Window Bearing Stability via Nested Form-Fit Connection

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Solution Overview

Problem

Existing window sash bearings lack stability and operating reliability, particularly under forces perpendicular to the links when the window is open, and conventional zinc die-cast bearings suffer from material limitations leading to instability.

Innovation Solution

A bearing design featuring a stepped recess with an expanded receiving area on the base plate and a widened head at the free end of the bearing eye, which engages behind the base plate, providing a secure form-fitting connection and increased stability, along with additional features like an inclined edge and web for enhanced stability and wear reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional zinc die-cast bearing or a simple sheet metal bearing with open structure is used, then the device complexity is low and manufacturing is easy, but the stability and operating reliability are insufficient under forces perpendicular to the links

Engineering Contradiction:
Improvestability and operating reliabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bearing eye is formed by bending a tab of the base plate itself, creating a nested structure where the bearing eye is integrated into the base plate. The extension of the bearing eye is inserted into a recess in the base plate and secured through deformable material flow, creating a nested, space-efficient design that enhances stability without adding external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention utilizes the deformable material flow characteristics of sheet metal to create a form-fit connection. The material is plastically deformed during assembly to lock the extension in place, combining the benefits of metal strength with the advantages of interference fitting, thereby achieving high reliability without complex composite material assemblies.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If the bearing eye is formed as a one-piece tab on the base plate with an extension engaging in a recess, then the stability improves, but the manufacturing precision requirements increase due to the form-fitting connection

Engineering Contradiction:
Improvebearing stabilityVSAvoidform-fit connection precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The invention exploits the parameter of material deformability during the assembly process. The deformable material flow allows the extension to be plastically deformed as it is inserted into the recess, enabling the connection to accommodate minor dimensional variations and tolerance deviations, thereby reducing the stringent precision requirements while maintaining stable assembly.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the recess is designed in steps with an expanded receiving area and the extension has a widened head, then the stability and resistance to displacement increase, but the manufacturing complexity and time increase

Engineering Contradiction:
Improveresistance to displacement and deformationVSAvoidassembly efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The bearing eye and its extension are formed as an integrated feature of the base plate through a single bending operation. The stepped recess with expanded receiving area is formed directly in the base plate, combining multiple features (bearing eye, extension, recess, and locking mechanism) into one unified forming process, thereby eliminating separate assembly steps and maintaining high productivity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3543444B1Bearing for a fitting device of a window
Publication Date: 2020.10.28 WINKHAUS
  • EP3543444B1 patent drawingFigure 1
  • EP3543444B1 patent drawingFigure 2~3
  • EP3543444B1 patent drawingFigure 4~5

AI summary

A bearing (3) for a wing (2) that pivots against a frame (1) is formed in one piece by forming such that the bearing eye (8) has a fixed first end (23) and a second end (24). The second end (24) of the bearing eye (8) is positively connected to the base plate (7) to increase the stability of the bearing (3).