Sliding Door Lock Preventing Gear Rotation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing locks for sliding closure members can be forcibly rotated into an unlatched position despite the locking mechanism being engaged, compromising security.

Innovation Solution

Incorporating a locking element biased towards a locking state by a predefined force, which prevents rotation of the gear member, and utilizing a self-latching mechanism to ensure the lock remains secured even when closed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking mechanism with a locking member is used to prevent rotation of the spindle follower, then the lock is secured against unauthorized opening, but the latch bolt can still be forcibly rotated using tools to overcome the coil spring force and unlatch the lock

Engineering Contradiction:

Improvelocking securityVSAvoidforcible rotation of latch bolt

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The locking mechanism is divided into two independent locking elements: a first locking member that locks the spindle follower, and a second locking element that locks the gear member. This segmentation ensures that even if one locking element is compromised, the other remains intact to prevent unauthorized opening.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The locking elements are nested within the same lock body structure, with the first locking member and second locking element operating in conjunction within the confined space of the lock mechanism. The gear member itself serves as part of the locking structure when in the locked position.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If a rigid and immovable locking element is used to prevent gear member rotation, then security is improved, but the self-latching function during closing motion cannot be achieved

Engineering Contradiction:

Improvesecurity against forcible rotationVSAvoidself-latching during closing

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The locking element is designed to be dynamic rather than static, allowing it to move between a locked position (preventing gear member rotation) and an unlocked position (allowing self-latching during closing). The biasing member provides the restoring force that enables this dynamic behavior.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The state of the locking element changes based on the operational phase: during normal closing, the biasing force parameter allows the gear member to rotate and latch; during security mode, the locking element engages to change the rotational parameter of the gear member to zero.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the locking element is biased towards locking state by a predefined biasing force, then security is enhanced, but the force required to overcome the biasing force during self-latching increases

Engineering Contradiction:

Improvelocking state stabilityVSAvoidforce required for self-latching

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The biasing member is pre-loaded to provide a locking bias, but the closing motion of the door pre-actuates the mechanism by engaging the gear member with the latch bolt keep, which then overcomes the biasing force in a controlled manner during the natural closing sequence.

Inventive Principle:

Principle #10Preliminary action

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

Enhances security by preventing unauthorized rotation of the latch bolt, ensuring the lock remains locked unless intentionally unlocked, thus providing robust protection against tampering.

Implementation Method 1

the locking element is biased towards its locking state by a predefined biasing force

Methodology Applied

Scientific EffectSpring force: Spring

Implementation Method 2

a locking element movably mounted on the frame between a locking state in which the locking element prevents a rotation of the gear member

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Implementation Method 3

a gear member engaging the spindle follower and the latch bolt and being movable between an idle position and an activated position

Methodology Applied

Scientific EffectGear mechanism: Gear

Implementation Method 4

a spindle follower rotatably mounted on the frame about a further rotation axis between a rest position and an actuated position

Methodology Applied

Scientific EffectLever rotation: Lever

Data Source

PatentEP4575153A1A lock for a sliding closure member and a closure system comprising the same

Publication Date: 2025.06.25 LOCINOX NV

Figure 1
Figure 2A
Figure 2B

AI summary

A lock for a slidable closure member comprises: a frame (5, 7, 8); a latch bolt (4) rotatably mounted on the frame between a latching position and an unlatching position; a latch bolt actuating mechanism configured to rotate the latch bolt and a locking mechanism. The latch bolt actuating mechanism comprises: a spindle follower (24) rotatably mounted on the frame, and a gear member (31) engaging the spindle follower and the latch bolt and configured to move the latch bolt to its unlatching state when the spindle follower is actuated. The locking mechanism comprises: a locking member (50) movably mounted on the frame between a locking position in which the locking member prevents a rotation of the spindle follower and an unlocking position; and a locking element (60) movably mounted on the frame between a locking state in which the locking element prevents a rotation of the gear member and an unlocking state.