External Bone Fixator Hinge With Tool-Free Precision Clamping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing external fixators face issues with imprecise clamping and the risk of loosening due to the need for tools, particularly in austere environments, compromising their effectiveness.
Innovation Solution
A hinge apparatus with adjustable outrigger bars and a torque amplifying knob that allows for tool-free, ergonomic operation, featuring collapsible turn levers and a joint screw mechanism for precise adjustment and secure fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a universal clamp apparatus with a collapsible handle and cam mechanism is used to secure outrigger bars and bone pins, then the clamping operation can be performed without tools, but the clamping force becomes imprecise and fixed, and there is a risk of handle loosening causing instability
Solution Approach 1:
The clamp mechanism transitions from a static cam-based system to a dynamic progressive tightening system using a screw thread. The screw thread allows continuous adjustment of clamping force while maintaining tool-free operation through the collapsible handle, resolving the contradiction between ease of operation and clamping precision.
Solution Approach 2:
The ratchet mechanism provides mechanical feedback by allowing rotation in one direction (tightening) while preventing reverse rotation (loosening). This ensures that once clamping force is applied, it cannot be accidentally reduced, eliminating the handle loosening risk while maintaining tool-free operation.
2Ease of operation
If a collapsible handle with cam mechanism is used for clamping, then tool-free operation is enabled, but the handle may catch objects and become loosened, causing loss of stability
Solution Approach 1:
The ratchet mechanism provides one-way mechanical feedback that prevents reverse motion. The teeth engagement allows tightening rotation but blocks loosening rotation, ensuring that even if the handle catches an object, the clamp cannot loosen and maintain stable clamping force.
Solution Approach 2:
The ratchet mechanism acts as a preventive measure against handle loosening before it can occur. By designing the mechanism to physically block reverse rotation, it cushions against the potential harmful effect of handle catching and loosening.
3Measurement precision
If external fixators require tools for tightening and loosening clamps, then precise clamping force can be applied, but the complexity increases and tools may be lost in austere environments
Solution Approach 1:
The tool (collapsible handle) is merged with the clamp mechanism itself. The handle collapses into the clamp body when not in use, eliminating the need for separate tool storage and reducing overall system complexity while maintaining precise clamping capability.
Solution Approach 2:
The clamp mechanism serves itself by incorporating the tightening and locking functions directly into the clamp assembly. The screw thread and ratchet mechanism allow the clamp to apply and maintain precise clamping force without requiring external tools or additional components.
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
Enables precise and stable fixation of bone fragments without tools, ensuring consistent clamping force and reducing the risk of loosening, particularly beneficial in resource-limited settings.
Implementation Method 1
A joint screw extends through and connects the first and second joint bodies. A torque amplifying knob with collapsible turn levers rotates a central screw turn actuator engaged with the joint screw so that movement of the actuator is caused in opposite first and second linear directions along the cylindrical threaded body when rotational force is applied
Implementation Method 2
A torque amplifying knob with collapsible turn levers rotates a central screw turn actuator. The turn levers of each knob can be collapsed in a generally mating, side-by-side arrangement and are ergonomically designed so that the knobs can be hand operated, without tools
Implementation Method 3
A hinge apparatus has first and second outrigger bars that attach to and extend outwardly from first and second joint bodies. The outrigger bars can be adjusted at various angles relative to each other
Implementation Method 4
The central screw turn actuator is engaged with the joint screw so that movement of the actuator is caused in opposite first and second linear directions along the cylindrical threaded body when rotational force is applied in opposite first and second rotational directions, respectively
Data Source
AI summary
A hinge apparatus has a pair of outrigger bars that attach to and extend outwardly from respective joint bodies. The outrigger bars can be adjusted at various angles relative to each other. The joint bodies have respective surfaces that face and engage each other. A joint screw connects the joint bodies. A torque amplifying knob with collapsable turn levers rotates a central screw turn actuator. The actuator is engaged with the screw so that movement of the actuator is caused in opposite first and second linear directions along the threaded body when rotational force is applied in opposite first and second rotational directions, respectively, to the torque amplifying knob. The turn levers of each knob can be collapsed in a side-by-side arrangement. The turn levers of the knobs are ergonomically designed so that the knobs can be hand operated, without tools, in the collapsed and un-collapsed configurations.