Fluid Dispenser Pump Mechanical Stop and Sealing Design
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Solution Overview
Problem
Existing fluid dispenser pumps suffer from large dose dispersion between successive doses and operational unreliability, especially during non-axial actuation, due to flexible components and inadequate guidance of the piston within the pump body.
Innovation Solution
The pump design incorporates a mechanical stop using axial ribs in the valve holder to define the actuation stroke and a gland with an inner sealing lip to enhance sealing and dose reproducibility, along with a return spring and actuating spring to manage pressure and sealing effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-based actuation mechanism is used to transmit force from the rod to the piston, then the pump can achieve actuation functionality, but the dose dispersion between successive doses becomes large and operational reliability is reduced during non-axial actuation
Solution Approach 1:
The invention extracts the spring-based actuation mechanism from the force transmission path by introducing a direct mechanical connection between the rod and piston. The rod is directly coupled to the piston via a connection element, eliminating the spring intermediary that caused dose dispersion and reliability issues during non-axial actuation.
Solution Approach 2:
The invention introduces a connection element as an intermediary component between the rod and piston. This connection element provides a rigid, reliable force transmission path that maintains operational reliability during non-axial actuation while ensuring consistent dosing, replacing the spring-based intermediary that caused problems.
2Manufacturing precision
If the piston is guided solely by the pump body walls, then the structure remains simple, but the piston lacks adequate guidance leading to poor sealing and dose dispersion
Solution Approach 1:
The invention segments the guidance function by introducing a separate guidance structure (guiding element) that is distinct from the pump body walls. This guiding element provides precise piston guidance and sealing, improving sealing precision without requiring the entire pump body to be redesigned for guidance purposes.
Solution Approach 2:
The guiding element acts as an intermediary component between the piston and the pump body walls. It provides the necessary guidance and sealing function, allowing the piston to move precisely within the pump body while maintaining simple overall structure.
3Adaptability or versatility
If flexible components are used for sealing and actuation, then the pump can accommodate some movement flexibility, but deformation of these components causes dose dispersion and operational unreliability
Solution Approach 1:
The invention extracts the flexible sealing components from the force transmission path by implementing a rigid mechanical connection between the rod and piston. This eliminates deformation of flexible components during actuation, ensuring operational reliability while maintaining adaptability through the gland's flexible sealing lip.
Solution Approach 2:
The invention applies local quality by using flexible material only where needed for sealing (the gland's sealing lip), while using rigid materials for force transmission (the connection element between rod and piston). This localized flexibility maintains operational reliability by preventing deformation in critical force transmission areas while preserving sealing adaptability.
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
This design significantly reduces dose dispersion by 48% and improves operational reliability by ensuring consistent dose delivery, even during non-axial actuation, through direct force transmission and reduced deformation of flexible components.
Implementation Method 1
a pump body (14), comprising an opening closed by an inlet valve (20), held in place by a valve holder (21) fastened in said pump body (14), a piston (16) sliding in a sealed manner in said pump body (14), around a hollow rod (15), provided with an inner axial channel (15a) axially closed on the lower side of said rod (15) and communicating with the outside of the rod (15) via a radial orifice (15b)
Implementation Method 2
an actuating spring (24) disposed between said rod (15) and said piston (16), a return spring (25) disposed between said valve holder (21) and said rod (15), biasing said piston (16) towards its rest position
Implementation Method 3
said piston (16) comprising, on an outer radial edge, an outer sealing lip (16a) for ensuring the sealing with respect to said pump body (14), and on an inner radial edge, an inner sealing lip (31), for ensuring the sealing with respect to said rod (15)
Data Source
AI summary
A pump for a fluid product having a pump body held in place by a valve holder fastened in the pump body; a piston sliding around a rod, provided with an inner axial channel axially closed on the lower side of the rod and communicating with the outside of the rod via a radial orifice, the piston having an outer sealing lip and an inner sealing lip; a gland having upwards an oblique or frustoconical surface of inclination appropriate to that of the inner sealing lip of the piston; an actuating spring between the rod and piston; and a return spring between the valve holder and the rod, urging the piston towards its rest position. The valve holder has an axial sleeve having an axial rib forming a mechanical stop in the actuating position between the lower axial end of the rod and the rib.