Blank Ring Inner Rim Forming for Secure Coin Core Assembly

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Solution Overview

Problem

Existing coin minting technologies face challenges in creating a secure and efficient connection between blank rings and cores, leading to accidental separation of coin components during the minting process.

Innovation Solution

A forming device with a lower tool and upper tool setup, featuring a punch, turret plate, holding sleeve, and expanding forming tool, which positions and reshapes the inner edge of the blank ring to enhance its connection with adjacent components, ensuring a stable and defined outer diameter and precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the inner edge of the blank ring is reshaped to improve connection with blank core, then the connection strength increases, but the manufacturing complexity increases

Engineering Contradiction:
Improveconnection strengthVSAvoidforming device complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The forming tool is divided into multiple spreading elements that can be independently actuated. Each element can be expanded radially to form specific features on the inner edge of the blank ring, allowing complex geometries to be created through coordinated movement of simpler individual components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The forming device uses an expanding mechanism where the spreading elements can dynamically change their radial position. This allows the tool to transition between a compact state for insertion and an expanded state for forming, enabling complex forming actions with a relatively simple device structure.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the blank ring is securely held during forming to maintain outer diameter, then the manufacturing precision increases, but the device complexity increases

Engineering Contradiction:
Improveouter diameter precisionVSAvoidholding mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The blank ring is held within a holding sleeve that is part of the upper tool assembly. The holding sleeve provides a confined space that naturally constrains the blank ring's outer diameter during the forming process, achieving precise dimensional control through a relatively simple nested structural arrangement.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Strength

If the forming tool is expanded radially to reshape inner edge, then the connection strength improves, but the force required increases

Engineering Contradiction:
Improveconnection strengthVSAvoidexpanding force
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The spreading elements are designed to expand radially in a controlled sequence, allowing the forming force to be applied progressively rather than all at once. This dynamic expansion process reduces the peak force requirement while still achieving the necessary plastic deformation for strong connections.

Inventive Principle:
Principle #15Dynamics

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 provides a secure and accurate reshaping of the inner edge of the blank ring, ensuring a strong connection with the blank core during the minting process, preventing accidental separation and improving the overall coin production process.

Implementation Method 1

The lower tool has a punch (39) which is set up to move the round blank ring (31) along the working axis from a transport plane (T) into a forming position (U)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

the forming tool (47, 72) is pressed against the inner edge (31a) of the blank ring (31) for forming

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 3

The spreading tool (48) is set up to be expanded radially to the working axis A in the forming position of the blank ring (31)

Methodology Applied
Scientific EffectRadial Expansion:

Implementation Method 4

the deforming projection (53) is pressed into the inner edge (31a) of the round blank ring (31)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 5

The support ring (40) is set up to move the round blank ring (31) out of the transport plane (T) into the forming position (U)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 6

The ejector device (62) is set up to move the formed blank ring (31) back from the forming position (U) into the transport plane (T)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3370914B1Forming device and method for forming an inner rim of an annular circular blank
Publication Date: 2023.03.01 SCHULER PRESSEN GMBH & CO KG
  • EP3370914B1 patent drawingFigure 1
  • EP3370914B1 patent drawingFigure 2
  • EP3370914B1 patent drawingFigure 3

AI summary

The invention relates to a forming device (30) and to a method for forming an inner rim (31a) of an annular circular blank (31). The forming device (30) has a lower tool (37) with a movable die (39) and an upper tool (38) arranged opposite the lower tool (37) along a working axis (A). By means of the die (39), the annular circular blank (31) is moved out of a transport plane (T) and into a forming position (U) towards the upper tool (38) and into the interior of a holding sleeve (61). Subsequently, the inner rim (31a) is formed with the aid of a forming tool (47), (72). After forming, the annular circular blank (31) is moved out of the forming position (U) and back into the transport plane (T) by means of the lower tool (37) and/or the upper tool (38). The forming device (30) and the forming method can occur while the circular blanks are being fed, as takes place in any case, to the embossing station or embossing press, for example while the circular blank parts or the circular blank is/are being transported by means of a turret plate.