Slam Latch Tapered Bolt Angled Keeper Rattling Reduction

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Solution Overview

Problem

Conventional slam latches experience rattling issues and operational inefficiencies, particularly in agricultural applications where high-speed door closure is common, leading to potential animal or human safety risks and operator discomfort due to high impact shock stress.

Innovation Solution

A slam latch design featuring a latch bolt with a tapered keeper-engaging region and a keeper with angled walls to minimize rattling, combined with a biasing mechanism and cam system for secure locking and easy operation, ensuring the latch bolt engages both keeper walls for stable closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the keeper opening is made larger to allow sufficient time for the latch bolt to engage, then the reliability of latch engagement is improved, but excessive gap causes rattling which increases stress on the animal and reduces comfort

Engineering Contradiction:
Improvelatch engagement reliabilityVSAvoidrattling stress on animal
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The keeper opening is designed with non-uniform geometry: the leading wall is angled to guide the latch bolt during engagement, while the trailing wall is positioned to limit the gap. This creates different local characteristics within the same opening - the angled leading wall facilitates reliable engagement, while the constrained trailing wall minimizes rattling space, thus resolving the contradiction between engagement reliability and rattling prevention.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the operator maintains contact with the door handle during closure, then control over the door is improved, but the operator's hand is subjected to high impact shock stress

Engineering Contradiction:
Improvedoor controlVSAvoidimpact shock stress on operator's hand
Core Design Contradiction:
Ease of operationVSStress or pressure

Solution Approach 1:

The latch bolt is spring-loaded and automatically propels outward to engage the keeper opening before the door completes its closure. This preliminary engagement action occurs before the door fully closes, absorbing the impact energy and preventing the door from slamming. The operator can then close the door with controlled force, maintaining contact with the handle without experiencing high impact shock stress.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the latch bolt is allowed to propel outwards at high speed to secure the door, then the productivity of door closure is improved, but the latch bolt may overshoot or fail to engage properly

Engineering Contradiction:
Improvedoor closure speedVSAvoidlatch engagement accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The keeper opening geometry provides inherent feedback control: the angled leading wall guides the latch bolt during engagement, and the trailing wall position provides a mechanical stop that prevents overshooting. As the latch bolt engages the keeper, the geometry of the opening provides tactile feedback to the spring mechanism, automatically regulating the engagement depth and ensuring reliable positioning regardless of the door closure speed.

Inventive Principle:
Principle #23Feedback

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 effectively reduces rattling, enhances operational safety by preventing latch bolt overshooting, and allows operators to maintain control without high impact shock stress, ensuring reliable and secure door closure in agricultural settings.

Implementation Method 1

a latch bolt positioner comprising a biasing mechanism to bias the latch bolt to the locking position

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2855808B1Slam latch
Publication Date: 2020.09.23 CLIPEX IP LTD
  • EP2855808B1 patent drawingFigure 1~2
  • EP2855808B1 patent drawingFigure 3~4
  • EP2855808B1 patent drawingFigure 5~6

AI summary

This invention relates to a slam latch, and to methods of operating a gate/panel using the slam latch. The slam latch comprises (i) a mounting body; (ii) a latch bolt having a longitudinal axis and being mounted relative to the mounting body for axial movement relative to the mounting body between a locking position and an unlocking position, said latch bolt having a keeper-engaging end extending from the mounting body; and (iii) a keeper adapted to receive the keeper-engaging end of the latch bolt when the latch bolt is in the locking position.