Injection-Molded Sealing Element for Torque-Stable Bolt Sealing

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Solution Overview

Problem

Existing sealing elements with annular bases face issues such as shifting sealing rings during torque application, complex attachment processes, and unreliable long-term durability of liquid sealants, making them unsuitable for efficient and automated assembly.

Innovation Solution

A sealing element with plastic sealing rings injection-molded onto a sheet metal base body, featuring a fastening device for bolts and positive-locking connections, ensuring a stable and secure seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a sealing ring is merely placed on the annular base body, then the assembly process is simple, but the sealing ring will shift during torque application and the sealing effect is impaired

Engineering Contradiction:
Improveassembly process simplicityVSAvoidsealing effect
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sealing ring and base body are merged into a single integrated component through injection molding. The sealing ring is formed directly on the base body in one manufacturing process, eliminating separate attachment steps while ensuring permanent, shift-proof positioning that maintains sealing integrity under torque loads.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sealing ring is pre-formed and integrated onto the base body during the injection molding process before final assembly. This preliminary formation ensures the sealing ring is permanently positioned and cannot shift during subsequent torque application or assembly operations.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a sealing ring is permanently attached by force-fitting or bonding, then the sealing effect is improved, but the attachment process becomes complex and time-consuming

Engineering Contradiction:
Improvesealing effectVSAvoidattachment process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing ring attachment is merged with the base body manufacturing process through injection molding. The sealing ring and base body are formed as one piece in a single operation, eliminating separate force-fitting or bonding steps while achieving permanent, reliable attachment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The injection molding process automatically forms and attaches the sealing ring to the base body without requiring additional manual operations. The process is self-contained, with the sealing ring being created and secured in one automated step, reducing complexity and improving efficiency.

Inventive Principle:
Principle #25Self-service

3Reliability

If liquid sealant is used for sealing, then the sealing effect is improved, but the long-term durability is problematic and application is complex

Engineering Contradiction:
Improvesealing effectVSAvoidlong-term durability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces durable but complex mechanical sealing structures with a simple, integrated plastic sealing ring that provides sufficient sealing for the application. The injection-molded ring offers long-term durability without the complexity of liquid sealants, maintaining sealing integrity over years of service.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The sealing ring is made from plastic material that combines sealing functionality with structural integration. This composite approach uses the properties of plastic to provide both the sealing effect and permanent attachment, eliminating the need for liquid sealants and improving long-term durability.

Inventive Principle:
Principle #40Composite materials

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 reliable, efficient, and cost-effective seal that withstands torque and facilitates automated assembly processes, with enhanced durability and ease of integration.

Implementation Method 1

The molten plastic material is preferably injected in a mold in which the base body made of sheet metal is placed, whereby the plastic material hardens to form the two sealing rings on the base body and is directly bonded to it.

Methodology Applied
Scientific EffectInjection molding:

Data Source

PatentEP4667759A1Sealing element and method for forming the sealing element
Publication Date: 2025.12.24 FISCHER & KAUFMANN GMBH & CO KG
  • EP4667759A1 patent drawingFigure 1
  • EP4667759A1 patent drawingFigure 2
  • EP4667759A1 patent drawingFigure 3

AI summary

The invention relates to a sealing element comprising an annular base body (12) made of sheet metal, a central opening (14) arranged in the base body (12) for receiving and holding a bolt (30), in particular a screw bolt, and at least one sealing ring arranged on the base body. According to the invention, a first sealing ring (21) is arranged on a first side of the base body (12), a second sealing ring (22) is arranged on the base body (12) on a second side facing away from the first side, and the first sealing ring (21) and the second sealing ring (22) are formed from a plastic material by injection molding onto the base body (12) and are firmly attached thereto.