Air Cleaner Restriction Indicator With Low-Profile Snap-Fit Mounting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air cleaner assemblies face challenges with difficult installation and service of restriction indicators, visibility issues, and damage susceptibility due to complex connection mechanisms and placement on the air cleaner housing.

Innovation Solution

A removable restriction indicator with a snap-fit connection, featuring a stem inserted into a bore and tabs engaging apertures for easy installation, providing a low profile and wide viewing angle with calibrated indication elements for filter restriction levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a threaded connection is used to mount the restriction indicator, then the connection is secure and reliable, but the installation and service become difficult and time-consuming

Engineering Contradiction:
Improveconnection reliabilityVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The mounting connection is divided into separate components: a mounting post with external threading and a separate mounting bracket with internal threading. This segmentation allows the indicator to be easily attached and detached without complex threading operations, improving both installation ease and connection reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A mounting bracket serves as an intermediary component between the indicator and the housing. The bracket provides a secure threaded connection point while allowing the indicator itself to remain simple and easy to install, resolving the contradiction between secure mounting and easy installation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a quick-connect fitting is used to mount the restriction indicator, then the installation and service become easier, but the indicator protrudes far from the housing and becomes more easily damaged

Engineering Contradiction:
Improveinstallation easeVSAvoiddamage susceptibility
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

Instead of having the indicator protrude outward with a quick-connect mechanism, the mounting post extends into the housing and the indicator mounts flush or recessed. This inverts the traditional quick-connect approach, maintaining ease of installation while eliminating the protrusion that causes damage susceptibility.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The indicator is nested within or flush with the housing profile when mounted. The mounting post fits into the housing and the indicator body, creating a compact assembly that doesn't protrude and is therefore less susceptible to external damage while remaining easy to install and remove.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If the restriction indicator is placed on the air cleaner housing, then it is accessible to users, but visibility is limited due to placement constraints and lack of wide viewing angle

Engineering Contradiction:
Improveuser accessibilityVSAvoidvisibility
Core Design Contradiction:
Ease of operationVSDifficulty of detecting and measuring

Solution Approach 1:

The viewing surface of the indicator is oriented to provide visibility from multiple angles rather than a single fixed position. The indicator element is positioned and angled to project information outward, allowing users to view the restriction level from various positions around the air cleaner, thereby improving visibility while maintaining accessibility.

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

Data Source

PatentEP4074404B1Air cleaner assembly with restriction indicator
Publication Date: 2025.09.03 DONALDSON CO INC
  • EP4074404B1 patent drawingFigure 1
  • EP4074404B1 patent drawingFigure 2
  • EP4074404B1 patent drawingFigure 3

AI summary

An air cleaner assembly (10) with a restriction indicator includes a housing (12) having an exterior surface around an interior volume (20). The housing (12) includes a bore (42) extending through a portion of the exterior surface of the housing surrounded by a bore wall (38) protruding from the portion of the exterior surface. A receptacle wall (24) of the housing (12) is disposed around the bore wall (38) and is radially spaced from the bore wall to form a channel between the bore wall (38) and the receptacle wall (24). A restriction indicator (24) measures a restriction in the interior volume (20) and displays an indication of the restriction. The restriction indicator includes a stem (46) that is at least partially insertable into the bore (42) that engages an inner surface of the bore wall (38). One or more tabs (52) of the restriction indicator are at least partially insertable in the channel and removably couple to the receptacle wall (24).