Robot Arm Locking Mechanism for Power-Failure Rotation Blocking
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Solution Overview
Problem
Existing locking devices for robot arms are ineffective in preventing uncontrolled movement due to gravity during power failures, particularly in robot arms with vertical axes, and do not allow the screw to be locked by limiting its rotation.
Innovation Solution
An automatic locking device comprising a crown, hub, plate, rocker, groove, guide ramp, pin, and return spring, which blocks the movement of a second member relative to a first member during power cuts by using a pin to interpose between a bore and guide ramp, ensuring the rocker returns to a release position when power is restored.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the locking device uses a pin blocked between bore and guide ramp, then rotation is effectively blocked during power failure, but the device complexity increases
Solution Approach 1:
The locking mechanism is divided into distinct functional segments: the rocker assembly that detects failure conditions, the pin that provides the locking action, the groove that guides the pin's movement, and the bore-ramp assembly that provides the blocking surfaces. This segmentation allows each component to be optimized for its specific function while working together as an integrated system.
Solution Approach 2:
The pin acts as an intermediary element that translates the rocker's movement into a locking action. When the rocker pivots due to power failure or belt breakage, the pin is driven along the groove and blocked between the bore and guide ramp, providing the locking function. This intermediary mechanism efficiently converts one type of motion into the desired locking action.
2Ease of operation
If the rocker is designed to move between locking and release positions, then automatic unlocking is enabled when power is restored, but the mechanism requires additional space and complexity
Solution Approach 1:
The locking device operates in periodic cycles: during normal operation the pin is in the released position allowing rotation, upon power failure the rocker pivots and the pin moves to the locked position blocking rotation, and when power is restored the spring returns the rocker to its original position releasing the pin. This periodic action between locked and released states enables automatic unlocking while maintaining a relatively simple mechanism.
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
Effectively prevents uncontrolled movement of robot arm components by blocking rotation during power failures, allowing automatic unlocking when power is restored, and is applicable to various mechanical transmissions.
Implementation Method 1
a return spring, acting between the plate and the rocker to apply a return force bringing the rocker back to the release position
Implementation Method 2
Articulated industrial robot arms are subject to gravity, and, depending on their configuration, a sudden stop of the power supply to the axis motors can cause uncontrolled movement of the arm before the motor brake is effectively engaged
Data Source
AI summary
The present invention relates to a locking device including: a crown provided with a bore, a hub, mobile in rotation relative to the crown, a plate, integral with the hub, a rocker, mobile in rotation between a locking position and a release position, a groove, opening onto the bore and formed in the rocker or the plate, a guide ramp, formed at a periphery of the rocker or the plate, a pin, mounted in the groove to be blocked between the bore and the guide ramp when the rocker is in the locking position, and a return spring, acting between the plate and the rocker to bring the rocker back to the release position.