Polymer Compression Spring Assembly for Recyclable Dispensing Pumps
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Solution Overview
Problem
The presence of metal springs in dispensing pumps hinders the recycling process due to the need to separate them from plastic components, making all-plastic spring assemblies necessary for efficient recycling.
Innovation Solution
A dispensing pump with a polymer compression spring assembly, featuring a slotted tubular spring element and loading cones, where the spring element is formed from tensile polymer material, allowing for radial expansion and creating an opposing axial extension force, enabling the entire pump to be molded from a single plastic material for easy recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal spring is used in the dispensing pump, then the spring provides reliable compression and extension forces, but the pump cannot be easily recycled due to separation requirements
Solution Approach 1:
The spring element is formed from a homogeneous polymer material that matches the other pump components, eliminating material heterogeneity. This allows the entire pump assembly to be recycled together as a single material type, resolving the contradiction between reliable spring function and recycling ease.
Solution Approach 2:
The traditional metal mechanical spring is replaced with a polymer-based spring element that achieves the same mechanical compression and extension functions through elastic deformation of the polymer structure, enabling compatibility with plastic pump components for unified recycling.
2Ease of manufacture
If a polymer spring element is used instead of metal, then recycling is simplified, but the spring material must withstand repeated compression and extension forces
Solution Approach 1:
The polymer material's physical and chemical parameters are optimized to achieve the necessary mechanical strength and elasticity for spring function. The polymer is selected or formulated to have appropriate tensile strength, elasticity, and fatigue resistance to withstand repeated compression and extension cycles.
Solution Approach 2:
The spring element may utilize composite polymer structures or reinforced polymer formulations that combine multiple material properties to achieve both the required mechanical strength for durability and the elastic properties for spring function, while remaining compatible with recycling processes.
3Device complexity
If the spring element is made from tensile polymer material, then the material can be molded as a single piece with the pump, but the polymer must maintain structural integrity during deformation
Solution Approach 1:
The spring element is designed with a segmented or slotted structure that allows controlled deformation during compression and extension while maintaining overall structural integrity. The segmentation enables the polymer to flex and return to its original shape without compromising the material's compositional stability.
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 all-plastic compression spring assembly facilitates easy recycling of the dispensing pump by eliminating the need for metal components and ensuring the entire system can be classified and processed as a single plastic material, enhancing recyclability and extending the spring's life cycle through strain distribution.
Implementation Method 1
said tubular spring element being received coaxially about the piston stem between said first and second loading cones, said second loading cone being axially compressible with said piston stem and/or dispensing head toward the first loading cone and within said slotted tubular spring element, whereby said slotted tubular spring element radially expands in tension to create an opposing axial extension spring force
Data Source
Figure 1
Figure 2~3
Figure 4~7
AI summary
A dispensing pump (700) includes a polymer compression spring assembly (706). The dispensing pump (700) includes a pump base (702), and a dispensing head having a piston stem. The polymer compression spring assembly (706) includes a slotted tubular spring element (722) and first and second loading cones (724,726) received at opposing ends of the slotted tubular spring element (722). The first loading cone (724) is fixed relative to the pump base (702) while the second loading cone (726) is axially movable with the piston stem (716) and dispensing head (704). The tubular spring element (722) is disposed coaxially about the piston stem (716) between the cones (724,726). When the dispensing head (704) is compressed, the loading cones (724,726) axially compress toward each other whereby the slotted tubular spring element (722) radially expands to create an opposing contraction force, and in turn, an axial extension force. When released, the spring element (722) elastically contracts to its at rest shape, returning the loading cones (724,726) and dispensing head (704) to their at rest positions.