Surgical Handle Self-Locking Spring Assembly for Stepless Gripping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medical instruments face issues with locking mechanisms that only allow immobilization at predefined intervals, leading to excessive force application and potential damage to the instrument or the object being grasped, and require separate release mechanisms.
Innovation Solution
A medical instrument with a self-locking mechanism using a torsion spring assembly that provides stepless immobilization and automatic release, preventing unintended movement of the tool by increasing friction between the spring coil and pin based on applied force direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking mechanism with locking teeth is used to immobilize the movable grip section, then the tool can be locked in position, but locking is only possible at predefined intervals determined by the spacing of adjacent teeth, which forces the surgeon to move the movable handle further than necessary and can lead to excessive force application and potential damage
Solution Approach 1:
The patent replaces the traditional mechanical locking teeth system with a friction-based locking mechanism. The friction element creates continuous frictional resistance against the force transmission element, providing stepless locking at any position rather than discrete locking points. This substitution eliminates the need for predefined locking intervals and allows precise control of the movable grip section at any position along its range of motion.
2Device complexity
If locking teeth are spaced further apart to reduce the number of locking points, then the mechanism is simpler, but the surgeon must move the handle even further which increases tension in the force transmission element and can cause it to break
Solution Approach 1:
The friction-based locking mechanism replaces the discrete locking teeth system, providing continuous locking capability without requiring multiple teeth spaced along the force transmission element. This eliminates the need to increase the number of locking points or reduce spacing, thereby maintaining element strength while providing simplified continuous locking.
Solution Approach 2:
The friction element automatically engages and disengages based on the position of the movable grip section, providing self-regulating locking without requiring active control or complex mechanisms. The frictional force naturally adjusts to maintain locking at any position, eliminating the need for predefined locking intervals and reducing stress on the force transmission element.
3Adaptability or versatility
If a separate release mechanism is added to the locking mechanism, then the tool can be locked and released independently, but the device complexity increases and the operation becomes more cumbersome
Solution Approach 1:
The friction element serves multiple functions: it provides locking when engaged and automatic release when the movable grip section moves. This single component performs both locking and release functions, eliminating the need for separate mechanisms and reducing overall device complexity while maintaining full control capability.
Solution Approach 2:
The locking mechanism automatically releases when the movable grip section moves, without requiring a separate release action. The friction-based system self-regulates, engaging to prevent unintended opening and automatically disengaging when operational movement occurs, thereby eliminating the need for independent release mechanisms.
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 self-locking mechanism ensures secure grasping without excessive force, prevents damage to the instrument, and simplifies operation by eliminating the need for separate release mechanisms.
Implementation Method 1
the friction between the spring coil and pin increases based on the direction of applied force
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
The invention relates to a medical instrument having an elongated shaft (12), a movable tool (14) at the distal end of the shaft (12), a handle (20) with a movable grip part (24) at the proximal end of the shaft (12), and a force transmission element (32) which can be moved in the longitudinal direction of the instrument and is operatively connected to the movable grip part (24) and to the tool (14) such that an actuation of the movable grip part (24) is converted into a movement of the tool (14). The instrument 1 has a spring assembly (42) that is arranged on the handle (20) and has at least one leg spring (44), which has at least one winding (46) and two legs (48, 50), and a pin (52), wherein the at least one winding (46) extends about the pin (52). When the movable grip part (24) is actuated, a force is applied to at least one of the legs (48, 50) of the leg spring (44), said force reducing the friction between the winding (46) and the pin (52) such that the leg spring (44) can be rotated about the pin (52) and the force transmission element (32) and the tool (14) can be moved. When a force is transmitted from the tool (14) to the force transmission element (32) in the longitudinal direction thereof, the leg spring (44) cannot be rotated about the pin (52) such that the force transmission element (32) and the tool (14) cannot be moved.