Nested Rotation Converter for Bidirectional Trim Handle Actuation

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Solution Overview

Problem

Existing rotation converters for exit device assemblies are bulky and require replacement of the entire trim assembly to enable actuation of the latch control assembly by rotation of the handle in both directions, which is costly and time-consuming, and lack the aesthetic appeal of traditional designs.

Innovation Solution

A compact rotation converter with an input component, an output component, and an intermediate component that moves to an actuated position in response to rotation in either direction, rotating the output component in an actuating direction, allowing the handle to actuate the latch control assembly regardless of rotation direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rotation converter mechanism is added to enable bidirectional actuation, then the functionality is improved, but the size and bulkiness of the trim assembly increases

Engineering Contradiction:

Improvebidirectional actuation capabilityVSAvoidtrim assembly size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The rotation converter mechanism is nested within the existing trim assembly structure. The intermediate component is positioned within the hollow cylindrical housing, utilizing the internal space rather than adding external bulk. The input component receives rotation from the drive spindle and transfers it through the intermediate component to the output component, all contained within the existing trim assembly footprint.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The rotation converter is divided into separate functional components: an input component (crown gear), an intermediate component (rack and pinion mechanism), and an output component. This segmentation allows each component to be optimized for its specific function while maintaining a compact overall structure. The intermediate component's rack translates rotational motion linearly, and the pinion gear converts it back to rotation in the correct direction.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If existing rotation converter mechanisms are used to enable bidirectional actuation, then the functionality is improved, but the aesthetic appeal is reduced due to bulky design

Engineering Contradiction:

Improvebidirectional actuation capabilityVSAvoidaesthetic appeal

Core Design Contradiction:

Adaptability or versatilityVSShape

Solution Approach 1:

The entire rotation converter mechanism is nested within the existing hollow cylindrical housing of the trim assembly. The input component, intermediate component, and output component are all positioned inside the housing, maintaining the sleek external appearance of the traditional trim assembly design while enabling bidirectional actuation functionality.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The intermediate component features a rack with teeth on only one surface, and the pinion gear is positioned to engage only with those teeth. This asymmetric local quality allows the mechanism to convert rotation from either direction into unidirectional output rotation, enabling bidirectional actuation while maintaining a compact form factor that preserves aesthetic appeal.

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If the entire trim assembly is replaced to enable bidirectional actuation, then the functionality is improved, but the cost and time consumption increase

Engineering Contradiction:

Improvebidirectional actuation capabilityVSAvoidupgrade time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The rotation converter mechanism is extracted as a separate, self-contained unit that can be independently installed within the existing trim assembly. The input component, intermediate component, and output component form a modular assembly that can be installed without replacing the entire trim assembly, reducing both cost and time requirements for upgrading to bidirectional actuation capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The intermediate component is designed with a rack that can engage with the pinion gear regardless of the direction of input rotation. This universal design allows the mechanism to accept rotation from either direction (clockwise or counter-clockwise) and consistently produce output rotation in the actuating direction, enabling bidirectional actuation with a single standardized component design.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11851915B2Rotation converter

Publication Date: 2023.12.26 SCHLAGE LOCK CO LLC

AI summary

An exemplary rotation converter includes an input component, an output component, and an intermediate component engaged between the input component and the output component. The input component is rotatable from an input component home position in each of a first direction and an opposite second direction. The intermediate component is configured to move to an actuated position in response to rotation of the input component in either direction, and to rotate the output component in an actuating direction as the intermediate component moves to the actuated position.