Cylindrical Key Plug Profile Member Cavity Design

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Solution Overview

Problem

Existing cylinder locks have limited space for movable locking tumblers due to the volume occupied by profile members and their cavities, making it difficult to accommodate additional bores and requiring complex tools for manufacturing varied profile sections.

Innovation Solution

The design features cavities formed by a first part at a lateral distance from the keyway and a second part that communicates with it via a narrowed section, allowing profile members with non-rotatable, non-circular cross-sections to occupy a smaller volume, enabling more space for locking tumblers and allowing for easy, cost-effective manufacturing of key plugs with varied profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If cylindrical cavities are used to accommodate profile members with varying diameter, then the profile members can define the desired keyway profile, but the cavities occupy substantial volume leaving limited space for locking tumblers

Engineering Contradiction:
Improvekeyway profileVSAvoidcavity volume
Core Design Contradiction:
ShapeVSVolume of stationary object

Solution Approach 1:

The cavity is divided into two separate parts: a first cylindrical part for accommodating the profile member and a second part for the keyway. This segmentation allows the profile member to be held in a dedicated space while the keyway can be formed in the remaining volume, resolving the conflict between profile definition and space availability for tumblers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The profile member is positioned at an angle relative to the keyway axis, utilizing three-dimensional space more efficiently. This angular arrangement allows the profile member to define the keyway profile while occupying less volumetric space than a conventional axial arrangement would require.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If profile members with varying diameter are used to define keyway profile, then diverse profile sections can be achieved, but complex tools are required for manufacturing

Engineering Contradiction:
Improveprofile section varietyVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The profile member is extracted as a separate, interchangeable component from the key plug body. This allows the profile to be defined by the inserted profile member rather than by complex tooling in the plug itself, simplifying manufacturing while enabling profile variety through different member inserts.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The profile member's diameter is made variable along its length to define different profile sections. By changing the dimensional parameters of the inserted member rather than redesigning the entire key plug, the system achieves profile variety with simpler manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

3Volume of stationary object

If cavities are positioned close to the keyway to minimize volume, then more space is available for tumblers, but the profile member cannot be securely positioned

Engineering Contradiction:
Improvecavity volumeVSAvoidprofile member position
Core Design Contradiction:
Volume of stationary objectVSStability of the object's composition

Solution Approach 1:

The profile member is nested within the first cylindrical cavity part, which itself is positioned within the overall key plug structure. This nested arrangement provides secure positioning through the cylindrical confinement while maintaining compact overall dimensions and leaving space for tumblers in the second cavity part.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3371394B1A set of profile members in combination with a key plug, a method to manufacture such a key plug and a combination also including an associated key
Publication Date: 2020.01.08 WINLOC
  • EP3371394B1 patent drawingFigure 1a~3
  • EP3371394B1 patent drawingFigure 4a~4c
  • EP3371394B1 patent drawingFigure 5~7a

AI summary

The invention relates to cylindrical locks and more specifically to a set of profile members (44, 43a, 43b, 43c) in combination with a rotatable cylindrical key plug (30) having a longitudinal keyway (39) with a profile corresponding to an associated key (10). Each profile member is accommodated in an associated cavity (34, 33a, 33b, 33c) in the key plug at a lateral side of said keyway so as to form a lateral part thereof. The profile members have a non-circular cross-section and are non-rotatably mounted in the associated cavities at a location adjacent to the keyway. A portion of each profile member has a profiled surface portion facing inwards toward the opposite lateral side of the keyway, said profiled surface portion having, in a plane being transversal to a longitudinal axis of said key plug (30), a specific profile section defining a local, lateral part of the keyway. The invention also relates to an associated key, and a method to manufacture a cylindrical key plug with such profile members.