Pipette Tip Ejection Lever Mechanism for Ergonomic Force Reduction
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Solution Overview
Problem
Existing manual-actuated mechanical pipettes require substantial effort to eject collection cones due to frictional forces, leading to ergonomic challenges and potential damage during the ejection process.
Innovation Solution
A cone ejection system featuring a control lever that reduces the ejection force required, incorporating an elastic return mechanism and a control lever with a sphere-plane connection to minimize friction and ensure axial force transmission, allowing for a linear and efficient cone ejection motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the ejection knob directly pushes the collection cone, then the ejection function is simple, but the ejection force required is high due to frictional forces
Solution Approach 1:
A control lever is introduced as an intermediary element between the ejection knob and the collection cone. The lever pivots about a pivot axis and transmits the ejection force from the knob to the cone through its intermediate portion, reducing the direct frictional contact and required ejection force.
Solution Approach 2:
The ejection mechanism transitions from direct linear pushing to a rotational pivoting motion. The control lever rotates about a pivot axis, converting the linear motion of the ejection knob into a rotational motion that reduces friction and required force.
2Reliability
If substantial effort is applied to the ejection knob, then the collection cone can be ejected, but the risk of damage to pipette components increases
Solution Approach 1:
The control lever acts as a force-distributing intermediary that reduces peak forces on individual components. By distributing the ejection force through the lever's pivot mechanism, the risk of damage to the ejection knob, pivot connections, and collection cone is reduced.
Solution Approach 2:
The elastic return means provides a cushioning effect by using elastic deformation to absorb and gradually release energy during the ejection process, preventing sudden force spikes that could damage components.
3Ease of operation
If a hinged control lever is used, then the ejection force is reduced and ergonomics improved, but the mechanism complexity increases
Solution Approach 1:
The control lever is divided into distinct functional portions: a first end for mounting and pivoting, a second end for receiving the ejection knob force, and an intermediate portion for actuating the ejection device. This segmentation allows each portion to be optimized for its specific function while maintaining overall simplicity.
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 solution significantly reduces the ejection force needed, enhancing ergonomics and reducing the risk of damage to the pipette components, while maintaining a solid and efficient cone ejection mechanism.
Implementation Method 1
elastic return means capable of returning the cone ejection device into a high position
Data Source
AI summary
A system for ejecting tips of sampling pipettes, the system comprising: —a button for ejecting a tip which is intended to be moved in translation by an operator's thumb; —a tip ejection device; and —return spring for returning the tip ejection device to a raised position. According to the invention, the system also comprises a lever for controlling the ejection device, the control lever comprising: —a first end which is intended to be fitted onto a part of the pipette; —a second end cooperating with the eject button so as to be acted upon by the latter; and —an intermediate portion for actuating the ejection device.