This mechanism allows a pinion gear to drive a large internal ring gear while the input shaft pivots freely across a large angular window. The secret lies in the geometry of the ring: its teeth follow a curved, toroidal path that keeps the pinion properly aligned even when the shaft is tilted. As the blue handle rotates the green pinion, the gear remains fully engaged with the pink ring, transmitting torque without interruption and causing the entire ring to spin smoothly.

Components — Pink internal ring gear with curved tooth profile, green pinion gear, blue tilting input shaft with hand knob, three-armed ring support, and mounting block.

How it works — Rotating the blue shaft spins the green pinion, which meshes with the inner surface of the pink ring gear. Because the ring¡¯s teeth are shaped to accommodate the pinion across a wide angular range, the pinion stays fully engaged even when the shaft is swung upward, downward, or sideways. This lets the user adjust the shaft angle freely while still transmitting continuous rotational motion into the ring gear.

Applications — Adjustable tool heads, flexible drive couplings, steering joints, camera gimbal systems, and machines where a rotating output must be driven from a tilt-capable input.

Why it matters — It provides rigid, uninterrupted torque transfer without the backlash, vibration, or complexity of universal joints. By shaping the gearing for angular flexibility, the mechanism keeps drive quality high even when the input cannot remain aligned¡ªa valuable trait for compact tools and articulated mechanisms.