Two-Phase Gripper for Passive Reorientation and Secure Grasping
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Solution Overview
Problem
Current robotic systems lack robust solutions for object manipulation, particularly in reorienting and securely grasping objects, which limits their application in assembly tasks and increases setup costs due to the need for specialized part feeders and inflexible automation systems.
Innovation Solution
A two-phase gripper design featuring parallel jaw fingers with a cavity covered by an elastic strip, allowing for low-friction point contact during reorientation and high-friction multi-point contact for secure grasping, enabling passive reorientation and secure holding of cylindrical or prismatic objects as the gripping force increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional gripper is used to securely grasp an object, then grasping force is sufficient, but the object cannot rotate under gravity for reorientation
Solution Approach 1:
The gripper transitions from a static high-friction grasp to a dynamic two-phase operation. During Phase 1, the elastic strip maintains low friction to enable rotational motion under gravity. During Phase 2, the strip deforms to increase friction for secure grasping. This dynamic adaptation resolves the contradiction between grasping security and reorientation capability.
Solution Approach 2:
The friction parameter between the gripper and object is changed dynamically through the elastic strip deformation. By altering the contact geometry from point contact to multi-point contact, the friction coefficient transitions from low to high, enabling both reorientation and secure grasping functions within the same gripper system.
2Adaptability or versatility
If specialized part feeders are used to reorient objects, then reorientation is achieved, but space, time, and setup requirements increase significantly
Solution Approach 1:
The invention merges the reorientation function traditionally performed by separate part feeders with the grasping function in a single integrated gripper. The two-phase fingers combine passive reorientation mechanics with active grasping, eliminating the need for ancillary reorientation systems and reducing overall device complexity.
Solution Approach 2:
The gripper performs multiple functions: it reorients objects passively during Phase 1 and secures them during Phase 2. This multi-functionality eliminates the need for specialized part feeders and other ancillary systems, making the gripper a universal solution for both reorientation and grasping tasks.
3Reliability
If high friction contact is used for secure grasping, then grasping security is achieved, but the object cannot passively reorient under gravity
Solution Approach 1:
The gripper operation is divided into periodic phases: Phase 1 with low friction for reorientation, followed by Phase 2 with high friction for secure grasping. This periodic switching of friction characteristics enables both fast passive reorientation and reliable secure grasping in sequence, resolving the contradiction between speed and security.
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 efficient and reliable reorientation and grasping of objects in a single continuous motion, reducing the need for part feeders and minimizing setup costs, while being adaptable to various parts with minimal reconfiguration.
Implementation Method 1
each finger including a cavity covered by an elastic strip... Closure of the jaws of the gripper on the object at a second, relatively higher force causes the elastic strip to recede into the cavity resulting in multi-point contact with higher friction
Implementation Method 2
Closure of the jaws of the gripper on the object at a first, relatively lower force results in contact at lower friction between the point contact on the elastic strip on the ringers and the object allowing the object to rotate under gravity as the gripper is raised
Data Source
AI summary
Two-phase gripper. The gripper reorients and grasps an object while being picked up. The gripper includes a parallel jaw gripper including a pair of opposed, two-phase fingers, each finger including a cavity covered by an elastic strip wherein the elastic strip includes a point contact. Closure of the jaws of the gripper on an object at a first relatively lower force results in contact with lower friction between the point contact on the elastic strip on the fingers and the object allowing the object to rotate under gravity as the gripper is raised. Thereafter, closure of the jaws of the gripper on the object at a second relatively higher force causes the elastic strip to receded into the cavity resulting in multi-point contact with higher friction between the fingers and the object to securely grasp the object. In a preferred embodiment, the cavity is a Y-shaped groove and the object is cylindrical or prismatic.