Pipette Tip Mounting Shaft Locking Lobes
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Solution Overview
Problem
Existing pipette tip mounting systems require excessive force for secure engagement and stable orientation, often leading to unintentional removal due to inadequate sealing and stability, especially under lateral momentum or knocking forces.
Innovation Solution
A pipette tip mounting shaft configuration with a locking section and lower sealing section, featuring outwardly extending locking lobes and a recessed relief portion, which flexes the tip collar out of round for secure engagement with ergonomic feedback, and a stop member for precise positioning, along with a sealing ring for reliable sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tapered fit between mounting shaft and pipette tip collar is used to secure the tip, then sealing engagement is improved, but excessive insertion and ejection forces are required
Solution Approach 1:
The mounting shaft is segmented into distinct functional zones: a tapered lower sealing section for sealing engagement, an upper locking section with lobes for mechanical locking, and a stop member for depth control. The pipette tip collar is similarly segmented with a sealing area, locking ring, and shelf. This segmentation allows each zone to perform its specific function independently, achieving reliable sealing without requiring excessive force throughout the entire assembly.
Solution Approach 2:
Different sections of the mounting shaft and tip collar are given different geometric properties tailored to their specific functions. The lower section has a tapered geometry optimized for sealing, while the upper section has lobes with specific radii and angles optimized for locking. This local differentiation of geometric properties allows each region to contribute optimally to the overall performance without compromising other functions.
2Stability of the object's composition
If excessive force is applied to jam the mounting shaft into the tip for stability, then tip stability is improved, but unintentional removal resistance deteriorates due to collar deformation
Solution Approach 1:
The locking mechanism incorporates dynamic elements including the flexible locking ring that can deform during insertion and ejection, and the lobes with ramp portions that guide the deformation process. The recessed relief portions provide controlled compliance zones that allow the collar to flex without permanent deformation. This dynamic behavior enables the system to absorb lateral forces and knocking during use while maintaining stable engagement and preventing unintentional removal.
3Reliability
If a tapered mounting shaft is used to achieve proper seal, then sealing is improved, but device complexity increases due to multiple engagement mechanisms
Solution Approach 1:
The invention merges multiple functions into a unified integrated structure. The mounting shaft combines the tapered sealing section, lobes for locking, stop member for depth control, and recessed relief portions for compliance all in one continuous component. Similarly, the tip collar integrates the sealing area, locking ring, and shelf. This merging of functions into integrated components achieves reliable sealing and stable engagement without the complexity of separate discrete mechanisms for each function.
Solution Approach 2:
The mounting shaft and tip collar are designed as multi-functional components where each element serves multiple purposes. For example, the lobes both provide mechanical locking and guide the insertion process, the stop member both limits insertion depth and provides tactile feedback, and the recessed relief portions both accommodate collar deformation and reduce insertion force. This multi-functionality reduces the need for separate dedicated components for each function, simplifying the overall device.
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 configuration achieves robust sealing with low insertion and ejection forces, providing tactile feedback and enhanced resistance to unintentional removal, ensuring stable tip orientation and easy ejection with stored energy.
Implementation Method 1
The ramp portion 60 of each lobe 50 is adapted to flex and distort the collar 36 out of round as the mounting shaft 12 is inserted into the collar 36 of a mating pipette tip 14
Implementation Method 2
The lower sealing section 32 provides sealing engagement between the mounting shaft 12 and the pipette tip 14
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
In one aspect, the invention relates to a pipette tip mounting shaft configuration and a disposable pipette tip having a matching configuration. The mounting shaft (12) includes a locking section (30) located above a lower sealing section (32). The locking section (30) has outwardly extending locking lobes located above a stop member (34) and a lower sealing section (32) located below the stop member (34). When the mounting shaft (12) is fully- inserted into the collar (36) of the mating disposable pipette tip (14), the tip locks onto the mounting shaft (12). The bore of the pipette tip includes a circumferential shelf or shoulder separating its upper collar from the tip sealing area which is located below the circumferential shelf. The tip collar preferably includes a locking ring located at or near the upper opening for the mounting shaft (12). The dimensions of the collar, and in particular the distance between its circumferential shelf and the locking ring, are selected to match the dimensions of the mounting shaft (12) between the stop member (34) and the upper end of the locking lobes, thus locking the pipette tip (14) in a secure, reliable position and orientation while using ergonomic insertion and ejection forces. The locking lobes preferably include a ramp portion that gently flexes and distorts the pipette tip collar (36) out of round as the mounting shaft i(12) s inserted in the pipette tip (14), rather than stretching the tip collar (36). The circumferential shelf on the pipette tip (14) between the tip collar (36) and the barrel (38) isolates the sealing area at the upper end of the barrel (38) from distortion, thus facilitating reliable sealing engagement between the lower sealing section (32) of the mounting shaft (12) and the sealing ring in the upper end of the barrel (38) of the pipette tip (14).