Cam-Driven Jaw External Fixation Clamp
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Solution Overview
Problem
Conventional external fixation systems face difficulties in efficiently assembling and securing bone pins and bars due to the need for partial tightening and insertion of fixation elements against spring force, making the process more challenging than necessary.
Innovation Solution
A clamping assembly with a cam mechanism that opens to allow easy insertion of fixation elements between jaws, captures them to prevent removal, and allows axial displacement or rotation while providing a locking system to secure the clamp in place, enabling simpler and more efficient setup of the external fixation system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional clamps are tightened partially to provisionally lock bone pin or bar, then the clamp can hold the fixation element, but the insertion and adjustment process becomes more difficult and time-consuming
Solution Approach 1:
The cam mechanism is pre-configured in a released state that automatically opens the jaws when the fixation element is inserted. The surgeon simply inserts the pin or bar, and the cam's geometry automatically triggers jaw opening and closing actions, eliminating the need for preliminary tightening or manual jaw manipulation.
Solution Approach 2:
The cam mechanism performs the locking action automatically through its geometric design. As the fixation element is inserted, the cam follower rides along the cam surface, which automatically opens the jaws to receive the element, then closes them to lock it in place without requiring additional surgeon intervention or separate tightening steps.
2Reliability
If fixation elements are inserted against spring force in conventional clamps, then the clamp can secure the element, but the insertion becomes more difficult than necessary
Solution Approach 1:
Instead of using spring force to resist insertion (as in conventional clamps), this invention uses the cam mechanism to convert the insertion motion into jaw opening motion. The spring force is redirected to assist the locking action after insertion rather than opposing it during insertion. The cam geometry inverts the traditional approach by making insertion the driving force for jaw opening.
Solution Approach 2:
The cam mechanism acts as an intermediary between the fixation element insertion and the jaw closing action. Rather than springs directly opposing insertion, the cam translates insertion motion into controlled jaw movement. The spring force is mediated through the cam mechanism to provide assisted locking rather than resistive force during insertion.
3Reliability
If clamps require multiple tightening steps to secure fixation elements, then the clamp can be reliably locked, but the assembly process becomes more complex and time-consuming
Solution Approach 1:
The cam mechanism performs multiple functions automatically: it opens the jaws to receive the fixation element, closes the jaws to secure it, and maintains constant clamping pressure. This single self-service mechanism replaces multiple manual tightening steps, significantly accelerating assembly while maintaining reliable locking through the cam's geometric design and integrated spring assistance.
Solution Approach 2:
The cam mechanism provides continuous useful action throughout the insertion process. As the fixation element is inserted, the cam continuously converts this motion into jaw opening and closing actions. The spring force continuously assists the locking action. This continuous action eliminates idle steps between tightening operations, maintaining productive motion throughout the entire assembly process.
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 cam mechanism simplifies the assembly and adjustment of the external fixation system by allowing easy insertion and secure locking of fixation elements, enhancing the efficiency and stability of bone stabilization, allowing for angulation and orientation necessary for healing.
Implementation Method 1
The cam mechanism opens the clamp to permit a health care provider to introduce a fixation element, such as a fixation rod or bar (or other fixation elements) and/or pin (or other fixation elements), between opposing jaws and into the clamp.
Data Source
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AI summary
A clamp includes an opening structurally arranged to receive a fixation element with a cam driven jaw. The clamping assembly includes a first jaw and a second jaw disposed relative to the first jaw. The first and second jaws may be cooperatively positioned to receive the fixation element. A sliding cam is configured to displace relative the first and second jaws. The sliding cam may be associated with the first and second jaws to force the first jaw to vertically displace relative to the second jaw. In one aspect, the sliding cam is structured to vertically displace the first jaw enough to permit an external fixation element to be received between the first and second jaws.