Roll-Form Tie Bar Guide for Casement Window

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Solution Overview

Problem

Existing tie bar systems for casement windows are complex to assemble, impair the aesthetic appearance of the window, and increase the risk of water and air infiltration due to their large installed height and transverse movement restrictions.

Innovation Solution

A roll-form tie bar with snap-on guides and eccentric rivet locking points that reduce the overall height of the assembly, allowing for a closer fit within the window frame and improved security, along with offset fasteners to accommodate various window profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tie bar extends through an aperture in the guide with portions surrounding the tie-bar, then the guide can secure the tie bar and prevent transverse movement, but the installed height of the assembly becomes relatively large, impairing aesthetic appearance and increasing water and air infiltration risk

Engineering Contradiction:

Improvesecurity against transverse movementVSAvoidinstalled height

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

Instead of the tie bar extending through the guide as in prior art, the guide is inverted to surround and receive the tie bar within a recess. This reversal of the spatial relationship allows the guide to secure the tie bar effectively while minimizing the overall installed height, thus resolving the contradiction between security and aesthetic appearance.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The guide is designed with a recess that receives and nests the tie bar, allowing the tie bar to be contained within the guide structure rather than extending through it. This nesting arrangement reduces the protruding height of the assembly while maintaining the security function of preventing transverse movement.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of manufacture

If self-locating tie bar guides with tabs or pins are used to simplify assembly, then installation is easier and faster, but the design becomes complex and requires frangible features or detent mechanisms

Engineering Contradiction:

Improveassembly simplicityVSAvoidguide structure complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The guide incorporates a self-locating feature where a tab on the guide engages with a corresponding opening in the tie bar, automatically positioning the guide correctly during installation without requiring pre-drilled holes, jigs, or fixtures. This self-service mechanism simplifies assembly while avoiding complex frangible tabs or detent systems.

Inventive Principle:

Principle #25Self-service

3Reliability

If locking points are positioned on the tie bar, then security is provided, but the locking points must be located away from the guide to avoid striking it during operation

Engineering Contradiction:

ImprovesecurityVSAvoidtie bar movement freedom

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

By inverting the guide design to surround the tie bar within a recess rather than having the tie bar extend through the guide, the locking points can be positioned closer to the guide without risk of striking it. This spatial reconfiguration allows both security and ease of operation to be achieved simultaneously.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS12163361B2Roll-form tie bar and guide for casement window

Publication Date: 2024.12.10 TRUTH HARDWARE CORPORATION

AI summary

A casement window lock and tie bar assembly including a flexible guide pre-formed with an arcuate deflection. The guide receives a tie bar having a c-shaped cross-section. The arcuate deflection of the guide causes the guide to be frictionally held in an initial position on the longitudinal axis of tie bar. When fasteners are tightened to attach the guide to a window frame, the guide is flattened to enable the tie bar to freely slide on the guide.