Endoscope Bending Tube Torsion Prevention via Slot Array Design
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Solution Overview
Problem
Conventional endoscope bending tubes face challenges in maintaining durability and torsional rigidity while allowing for effective bending and rotation operations, particularly when using super-elastic alloys, as stress concentration occurs at the proximal ends of the bending slots, leading to potential torsional issues.
Innovation Solution
The design incorporates a cylindrical bending tube body made of super-elastic alloy with slots arranged in alternating arrays, where torsion preventing tab mechanisms are omitted at specific positions to alleviate stress concentration, and circular or elliptical holes are used at end portions to disperse stress, enhancing durability without compromising torsional rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If torsion preventing tab mechanisms are provided at all slots for bending, then torsional rigidity is improved, but stress concentration occurs at the proximal ends of the slots leading to reduced durability
Solution Approach 1:
The patent applies local quality by providing torsion preventing tab mechanisms only at specific slots for bending (those not located at the most proximal end among slots in the same array), rather than uniformly at all slots. This localized approach prevents torsion where needed while avoiding stress concentration at the proximal end slots, thereby resolving the contradiction between torsional rigidity and durability.
2Adaptability or versatility
If slots for bending are arranged in alternating arrays, then bending flexibility is improved, but structural complexity increases
Solution Approach 1:
The patent employs asymmetry by arranging slots for bending in alternating arrays where slots in different bending directions are positioned asymmetrically relative to each other. This asymmetric arrangement enables the bending tube to bend in multiple directions (improving flexibility) while the alternating pattern maintains a regular, manufacturable structure (controlling complexity).
Solution Approach 2:
The patent segments the slots for bending into multiple independent arrays, each responsible for a specific bending direction. This segmentation allows the bending tube to achieve multi-directional flexibility through coordinated bending of separate slot arrays, while each individual array maintains a simple, regular structure that is easy to manufacture.
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 enhances the durability and maintains appropriate torsional rigidity, allowing for effective bending and rotation operations, thereby improving the endoscope's ability to orient the distal end arbitrarily within a body cavity while reducing stress concentration.
Implementation Method 1
a cylindrical-shaped bending tube body made of a super-elastic alloy
Data Source
AI summary
In a bending tube for endoscope on which torsion preventing tab mechanisms are provided on the respective middle parts of first and second slots for bending located in an area from the proximal end of a bending tube body to a predetermined position on the distal end side (the torsion suppressing area), and the bending tube body being permitted to bend by the first and second slots for bending, the torsion preventing tab mechanism of at least any one of the first and second slots for bending arranged on the proximal end side of each of arrays (first and second arrays), other than the first and second slots for bending located at the most proximal end, among the first and second slots for bending arrayed in a same line, respectively, along a longitudinal direction of the bending tube body, is removed.