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US 4,659,280 AGranted
Robot with balancing mechanism having a variable counterbalance force
AssigneeGMF Robotics Corporation
InventorHadi A. Akeel
Life of this patent
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AssigneeGMF Robotics Corporation
InventorHadi A. Akeel
Estimating the term…
A robot including a balancing mechanism with a spring assembly which exerts a variable force to compensate for the gravitational moment transferred to the mechanism during relative rotation between an arm assembly of the robot and the rest of the robot about a pivotal axis. A spring of the spring assembly is chosen to have a force-deflection characteristic to account for the gravitational moment and the geometry of the mechanism. The arm assembly has a pivotal connection that pivotally supports the arm assembly on the rest of the robot for movement about the pivotal axis. The spring assembly has a longitudinal axis which extends towards and is substantially perpendicular to the pivotal axis. The moment arm is connected to the arm assembly at an attachment point offset from the pivotal axis. A first sprocket wheel is mounted on a drive gear of the arm assembly to rotate therewith and a second sprocket wheel is pivotally mounted at the free end of the spring assembly. A chain is wound about the first sprocket wheel to alternately wind and unwind during relative rotation about the pivotal axis. The opposite end of the chain is mounted to the gear to rotate therewith and an intermediate portion of the chain is trained over the second sprocket wheel.
A robot comprising:
An energystoring balancing mechanism adapted for use with a robot having an arm assembly and a pivotal connection which pivotally supports the arm assembly on the rest of the robot for movement about a pivotal axis, the mechanism including an energystoring member, an open loop, first means for movably connecting an intermediate portion of the loop to one end of the member and to permit the intermediate portion of the loop to move during rotation of the arm assembly and second means for connecting the ends of the loop to the arm assembly at a pair of attachment points offset from the pivotal axis, the member having a longitudinal axis extending towards and substantially perpendicular to the pivotal axis, wherein the effective length of the member varies and the attachment points rotate about the pivotal axis during relative rotation of the arm assembly about the pivotal axis and wherein the amount of energy stored in the member is dependent on the effective length.
Dependencies are inferred from the claim text.