Surgical Torque Limiter Handle Deformation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing torque limiter designs for surgical securement devices are complex and costly to manufacture, limiting their practical application in medical settings.

Innovation Solution

A torque limiting driving instrument with a handle and torque transfer member that deforms to prevent excessive torque transmission, allowing the handle to rotate relative to the shaft when a predetermined torque limit is exceeded, thereby limiting further rotation and securing fasteners effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional torque limiter designs are used, then torque limiting function is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvetorque limiting functionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the handle and torque transfer member into a single integrated component with monolithic construction, eliminating the need for separate torque limiting mechanisms. The handle itself is designed with deformation characteristics that provide torque limiting, merging multiple functions into one structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The handle automatically limits torque through its own deformation characteristics without requiring external sensing or control systems. When excessive torque is applied, the handle deforms elastically or plastically to slip relative to the shaft, self-regulating the torque transmission.

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional torque limiter designs are used, then torque limiting function is achieved, but manufacturing cost increases

Engineering Contradiction:
Improvetorque limiting functionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By integrating the torque limiting function into the handle's monolithic structure, the patent reduces the number of parts that need to be manufactured and assembled. This simplifies manufacturing processes and reduces assembly steps, leading to lower manufacturing costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent achieves torque limiting by modifying the physical parameters of the handle material or geometry, such as using materials with specific elastic or plastic deformation characteristics, or designing the handle with thin-walled sections that deform at predetermined torque levels.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the handle is rigid, then structural strength is maintained, but torque limiting capability is lost

Engineering Contradiction:
Improvestructural strengthVSAvoidtorque limiting capability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies local quality by making specific portions of the handle have different structural properties. The handle may have thin-walled sections or specific geometric features in torque-transfer regions that are designed to deform at predetermined torque levels, while other portions maintain full structural strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces dynamic characteristics to the handle by allowing it to deform elastically or plastically under excessive torque. This dynamic response enables the handle to automatically limit torque while maintaining structural integrity during normal operation.

Inventive Principle:
Principle #15Dynamics

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 instrument ensures secure fastening while preventing damage by allowing the handle to deform and rotate when the torque limit is reached, providing a cost-effective and efficient solution for surgical applications.

Implementation Method 1

the handle deforms to allow the handle to rotate along the direction relative to both the torque transfer member and the shaft

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2967696B1Surgical torque limiting instrument
Publication Date: 2019.06.12 DEPUY SYNTHES PROD INC
  • EP2967696B1 patent drawingFigure 1
  • EP2967696B1 patent drawingFigure 2
  • EP2967696B1 patent drawingFigure 3

AI summary

An instrument for limiting torque can include a method for limiting torque that is transferred from a handle of the instrument through a torque transfer member to a shaft that extends relative to the handle. The method can include applying a torque to the handle along a direction relative to the shaft. The method can include transmitting the applied torque from the handle through the torque transfer member to the shaft when the applied torque is less than a limited torque value. When the applied torque is greater than the limited torque value, at least one of the torque transfer member and the handle deforms so as to allow the handle to rotate along the direction relative to both the torque transfer member and the shaft.