EOAT Jaw Interface for Secure Retention in Compact Robotic Grippers
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Solution Overview
Problem
Existing robotic gripping systems face issues with retaining jaws on an end-of-arm tool (EOAT) due to insufficient friction, leading to slippage or falling off, especially under gravity and normal acceleration, and are bulky, making them incompatible with narrow part-gripping fingers.
Innovation Solution
A compact, low-profile EOAT design that securely holds jaws in any orientation, using a novel interface for engaging and disengaging jaws, jaw holders, and vises with spring-actuated tensioners to maintain grip without clamping force, allowing for shared use with part-gripping fingers or jaws.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the EOAT uses a long, spaced-apart aperture design to retain jaws, then the jaws are securely held, but the EOAT becomes bulky and incompatible with narrow part-gripping fingers
Solution Approach 1:
The patent transitions from a two-dimensional aperture design (long and wide spacing) to a three-dimensional interference fit design where theEOAT interface body engages the jaw interface with radial and axial interference. This dimensional change allows secure retention without increasing the EOAT's external dimensions, resolving the contradiction between jaw retention reliability and EOAT compactness.
Solution Approach 2:
The patent changes the engagement parameters from friction-based (relying on surface area and normal force) to interference-fit-based (relying on radial and axial interference dimensions). By modifying the engagement parameters to include radial interference (Rmin, Rmax) and axial interference (Zmin, Zmax), the system achieves secure jaw retention with a compact EOAT design that can accommodate narrow part-gripping fingers.
2Device complexity
If the EOAT relies on friction to retain jaws, then the structure is simple, but the jaws slip or fall off under gravity and normal acceleration
Solution Approach 1:
The patent applies preliminary anti-action by designing the interference fit to preemptively counteract the effects of gravity and normal acceleration before they can cause slippage. The radial and axial interference dimensions are specifically engineered to provide sufficient retention force under expected operational loads, preventing jaw drop without requiring complex active retention mechanisms.
Solution Approach 2:
The patent introduces an intermediary engagement mechanism (the interference fit interface between the EOAT interface body and jaw interface) that mediates between the simple structure requirement and the reliability requirement. This intermediary mechanism provides a reliable retention connection that is more secure than friction alone but does not require the complexity of active locking or clamping systems.
3Volume of moving object
If the EOAT uses a compact, low-profile design, then it can engage narrow part-gripping fingers, but it may not provide sufficient retention force for jaws
Solution Approach 1:
The patent changes the force generation mechanism from friction-based (dependent on normal force and surface area) to interference-fit-based (dependent on radial and axial interference dimensions). By modifying the engagement parameters to include controlled interference, the compact EOAT design generates sufficient retention force through elastic deformation and mechanical interlocking, resolving the contradiction between compact size and retention force.
Solution Approach 2:
The patent employs composite engagement characteristics combining radial interference (providing circumferential retention) and axial interference (providing axial retention). This composite approach to the interference fit mechanism allows the compact EOAT design to achieve sufficient retention force in multiple directions, accommodating both the size constraints and the force requirements for secure jaw and finger engagement.
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 solution ensures secure retention of jaws and fingers on the EOAT and vise, even without clamping force, preventing slippage and accommodating various part sizes and shapes, while allowing easy engagement and disengagement, enhancing operational flexibility and efficiency.
Implementation Method 1
spring-actuated tensioners to maintain grip without clamping force
Implementation Method 2
spring-actuated tensioners to maintain grip
Data Source
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AI summary
Disclosed are mechanical interfaces of an end-of-arm-tool (EOAT) and part-gripping devices. The EOAT mechanical interface is for operatively coupling a gripper actuator to the part-gripping device. The part-gripping device mechanical interface is matable to the EOAT mechanical interface for operatively coupling the EOAT to the part-gripping device. Among other improvements, also disclosed are improved gripper fingers.