Lock Clutch With Selective Shaft Coupling for Reliable Door Locks

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Solution Overview

Problem

Existing door locks face challenges in achieving reliable operation with low manufacturing costs and low power requirements for changing the clutch state.

Innovation Solution

A door lock clutch design comprising a first and second shaft with a movably supported coupling element that transitions between closed and open positions, providing torque-proof coupling in the closed position and allowing relative rotation in the open position, utilizing a minimal number of parts and innovative shaft configurations to enhance reliability and reduce manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional door lock mechanism is used, then reliable operation is achieved, but manufacturing costs and device complexity increase

Engineering Contradiction:
Improvereliable operationVSAvoidmanufacturing costs
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The door lock mechanism is divided into two independent shafts (first shaft and second shaft) that can rotate relative to each other. The coupling element selectively couples these shafts, creating modular segments that can be manufactured separately and assembled, reducing overall manufacturing complexity and costs while maintaining reliability through the selective coupling mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling element is designed to be movable between a first position (coupling the shafts) and a second position (releasing the coupling). This dynamic capability allows the lock to transition between locked and unlocked states, providing reliable operation while using a minimal number of parts that can be actuated by simple mechanisms.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a traditional door lock mechanism is used, then reliable operation is achieved, but power requirements for changing clutch state increase

Engineering Contradiction:
Improvereliable operationVSAvoidpower requirements for changing clutch state
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The coupling element is biased by a spring into the first position (coupled state). To unlock, the coupling element must be actively moved to the second position against the spring bias, but once released, the spring automatically returns it to the coupled position. This self-service mechanism reduces the power required for actuation, as the spring provides the return force without requiring additional energy input.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a minimal number of parts is used, then manufacturing costs are reduced, but reliability may worsen

Engineering Contradiction:
Improvenumber of partsVSAvoidreliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The coupling element serves multiple functions: it couples the first and second shafts together, transmits torque between them, and can be selectively disengaged to release the coupling. This multi-functionality allows the door lock to achieve reliable operation with a minimal number of parts, as the coupling element replaces what would traditionally require multiple separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The coupling element is received within a recess of the second shaft, creating a nested configuration. The first shaft extends into the recess of the second shaft, and the coupling element fits within this nested structure. This nesting arrangement consolidates multiple components into a compact configuration, reducing the number of separate parts while maintaining the reliability of the coupling mechanism.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4624707A1Lock clutch
Publication Date: 2025.10.01 UHLMANN & ZACHER
  • EP4624707A1 patent drawingFigure 1
  • EP4624707A1 patent drawingFigure 2
  • EP4624707A1 patent drawingFigure 3

AI summary

A lock clutch comprising a first shaft 100, a rotational axis 2), a second shaft 200 and a movably supported coupling element 300, wherein the coupling element establishes and/or provides for a positive locking between the first shaft 100 and the second shaft 200 if the coupling element is shifted from an open position into a closed position is particularly reliable and cost effective, if a first end section of the first shafts extends into a recess in a second end section of the second shaft, wherein the recess is delimited by a rotationally variant delimiting surface and if the first end section has a first peripheral surface section and a second peripheral surface section 120, wherein the first peripheral surface section is rotationally variant under a rotation around the first rotational axis. A first gap 231 is formed between the first peripheral surface section 110 and the delimiting surface 210. Axially adjacent to the first peripheral surface section 110 is the second peripheral surface section 120 with a maximum radial distance r2,max (φ, l) from the rotational axis being smaller than the minimum distance dmin(l) between the coupling element 300 in its open position and the axis 2. Further, in the closed position, the coupling element 300 extends into the first gap 231 and thereby provides for the positive locking between the first shaft 100 and the second shaft 200. In the open position, the coupling element 300 is axially aligned with the second peripheral surface section 120.