Engineering Contradiction:
Improvecap retentionVSAvoidmanufacturing capability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The mold cavity and movable core components are pre-configured with the geometry of the annular recess. During injection molding, the recess is formed directly in the cap as the material is injected, eliminating the need for subsequent collapsing or complex post-processing operations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3898166B1A mold and method for molding a body or cap for a connector
Publication Date: 2024.03.13 JOHN GUEST INT LTD
  • EP3898166B1 patent drawingFigure 1A~1B
  • EP3898166B1 patent drawingFigure 1C~1D
  • EP3898166B1 patent drawingFigure 1E~1F

AI summary

A mold for molding a body or cap for a connector. The mold comprises a mold body (1) and an axial core (2) which together define a mold cavity in the shape of the body or cap. The core has a sleeve (3) and an inner pin (4) each having complementary castellations (8, 10) which interdigitate in a first configuration. In the first configuration, the castellations (8, 10) are arranged such that respective recesses (11) are formed each bound by the proximal end of a first castellation (8) and the side walls of adjacent second castellations (10). Each recess has a shape to form a respective first portion of the body or cap. The sleeve (3) and inner pin (4) are axially movable to a second configuration in which the castellations (8, 10) are disengaged from one another. The inner pin (4) is rotatable to a third configuration in which the first castellations (8) can be axially withdrawn following a path occupied by the second castellations (10) in the first configuration.