Bidirectional Pivoting Joint with Form-Fit Locking
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Solution Overview
Problem
Existing bidirectional pivoting joints face issues with wear, limited load capacity, susceptibility to slippage, high actuation force requirements, and inadequate control over locking and unlocking, especially when multiple joints are connected in series, and they are not sterilizable.
Innovation Solution
A bidirectional pivoting joint with a concentric annular space and radially narrowing peripheral regions, featuring variable cross-section clamping members and an actuating device that easily transitions between holding and releasing states, ensuring a self-holding, wear-free, and hysteresis-free locking mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If frictionally engaged locking is used, then the locking mechanism can withstand loads, but it is subject to great wear and susceptible to slippage
Solution Approach 1:
The patent replaces friction-based mechanical locking with a form-fit locking mechanism using polygonal clamping members that engage with corresponding polygonal surfaces on the inner and outer bodies. The locking is achieved through geometric interlocking rather than friction, eliminating wear and slippage issues while maintaining load capacity.
Solution Approach 2:
Instead of using friction to create locking force, the patent inverts the approach by using geometric form-fit engagement where the polygonal clamping members physically interlock with the joint elements. The locking force is generated by the geometric constraint rather than frictional resistance.
2Ease of operation
If stepped or stepless snap locking systems are used, then locking can be achieved, but a relatively large actuation force is required due to hysteresis
Solution Approach 1:
The patent employs spring-loaded clamping members that automatically engage with the polygonal surfaces when the joint is assembled. The springs provide the necessary clamping force without requiring external actuation, making the system self-servicing and eliminating the need for large actuation forces.
Solution Approach 2:
The patent uses multiple clamping members distributed around the annular space, each providing partial locking action. The cumulative effect of multiple small clamping forces achieves the required total locking force without requiring any single clamping member to exert excessive force.
3Reliability
If known pivoting joints are used, then rotation locking can be achieved, but simultaneous triggering of locking or unlocking of multiple joints is impaired
Solution Approach 1:
The patent designs the control element to simultaneously actuate multiple clamping members through a common control mechanism. A single control input can trigger the locking or unlocking of all clamping members across multiple joints, enabling synchronized operation without complex individual control systems.
Solution Approach 2:
The patent merges the control mechanisms of multiple joints into a unified control system. The control elements are designed to be actuated simultaneously, combining the locking and unlocking functions of multiple joints into a single operational action, thereby reducing overall control complexity.
4Reliability
If known pivoting joints are used, then locking can be achieved, but they are not sterilisable and not even disinfectable
Solution Approach 1:
The patent employs a design where all components are made from sterilizable materials and have smooth, non-porous surfaces that can withstand autoclaving and chemical disinfection. The polygonal clamping members and control elements are designed without crevices or complex geometries that would trap contaminants, enabling complete sterilization.
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 provides a robust, reliable, and sterilizable pivoting joint that maintains constant force conditions, allows for precise control with minimal actuation force, and enables simultaneous operation of multiple joints, meeting safety and sterility requirements.
Implementation Method 1
at least two clamping members distributed over the annular periphery of the annular space and arranged therein, said clamping members each having a cross-section being variable in the peripheral direction of the annular space
Data Source
AI summary
A bidirectional pivoting joint comprises pivoting elements which are rotatable relative to one another, specifically in a coaxial arrangement, a cylindrical outer body and a cylindrical inner body and a locking device optionally locking and releasing the rotational movement. The locking device has an annular space between the outer body and the inner body. Provided between annular space surfaces, specifically an inner surface of the outer body and an outer surface of the inner body are radially narrowing and, on the other hand, radially wider, peripheral regions in alternating arrangement. Arranged in the annular space are at least two clamping members which are each adjustable in cross-section in the peripheral direction (u) of the annular space. In a holding state, each clamping member has a first said cross-section and lies in the narrowing peripheral regions against the outer body and the inner body. By this means, a self-holding clamping connection is established which blocks the relative rotational movement between the outer body and the inner body in each rotation direction (d). In a releasing state, each clamping member has a second said cross-section by means of which the clamping connection is released in order to free the rotational movement. An actuating device of the pivoting joint is equipped with an actuating means which acts on the clamping members to establish, firstly, the holding state and, secondly, the releasing state. A holding and positioning device comprises a plurality of said pivoting joints.