Forceps Treatment Instrument Electrode Posture Stabilization
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Solution Overview
Problem
Existing forceps type treatment instruments face issues with unstable opening and closing of forceps pieces and manufacturing costs due to small protrusion dimensions and potential damage from strong rotation forces, as well as instability in electrode posture during operation.
Innovation Solution
The design incorporates protrusion portions on the spacer member and notch portions on the forceps pieces, allowing for a larger contact area and preventing separation, along with cutout portions in the fitting holes to stabilize the forceps pieces' posture and prevent rotation with respect to the support member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a circular-arc concave groove and convex protrusion are used to define the opening and closing angle of the electrodes, then the electrode rotation is constrained, but the contact area between the protrusion and groove is insufficient, leading to separation under strong rotation forces and potential damage to the groove
Solution Approach 1:
The groove is divided into two separate grooves (first concave groove and second concave groove) positioned at different locations on the insulation spacer. Each groove engages with a corresponding protrusion to constrain rotation in opposite directions. This segmentation allows each groove to be smaller and better positioned while collectively providing sufficient contact area and reliable rotational constraint without the risk of separation.
2Manufacturing precision
If cutting is used to form the protrusion on the electrode while maintaining the sliding surface, then the protrusion can be formed, but the processing requires much effort and manufacturing cost increases
Solution Approach 1:
The protrusion is formed by injection molding the insulation spacer to include recesses that receive and shape the protrusions during the molding process. This replaces the need for subsequent mechanical cutting operations, significantly reducing manufacturing complexity and cost while maintaining precise geometric control of the protrusions.
3Device complexity
If the shaft portion and fitting hole have a circular cross-section, then the assembly is simple, but the insulation spacer may rotate with respect to the forceps support member during electrode opening and closing, causing unstable electrode posture
Solution Approach 1:
The fitting hole in the forceps support member and the corresponding shaft portion are given asymmetric cross-sectional shapes rather than circular shapes. This asymmetric geometry creates a non-rotational fit that prevents the insulation spacer from rotating relative to the forceps support member during electrode operation, thereby stabilizing the electrode posture while maintaining structural simplicity.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
[Object] To stably open and close an electrode. [Solving Means] A protrusion portion 33f is provided in a shaft portion 33a of an insulation spacer 33 rotatably supporting a pair of forceps pieces 31a and 31b. An inner peripheral surface of a shaft hole 31c of the forceps piece is provided with a notch portion 31h. The notch portion 31h includes an end portion 31i with which a protrusion portion comes into contact when grip portions of the forceps pieces rotate in an approaching (closing) direction and an end portion 31j with which a protrusion portion comes into contact when the grip portions of the forceps pieces rotate in a separating (opening) direction.