Swiveling Device Rigidity via Nested Couplers
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Solution Overview
Problem
Conventional swiveling devices for tools and instruments often suffer from low rigidity, limited movement range, and susceptibility to dirt and wear due to complex mechanisms and multiple joints, which restrict their effectiveness in applications like robotics and surgical instruments.
Innovation Solution
A device using a frame with crosswise displacement elements and coupling elements, featuring a crank mechanism that allows for 360° swiveling about a virtual stationary axis, achieved through a compact design with a short force path and rotational or translational drive movement, enhancing rigidity and reducing the risk of mechanical failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional swiveling devices with multiple joints and elements are used, then the device can achieve swiveling movement, but the rigidity of the device deteriorates due to the long chain of elements and multiple joints
Solution Approach 1:
The device is divided into two functional modules: a support coupling module that handles radial support and a guide coupling module that handles angular guidance. This segmentation allows each module to be optimized independently, reducing the overall complexity while maintaining rigidity through specialized functional design.
Solution Approach 2:
The guide coupling is positioned within the support coupling structure, with the guide coupling's rotary joint nested inside the support coupling's spherical joint mechanism. This nesting reduces the overall number of external joints and elements, thereby improving rigidity while maintaining the necessary degrees of freedom.
2Adaptability or versatility
If parallel crank mechanisms are used to guide surgical instruments, then swiveling about a fixed point is achieved, but the movement range is limited due to dead points of the mechanism
Solution Approach 1:
Instead of using a traditional parallel crank mechanism with limited movement ranges, the invention inverts the approach by using a spherical joint mechanism that allows rotation in multiple directions. The support coupling's spherical joint enables the tool to swivel about any axis passing through the puncture point, eliminating dead points and achieving 360-degree movement range.
Solution Approach 2:
The invention transitions from a planar parallel crank mechanism to a three-dimensional spherical joint mechanism. This dimensional change allows the tool to rotate about multiple axes simultaneously, achieving unrestricted 360-degree swiveling range while reducing mechanism complexity through the natural geometry of spherical joints.
3Measurement precision
If arc guide elements are used for manual swiveling, then precise orientation is achieved, but the device becomes heavy, cost-intensive, and the movement range is limited by collision space
Solution Approach 1:
The invention replaces heavy mechanical arc guide elements with a spherical joint mechanism that provides inherent geometric constraints. The spherical joint's geometry naturally guides the tool along the correct arc paths while allowing 360-degree movement, eliminating the need for physical arc guides and significantly reducing device weight.
Solution Approach 2:
Instead of using fixed arc guides that limit movement range, the invention inverts the approach by using an active spherical joint mechanism that dynamically maintains precise orientation. The spherical joint's geometry provides continuous angular guidance without physical collision limits, achieving both precision and full 360-degree range while reducing weight.
4Ease of operation
If multiple rotary joints and gear mechanism elements are used, then swiveling movement is achieved, but the device becomes susceptible to dirt, dust, and chips due to exposed joints
Solution Approach 1:
The support coupling and guide coupling are merged into a single integrated module where the guide coupling's rotary joint is positioned within the support coupling's spherical joint mechanism. This merging reduces the number of exposed external joints, minimizing contact points for dirt and chips while maintaining full swiveling functionality.
Solution Approach 2:
The guide coupling is nested within the support coupling structure, with its rotary joint positioned inside the spherical joint mechanism. This nesting protects the guide coupling's joints from external contaminants like dirt, dust, and chips, reducing wear and susceptibility to harmful factors while preserving the device's swiveling capabilities.
Data Source
AI summary
The invention relates to a device for swiveling an object around a stationary axis (16) which lies outside the space occupied by the device. The inventive device is characterized by unusually great rigidity. A supporting coupler (5) and a guiding coupler (10) are guided parallel to the frame (1) with the aid of cross-sliding elements. The supporting coupler (5) and the guiding coupler (10) are connected to a crank (4) by means of one respective revolute joint, the crank (4) guiding the supporting coupler (5) and the guiding coupler (10) along concentric, non-identical circular paths. The supporting coupler (5) and the guiding coupler (10) are provided with a second revolute joint located at the same distance from the first revolute joint, i.e. a revolute joint (5b) for the supporting coupler at the output end and a revolute joint (10b) for the guiding coupler at the output end, via which the two couplers (5, 10) are jointly connected to an output member (9). The tool is fixed to the output member (9), which follows a circular swiveling path about a stationary axis (16).