Switchable Prosthetic Gripper Linkage Mechanism
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Solution Overview
Problem
Conventional prosthetic devices struggle to quickly and easily switch between voluntary-open and voluntary-close modes of operation without extensive adjustments, limiting their functionality and user independence.
Innovation Solution
A gripping device with a movable and fixed jaw mechanism that uses a connecting link or mechanism positioned in different positions to alternate the jaw's movement, allowing the device to switch between voluntary-open and voluntary-close modes by altering the handle's motion, utilizing a singularity point in the mechanical linkage to change the jaw's direction of movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a prosthetic device uses a voluntary-open mode of operation, then the device can release objects easily, but switching to voluntary-close mode requires extensive adjustments to the initial jaw positions and Bowden cable attachment
Solution Approach 1:
The connecting link automatically switches between first and second positions through the user's own operational movements. When the user operates the Bowden cable to switch modes, the connecting link self-activates to change jaw movement direction without requiring external adjustment or reconfiguration by the user.
Solution Approach 2:
The connecting link dynamically changes its position based on operational needs. It transitions from a first position (for voluntary-open mode) to a second position (for voluntary-close mode) and vice versa, allowing the device to adapt its mechanical behavior without permanent structural changes or complex adjustments.
2Adaptability or versatility
If the connecting link position is changed to switch between modes, then the jaw movement direction changes, but the initial jaw position and Bowden cable attachment direction must be altered
Solution Approach 1:
The system uses the user's own operational input to trigger the mode switch. The connecting link detects and responds to the Bowden cable movement, automatically reconfiguring the jaw movement direction without requiring the user to perform separate adjustment operations or change the Bowden cable attachment point.
Solution Approach 2:
The connecting link acts as an intermediary between the Bowden cable and the movable jaw. It translates the cable's linear movement into rotational jaw movement in different directions depending on its position, mediating the control signal without requiring direct reattachment of the cable.
3Adaptability or versatility
If extensive adjustments are made to switch between voluntary-open and voluntary-close modes, then the device can change functionality, but the switching process becomes time-consuming and complex
Solution Approach 1:
The mode switching occurs automatically through the user's normal operational movements. The connecting link self-activates when the Bowden cable is operated, eliminating the need for separate mode-switching procedures or time-consuming adjustment processes.
Solution Approach 2:
The connecting link is pre-positioned to respond to Bowden cable movement in either direction. The mechanism is prepared in advance to switch modes automatically, so the user simply needs to operate the cable without worrying about the switching 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
Enables seamless switching between modes without changing the handle's starting position or movement direction, enhancing the device's versatility and user convenience by allowing easy adaptation between grasping and releasing objects.
Implementation Method 1
The connecting mechanism causes the alternating movements of the first moveable jaw by imparting a force on the first moveable jaw through a singularity. As used herein, a singularity refers to point along a mechanical linkage wherein the motion of the jaw on one side of the singularity is different in response to the same motion of the handle on the other side of the singularity.
Implementation Method 2
The mechanism includes one or more hydraulic channels operatively engaged to the first moveable jaw for causing the first moveable jaw to open relative to the second fixed jaw when the handle is moved inwardly or alternately causing the first moveable jaw to close relative to the second fixed jaw when the handle is moved inwardly.
Implementation Method 3
a cable is used as the mechanism that is operatively engaged to the first movable jaw for alternately causing the first moveable jaw to move inwardly or outwardly relative to the second fixed jaw when the handle is moved inwardly. The alternating movement of the first moveable jaw is accomplished by passing a cable through a singularity.
Data Source
AI summary
A gripping device that comprises a first moveable jaw and a second fixed jaw is disclosed. The gripping device has a handle operatively engaged to the first moveable jaw and a connecting link operatively engaged to the first moveable jaw. The connecting link is positioned in at least one of a first position or a second position. The change in the position of the connecting link allows the gripping device to have either a default closed position or a default open position, which can be defined by voluntarily-open or voluntary-close modes of operation, respectively. The first moveable jaw moves in either of the modes of operation. The change in the mode of operation is accomplished through use of a connecting link that is passed through a singularity during the switching process to achieve the different output positions and directions.