Rotating Cam Robotic Tool Coupling Locking Mechanism

The patent inverts the conventional piston mechanism by using a rotating cam member instead of an axially moving piston. The cam member rotates to urge ball members radially outward against angled surfaces, creating locking forces without requiring axial motion. This inversion resolves the technical contradiction by eliminating the need for complex axial piston movement while maintaining reliable locking through radial force generation.

The patent transitions from one-dimensional axial motion (piston moving along its axis) to two-dimensional radial motion (cam member rotating and balls moving radially outward). By changing the dimension of motion from axial to radial, the design achieves compactness while maintaining locking reliability. The angled surfaces convert radial ball forces into axial locking forces, solving the contradiction between compact design and reliable locking.

The patent incorporates a failsafe surface on the cam member that is positioned to engage the ball members before any potential unintended rotation can occur during power loss. This preliminary positioning of the failsafe surface ensures that if power is lost, the ball members are already constrained by the failsafe geometry, preventing decoupling. The angled surfaces are also designed to maintain locking forces passively once engaged, requiring positive action to decouple.

The patent converts the potential harm of power loss (which could cause unintended decoupling) into a benefit by designing the failsafe mechanism so that loss of actuating force automatically causes the ball members to settle into the failsafe position. The gravity and spring forces that could cause decoupling during power loss are instead harnessed to press the balls against the failsafe surface, which geometrically prevents rotation and maintains locking.

The patent designs the cam member with multiple surfaces (actuating surface, failsafe surface, locking surface) that each serve specific functions but are all integrated into a single rotating component. This multi-functionality allows one cam member to perform locking, failing safe, and force generation functions simultaneously, reducing the need for separate components and simplifying the overall mechanism despite the complex geometry of individual surfaces.

The cam member is segmented into distinct functional surfaces (actuating, failsafe, and locking surfaces) that operate at different stages of the rotation cycle. Each surface is optimized for its specific function, allowing the complex geometry to be broken down into manageable segments with clear purposes. This segmentation makes the complex geometry more manageable and easier to manufacture while maintaining all necessary functions.