Drawer Locking Mechanism With Linear Front-Gap Adjustment

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Solution Overview

Problem

Existing locking devices for furniture parts, such as drawers, face challenges with imprecise and limited adjustability of the front gap between the drawer and the furniture body, particularly due to short adjustment paths and instability in the engagement mechanism.

Innovation Solution

A locking device with a linearly adjustable receiving element, enabled by a mechanism converting rotational movement into translational movement, and featuring a sliding part that moves relative to a base part, with a rotatable receiving element and a locking mechanism that includes a heart-shaped link track or pawl for precise adjustment and enhanced stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a threaded rod with a ball is used for adjustment, then the engagement element position can be changed, but the adjustment path is short and adjustability is imprecise

Engineering Contradiction:
Improveadjustment precisionVSAvoidadjustment path
Core Design Contradiction:
Measurement precisionVSLength of moving object

Solution Approach 1:

The patent replaces the threaded rod mechanism with a cam mechanism. The cam profile is designed to convert rotational movement of the cam follower into precise linear displacement of the engagement element, providing both a long adjustment path and high positioning precision through the geometric design of the cam surface.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the geometric parameters of the cam profile to optimize the adjustment characteristics. By varying the cam radius, eccentricity, and profile shape, the system achieves a extended adjustment path while maintaining precise control over the engagement element position throughout the adjustment range.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the receiving element position is adjusted frequently, then the front gap can be changed, but the stability of the locking device decreases

Engineering Contradiction:
ImproveadjustabilityVSAvoidlocking stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The locking device incorporates a self-locking mechanism where the cam profile geometry inherently maintains the engagement element in its adjusted position. The cam follower design ensures that once positioned, the engagement element remains stable without requiring additional locking components, as the cam profile itself prevents backward movement and maintains positional integrity.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a simple locking mechanism is used, then the device complexity is reduced, but the reliability of the locking function decreases

Engineering Contradiction:
Improvelocking mechanism complexityVSAvoidlocking reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs a cam mechanism with a curved profile that provides inherent mechanical advantage and self-locking characteristics. The curved cam surface distributes contact forces optimally, ensuring reliable engagement and disengagement while maintaining a relatively simple overall structure. The geometry of the cam profile ensures positive locking without requiring additional complex locking components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution allows for easy, precise adjustment of the front gap and increased stability, ensuring the locking device remains set without further action, while also providing a space-saving design and overload safety mechanism for safe operation.

Implementation Method 1

the actuating element is operatively connected to guide means which are arranged on the linearly movably mounted sliding part, preferably via a spiral link track

Methodology Applied
Scientific EffectSpiral link track mechanism: Screw

Implementation Method 2

the locking mechanism has a preferably heart-shaped link track or a pawl

Methodology Applied
Scientific EffectHeart-shaped link track mechanism: Cam

Data Source

PatentEP2252178B1Immobilization device for locking a furniture part movably supported in or on a piece of furniture
Publication Date: 2012.05.16 JULIUS BLUM GMBH
  • EP2252178B1 patent drawingFigure 1~2b
  • EP2252178B1 patent drawingFigure 3~6
  • EP2252178B1 patent drawingFigure 7a~8

AI summary

The invention relates to an immobilization device (5) for locking a furniture part (2) that is movably supported in or on a piece of furniture (1), particularly a drawer, in a closed end position (E), comprising at least one locking element (6), which has a receiving element (7) for an engagement element (8), wherein the receiving element (7) or the engagement element (8) is disposed on the piece of furniture (1) and the other element is disposed on the movable furniture part (2), and the two elements are operatively connected at least in the closed end position (E) of the movable furniture part (2), wherein the relative position of the receiving element (7) to the engagement element (8) in the depth of the piece of furniture (1) can be varied in a linear fashion by means of an adjusting unit (9), which is configured to convert a rotational movement into a translatory movement.