Mechanical Hand Gripping Mechanism with Rotating Plate
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Solution Overview
Problem
Conventional gripping hands face limitations in operation stroke and gripping force, leading to difficulties in handling heavier objects and stability issues due to clearance between pins and cam grooves, which results in potential object dropping during external vibrations.
Innovation Solution
A hand design featuring first and second sliders with gripping members, a drive source, and a rotating plate with clamping links that allow for increased operation stroke and gripping force by aligning shafts to enhance gripping capability and stability, utilizing a coil spring for maintaining grip even without power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a disk cam with pins is used to move gripping members in opening/closing directions, then the gripping members can be driven linearly, but the pins fall out from cam grooves when rotation angle reaches a predetermined angle (approximately 45 degrees), limiting the operation stroke
Solution Approach 1:
The patent replaces the disk cam mechanism with a rotating plate mechanism. Instead of using pins sliding in cam grooves, the invention uses a rotating plate with a specific geometric shape that directly drives the gripping members through rotational motion. This substitution eliminates the pin-retention problem while achieving the desired linear movement of gripping members over a larger stroke range.
Solution Approach 2:
The patent changes the geometric parameters of the driving mechanism by using a rotating plate with a specific profile instead of a disk cam. The rotating plate's geometry is designed to maintain reliable contact throughout a larger rotation angle range, enabling the gripping members to achieve a longer operation stroke without the pins falling out of cam grooves.
2Force
If a disk cam with linear cam grooves is used, then the gripping members move linearly in opening/closing directions, but the gripping force remains approximately constant and not so large, making it difficult to grip heavier objects
Solution Approach 1:
The patent employs a rotating plate with a curved geometric profile instead of linear cam grooves. The curved shape of the rotating plate creates a non-linear motion relationship that amplifies the gripping force. As the rotating plate turns, the curved geometry transforms rotational motion into linear motion of the gripping members while generating progressively larger gripping forces, enabling the hand to grip heavier objects.
Solution Approach 2:
The patent changes the motion parameter relationship by using a rotating plate with a specific curved profile. This geometric parameter change transforms the linear motion relationship into a non-linear one, where the gripping force increases as the rotation angle increases. This allows the system to achieve both linear movement of gripping members and progressively increasing gripping force, overcoming the limitation of constant gripping force in conventional disk cam designs.
3Ease of operation
If clearance is provided between pins and cam grooves to allow smooth sliding, then the mechanism can operate, but an object may be dropped from the hand when external vibration is applied due to the presence of clearance
Solution Approach 1:
The patent replaces the pin-cam groove sliding mechanism with a rotating plate mechanism that uses a different geometric relationship to drive the gripping members. This substitution eliminates the clearance problem inherent in sliding contacts, as the rotating plate's geometric profile maintains continuous, reliable contact throughout the rotation cycle, preventing object drop during vibration while maintaining smooth operation.
4Reliability
If the rotation angle of the disk cam is limited to prohibit pins from falling off, then pin retention is maintained, but the operation stroke of the pair of gripping members is reduced
Solution Approach 1:
The patent substitutes the disk cam mechanism with a rotating plate mechanism that does not suffer from the pin-retention limitation. The rotating plate's geometric design allows for a larger effective rotation angle while maintaining reliable contact, thereby enabling the gripping members to achieve a longer operation stroke without compromising reliability.
Data Source
AI summary
A mechanical hand is provided that can increase the operation stroke and also the gripping force of a pair of gripping members. The hand includes first and second sliders, a driving source, a rotating plate, a first clamping link. Of these components, the first and second sliders are provided on a hand body so as to be linearly movable in opening and closing directions and the driving source is provided in the hand body. The rotating plate is rotatably driven by the driving source. The first clamping link is linked with the rotating plate so as to be only rotatable on a first shaft, and is linked with the first slider so as to be only rotatable on a second shaft. Moreover, the second clamping link is linked with the rotating plate so as to be only rotatable on a third shaft, and is linked with the second slider so as be only rotatable on a fourth shaft. The first and second sliders move linearly in the opening and closing directions by making the driving source rotate the rotating plate.