Discharge Pump Piston Guide Engaging Unit

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Solution Overview

Problem

In the manufacturing process of discharge pumps, there is a risk that the piston guide may detach from the stem during initial use due to improper application or incorrect attachment of silicone between the piston guide and the stem, leading to functional hindrance.

Innovation Solution

An engaging unit is introduced between the piston guide and the stem, comprising an engaging recess and a locking protrusion, which prevents idling and maintains frictional resistance, ensuring the piston guide remains attached to the stem during actuating member movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If silicone is applied to facing surfaces between the piston guide and the cylindrical piston to enable easy sliding, then the ease of operation is improved, but the reliability deteriorates because improper application or incorrect attachment may occur during manufacturing

Engineering Contradiction:
Improveease of slidingVSAvoidattachment reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an engaging unit consisting of an engaging recess and a locking protrusion as an intermediary mechanical feature between the piston guide and stem. This engaging unit serves as a mediator that provides positive mechanical engagement to ensure reliable attachment, compensating for potential manufacturing errors in silicone application while maintaining the ease of sliding function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the actuating member is raised from the stationary suction part during initial use, then the discharge pump functionality is activated, but the piston guide may detach from the stem due to insufficient frictional resistance

Engineering Contradiction:
Improvepump operationVSAvoidattachment stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The engaging unit with the locking protrusion and engaging recess is designed to prevent the harmful effect of detachment before it can occur during the raising operation. The locking protrusion fits into the engaging recess to create mechanical interlocking that counteracts the tendency of the piston guide to detach when the actuating member is raised during initial use or subsequent operations.

Inventive Principle:
Principle #9Preliminary anti-action

3Ease of manufacture

If silicone is not applied or is incorrectly attached during manufacturing, then the manufacturing process becomes simpler, but the discharge pump function is hindered due to piston guide detachment

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidfunctional reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The engaging unit acts as a pre-designed protective feature that cushions against the potential failure mode of piston guide detachment. By incorporating the locking protrusion and engaging recess into the manufacturing design, the system provides a safety mechanism that prevents functional failure even when silicone application is omitted or performed incorrectly, thereby maintaining functional reliability without complicating the manufacturing process.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 engaging unit effectively prevents the piston guide from detaching from the stem, ensuring the discharge pump functions correctly by maintaining necessary frictional resistance and secure attachment.

Implementation Method 1

a cylinder having a first check valve at a lower part thereof

Methodology Applied
Scientific EffectCheck valve: Valve

Implementation Method 2

a second check valve being formed between a lower end part of the annular piston and a lower part of the piston guide

Methodology Applied
Scientific EffectCheck valve: Valve

Implementation Method 3

an engaging unit which is configured to restrict the stem and the piston guide from idling each other when screwing of the actuating member to the stationary suction part is released and the actuating member is raised from the stationary suction part is provided

Methodology Applied
Scientific EffectMechanical engagement: Mechanical Fastener

Implementation Method 4

maintains frictional resistance, ensuring the piston guide remains attached to the stem

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3663225B1Discharge pump
Publication Date: 2023.05.10 YOSHINO KOGYOSHO CO LTD
  • EP3663225B1 patent drawingFigure 1
  • EP3663225B1 patent drawingFigure 2
  • EP3663225B1 patent drawingFigure 3~4

AI summary

A discharge pump (2) includes a stationary suction part (A) which includes a cylinder (A1) having a first check valve (VI) at a lower part thereof, and a mounting member (A3) to be mounted on a neck part of a container body, and an actuating member (B) which includes a discharge head (B4), a stem (B2), a piston guide (B1), and an annular piston (B3), a second check valve (V2) being formed between a lower end part of the annular piston and a lower part of the piston guide, and in a fitting part between the stem and the piston guide, an engaging unit (E) which is configured to restrict the stem and the piston guide from idling each other when screwing of the actuating member to the stationary suction part is released and the actuating member is raised from the stationary suction part is provided.