Spectacle Spring Hinge Plunger Retention via Wall Deformation

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Solution Overview

Problem

Existing spring hinge parts for spectacle frames face issues with the plunger being easily dislodged and lost during disassembly due to spring preload, requiring complex and difficult-to-manufacture mechanisms to prevent this, which can lead to instability and functional degradation over time.

Innovation Solution

A spring hinge part design featuring a receiving element with a deformation in the wall that acts as a stop for the plunger, preventing it from being pushed out by spring tension, allowing for simple and stable production without weakening the parts, and ensuring the plunger remains securely in place during disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastically yielding ribs are used to hold the plunger, then the plunger can be retained in the receiving recess, but the ram is weakened and requires complex manufacture

Engineering Contradiction:
Improveplunger retentionVSAvoidmanufacture complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The solution divides the retaining function into two independent parts: a simple deformation element (protrusion) for plunger retention and the intact ram structure for structural strength. This segmentation allows each element to perform its specific function optimally without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining function is extracted from the ram body itself and implemented as a separate deformation element (protrusion) on the wall. This removes the need to weaken the ram structure while still achieving reliable plunger retention through the protrusion-depression mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If the receiving element is made spring-elastic to clamp the plunger, then the plunger can be held securely, but the receiving element becomes difficult to manufacture and may sag over time

Engineering Contradiction:
Improveplunger retentionVSAvoidmanufacturing difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of making the entire receiving element elastic to achieve clamping, the solution inverts the approach by using a rigid receiving element with a localized deformation (protrusion) that creates a one-way clamping action. The plunger is retained when pushed in but cannot be pulled out due to the protrusion blocking the exit path.

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

Solution Approach 2:

The elastic or deformable property is localized only to the specific region where the protrusion is formed on the wall, while the rest of the receiving element remains rigid. This localized deformation provides the necessary retention function without requiring the entire receiving element to be spring-elastic, thereby simplifying manufacture and preventing sagging.

Inventive Principle:
Principle #3Local quality

3Reliability

If the wall is deformed to create a stop protruding radially, then the plunger can be held securely in the receiving recess, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveplunger retentionVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The solution changes the geometric parameter of the wall by forming a localized protrusion (deformation) that radially intrudes into the receiving recess. This parameter change creates an effective stop for the plunger without requiring complex multi-component structures, as the protrusion can be formed directly during molding or machining of the receiving element.

Inventive Principle:
Principle #35Parameter changes

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 effectively prevents the plunger from being dislodged during disassembly, maintaining the spring hinge's stability and functionality while simplifying the manufacturing process, ensuring the parts remain secure and robust.

Implementation Method 1

the plunger can be held in a simple and very safe manner in the spring hinge part that has been removed from a spring hinge, with the deformation being able to be easily introduced into the wall of the receiving element... the plunger can be pushed out of the receiving recess by the spring element... the spring preload of the spring element

Methodology Applied
Scientific EffectSpring preload: Spring

Data Source

PatentEP3531193B1Spring hinge part for a spectacle frame, spring hinge with such a spring hinge part and method for mounting such a spring hinge part
Publication Date: 2022.08.24 OBE GMBH & CO KG
  • EP3531193B1 patent drawingFigure 1
  • EP3531193B1 patent drawingFigure 2~3

AI summary

The invention relates to a spring hinge part (5) for a spectacle frame (3), comprising a receiving element (9) having a longitudinal axis (L), wherein the receiving element (9) has an end face (11), wherein a receiving recess (13) extends from the end face (11) into the interior of the receiving element (9), wherein the receiving recess (13) is bounded at least partially along an imaginary circumferential line by a wall (15) of the receiving element (9) and inside the receiving element (9) by a base (17), wherein two hinge arms (19, 19') spaced apart from each other perpendicular to the longitudinal axis (L) extend from the end face (11) opposite the receiving recess (13), which have aligned hinge bores (21, 21') for receiving a hinge axis (23), wherein a spring element (25) is arranged in the receiving recess (13).which is supported in the receiving recess (13) on one side against the base (17) and on the other side against a first end (27) of a plunger (29), the plunger (29) projecting with a second end (31) out of the receiving recess (13) and being arranged between the hinge arms (19, 19'). It is provided that the wall (15) of the receiving element (9) has a deformation (33) spaced from the end face (11) in the direction of the base (17), such that the deformation (33) of the wall (15) projects radially into the receiving recess (13) and forms a stop (35) for the plunger (29).