Hinge Pin Coupling for Microsurgical Leaf Spring Alignment
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Solution Overview
Problem
Existing micro surgical handheld instruments face difficulties in cleaning and conditioning due to non-releasable leaf spring connections, which cause handling challenges, potential damage to surgical gloves, and risk of plastic deformation leading to misalignment of handles.
Innovation Solution
A hinge-type coupling mechanism for leaf spring ends with a hinge pin and receiving eyelet, where the eyelet has a small oversize diameter and a continuous longitudinal slit, allowing for easy coupling and uncoupling without separate hinge pin manipulation, guiding the leaf springs and handles with minimal play.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If through-connections with T-shaped tab and rectangular opening are used to couple leaf spring ends, then uncoupling is easy, but considerable play is formed making the connection unsuitable for guiding
Solution Approach 1:
The invention changes the geometric parameters of the coupling connection by replacing the rectangular opening with a circular opening and the T-shaped tab with a rounded tab, thereby reducing play while maintaining ease of uncoupling through material elasticity
Solution Approach 2:
The invention applies different local qualities to the coupling components: the leaf spring material provides elasticity for easy uncoupling, while the precise circular geometry provides minimal play for accurate guidance
2Ease of operation
If leaf spring connections are made non-releasable, then handling is simplified, but cleaning and conditioning becomes difficult
Solution Approach 1:
The invention creates a dynamically reversible connection that is stable during operation but can be easily released when needed, allowing the instrument to switch between handled and cleaned states
3Reliability
If strong twisting is applied to insert T-shaped tab into rectangular opening, then coupling is achieved, but material stress may cause plastic deformation and handle misalignment
Solution Approach 1:
The invention changes the insertion mechanism from twisting to pressing, fundamentally altering the stress application method to avoid torsional loads that cause plastic deformation
Solution Approach 2:
Instead of forcing the tab through twisting motion, the invention inverts the approach by pressing the rounded tab directly through the circular opening, using compressive rather than torsional force
Data Source
AI summary
A surgical instrument includes a first lever element and a second lever element interconnected by a lever element hinge. Each lever element includes a grip portion and a jaw portion. A first spring portion and a second spring portion are proximally connected to the grip portions. A proximal free end of the first spring portion is coupled to a proximal free end of the second spring portion by a hinged joint. The hinged joint includes a hinge pin and at least one bearing eye. The at least one bearing eye forms a continuous longitudinal slit for radial insertion of the hinge pin. The slit extends diagonally relative to the axis of the at least one bearing eye so that at least one spring portion has to be twisted during radial insertion of the hinge pin into the at least one bearing eye.