Filtration Clamp Cam Locking for Low-Force Stable Sealing
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Solution Overview
Problem
Conventional vacuum filtration clamps require high operational force, leading to cumbersome designs, stability issues, and hazardous pinch points, making them difficult to control and use, especially in laboratory settings where sterility and ease of use are crucial.
Innovation Solution
A bimodal clamp design utilizing a torsion spring for initial membrane seal and a secondary locking mechanism with a rotating cam mechanism or rollers to provide additional clamping force, allowing for reduced handle size and single-handed operation while maintaining stability and preventing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a single high-force torsion spring is used to provide sufficient clamping force for both sealing and secure connection, then the clamping force requirement is met, but the handle size becomes large and cumbersome, affecting stability and creating hazardous pinch points
Solution Approach 1:
The clamping function is segmented into two distinct mechanisms: a low-force torsion spring for initial membrane sealing and a high-force cam/locking mechanism for secure component connection. This segmentation allows each mechanism to be optimized independently, with the cam mechanism providing high clamping force only when needed for stability, while the torsion spring handles the delicate sealing task with minimal force and smaller handles.
Solution Approach 2:
The clamp transitions from a static high-force design to a dynamic bimodal system that adjusts its force characteristics based on operational stage. The torsion spring provides continuous low-level force for sealing, while the cam mechanism can be dynamically engaged or disengaged to provide high force only when stability is required, allowing small handles that are easy to control.
2Force
If large handles are used to actuate a high-force torsion spring, then sufficient clamping force is achieved, but the clamp becomes cumbersome and affects the stability of the filtration apparatus
Solution Approach 1:
The force generation is segmented into two stages: initial sealing force from a compact torsion spring and additional stabilizing force from a cam mechanism. This allows the majority of the clamp structure to remain small and stable, with the cam providing supplemental force only when needed to prevent slippage, rather than requiring large handles that upset the apparatus balance.
Solution Approach 2:
The clamp force parameter is changed dynamically through the cam mechanism, which can engage to increase force only when stability is compromised. This allows the clamp to maintain a compact, stable design under normal conditions while providing high force on-demand to correct stability issues without requiring permanently large handles.
3Reliability
If a single high-force torsion spring is used to ensure secure connection, then clamping reliability is improved, but the design creates multiple pinch points and hazardous areas for the user
Solution Approach 1:
The clamping function is divided between a torsion spring for sealing and a cam/locking mechanism for secure connection. The cam mechanism incorporates safety features such as guarded moving parts and controlled engagement zones that eliminate exposed pinch points, while still providing the high force needed for reliable connection security.
Solution Approach 2:
The cam mechanism acts as an intermediary between the user's small input force and the high clamping force required for secure connection. This mechanical advantage system allows reliable connection security to be achieved through a controlled, safe motion path that avoids creating hazardous pinch points in the handle actuation mechanism.
4Force
If conventional clamps with large handles are used, then sufficient clamping force is achieved, but the handles are difficult to control and can cause the apparatus to fall over
Solution Approach 1:
The clamping operation is segmented into two phases: initial sealing with a lightly-sprung torsion mechanism that has small, easily-controlled handles, and optional stabilization with a cam mechanism that provides high force only when needed. This segmentation allows the handles to remain small and controllable while still achieving sufficient total clamping force when stability is required.
Solution Approach 2:
The clamp system dynamically adjusts its force profile based on operational needs. The torsion spring provides continuous low-level force with small, easily-controlled handles, while the cam mechanism can be dynamically engaged to provide high force only when stability issues arise, maintaining ease of operation under normal conditions.
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 clamp design reduces operational force requirements, enhances stability, and eliminates hazardous pinch points, enabling easier and safer operation while maintaining a secure seal, thus improving the usability and safety of vacuum filtration systems.
Implementation Method 1
utilizing a biasing member, such as a torsion spring, with a force high enough to achieve an initial membrane seal
Implementation Method 2
a rotating locking tab which employs a 'cam' mechanism mounted inside a jaw member of the clamp. The cam, when actuated such as by rotating the locking tab, interacts with a corresponding 'ramp' located on the underside of the other jaw member resulting in an interference fit which produces additional force on that jaw
Implementation Method 3
a vacuum source may be placed in communication with the apparatus and allows a vacuum to be drawn within the filtrate bottle or flask, thereby driving filtration by drawing the sample solution through the membrane filter
Implementation Method 4
Since the pressure differential across the filter is constant due to the application of the vacuum on the downstream side of the filter and atmospheric pressure present on the liquid surface of the open container
Data Source
AI summary
A clamp including a first jaw member having a camming surface, a second jaw member pivotable with respect to the first jaw member, a first biasing member biasing the first and second jaw members to a first position; and a locking mechanism that includes a cam or roller for cooperating with the camming surface of the jaw member, and a second biasing member biasing the cam or roller against the camming surface to lock the first and second jaw members in a second position. An optional alignment collar can be used to align components of the filtration apparatus prior to clamping. Filtration apparatus including the clamp, and also optionally including the alignment collar, is also disclosed.