Pull Knob Drainage Fitting with Adjustable Pull Bar

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Solution Overview

Problem

Existing pop-up waste fittings face challenges in adapting to different overall heights and through-hole arrangements, requiring complex rod connections and multiple production variants when using one-piece tie rods, which complicates installation and adjustment.

Innovation Solution

A two-part pull rod design with a first rod element connected to the plunger rod and a second rod element, featuring a curved clamping spring with spaced receiving openings for adjustable length and tool-free connection, allowing for secure clamping and easy assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If one-piece tie rods are used, then the structure is simple, but numerous production variants are required to adapt to different overall heights and through-hole arrangements

Engineering Contradiction:
Improverod structureVSAvoidadaptation to different heights and hole arrangements
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The pull rod is divided into two separate rod elements (first rod element and second rod element) that can be independently adjusted. The first rod element connects to the plunger rod while the second rod element carries the pull button. This segmentation allows each element to be positioned independently to accommodate different overall heights and through-hole arrangements without requiring multiple production variants.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If two mutually displaceable rod elements are assembled, then adaptability to different configurations is improved, but complicated rod connections requiring separate tools are needed

Engineering Contradiction:
Improveconfiguration adaptabilityVSAvoidinstallation simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The rod elements feature self-clamping connections where the second rod element automatically clamps onto the first rod element through friction and geometric interlocking when inserted. This self-service mechanism eliminates the need for separate tools or complex fastening operations during installation, allowing installers to simply insert and position the rod elements without requiring wrenches, screws, or other auxiliary tools.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a clamping spring is used to connect rod elements, then tool-free connection is achieved, but the spring must be precisely bent to create aligned receiving openings

Engineering Contradiction:
Improvetool-free connectionVSAvoidspring bending alignment
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The clamping spring is pre-bent during manufacturing to create receiving openings that are precisely aligned when the spring is in its clamped state. This preliminary action ensures that when the spring is installed and compressed between the two rod elements, the receiving openings are already positioned correctly to receive and align the rod elements without requiring field adjustment or complex bending operations during installation.

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

Enables adjustable length of the pull rod without requiring tools, simplifying installation and ensuring a secure connection through the clamping spring's self-clamping mechanism, reducing production complexity and assembly time.

Implementation Method 1

the edges of each receiving opening clamp the respective rod element guided through them due to the pretension applied by the bent clamping spring in the direction of its extended position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2360320B1Pull knob drainage fitting with length-adjustable pull bar
Publication Date: 2017.12.27 IDEAL STANDARD INT
  • EP2360320B1 patent drawingFigure 1
  • EP2360320B1 patent drawingFigure 2~3

AI summary

A pull-button drain assembly for washbasins, bidets or similar sanitary appliances, wherein the plunger rod and pull rod are arranged at an angle to each other and coupled to each other by means of a connecting element, is characterized in that the pull rod (15) is designed in two parts with a first rod element (20) connected to the plunger rod (14) and a second rod element (21) carrying the pull button, and for the variably adjustable connection of the rod elements (20, 21) of the pull rod (15) which are aligned parallel to each other with their longitudinal axes, a clamping spring (22) designed as a leaf spring aligned in the longitudinal direction of the rod elements (20, 21) to be connected is provided, which has two pairs of receiving openings (23, 24) arranged at a distance from each other for the respective receiving of the two rod elements (20, 21) to be connected.wherein, with the clamping spring (22) mounted, the central region (25) of the clamping spring (22) located between the pairs of openings is bent such that the edges of each receiving opening (23, 24) clamp the rod element (20, 21) guided through it due to the preload applied by the bent clamping spring (22) in the direction of its extended position and, when the free ends (26) of the clamping spring (22) are bent together, release the rod element (20, 21) for displacement through the receiving openings (23, 24).