Internal Door Lock Removable Locking Piece Deadlocking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Prior art locks for internal doors have complex structures that increase manufacturing costs, despite their simple locking operations, and often require multiple bolts, which is inefficient.

Innovation Solution

A lock design featuring a removable locking piece that can be moved by a second follower to deadlock a single latch bolt, with a force transmission mechanism and followers that allow for spring-loaded disconnection and guide the locking piece's movement, enabling cost-effective production using injection molding of plastic components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If prior art locks use multiple separate bolts operated from respective operating axes, then the locking function is achieved, but the structure becomes complicated and manufacturing costs increase

Engineering Contradiction:
Improvelocking functionVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple locking functions into a single integrated latch bolt mechanism. The locking piece integrates the function of multiple separate bolts into one unified component that can be operated through a single operating axis, thereby reducing structural complexity while maintaining the locking function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single latch bolt is designed to perform multiple functions: it can lock the door, be deadlocked when retracted, and be manually reversible for left-hand or right-hand usage. This multi-functional design eliminates the need for multiple separate bolts while achieving comprehensive locking capabilities.

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

2Ease of manufacture

If prior art locks use a single latch bolt, then manufacturing costs are reduced, but the ability to actively deadlock the bolt is limited

Engineering Contradiction:
Improvemanufacturing costVSAvoiddeadlocking capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The locking piece is designed with dynamic positioning capability through the second follower mechanism. It can actively move between different positions (first position allowing retraction, second position preventing retraction and providing deadlocking). This dynamic control system enables a single latch bolt to achieve active deadlocking capability that was previously only possible with multiple bolts.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the latch bolt is spring-loaded for automatic retraction, then the locking operation is simplified, but the bolt cannot be securely held in retracted position for deadlocking

Engineering Contradiction:
Improvelocking operationVSAvoidposition holding capability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking piece acts as an intermediary mechanism between the spring-loaded latch bolt and the deadlocking requirement. When the locking piece is in its second position, it mechanically blocks the latch bolt's retraction path, overriding the spring force and securely holding the bolt in the retracted position for deadlocking. This intermediary component enables both automatic spring operation and secure position holding.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The design simplifies the locking mechanism, reduces manufacturing costs, and allows for easy conversion between right-hand and left-hand usage, while maintaining security through deadlocking and resilient construction.

Implementation Method 1

the force transmission means can be turned to a position, in which force transmission from the first follower to the force transmission means is disconnected and the force transmission means is spring-loaded toward said position disconnecting the force transmission

Methodology Applied
Scientific EffectSpring-loaded mechanism: Spring

Implementation Method 2

said second restricting member, which is located farther away from the protruding end of the latch bolt, is given a resilient construction

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP1899560B1Lock for internal door
Publication Date: 2017.08.02 ABLOY OY
  • EP1899560B1 patent drawingFigure 1
  • EP1899560B1 patent drawingFigure 2
  • EP1899560B1 patent drawingFigure 3a~3d

AI summary

A lock for internal door comprising a lock casing (1) with a latch bolt (2) spring-loaded into a position, in which it protrudes from the lock casing, a first operating axis (4), on which a first follower (5) is mounted, which follower is turnable by a lever handle, turning knob or the like and arranged, with the help of a turnable force transmission means (7), to retract the latch bolt (2) into the lock casing (1), and a second operating axis (11), on which a second follower (12) is mounted, which follower is turnable by a key, turning knob or the like for locking the latch bolt (2) optionally into its protruding position. The lock casing (1) is provided with a locking piece (13) which is removable independent on the latch bolt (2) and which may, by means of said second follower (12), be moved from a first position allowing the retraction of the latch bolt (2), to a second position, in which it is adapted to prevent the retraction of the latch bolt (2) and to provide dead- locking of the latch bolt (2).